PRINT HEAD CONTROL CIRCUIT, PRINT HEAD, AND LIQUID DISCHARGE APPARATUS

The present application is based on, and claims priority from JP Application Serial Number 2018-174371, filed Sep. 19, 2018 and JP Application Serial Number 2019-036739, filed Feb. 28, 2019, the disclosures of which are hereby incorporated by reference herein in their entirety.

BACKGROUND
1. Technical Field

The present disclosure relates to a print head control circuit, a print head, and a liquid discharge apparatus.

2. Related Art

It is known that, for example, a piezoelectric element is used in an ink jet printer that performs printing of an image or a document by discharging an ink as a liquid. In such an ink jet printer, piezoelectric elements are provided to correspond to a plurality of nozzles in a print head, respectively. If a driving signal is supplied to the piezoelectric element at a predetermined timing, the piezoelectric element drives and a predetermined amount of the ink is discharged from the nozzles, and thereby an image or a document is formed on a print medium.

JP-A-2017-114020 discloses a liquid discharge apparatus that selects a driving signal to be supplied to each of a plurality of piezoelectric elements based on a print signal (print data signal) synchronized to a clock signal, and supplies the selected driving signal to each of the plurality of piezoelectric elements in a period defined by a change signal and a latch signal, and thus discharges a predetermined amount of an ink from a nozzle corresponding to each of the plurality of piezoelectric elements at a predetermined timing.

In recent years, an increase of the speed of printing and high definition of printing in a liquid discharge apparatus are required. The number of nozzles provided in a print head increases with the request of the increase of the speed of printing and high definition of printing. As a result, an increase of a propagation speed of various control signals supplied to the print head and reduction in distortion of a waveform occurring in the control signal are required.

In particular, among the various control signals supplied to the print head, an increase of the speed of a clock signal for defining timings of the control signals is required. Thus, when the waveform of the clock signal is distorted, a timing at which a print data signal synchronized to the clock signal is input to the print head may vary, and thus a discharge timing and a discharge amount of an ink to be discharged from a plurality of nozzles may vary. However, a technology for reducing distortion of the waveform of a signal for controlling the print head is not disclosed in JP-A-2017-114020.

SUMMARY

According to an aspect of the present disclosure, a print head control circuit controls an operation of a print head including a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal, a second terminal, a third terminal, a fourth terminal. The circuit includes a first propagation wiring for propagating a clock signal input to the first terminal, a second propagation wiring for propagating a signal which is input to the second terminal and indicates a diagnosis result of the temperature abnormality detection circuit, a third propagation wiring for propagating a first voltage signal which is input to the third terminal and is supplied to the driving signal selection circuit, a fourth propagation wiring for propagating a second voltage signal input to the fourth terminal, a driving signal output circuit that outputs the driving signal, and a power voltage output circuit that outputs the first voltage signal and the second voltage signal. When the second propagation wiring and the fourth propagation wiring are electrically coupled to the print head, the second propagation wiring and the fourth propagation wiring are electrically coupled to each other via the second terminal and the fourth terminal. The first propagation wiring and the second propagation wiring are located to be aligned. The first propagation wiring and the fourth propagation wiring are located to be adjacent to each other in a direction in which the first propagation wiring and the second propagation wiring are aligned.

According to another aspect of the present disclosure, a print head control circuit controls an operation of a print head including a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal, a second terminal, a third terminal, a fourth terminal. The circuit includes a first propagation wiring for propagating a clock signal input to the first terminal, a second propagation wiring for propagating a signal which is input to the second terminal and indicates a diagnosis result of the temperature abnormality detection circuit, a third propagation wiring for propagating a first voltage signal which is input to the third terminal and is supplied to the driving signal selection circuit, a fourth propagation wiring for propagating a second voltage signal input to the fourth terminal, a driving signal output circuit that outputs the driving signal, and a power voltage output circuit that outputs the first voltage signal and the second voltage signal. When the second propagation wiring and the fourth propagation wiring are electrically coupled to the print head, the second propagation wiring and the fourth propagation wiring are electrically coupled to each other via the second terminal and the fourth terminal. The first propagation wiring and the fourth propagation wiring are located to overlap each other in a direction intersecting a direction in which the first propagation wiring and the second propagation wiring are aligned.

The print head control circuit may further include a first ground signal propagation wiring for propagating a ground signal. The first propagation wiring and the first ground signal propagation wiring may be located to be adjacent to each other in the direction in which the first propagation wiring and the second propagation wiring are aligned.

The print head control circuit may further include a fifth propagation wiring for propagating a third voltage signal having a voltage value larger than a voltage value of the first voltage signal. The fourth propagation wiring and the fifth propagation wiring may not be located to be adjacent to each other in the direction in which the first propagation wiring and the second propagation wiring are aligned.

The print head control circuit may further include a fifth propagation wiring for propagating a third voltage signal having a voltage value larger than a voltage value of the first voltage signal. The fourth propagation wiring and the fifth propagation wiring may not be located to overlap each other in a direction perpendicular to the direction in which the first propagation wiring and the second propagation wiring are aligned.

The print head control circuit may further include a second ground signal propagation wiring for propagating the ground signal. The fifth propagation wiring and the second ground signal propagation wiring may be located to be adjacent to each other in the direction in which the first propagation wiring and the second propagation wiring are aligned.

The print head control circuit may further include a second ground signal propagation wiring for propagating the ground signal. The fifth propagation wiring and the second ground signal propagation wiring may be located to overlap each other in a direction intersecting the direction in which the first propagation wiring and the second propagation wiring are aligned.

According to still another aspect of the present disclosure, a print head includes a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal to which a clock signal is input, a second terminal to which a signal indicating a diagnosis result of the temperature abnormality detection circuit is input, a third terminal to which a first voltage signal to be supplied to the driving signal selection circuit is input, and a fourth terminal to which a second voltage signal is input. The second terminal and the fourth terminal are electrically coupled to each other. The first terminal and the second terminal are located to be aligned. The first terminal and the fourth terminal are located to be adjacent to each other in a direction in which the first terminal and the second terminal are aligned.

According to still another aspect of the present disclosure, a print head includes a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal to which a clock signal is input, a second terminal to which a signal indicating a diagnosis result of the temperature abnormality detection circuit is input, a third terminal to which a first voltage signal to be supplied to the driving signal selection circuit is input, and a fourth terminal to which a second voltage signal is input. The second terminal and the fourth terminal are electrically coupled to each other. The first terminal and the second terminal are located to be aligned. The first terminal and the fourth terminal are located to overlap each other in a direction intersecting a direction in which the first terminal and the second terminal are aligned.

The print head may further include a first ground terminal to which a ground signal is input. The first terminal and the first ground terminal may be located to be adjacent to each other in the direction in which the first terminal and the second terminal are aligned.

The print head may further include a fifth terminal to which a third voltage signal having a voltage value larger than a voltage value of the first voltage signal is input. The fourth terminal and the fifth terminal may not be located to be adjacent to each other in the direction in which the first terminal and the second terminal are aligned.

The print head may further include a fifth terminal to which a third voltage signal having a voltage value larger than a voltage value of the first voltage signal is input. The fourth terminal and the fifth terminal may not be located to overlap each other in a direction perpendicular to the direction in which the first terminal and the second terminal are aligned.

The print head may further include a second ground terminal to which the ground signal is input. The fifth terminal and the second ground terminal may be located to be adjacent to each other in the direction in which the first terminal and the second terminal are aligned.

The print head may further include a second ground terminal to which the ground signal is input. The fifth terminal and the second ground terminal may be located to overlap each other in a direction intersecting the direction in which the first terminal and the second terminal are aligned.

According to an aspect of the present disclosure, a liquid discharge apparatus includes a print head, and a print head control circuit that controls an operation of the print head. The print head includes a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal to which a clock signal is input, a second terminal to which a signal indicating a diagnosis result of the temperature abnormality detection circuit is input, a third terminal to which a first voltage signal to be supplied to the driving signal selection circuit is input, and a fourth terminal to which a second voltage signal is input. The print head control circuit includes a first propagation wiring for propagating the clock signal, a second propagation wiring for propagating a signal indicating the diagnosis result of the temperature abnormality detection circuit, a third propagation wiring for propagating the first voltage signal, a fourth propagation wiring for propagating the second voltage signal, a driving signal output circuit that outputs the driving signal, and a power voltage output circuit that outputs the first voltage signal and the second voltage signal. The first propagation wiring and the first terminal are electrically in contact with each other at a first contact section. The second propagation wiring and the second terminal are electrically in contact with each other at a second contact section. The third propagation wiring and the third terminal are electrically in contact with each other at a third contact section. The fourth propagation wiring and the fourth terminal are electrically in contact with each other at a fourth contact section. The second propagation wiring and the fourth propagation wiring are electrically coupled to each other via the second terminal, the second contact section, the fourth contact section, and the fourth terminal. The first contact section and the second contact section are located to be aligned. The first propagation wiring and the fourth propagation wiring are located to be adjacent to each other in a direction in which the first contact section and the second contact section are aligned.

According to an aspect of the present disclosure, a liquid discharge apparatus includes a print head, and a print head control circuit that controls an operation of the print head. The print head includes a driving element that drives based on a driving signal, so as to discharge a liquid from a nozzle, a driving signal selection circuit that controls a supply of the driving signal to the driving element, a temperature abnormality detection circuit that diagnoses whether or not temperature abnormality occurs, a first terminal to which a clock signal is input, a second terminal to which a signal indicating a diagnosis result of the temperature abnormality detection circuit is input, a third terminal to which a first voltage signal to be supplied to the driving signal selection circuit is input, and a fourth terminal to which a second voltage signal is input. The print head control circuit includes a first propagation wiring for propagating the clock signal, a second propagation wiring for propagating a signal indicating the diagnosis result of the temperature abnormality detection circuit, a third propagation wiring for propagating the first voltage signal, a fourth propagation wiring for propagating the second voltage signal, a driving signal output circuit that outputs the driving signal, and a power voltage output circuit that outputs the first voltage signal and the second voltage signal. The first propagation wiring and the first terminal are electrically in contact with each other at a first contact section. The second propagation wiring and the second terminal are electrically in contact with each other at a second contact section. The third propagation wiring and the third terminal are electrically in contact with each other at a third contact section. The fourth propagation wiring and the fourth terminal are electrically in contact with each other at a fourth contact section. The second propagation wiring and the fourth propagation wiring are electrically coupled to each other via the second terminal, the second contact section, the fourth contact section, and the fourth terminal. The first contact section and the second contact section are located to be aligned. The first propagation wiring and the fourth propagation wiring are located to overlap each other in a direction intersecting a direction in which the first contact section and the second contact section are aligned.

In the liquid discharge apparatus, the print head may further include a first ground terminal to which a ground signal is input. The print head control circuit may further include a first ground signal propagation wiring for propagating the ground signal. The first ground signal propagation wiring and the first ground terminal may be electrically in contact with each other at a first ground contact section. The first contact section and the first ground contact section may be located to be adjacent to each other in the direction in which the first contact section and the second contact section are aligned.

In the liquid discharge apparatus, the print head may further include a fifth terminal to which a third voltage signal having a voltage value larger than a voltage value of the first voltage signal is input. The print head control circuit may further include a fifth propagation wiring for propagating the third voltage signal. The fifth propagation wiring and the fifth terminal may be electrically in contact with each other at a fifth contact section. The fourth contact section and the fifth contact section may not be located to be adjacent to each other in the direction in which the first contact section and the second contact section are aligned.

In the liquid discharge apparatus, the print head may further include a fifth terminal to which a third voltage signal having a voltage value larger than a voltage value of the first voltage signal is input. The print head control circuit may further include a fifth propagation wiring for propagating the third voltage signal. The fifth propagation wiring and the fifth terminal may be electrically in contact with each other at a fifth contact section. The fourth contact section and the fifth contact section may not be located to overlap each other in a direction perpendicular to the direction in which the first contact section and the second contact section are aligned.

In the liquid discharge apparatus, the print head may further include a second ground terminal to which the ground signal is input. The print head control circuit may further include a second ground signal propagation wiring for propagating the ground signal. The second ground signal propagation wiring and the second ground terminal may be electrically in contact with each other at a second ground contact section. The fifth contact section and the second ground contact section may be located to be adjacent to each other in the direction in which the first contact section and the second contact section are aligned.

In the liquid discharge apparatus, the print head may further include a second ground terminal to which the ground signal is input. The print head control circuit may further include a second ground signal propagation wiring for propagating the ground signal. The second ground signal propagation wiring and the second ground terminal may be electrically in contact with each other at a second ground contact section. The fifth propagation wiring and the second ground signal propagation wiring may be located to overlap each other in a direction intersecting the direction in which the first contact section and the second contact section are aligned.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an overall configuration of a liquid discharge apparatus.

FIG. 2 is a block diagram illustrating an electrical configuration of the liquid discharge apparatus.

FIG. 3 is a diagram illustrating an example of a waveform of a driving signal COM.

FIG. 4 is a diagram illustrating an example of a waveform of a driving signal VOUT.

FIG. 5 is a diagram illustrating a configuration of a driving signal selection circuit.

FIG. 6 is a diagram illustrating decoding contents in a decoder.

FIG. 7 is a diagram illustrating a configuration of a selection circuit corresponding to one discharge section.

FIG. 8 is a diagram illustrating an operation of the driving signal selection circuit.

FIG. 9 is a diagram illustrating a configuration of a temperature abnormality detection circuit.

FIG. 10 is a schematic diagram illustrating an internal configuration of the liquid discharge apparatus when viewed from a Y-direction.

FIG. 11 is a diagram illustrating a configuration of a cable.

FIG. 12 is a perspective view illustrating a configuration of a print head.

FIG. 13 is a plan view illustrating a configuration of an ink discharge surface.

FIG. 14 is a diagram illustrating an overall configuration of one of a plurality of discharge sections in the head.

FIG. 15 is a plan view when a substrate is viewed from a surface 322.

FIG. 16 is a plan view when the substrate is viewed from a surface 321.

FIG. 17 is a diagram illustrating a configuration of a connector.

FIG. 18 is a diagram illustrating another configuration of the connector.

FIG. 19 is a diagram illustrating a specific example when the cable is attached to the connector.

FIG. 20 is a diagram illustrating details of a signal propagated in the cable.

FIG. 21 is a schematic diagram illustrating an internal configuration of a liquid discharge apparatus according to a second embodiment when viewed from the Y-direction.

FIG. 22 is a perspective view illustrating a configuration of a print head in the second embodiment.

FIG. 23 is a diagram illustrating configurations of connectors in the second embodiment.

FIG. 24 is a diagram illustrating details of a signal propagated in a cable 19a in the second embodiment.

FIG. 25 is a diagram illustrating details of a signal propagated in a cable 19b in the second embodiment.

FIG. 26 is a block diagram illustrating an electrical configuration of a liquid discharge apparatus according to a third embodiment.

FIG. 27 is a schematic diagram illustrating an internal configuration of the liquid discharge apparatus in the third embodiment when viewed from the Y-direction.

FIG. 28 is a perspective view illustrating a configuration of a print head in the third embodiment.

FIG. 29 is a diagram illustrating configurations of connectors in the third embodiment.

FIG. 30 is a diagram illustrating details of a signal propagated in a cable 19a in the third embodiment.

FIG. 31 is a diagram illustrating details of a signal propagated in a cable 19b in the third embodiment.

FIG. 32 is a diagram illustrating details of a signal propagated in a cable 19c in the third embodiment.

FIG. 33 is a diagram illustrating details of a signal propagated in a cable 19d in the third embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, preferred embodiments of the present disclosure will be described with reference to the drawings. The drawings are used for easy descriptions. The embodiments described below do not limit the scope of the present disclosure described in the claims. All components described later are not necessarily essential constituent elements of the present disclosure.

1. First Embodiment
1.1. Outline of Liquid Discharge Apparatus

FIG. 1 is a diagram illustrating an overall configuration of a liquid discharge apparatus 1. The liquid discharge apparatus 1 is a serial printing type ink jet printer that forms an image on a medium P in a manner that a carriage 20 discharges an ink to the transported medium P with reciprocating. In the carriage 20, a print head 21 that discharges the ink as an example of a liquid is mounted. In the following descriptions, descriptions will be made on the assumption that a direction in which the carriage 20 moves is an X-direction, a direction in which the medium P is transported is a Y-direction, and a direction in which the ink is discharged is a Z-direction. Descriptions will be made on the assumption that the X-direction, the Y-direction, and the Z-direction are perpendicular to each other. As the medium P, any printing target such as print paper, a resin film, and a cloth can be used.

The liquid discharge apparatus 1 includes a liquid container 2, a control mechanism 10, the carriage 20, a movement mechanism 30, and a transport mechanism 40.

Plural kinds of inks to be discharged onto a medium P are stored in the liquid container 2. As the color of the ink stored in the liquid container 2, black, cyan, magenta, yellow, red, and gray are exemplified. As the liquid container 2 in which such an ink is stored, an ink cartridge, a bag-like ink pack formed of a flexible film, an ink tank capable of replenishing ink, or the like is used.

The control mechanism 10 includes, for example, a processing circuit such as a central processing unit (CPU) or a field programmable gate array (FPGA) and a storage circuit such as a semiconductor memory. The control mechanism 10 controls elements of the liquid discharge apparatus 1.

The print head 21 is mounted in the carriage 20. The carriage 20 is fixed to an endless belt 32 of the movement mechanism 30. The liquid container 2 may also be mounted in the carriage 20.

A control signal Ctrl-H and one or a plurality of driving signals COM are input to the print head 21. The control signal Ctrl-H is output by the control mechanism 10 and is used for controlling the print head 21. The driving signal COM is output by the control mechanism 10 and is used for driving the print head 21. The print head 21 discharges an ink supplied from the liquid container 2 based on the control signal Ctrl-H and the driving signal COM.

The movement mechanism 30 includes a carriage motor 31 and the endless belt 32. The carriage motor 31 operates based on a control signal Ctrl-C input from the control mechanism 10. The endless belt 32 rotates by the operation of the carriage motor 31. Thus, the carriage 20 fixed to the endless belt 32 reciprocates in the X-direction.

The transport mechanism 40 includes a transport motor 41 and a transport roller 42. The transport motor 41 operates based on a control signal Ctrl-T input from the control mechanism 10. The transport roller 42 rotates by the operation of the transport motor 41. A medium P is transported in the Y-direction with the rotation of the transport roller 42.

As described above, the liquid discharge apparatus 1 forms a desired image on a medium P by landing an ink at any position on the surface of the medium P in a manner that the liquid discharge apparatus discharges the ink from the print head 21 mounted in the carriage 20 with transport of the medium P by the transport mechanism 40 and reciprocation of the carriage 20 by the movement mechanism 30.

1.2. Electrical Configuration of Liquid Discharge Apparatus

FIG. 2 is a block diagram illustrating an electrical configuration of the liquid discharge apparatus 1. The liquid discharge apparatus 1 includes the control mechanism 10, the print head 21, the carriage motor 31, the transport motor 41, and a linear encoder 90.

The control mechanism 10 includes a driving signal output circuit 50, a control circuit 100, and a power circuit 110. The control circuit 100 includes a processor such as a microcontroller, for example. The control circuit 100 generates and outputs data or various signals for controlling the liquid discharge apparatus 1, based on various signals such as image data, which are input from a host computer.

Specifically, the control circuit 100 recognizes a scanning position of the print head 21 based on a detection signal input from the linear encoder 90. The control circuit 100 generates and outputs various signals corresponding to the scanning position of the print head 21. Specifically, the control circuit 100 generates the control signal Ctrl-C for controlling reciprocation of the print head 21 and outputs the control signal Ctrl-C to the carriage motor 31. The control circuit 100 generates the control signal Ctrl-T for controlling transport of the medium P and outputs the control signal Ctrl-T to the transport motor 41. The control signal Ctrl-C may be signal-converted via a carriage motor driver (not illustrated) and then be input to the carriage motor 31. Similarly, the control signal Ctrl-T may be signal-converted via a transport motor driver (not illustrated) and then be input to the transport motor 41.

The control circuit 100 generates print data signals SI1 to SIn, a change signal CH, a latch signal LAT, and a clock signal SCK as the control signal Ctrl-H for controlling the print head 21, based on the various signals such as image data, which are input from the host computer and the scanning position of the print head 21. Then, the control circuit 100 outputs the generated signals to the print head 21.

The control circuit 100 outputs a driving control signal dA as a digital signal to the driving signal output circuit 50.

The driving signal output circuit 50 includes a driving circuit 50a. The driving control signal dA is input to the driving circuit 50a. The driving circuit 50a generates the driving signal COM by performing D-class amplification on an analog signal obtained by performing digital-to-analog signal conversion on the driving control signal dA. That is, the driving control signal dA is a digital signal for defining a waveform of the driving signal COM. The driving circuit 50a generates the driving signal COM by performing D-class amplification on a waveform defined by the driving control signal dA. That is, the driving signal output circuit 50 outputs the driving signal COM generated by the driving circuit 50a. Thus, the driving control signal dA may be a signal capable of defining the waveform of the driving signal COM. For example, the driving control signal dA may be an analog signal. The driving circuit 50a may be capable of amplifying the waveform defined by the driving control signal dA. For example, the driving circuit 50a may be configured by an A-class amplifier circuit, a B-class amplifier circuit, or an AB-class amplifier circuit.

The driving signal output circuit 50 outputs a reference voltage signal CGND indicating a reference potential of the driving signal COM. The reference voltage signal CGND may be, for example, a signal which has a voltage value of 0 V and has a ground potential. The reference voltage signal CGND may be a signal having a DC voltage having a voltage value of 6 V, for example.

The driving signal COM and the reference voltage signal CGND are divided in the control mechanism 10 and then are output to the print head 21. Specifically, the driving signal COM is divided into n pieces of driving signals COM1 to COMn respectively corresponding to n pieces of driving signal selection circuits 200 described later in the control mechanism 10. Then, the driving signals COM1 to COMn are output to the print head 21. Similarly, the reference voltage signal CGND is divided into n pieces of reference voltage signals CGND1 to CGNDn in the control mechanism 10, and then is output to the print head 21. The driving signal COM including the driving signals COM1 to COMn is an example of the driving signal.

The power circuit 110 generates and outputs voltages VHV, VDD1, and VDD2 and a ground signal GND. The voltage VHV is a signal having a DC voltage having a voltage value of 42 V, for example. The voltages VDD1 and VDD2 are signals having a DC voltage having a voltage value of 3.3 V, for example. The ground signal GND is a signal indicating the reference potential of the voltages VHV, VDD1, and VDD2. For example, the ground signal GND is a signal having a voltage value of 0 V and having a ground potential. That is, the voltage VHV has a voltage value larger than the voltages VDD1 and VDD2. The voltage VHV is used, for example, as a voltage for amplification in the driving signal output circuit 50. Each of the voltages VDD1 and VDD2 is used, for example, as a power source voltage or a control voltage of various components in the control mechanism 10. The voltages VHV, VDD1, and VDD2 and the ground signal GND are also output to the print head 21. The voltage values of the voltages VHV, VDD1, and VDD2 and the ground signal GND are not limited to 42 V, 3.3 V, and 0 V as described above. The power circuit 110 may generate signals having a plurality of voltage values in addition to the voltages VHV, VDD1, and VDD2 and the ground signal GND. The power circuit 110 is an example of a power voltage output circuit.

The print head 21 includes driving signal selection circuits 200-1 to 200-n, a temperature detection circuit 210, temperature abnormality detection circuits 250-1 to 250-n, and a plurality of discharge sections 600.

The voltages VHV and VDD1, the clock signal SCK, the latch signal LAT, and the change signal CH are input to each of the driving signal selection circuits 200-1 to 200-n. The driving signals COM1 to COMn and the print data signals SI1 to SIn are input to the driving signal selection circuits 200-1 to 200-n, respectively. The voltages VHV and VDD1 are used as a power source voltage of each of the driving signal selection circuits 200-1 to 200-n and a voltage for generating various control signals. The driving signal selection circuits 200-1 to 200-n select or do not select the driving signals COM1 to COMn based on the print data signals SI1 to SIn, the clock signal SCK, the latch signal LAT, and the change signal CH, which are input, so as to generate driving signals VOUT1 to VOUTn, respectively.

Each of the driving signals VOUT1 to VOUTn respectively generated by the driving signal selection circuits 200-1 to 200-n is supplied to the piezoelectric element 60 which is provided in the corresponding discharge section 600 and is an example of a driving element. If each of the driving signals VOUT1 to VOUTn is supplied, the piezoelectric element 60 performs displacement. The ink of an amount depending on the displacement is discharged from the discharge section 600.

Specifically, the driving signal COM1, the print data signal SI1, the latch signal LAT, the change signal CH, and the clock signal SCK are input to the driving signal selection circuit 200-1. The driving signal selection circuit 200-1 selects or does not select the waveform of the driving signal COM1 based on the print data signal SI1, the latch signal LAT, the change signal CH, and the clock signal SCK, so as to generate the driving signal VOUT1. The driving signal VOUT1 is supplied to one end of the piezoelectric element 60 in the discharge section 600 provided to correspond to the driving signal VOUT1. The reference voltage signal CGND1 is supplied to the other end of the piezoelectric element 60. The piezoelectric element 60 performs displacement by a potential difference between the driving signal VOUT1 and the reference voltage signal CGND1.

Similarly, the driving signal COMi, the print data signal SIi (i is any of 1 to n), the latch signal LAT, the change signal CH, and the clock signal SCK are input to the driving signal selection circuit 200-i. The driving signal selection circuit 200-i selects or does not select the waveform of the driving signal COMi based on the print data signal SIi, the latch signal LAT, the change signal CH, and the clock signal SCK, so as to generate the driving signal VOUTi. The driving signal VOUTi is supplied to one end of the piezoelectric element 60 in the discharge section 600 provided to correspond to the driving signal VOUTi. The reference voltage signal CGNDi is supplied to the other end of the piezoelectric element 60. The piezoelectric element 60 performs displacement by a potential difference between the driving signal VOUTi and the reference voltage signal CGNDi.

Here, the driving signal selection circuits 200-1 to 200-n have the similar circuit configuration. Therefore, when it is not necessary to distinguish the driving signal selection circuits 200-1 to 200-n from each other in the following descriptions, the driving signal selection circuits 200-1 to 200-n are referred to as a driving signal selection circuit 200. In this case, the driving signals COM1 to COMn input to the driving signal selection circuit 200 are referred to as a driving signal COM. The print data signals SI1 to SIn are referred to as a print data signal SI, and the driving signals VOUT1 to VOUTn output from the driving signal selection circuit 200 are referred to as a driving signal VOUT. Details of the operation of the driving signal selection circuit 200 will be described later. Here, each of the driving signal selection circuits 200-1 to 200-i is configured by an integrated circuit (IC) apparatus, for example.

The temperature abnormality detection circuits 250-1 to 250-n are provided to correspond to the driving signal selection circuits 200-1 to 200-n, respectively. Each of the temperature abnormality detection circuits 250-1 to 250-n diagnoses whether or not temperature abnormality occurs in the corresponding circuit of the driving signal selection circuits 200-1 to 200-n. Specifically, the temperature abnormality detection circuits 250-1 to 250-n operate using the voltage VDD2 as the power source voltage. Each of the temperature abnormality detection circuits 250-1 to 250-n detects the temperature of the corresponding circuit of the driving signal selection circuits 200-1 to 200-n. When the temperature abnormality detection circuit diagnoses that the temperature is normal, the temperature abnormality detection circuit generates an abnormality signal XHOT having a high level (H level) and outputs the abnormality signal XHOT to the control circuit 100. When the temperature abnormality detection circuit diagnoses that the temperature of the corresponding circuit of the driving signal selection circuits 200-1 to 200-n is abnormal, each of the temperature abnormality detection circuits 250-1 to 250-n generates the abnormality signal XHOT having a low level (L level) and outputs the abnormality signal XHOT to the control circuit 100.

Here, the temperature abnormality detection circuits 250-1 to 250-n have the similar circuit configuration. Therefore, when it is not necessary to distinguish the temperature abnormality detection circuits 250-1 to 250-n from each other in the following descriptions, the temperature abnormality detection circuits 250-1 to 250-n are referred to as a temperature abnormality detection circuit 250. Details of the temperature abnormality detection circuit 250 will be described later. Here, each of the temperature abnormality detection circuits 250-1 to 250-i is configured by an integrated circuit apparatus, for example. The temperature abnormality detection circuit 250-i and the driving signal selection circuit 200-i may be configured by one integrated circuit apparatus.

The temperature detection circuit 210 includes a temperature detection element such as a thermistor. The temperature detection circuit 210 generates a temperature signal TH which is an analog signal and includes temperature information of the print head 21, based on a detection signal obtained by detection of the temperature detection element. The temperature detection circuit outputs the temperature signal TH to the control circuit 100.

1.3. Example of Waveform of Driving Signal

Here, an example of the waveform of the driving signal COM generated by the driving signal output circuit 50 and an example of the waveform of the driving signal VOUT supplied to the piezoelectric element 60 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a diagram illustrating an example of the waveform of the driving signal COM. As illustrated in FIG. 3, the driving signal COM is a waveform in which a trapezoid waveform Adp1, a trapezoid waveform Adp2, and a trapezoid waveform Adp3. The trapezoid waveform Adp1 is disposed in a period T1 from when the latch signal LAT rises until the change signal CH rises. The trapezoid waveform Adp2 is disposed in a period T2 until the change signal CH rises the next time after the period T1. The trapezoid waveform Adp3 is disposed in a period T3 until the latch signal LAT rises the next time after the period T2. When the trapezoid waveform Adp1 is supplied to the one end of the piezoelectric element 60, the medium amount of the ink is discharged from the discharge section 600 corresponding to this piezoelectric element 60. When the trapezoid waveform Adp2 is supplied to the one end of the piezoelectric element 60, the ink having an amount smaller than the medium amount is discharged from the discharge section 600 corresponding to this piezoelectric element 60. When the trapezoid waveform Adp3 is supplied to the one end of the piezoelectric element 60, the ink is not discharged from the discharge section 600 corresponding to this piezoelectric element 60. The trapezoid waveform Adp3 is a waveform for finely vibrating the ink in the vicinity of a nozzle opening portion of the discharge section 600 to prevent an increase of ink viscosity. Here, a period Ta (illustrated in FIG. 3) from the latch signal LAT rises until the latch signal LAT rises the next time corresponds to a printing period in which a new dot is formed on the medium P.

All voltages at a start timing and an end timing of each of the trapezoid waveforms Adp1, Adp2, and Adp3 are common and a voltage Vc. That is, each of the trapezoid waveforms Adp1, Adp2, and Adp3 is a waveform which starts at the voltage Vc and ends at the voltage Vc. The driving signal COM may be a signal having a waveform in which one or two trapezoid waveforms are continuous in the period Ta, or may be a signal having a waveform in which four trapezoid waveforms or more are continuous in the period Ta.

FIG. 4 is a diagram illustrating an example of the waveform of the driving signal VOUT corresponding to each of “a large dot”, “a medium dot”, “a small dot”, and “non-recording”.

As illustrated in FIG. 4, the driving signal VOUT corresponding to “the large dot” has a waveform in which the trapezoid waveform Adp1 disposed in the period T1, the trapezoid waveform Adp2 disposed in the period T2, and a waveform which is disposed in the period T3 and is constant at the voltage Vc are continuous in the period Ta. When the driving signal VOUT is supplied to the one end of the piezoelectric element 60, the medium amount of the ink and the small amount of the ink are discharged from the discharge section 600 corresponding to this piezoelectric element 60, in the period Ta. Thus, the inks are landed on the medium P and are coalesced, and thereby a large dot is formed on the medium P.

The driving signal VOUT corresponding to “the medium dot” has a waveform in which the trapezoid waveform Adp1 disposed in the period T1 and a waveform which is disposed in the periods T2 and T3 and is constant at the voltage Vc are continuous in the period Ta. When the driving signal VOUT is supplied to the one end of the piezoelectric element 60, the medium amount of the ink is discharged from the discharge section 600 corresponding to this piezoelectric element 60, in the period Ta. Thus, the ink is landed on the medium P, and thereby a medium dot is formed on the medium P.

The driving signal VOUT corresponding to “the small dot” has a waveform in which a waveform which is disposed in the periods T1 and T3 and is constant at the voltage Vc and the trapezoid waveform Adp2 disposed in the period T2 are continuous in the period Ta. When the driving signal VOUT is supplied to the one end of the piezoelectric element 60, the small amount of the ink is discharged from the discharge section 600 corresponding to this piezoelectric element 60, in the period Ta. Thus, the ink is landed on the medium P, and thereby a small dot is formed on the medium P.

The driving signal VOUT corresponding to “non-recording” has a waveform in which a waveform which is disposed in the periods T1 and T2 and is constant at the voltage Vc and the trapezoid waveform Adp3 disposed in the period T3 are continuous in the period Ta. When the driving signal VOUT is supplied to the one end of the piezoelectric element 60, in the period Ta, only the ink in the vicinity of the nozzle opening portion of the discharge section 600 corresponding to this piezoelectric element 60 finely vibrates, and the ink is not discharged. Thus, the ink is not landed on the medium P and a dot is not formed on the medium P.

Here, the waveform constant at the voltage Vc means a waveform in which the previous voltage Vc is configured by a voltage held by a capacitive component of the piezoelectric element 60 when any of the trapezoid waveforms Adp1, Adp2, and Adp3 is not selected as the driving signal VOUT. Therefore, when any of the trapezoid waveforms Adp1, Adp2, and Adp3 is not selected as the driving signal VOUT, the voltage Vc is supplied to the piezoelectric element 60 as the driving signal VOUT.

The driving signal COM and the driving signal VOUT illustrated in FIGS. 3 and 4 are just examples. Signals having various combinations of waveforms may be used in accordance with a moving speed of the carriage 20 in which the print head 21 is mounted, the physical properties of the ink to be supplied to the print head 21, the material of the medium P, and the like.

1.4. Configuration of Driving Signal Selection Circuit

Next, a configuration and an operation of the driving signal selection circuit 200 will be described with reference to FIGS. 5 to 8. FIG. 5 is a diagram illustrating a configuration of the driving signal selection circuit 200. As illustrated in FIG. 5, the driving signal selection circuit 200 includes a selection control circuit 220 and a plurality of selection circuits 230.

The print data signal SI, the latch signal LAT, the change signal CH, and the clock signal SCK are input to the selection control circuit 220. A set of a shift register (S/R) 222, a latch circuit 224, and a decoder 226 is provided in the selection control circuit 220 to correspond to each of the plurality of discharge sections 600. That is, the driving signal selection circuit 200 includes sets of shift registers 222, latch circuits 224, and decoders 226. The number of sets is equal to the total number m of discharge sections 600. Here, the clock signal SCK is a clock signal for defining a timing at which the print data signal SI is input.

Specifically, the print data signal SI is a signal synchronized with the clock signal SCK. The print data signal SI is a signal which has 2 m bits in total and includes 2-bit print data [SIH, SIL] for selecting any of “the large dot”, “the medium dot”, “the small dot”, and “non-recording” for each of m pieces of discharge sections 600. Regarding the print data signal SI, each 2-bit print data [SIH, SIL] which corresponds to the discharge section 600 and is included in the print data signal SI is held in the shift register 222. Specifically, the shift registers 222 from the first stage to the m-th stage, which correspond to the discharge sections 600 are cascade-coupled to each other, and the print data signal SI input in a serial manner is sequentially transferred to the subsequent stage in accordance with the clock signal SCK. In FIG. 5, in order to distinguish the shift registers 222 from each other, the shift registers 222 are described as being the first stage, the second stage, . . . , and the m-th stage in order from the upstream on which the print data signal SI is input.

Each of the m pieces of latch circuits 224 latches the 2-bit print data [SIH, SIL] held in each of the m pieces of shift registers 222, at a rising edge of the latch signal LAT.

Each of the m pieces of decoders 226 decodes the 2-bit print data [SIH, SIL] latched by each of the m pieces of latch circuits 224. The decoder 226 outputs a selection signal S for each of the periods T1, T2, T3 defined by the latch signal LAT and the change signal CH.

FIG. 6 is a diagram illustrating decoding contents in the decoder 226. The decoder 226 outputs the selection signal S in accordance with the latched 2-bit print data [SIH, SIL]. For example, when the 2-bit print data [SIH, SIL] is [1, 1], the decoder 226 outputs the selection signal S having a logical level which is respectively set to an H level, an H level, and an L level in the periods T1, T2, and T3.

The selection circuits 230 are provided to correspond to the discharge sections 600, respectively. That is, the number of selection circuits 230 of the driving signal selection circuit 200 is equal to the total number m of the discharge sections 600. FIG. 7 is a diagram illustrating a configuration of the selection circuit 230 corresponding to one discharge section 600. As illustrated in FIG. 7, the selection circuit 230 includes an inverter 232 being a NOT circuit, and a transfer gate 234.

The selection signal S is logically inverted by the inverter 232 and is input to a negative control end of the transfer gate 234, which is marked with a circle, while the selection signal S is input to a positive control end of the transfer gate 234, which is not marked with a circle. The driving signal COM is supplied to an input end of the transfer gate 234. Specifically, the transfer gate 234 electrically connects (turns on between) the input end and an output end when the selection signal S has an H level, and does not electrically connect (turns off between) the input end and the output end when the selection signal S has an L level. In this manner, the driving signal VOUT is output from the output end of the transfer gate 234.

Here, the operation of the driving signal selection circuit 200 will be described with reference to FIG. 8. FIG. 8 is a diagram illustrating the operation of the driving signal selection circuit 200. The print data signal SI is serially input in synchronization with the clock signal SCK and is sequentially transferred into the shift registers 222 corresponding to the discharge sections 600. If the input of the clock signal SCK stops, the 2-bit print data [SIH, SIL] corresponding to each of the discharge sections 600 is held in each of the shift registers 222. The print data signal SI is input in order of the discharge sections 600 corresponding to the m-th stage, . . . , the second stage, and the first stage of shift registers 222.

If the latch signal LAT rises, the latch circuits 224 simultaneously latch the 2-bit print data [SIH, SIL] held by the shift registers 222. In FIG. 8, LT1, LT2, . . . , and LTm indicate the 2-bit print data [SIH, SIL] latched by the latch circuits 224 respectively corresponding to the first stage, the second stage, . . . , and the m-th stage of shift registers 222.

The decoder 226 outputs the logical level of the selection signal S in each of the periods T1, T2, and T3, based on the contents in FIG. 6, in accordance with the size of a dot defined by the latched 2-bit print data [SIH, SIL].

Specifically, when the print data [SIH, SIL] is [1, 1], the decoder 226 sets the selection signal S to have an H level, an H level, and an L level in the periods T1, T2, and T3. In this case, the selection circuit 230 selects the trapezoid waveform Adp1 in the period T1, selects the trapezoid waveform Adp2 in the period T2, and does not select the trapezoid waveform Adp3 in the period T3. As a result, the driving signal VOUT corresponding to “the large dot” illustrated in FIG. 4 is generated.

When the print data [SIH, SIL] is [1, 0], the decoder 226 sets the selection signal S to have an H level, an L level, and an L level in the periods T1, T2, and T3. In this case, the selection circuit 230 selects the trapezoid waveform Adp1 in the period T1, does not select the trapezoid waveform Adp2 in the period T2, and does not select the trapezoid waveform Adp3 in the period T3. As a result, the driving signal VOUT corresponding to “the medium dot” illustrated in FIG. 4 is generated.

When the print data [SIH, SIL] is [0, 1], the decoder 226 sets the selection signal S to have an L level, an H level, and an L level in the periods T1, T2, and T3. In this case, the selection circuit 230 does not select the trapezoid waveform Adp1 in the period T1, selects the trapezoid waveform Adp2 in the period T2, and does not select the trapezoid waveform Adp3 in the period T3. As a result, the driving signal VOUT corresponding to “the small dot” illustrated in FIG. 4 is generated.

When the print data [SIH, SIL] is [0, 0], the decoder 226 sets the selection signal S to have an L level, an L level, and an H level in the periods T1, T2, and T3. In this case, the selection circuit 230 does not select the trapezoid waveform Adp1 in the period T1, does not select the trapezoid waveform Adp2 in the period T2, and selects the trapezoid waveform Adp3 in the period T3. As a result, the driving signal VOUT corresponding to “non-recording” illustrated in FIG. 4 is generated.

As described above, the driving signal selection circuit 200 selects the waveform of the driving signal COM based on the print data signal SI, the latch signal LAT, the change signal CH, and the clock signal SCK, and outputs the driving signal VOUT. In other words, the driving signal selection circuit 200 controls a supply of the driving signal COM to the piezoelectric element 60.

1.5. Configuration of Temperature Abnormality Detection Circuit

Next, the temperature abnormality detection circuit 250 will be described with reference to FIG. 9. FIG. 9 is a diagram illustrating a configuration of the temperature abnormality detection circuit 250. As illustrated in FIG. 9, the temperature abnormality detection circuit 250 includes a comparator 251, a reference voltage generation circuit 252, a transistor 253, a plurality of diodes 254, and resistors 255 and 256. As described above, all the temperature abnormality detection circuits 250-1 to 250-n have the same configuration. Therefore, in FIG. 9, detailed illustrations of the configuration of the temperature abnormality detection circuit 250-2 to 250-n are omitted.

The voltage VDD2 is input to the reference voltage generation circuit 252. The reference voltage generation circuit 252 generates a voltage Vref by transforming the voltage VDD2 and supplies the voltage Vref to a positive-side input terminal of the comparator 251. The reference voltage generation circuit 252 is configured by a voltage regulator circuit, for example.

The plurality of diodes 254 is coupled in series. Among the plurality of diodes 254 coupled in series, the voltage VDD2 is supplied to an anode terminal of the diode 254 located on the highest potential side via the resistor 255, and the ground signal GND is supplied to a cathode terminal of the diode 254 located on the lowest potential side. Specifically, the temperature abnormality detection circuit 250 has diodes 254-1, 254-2, 254-3, and 254-4 as the plurality of diodes 254. The voltage VDD2 is supplied to the anode terminal of the diode 254-1 via the resistor 255, and the anode terminal of the diode 254-1 is coupled to a negative-side input terminal of the comparator 251. A cathode terminal of the diode 254-1 is coupled to an anode terminal of the diode 254-2. A cathode terminal of the diode 254-2 is coupled to an anode terminal of the diode 254-3. A cathode terminal of the diode 254-3 is coupled to an anode terminal of the diode 254-4. The ground signal GND is supplied to the cathode terminal of the diode 254-4. With the resistor 255 and the plurality of diodes 254 configured in a manner as described above, a voltage Vdet is supplied to a negative-side input terminal of the comparator 251. The voltage Vdet is the sum of forward voltages of the plurality of diodes 254. The number of the plurality of diodes 254 in the temperature abnormality detection circuit 250 is not limited to four.

The comparator 251 operates by a potential difference between the voltage VDD2 and the ground signal GND. The comparator 251 compares the voltage Vref supplied to the positive-side input terminal and the voltage Vdet supplied to the negative-side input terminal to each other, and outputs a signal based on the comparison result from an output terminal.

The voltage VDD2 is supplied to the drain terminal of the transistor 253 via the resistor 256. The gate terminal of the transistor 253 is coupled to the output terminal of the comparator 251. The ground signal GND is supplied to the source terminal of the transistor 253. The voltage supplied to the drain terminal of the transistor 253 coupled in a manner as described above is output from the temperature abnormality detection circuit 250 as the abnormality signal XHOT.

The voltage value of the voltage Vref generated by the reference voltage generation circuit 252 is less than the voltage Vdet when the temperature of the plurality of diodes 254 is within a predetermined range. In this case, the comparator 251 outputs a signal having an L level. Thus, the transistor 253 is controlled to turn off. As a result, the temperature abnormality detection circuit 250 outputs the abnormality signal XHOT having an H level.

The forward voltage of the diode 254 has characteristics in which the forward voltage decreases as the temperatures increases. Thus, when temperature abnormality occurs in the print head 21, the temperature of the diode 254 increases, and thereby the voltage Vdet decreases. When the voltage Vdet becomes less than the voltage Vref by the temperature increase, the output signal of the comparator 251 changes from an L level to an H level. Accordingly, the transistor 253 is controlled to turn on. As a result, the temperature abnormality detection circuit 250 outputs the abnormality signal XHOT having an L level. That is, if the transistor 253 is controlled to turn on or off based on the temperature of the driving signal selection circuit 200, the temperature abnormality detection circuit 250 outputs the voltage VDD2 supplied as the pull-up voltage of the transistor 253, as the abnormality signal XHOT having an H level and outputs the ground signal GND as the abnormality signal XHOT having an L level.

As illustrated in FIG. 9, outputs of the n pieces of temperature abnormality detection circuits 250-1 to 250-n are commonly coupled. Thus, when temperature abnormality occurs in any of the temperature abnormality detection circuits 250-1 to 250-n, the transistor 253 corresponding to the temperature abnormality detection circuit 250 in which the temperature abnormality occurs is controlled to turn on. As a result, the ground signal GND is supplied to a node to which the abnormality signal XHOT is output, via the transistor 253. Thus, the abnormality signals XHOT output by the temperature abnormality detection circuits 250-1 to 250-n are controlled to have an L level. That is, the temperature abnormality detection circuits 250-1 to 250-n are coupled in a wired-OR manner. Thus, even when the plurality of temperature abnormality detection circuits 250 is provided in the print head 21, it is possible to propagate the abnormality signal XHOT indicating whether or not temperature abnormality occurs in the print head 21, without increasing the number of wirings for propagating the abnormality signal XHOT.

1.6. Configurations of Print Head and Print Head Control Circuit

Next, details of an electrical coupling between the control mechanism 10 and the print head 21 will be described. In the following descriptions, descriptions will be made on the assumption that the print head 21 in the first embodiment includes four driving signal selection circuits 200-1 to 200-4. That is, four print data signals SI1 to SI4, four driving signals COM1 to COM4, and four reference voltage signals CGND1 to CGND4, which respectively correspond to the four driving signal selection circuits 200-1 to 200-4 are input to the print head 21 in the first embodiment.

FIG. 10 is a schematic diagram illustrating an internal configuration of the liquid discharge apparatus 1 when viewed from the Y-direction. As illustrated in FIG. 10, the liquid discharge apparatus 1 includes a main substrate 11, a cable 19, and the print head 21.

Various circuits including the driving signal output circuit 50, the control circuit 100, and the power circuit 110 provided in the control mechanism 10 illustrated in FIGS. 1 and 2 are mounted on the main substrate 11. A connector 12 to which one end of the cable 19 is attached is mounted on the main substrate 11. FIG. 10 illustrates one circuit substrate as the main substrate 11. However, the main substrate 11 may be configured by two circuit substrates or more.

The print head 21 includes a head 310, a substrate 320, and a connector 350. The other end of the cable 19 is attached to the connector 350. Thus, various signals generated by the control mechanism 10 are input to the print head 21 via the cable 19. Details of the configuration of the print head 21 and details of the signal propagated in the cable 19 will be described later.

The liquid discharge apparatus 1 configured in a manner as described above controls the operation of the print head 21 based on various signals including the driving signals COM1 to COM4, the reference voltage signals CGND1 to CGND4, the print data signals SI1 to SI4, the latch signal LAT, the change signal CH, and the clock signal SCK, which are output from the control mechanism 10 mounted on the main substrate 11. That is, in the liquid discharge apparatus 1 illustrated in FIG. 10, a configuration including the control mechanism 10 that outputs various signals for controlling the operation of the print head 21 and the cable 19 for propagating the various signals for controlling the operation of the print head 21 is an example of the print head control circuit 15 that controls the operation of the print head 21.

FIG. 11 is a diagram illustrating a configuration of the cable 19. The cable 19 has a substantially rectangular shape having short sides 191 and 192 facing each other and long sides 193 and 194 facing each other. For example, the cable 19 is a flexible flat cable (FFC). The cable 19 includes a plurality of terminals 195 aligned in parallel along the short side 191, a plurality of terminals 196 aligned in parallel along the short side 192, and a plurality of wirings 197 that electrically couples the plurality of terminals 195 and the plurality of terminals 196 to each other.

Specifically, 29 terminals 195 are aligned in parallel from the long side 193 toward the long side 194, on the short side 191 side of the cable 19 in order of the terminals 195-1 to 195-29. 29 terminals 196 are aligned in parallel from the long side 193 toward the long side 194, on the short side 192 side of the cable 19 in order of the terminals 196-1 to 196-29. In the cable 19, 29 wirings 197 that electrically couple the terminals 195 and the terminals 196 to each other are aligned in parallel from the long side 193 toward the long side 194 in order of the wirings 197-1 to 197-29. The wiring 197-1 electrically couples the terminal 195-1 and the terminal 196-1 to each other. Similarly, the wiring 197-k (k is any of 1 to 29) electrically couples the terminal 195-k and the terminal 196-k to each other.

The wirings 197-1 to 197-29 are insulated between the wirings and between the wiring and the outside of the cable 19, by an insulator 198. The cable 19 causes a signal input from the terminal 195-k to propagate in the wiring 197-k and to be output from the terminal 196-k. The configuration of the cable 19 illustrated in FIG. 11 is an example, and the embodiment is not limited thereto. For example, the plurality of terminals 195 and the plurality of terminals 196 may be provided on the different surfaces of the cable 19. The number of terminals 195, the number of terminals 196, and the number of wirings 197, which are provided in the cable 19, are not limited to 29.

Next, the configuration of the print head 21 will be described. FIG. 12 is a perspective view illustrating the configuration of the print head 21. As illustrated in FIG. 12, the print head 21 includes the head 310 and the substrate 320. An ink discharge surface 311 on which the plurality of discharge sections 600 are formed is located on a lower surface of the head 310 in the Z-direction.

FIG. 13 is a plan view illustrating a configuration of the ink discharge surface 311. As illustrated in FIG. 13, four nozzle plates 632 are provided on the ink discharge surface 311 to be aligned in the X-direction. The nozzle plate 632 has nozzles 651 provided in the plurality of discharge sections 600. In each of the nozzle plates 632, the nozzles 651 are provided to be aligned in the Y-direction. That is, four nozzle columns L1 to L4 are formed in the ink discharge surface 311. In FIG. 13, the nozzles 651 are provided to be aligned in one line in the Y-direction, in each of the nozzle columns L1 to L4 which are respectively formed in the nozzle plates 632. However, the nozzles 651 may be provided to be aligned in two or more lines in the Y-direction.

The nozzle columns L1 to L4 are provided to correspond to the driving signal selection circuits 200-1 to 200-4, respectively. Specifically, the driving signal VOUT1 output by the driving signal selection circuit 200-1 is supplied to the one end of the piezoelectric element 60 in a plurality of discharge sections 600 provided in the nozzle column L1. The reference voltage signal CGND1 is supplied to the other end of this piezoelectric element 60. Similarly, the driving signals VOUT2 to VOUT4 output by the driving signal selection circuits 200-2 to 200-4 are respectively supplied to one ends of the piezoelectric elements 60 in a plurality of discharge sections 600 provided in the nozzle columns L2 to L4. The reference voltage signals CGND2 to CGND4 are supplied to the other ends of the corresponding piezoelectric elements 60, respectively.

Next, the configuration of the discharge section 600 in the head 310 will be described with reference to FIG. 14. FIG. 14 is a diagram illustrating an overall configuration of one of the plurality of discharge sections 600 in the head 310. As illustrated in FIG. 14, the head 310 includes the discharge section 600 and a reservoir 641.

The reservoir 641 is provided to correspond to each of the nozzle columns L1 to L4. The ink is supplied from the ink supply port 661 into the reservoir 641.

The discharge section 600 includes the piezoelectric element 60, a vibration plate 621, a cavity 631, and the nozzle 651. The vibration plate 621 deforms by displacement of the piezoelectric element 60 provided on an upper surface in FIG. 14. The vibration plate 621 functions as a diaphragm of increasing and reducing the internal volume of the cavity 631. The cavity 631 is filled with the ink. The cavity 631 functions as a pressure chamber having an internal volume which changes by the displacement of the piezoelectric element 60. The nozzle 651 is an opening portion which is formed in the nozzle plate 632 and communicates with the cavity 631. The ink stored in the cavity 631 is discharged from the nozzle 651 by the change of the internal volume of the cavity 631.

The piezoelectric element 60 has a structure in which a piezoelectric substance 601 is interposed between a pair of electrodes 611 and 612. In the piezoelectric element 60 having such a structure, the central portions of the electrodes 611 and 612 and the vibration plate 621 bend with respect to both end portions thereof in an up-and-down direction in FIG. 14, in accordance with a voltage supplied to the electrodes 611 and 612. Specifically, the driving signal VOUT is supplied to the electrode 611, and the reference voltage signal CGND is supplied to the electrode 612. If the voltage of the driving signal VOUT is high, the central portion of the piezoelectric element 60 bends upward. If the voltage of the driving signal VOUT is low, the central portion of the piezoelectric element 60 bends downward. That is, if the piezoelectric element 60 bends upward, the internal volume of the cavity 631 increases. Thus, the ink is drawn from the reservoir 641. If the piezoelectric element 60 bends downward, the internal volume of the cavity 631 is reduced. Accordingly, the ink of the amount depending on the degree of the internal volume of the cavity 631 being reduced is discharged from the nozzle 651. As described above, the piezoelectric element 60 drives by the driving signal VOUT based on the driving signal COM, and the ink is discharged from the nozzle 651 by the piezoelectric element 60 driving. The piezoelectric element 60 is not limited to the structure illustrated in FIG. 14. Any type may be provided so long as the piezoelectric element is capable of discharging the ink with the displacement of the piezoelectric element 60. The piezoelectric element 60 is not limited to flexural vibration, and may be configured to use longitudinal vibration.

Returning to FIG. 12, the substrate 320 has a surface 321 and a surface 322 different from the surface 321. Here, the surface 321 and the surface 322 are surfaces located to face each other with a base material of the substrate 320 interposed between the surfaces 321 and 322. In other words, the surface 321 and the surface 322 are the front surface and the back surface of the substrate 320. The substrate 320 has a substantially rectangular shape formed by a side 323, a side 324 (facing the side 323 in the X-direction), a side 325, and a side 326 (facing the side 325 in the Y-direction). In other words, the substrate 320 has the side 323, the side 324 different from the side 323, the side 325 intersecting the sides 323 and 324, and the side 326 different from the side 325 intersecting the sides 323 and 324. Here, the sides 325 and 326 intersecting the sides 323 and 324 mean a case where a virtual extension line of the side 325 intersects a virtual extension line of the side 323 and a virtual extension line of the side 324, and a virtual extension line of the side 326 intersects a virtual extension line of the side 323 and a virtual extension line of the side 324. That is, the shape of the substrate 320 is not limited to a rectangle. For example, the shape of the substrate 320 may be a polygon such as a hexagon or an octagon, or may have a shape in which a notch or an arc is formed at a portion thereof.

Here, details of the substrate 320 will be described with reference to FIGS. 15 and 16. FIG. 15 is a plan view when the substrate 320 is viewed from the surface 322. FIG. 16 is a plan view when the substrate 320 is viewed from the surface 321. As illustrated in FIG. 15, electrode groups 330a to 330d are provided on the surface 322 of the substrate 320. Specifically, each of the electrode groups 330a to 330d includes a plurality of electrodes aligned in the Y-direction. The electrode groups 330a to 330d are provided to be aligned from the side 323 toward the side 324 in order of the electrode groups 330a, 330b, 330c, and 330d. A flexible printed circuit (FPC) (not illustrated) is electrically coupled to each of the electrode groups 330a to 330d provided in a manner as described above.

As illustrated in FIGS. 15 and 16, FPC insertion holes 332a and 332b and ink supply path insertion holes 331a to 331d being through-holes penetrating the surfaces 321 and 322 are formed in the substrate 320.

The FPC insertion hole 332a is located between the electrode group 330a and the electrode group 330b in the X-direction. An FPC electrically coupled to the electrode group 330a and an FPC electrically coupled to the electrode group 330b are inserted into the FPC insertion hole 332a. The FPC insertion hole 332b is located between the electrode group 330c and the electrode group 330d in the X-direction. An FPC electrically coupled to the electrode group 330c and an FPC electrically coupled to the electrode group 330d are inserted into the FPC insertion hole 332b.

The ink supply path insertion hole 331a is located on the side 323 side of the electrode group 330a in the X-direction. The ink supply path insertion holes 331b and 331c are located between the electrode group 330b and the electrode group 330c in the X-direction. The ink supply path insertion holes 331b and 331c are located to be aligned in the Y-direction such that the ink supply path insertion hole 331b is located on the side 325 side, and the ink supply path insertion hole 331c is located on the side 326 side. The ink supply path insertion hole 331d is located on the side 324 side of the electrode group 330d in the X-direction. A portion of an ink supply path (not illustrated) is inserted into each of the ink supply path insertion holes 331a to 331d. The ink supply path communicates with an ink supply port 661 for supplying the ink to the discharge section 600 corresponding to each of the nozzle columns L1 to L4.

As illustrated in FIGS. 15 and 16, the substrate 320 has fixation portions 346 to 349 for fixing the substrate 320 in the print head 21 to the carriage 20 illustrated in FIG. 1. Each of the fixation portions 346 to 349 is a through-hole penetrating the surfaces 321 and 322 of the substrate 320. The substrate 320 is fixed to the carriage 20 in a manner that screws (not illustrated) inserted into the fixation portion 346 to 349 are attached to the carriage 20. The fixation portions 346 to 349 are not limited to through-holes formed in the substrate 320. For example, the substrate 320 may be fixed to the carriage 20 by fitting the fixation portions 346 to 349.

The fixation portions 346 and 347 are located on the side 323 side of the ink supply path insertion hole 331a in the X-direction and are provided to be aligned such that the fixation portion 346 is located on the side 325 side, and the fixation portion 347 is located on the side 326 side. The fixation portions 348 and 349 are located on the side 324 side of the ink supply path insertion hole 331d in the X-direction and are provided to be aligned such that the fixation portion 348 is located on the side 325 side, and the fixation portion 349 is located on the side 326 side.

As illustrated in FIG. 16, the connector 350 is provided on the substrate 320. The connector 350 is provided along the side 323 on the surface 321 side of the substrate 320.

Here, a configuration of the connector 350 will be described with reference to FIG. 17. FIG. 17 is a diagram illustrating the configuration of the connector 350. As illustrated in FIG. 17, the connector 350 includes a housing 351, a cable attachment section 352 formed in the housing 351, and a plurality of terminals 353. The plurality of terminals 353 is aligned in parallel along the side 323. Specifically, 29 terminals 353 are aligned in parallel along the side 323 in the connector 350 in the first embodiment. Here, the 29 terminals 353 are referred to as terminals 353-1, 353-2, . . . , and 353-29 in order from the side 325 toward the side 326 in a direction along the side 323. The cable attachment section 352 is located on the substrate 320 side of the plurality of terminals 353 in the Z-direction. The cable 19 is attached to the cable attachment section 352. When the cable 19 is attached to the cable attachment section 352, the terminals 196-1 to 196-29 in the cable 19 electrically come into contact with the terminals 353-1 to 353-29 in the connector 350, respectively.

Here, in the connector 350 illustrated in FIG. 17, the cable attachment section 352 is located on the substrate 320 side in the Z-direction, and the plurality of terminals 353 is located on the ink discharge surface 311 side in the Z-direction. However, as in the connector 350 illustrated in FIG. 18, the plurality of terminals 353 is more preferably located on the substrate 320 side in the Z-direction, and the cable attachment section 352 is preferably located on the ink discharge surface 311 side in the Z-direction.

FIG. 18 is a diagram illustrating another configuration of the connector 350. In the liquid discharge apparatus 1, most of the ink discharged from the nozzle 651 are landed on a medium P and form an image. However, a portion of the ink discharged from the nozzle 651 may be misted before being landed on the medium P, and thus may float in the liquid discharge apparatus 1. Even after the ink discharged from the nozzle 651 is landed on the medium P, the ink landed on the medium P may float again in the liquid discharge apparatus 1 by an air flow generated with moving the carriage 20 in which the print head 21 is mounted or transporting the medium P. Thus, when the ink floating in the liquid discharge apparatus 1 adheres to the plurality of terminals 353 in the connector 350 or to the terminals 196 in the cable 19 for propagating a signal to the print head 21, the terminals may be short-circuited. As a result, the waveforms of the various signals input to the print head 21 may be distorted, and thus discharge accuracy of the ink discharged from the print head 21 may be deteriorated.

As in the connector 350 illustrated in FIG. 18, when the plurality of terminals 353 is located on the substrate 320 side in the Z-direction, the cable attachment section 352 is located on the ink discharge surface 311 side in the Z-direction, and the cable 19 is attached to the connector 350, a possibility that the terminal 353 and the terminal 196 are exposed to the ink discharge surface 311 side having a high possibility of the floating ink adhering is reduced. Therefore, it is possible to reduce the concern that the plurality of terminals 353 in the connector 350 or the terminals 196 in the cable 19 are short-circuited by the ink floating in the liquid discharge apparatus 1. Accordingly, it is possible to reduce the concern that the signal propagated in the cable 19 is distorted.

Here, a specific example of electrical coupling between the cable 19 and the connector 350 will be described with reference to FIG. 19. FIG. 19 is a diagram illustrating a specific example when the cable 19 is attached to the connector 350. As illustrated in FIG. 19, the terminal 353 of the connector 350 has a substrate attachment section 353a, a housing insertion section 353b, and a cable maintaining section 353c. The substrate attachment section 353a is located at a lower portion of the connector 350 and is provided between the housing 351 and the substrate 320. The substrate attachment section 353a is electrically coupled to an electrode (not illustrated) provided on the substrate 320, by a solder, for example. The housing insertion section 353b is inserted into the housing 351. The housing insertion section 353b electrically couples the substrate attachment section 353a and the cable maintaining section 353c to each other. The cable maintaining section 353c has a curved shape that protrudes toward the inside of the cable attachment section 352. When the cable 19 is attached to the cable attachment section 352, the cable maintaining section 353c and the terminal 196 electrically come into contact with each other via a contact section 180. Thus, the cable 19 is electrically coupled to the connector 350 and the substrate 320. In this case, since the cable 19 is attached, stress is applied to the curved shape formed at the cable maintaining section 353c. With the stress, the cable 19 is held in the cable attachment section 352.

As described above, the cable 19 and the connector 350 are electrically coupled to each other by the terminal 196 and the terminal 353 coming into contact with each other via the contact section 180. FIG. 11 illustrates contact sections 180-1 to 180-29 at which each of the terminals 196-1 to 196-29 is electrically in contact with the terminal 353 of the connector 350. Thus, the terminal 195-k in the cable 19 is electrically coupled to the connector 12, and the terminal 196-k in the cable 19 is electrically coupled to the connector 350 via the contact section 180-k.

In the print head 21 configured in a manner as described above, a plurality of signals including the driving signals COM1 to COM4, the reference voltage signals CGND1 to CGND4, the print data signals SI1 to SI4, the latch signal LAT, the change signal CH, and the clock signal SCK, which are output from the control mechanism 10, is input to the print head 21 via the connector 350. The plurality of signals is propagated in a wiring pattern (not illustrated) provided on the substrate 320 and then is input to each of the electrode groups 330a to 330d.

The various signals input to each of the electrode groups 330a to 330d are input to the driving signal selection circuits 200-1 to 200-4 respectively corresponding to the nozzle columns L1 to L4, via an FPC electrically coupled to each of the electrode groups 330a to 330d. The driving signal selection circuits 200-1 to 200-4 generate the driving signals VOUT1 to VOUT4 based on the input signals and supply the driving signals VOUT1 to VOUT4 to the piezoelectric elements 60 in the nozzle columns L1 to L4, respectively. In this manner, the various signals input to the connector 350 are supplied to the piezoelectric elements 60 in the plurality of discharge sections 600. Each of the driving signal selection circuits 200-1 to 200-4 may be provided in the head 310 or may be mounted on an FPC in a manner of chip-on-film (COF).

1.7. Details of Signal Propagated in Cable

In the liquid discharge apparatus 1 configured in a manner as described above, details of the signal propagated between the print head control circuit 15 and the print head 21 will be described with reference to FIG. 20.

FIG. 20 is a diagram illustrating details of the signal propagated in the cable 19. As illustrated in FIG. 20, the cable 19 includes wirings for propagating driving signals COM1 to COM4, wirings for propagating reference voltage signals CGND1 to CGND4, wirings for propagating a temperature signal TH, a latch signal LAT, a clock signal SCK, a change signal CH, print data signals SI1 to SI4, and an abnormality signal XHOT, wirings for propagating voltages VHV, VDD1, and VDD2, and a plurality of wirings for propagating a plurality of ground signals GND. In the print head control circuit 15, the wiring 197-23 for propagating the clock signal SCK and the wiring 197-11 for propagating the abnormality signal XHOT are provided to be aligned. The wiring 197-23 for propagating the clock signal SCK and the wiring 197-24 for propagating the voltage VDD2 are located to be adjacent to each other in a direction in which the wiring 197-23 and the wiring 197-11 are aligned. The terminal 353-23 to which the clock signal SCK and the terminal 353-11 to which the abnormality signal XHOT are located to be aligned in the print head 21. The terminal 353-23 to which the clock signal SCK is input and the terminal 353-24 to which the voltage VDD2 is input are located to be adjacent to each other in a direction in which the terminal 353-23 and the terminal 353-11 are aligned. In the liquid discharge apparatus 1, the contact section 180-23 at which the wiring 197-23 for propagating the clock signal SCK and the terminal 353-23 to which the clock signal SCK is input are electrically in contact with each other and the contact section 180-11 at which the wiring 197-11 for propagating the abnormality signal XHOT and the terminal 353-11 to which the abnormality signal XHOT is input are electrically in contact with each other are located to be aligned. The contact section 180-23 to which the clock signal SCK is input and the contact section 180-24 to which the voltage VDD2 is input are located to be adjacent to each other in a direction in which the contact section 180-23 and the contact section 180-11 are aligned.

Specifically, the driving signals COM1 to COM4 and the reference voltage signals CGND1 to CGND4 are input to the cable 19 from the terminals 195-1 to 195-8, respectively. The driving signals COM1 to COM4 and the reference voltage signals CGND1 to CGND4 are propagated in the wirings 197-1 to 197-8, and then are input to the terminals 353-1 to 353-8 of the connector 350 via the terminals 196-1 to 196-8, respectively.

The latch signal LAT is input from the terminal 195-25 to the cable 19 and is propagated in the wiring 197-25. Then, the latch signal LAT is input to the terminal 353-25 of the connector 350 via the terminal 196-25 and the contact section 180-25.

The clock signal SCK is input from the terminal 195-23 to the cable 19 and is propagated in the wiring 197-23. Then, the clock signal SCK is input to the terminal 353-23 of the connector 350 via the terminal 196-23 and the contact section 180-23. Here, the terminal 353-23 to which the clock signal SCK is input is an example of a first terminal in the first embodiment. The wiring 197-23 for propagating the clock signal SCK is an example of a first propagation wiring in the first embodiment. The contact section 180-23 at which the wiring 197-23 and the terminal 353-23 are electrically in contact with each other is an example of a first contact section in the first embodiment.

The change signal CH is input from the terminal 195-21 to the cable 19 and is propagated in the wiring 197-21. Then, the change signal CH is input to the terminal 353-21 of the connector 350 via the terminal 196-21 and the contact section 180-21.

The print data signals SI1 to S14 are input to the cable 19 from the terminals 195-19, 195-17, 195-15, and 195-13 and are propagated in the wirings 197-19, 197-17, 197-15, and 197-13, respectively. Then, the print data signals SI1 to S14 are input to the terminals 353-19, 353-17, 353-15, and 353-13 of the connector 350 via the terminals 196-19, 196-17, 196-15, and 196-13 and the contact sections 180-19, 180-17, 180-15, and 180-13, respectively.

The abnormality signal XHOT is input to the terminal 353-11 of the connector 350, and then, is input to the cable 19 via the contact section 180-11 and the terminal 196-11. The abnormality signal XHOT is propagated in the wiring 197-11, and then is input from the terminal 195-11 to the main substrate 11. Here, the terminal 353-11 to which the abnormality signal XHOT is input is an example of a second terminal in the first embodiment. The wiring 197-11 for propagating the abnormality signal XHOT is an example of a second propagation wiring in the first embodiment. The contact section 180-11 at which the wiring 197-11 and the terminal 353-11 are electrically in contact with each other is an example of a second contact section in the first embodiment.

The temperature signal TH is input to the terminal 353-27 of the connector 350, and then, is input to the cable 19 via the contact section 180-27 and the terminal 196-27. The temperature signal TH is propagated in the wiring 197-27, and then is input from the terminal 195-27 to the main substrate 11.

The voltage VDD1 is input from the terminal 195-29 to the cable 19 and is propagated in the wiring 197-29. Then, the voltage VDD1 is input to the terminal 353-29 of the connector 350 via the terminal 196-29 and the contact section 180-29. The voltage VDD1 supplied to the terminal 353-29 is supplied to the driving signal selection circuit 200. The voltage VDD1 is used as the power source voltage of the driving signal selection circuit 200 and is used as a voltage for generating various control signals for controlling the operation of the driving signal selection circuit 200. Here, the voltage VDD1 is an example of a first voltage signal in the first embodiment. The terminal 353-29 to which the voltage VDD1 is input is an example of a third terminal in the first embodiment. The wiring 197-29 for propagating the voltage VDD1 is an example of a third propagation wiring in the first embodiment. The contact section 180-29 at which the wiring 197-29 and the terminal 353-29 are electrically in contact with each other is an example of a third contact section in the first embodiment.

The voltage VDD2 is input from the terminal 195-24 to the cable 19 and is propagated in the wiring 197-24. Then, the voltage VDD2 is input to the terminal 353-24 of the connector 350 via the terminal 196-24 and the contact section 180-24. The voltage VDD2 supplied to the terminal 353-24 is supplied to the temperature abnormality detection circuit 250. As illustrated in FIG. 9, the voltage VDD2 is used as a power source voltage of the comparator 251 in the temperature abnormality detection circuit 250 and is used as a pull-up voltage for generating the abnormality signal XHOT. That is, when the wiring 197-11 for propagating the abnormality signal XHOT and the wiring 197-24 for propagating the voltage VDD2 are electrically coupled to the print head 21, the wiring 197-11 and the wiring 197-24 are electrically coupled to the print head 21 via the terminal 353-11 and the terminal 353-24 of the connector 350. In other words, in the print head 21, the terminal 353-11 of the connector 350 is electrically coupled to the terminal 353-24. Further, the contact section 180-11 and the contact section 180-24 are electrically coupled. The phrase of being electrically coupled is not limited to a case of being directly or indirectly via a wiring pattern provided on the substrate 320 and may include, for example, a case of being electrically coupled via a resistor element or a capacitor element. Here, the voltage VDD2 is an example of a second voltage signal in the first embodiment. The terminal 353-24 to which the voltage VDD2 is input is an example of a fourth terminal in the first embodiment. The wiring 197-24 for propagating the voltage VDD2 is an example of a fourth propagation wiring in the first embodiment. The contact section 180-24 at which the wiring 197-24 and the terminal 353-24 are electrically in contact with each other is an example of a fourth contact section in the first embodiment.

The voltage VHV is input from the terminal 195-9 to the cable 19 and is propagated in the wiring 197-9. Then, the voltage VHV is input to the terminal 353-9 of the connector 350 via the terminal 196-9 and the contact section 180-9. The voltage VHV is supplied to the driving signal selection circuit 200 via the terminal 353-9. The voltage VHV is used as a voltage and the like for performing level shift of the logical level of the selection signal S to a high amplitude logic level in the driving signal selection circuit 200. Here, the voltage VHV is an example of a third voltage signal in the first embodiment. The terminal 353-9 to which the voltage VHV is an example of a fifth terminal in the first embodiment. The wiring 197-9 for propagating the voltage VHV is an example of a fifth propagation wiring in the first embodiment. The contact section 180-9 at which the wiring 197-9 and the terminal 353-9 are electrically in contact with each other is an example of a fifth contact section in the first embodiment.

The ground signal GND is input to the cable 19 from each of the terminals 195-10, 195-12, 195-14, 195-16, 195-18, 195-20, 195-22, 195-26, and 195-28 and is propagated in each of the wirings 197-10, 197-12, 197-14, 197-16, 197-18, 197-20, 197-22, 197-26, and 197-28. Then, the ground signal GND is input to each of the terminals 353-10, 353-12, 353-14, 353-16, 353-18, 353-20, 353-22, 353-26, and 353-28 of the connector 350 via each of the terminals 196-10, 196-12, 196-14, 196-16, 196-18, 196-20, 196-22, 196-26, and 196-28 and each of the contact sections 180-10, 180-12, 180-14, 180-16, 180-18, 180-20, 180-22, 180-26, and 180-28.

Among the signals supplied to the print head 21 via the cable 19 and the connector 350 described above, the voltages VHV and VDD1 are supplied to the driving signal selection circuit 200. The voltages VHV and VDD1 are used as voltages for generating the various control signals for controlling the operation of the driving signal selection circuit 200. The driving signal selection circuit 200 selects or does not select the waveform of the driving signal COM so as to generate the driving signal VOUT. Thus, the driving signal selection circuit 200 operates at a high speed in accordance with a discharge rate of the ink. Therefore, noise depending on the operation of the driving signal selection circuit 200 may be superimposed on the voltages VHV and VDD1 used as the power source voltage and the various control voltages of the driving signal selection circuit 200.

On the contrary, the voltage VDD2 is supplied to the temperature abnormality detection circuit 250. In other words, the voltage VDD2 is not supplied to the driving signal selection circuit 200. The voltage VDD2 is used as a power source voltage of the temperature abnormality detection circuit 250 and as a pull-up voltage for generating the abnormality signal XHOT. The temperature abnormality detection circuit 250 outputs a signal having an L level when the diagnosis result obtained by diagnosing whether or not the temperature is abnormal indicates being abnormal, and outputs a signal having an H level when the diagnosis result obtained by diagnosing whether or not the temperature is abnormal indicates being normal. That is, the logical level of the abnormality signal XHOT is continuously an H level when abnormality does not occur in the print head 21. Thus, a possibility that noise depending on the operation of the temperature abnormality detection circuit 250 is superimposed on the voltage VDD2 used as the power source voltage of the temperature abnormality detection circuit 250 and the pull-up voltage is low.

The ground signal GND is a signal of a reference potential for a plurality of signals including the voltages VHV, VDD1, and VDD2. Therefore, a current caused by the plurality of signals including the voltages VHV, VDD1, and VDD2 flows in the wiring in which the ground signal GND is propagated. That is, when noise caused by the operation of the driving signal selection circuit 200 is superimposed on the voltages VHV and VDD1, a current caused by the voltages VHV and VDD1 on which the noise is superimposed flows in the wiring in which the ground signal GND is propagated. As a result, noise may also be superimposed in the wiring in which the ground signal GND is propagated.

As described above, the voltage VDD2 is a signal having a more stable potential when compared to the voltages VDD1 and VHV and the ground signal GND. As illustrated in FIG. 20, in the print head control circuit 15 of the liquid discharge apparatus 1 in the first embodiment, the wiring 197-23 for propagating the clock signal SCK and the wiring 197-11 for propagating the abnormality signal XHOT are provided to be aligned. The wiring 197-24 in which the voltage VDD2 being a signal having a stable potential is propagated and the wiring 197-23 in which the clock signal SCK is propagated are located to be adjacent to each other in a direction in which the wiring 197-23 and the wiring 197-11 are aligned. In other words, the wiring 197-24 in which the voltage VDD2 being a signal having a stable potential is propagated and the wiring 197-23 in which the clock signal SCK is propagated are provided in the same cable 19 and are located to be adjacent to each other. Here, the phrase of being located to be adjacent includes a case in which the wiring 197-23 and the wiring 197-24 in the cable 19 are located to be adjacent to each other through the insulator 198, a space, or the like.

In the print head 21 of the liquid discharge apparatus 1 in the first embodiment, the terminal 353-23 to which the clock signal SCK is input and the terminal 353-11 to which the abnormality signal XHOT is input are provided to be aligned. Thus, the terminal 353-24 to which the voltage VDD2 being a signal having a stable potential is input and the terminal 353-23 to which the clock signal SCK is input are provided to be adjacent to each other in a direction in which the terminal 353-23 and the terminal 353-11 are aligned. In other words, the terminal 353-24 to which the voltage VDD2 having a stable potential is input and the terminal 353-23 to which the clock signal SCK is input are provided in the same connector 350 and are located to be adjacent to each other. Here, the phrase of being located to be adjacent includes a case in which the terminal 353-23 and the terminal 353-24 in the connector 350 are located to be adjacent to each other through an insulating member such as the housing 351, an internal space of the cable attachment section 352, or the like.

That is, in the connector 350, the terminal 353-24 to which the voltage VDD2 is input is located in the vicinity of the terminal 353-23 to which the clock signal SCK is input. In other words, in the connector 350, the shortest distance between the terminal 353-23 and the terminal 353-24 is shorter than the shortest distance between the terminal 353-23 and the terminal 353-29 to which the voltage VDD1 is input and is shorter than the shortest distance between the terminal 353-23 and the terminal 353-9 to which the voltage VHV is input, in the direction in which the terminal 353-23 and the terminal 353-25 are aligned.

In the liquid discharge apparatus 1 in the first embodiment, the contact section 180-23 to which the clock signal SCK is input and the contact section 180-11 to which the abnormality signal XHOT is input are provided to be aligned. Thus, the contact section 180-24 to which the voltage VDD2 being a signal having a stable potential is input and the contact section 180-23 to which the clock signal SCK is input are provided to be adjacent to each other in a direction in which the contact section 180-23 and the contact section 180-11 are aligned. In other words, the contact section 180-24 to which the voltage VDD2 having a stable potential is input and the contact section 180-23 to which the clock signal SCK is input are provided in the same connector 350 and are located to be adjacent to each other. Here, the phrase of being located to be adjacent includes a case in which the contact section 180-23 and the contact section 180-24 in the plurality of contact sections 180 at which the cable 19 and the connector 350 are electrically in contact with each other are located to be adjacent to each other through an insulating member such as the housing 351, an internal space of the cable attachment section 352, and the like.

That is, in the plurality of contact sections 180, the terminal 353-24 to which the voltage VDD2 is input is located in the vicinity of the terminal 353-23 to which the clock signal SCK is input. In other words, in the connector 350, the shortest distance between the terminal 353-23 and the terminal 353-24 is shorter than the shortest distance between the terminal 353-23 and the terminal 353-29 to which the voltage VDD1 is input and is shorter than the shortest distance between the terminal 353-23 and the terminal 353-9 to which the voltage VHV is input, in the direction in which the terminal 353-23 and the terminal 353-25 are aligned.

The clock signal SCK is a signal synchronized with the print data signal SI for defining a timing and a discharge amount of the ink discharged from the print head 21. When noise is superimposed on the clock signal SCK, and the waveform of the clock signal SCK is distorted, a timing at which the print data signal SI is supplied to the print head 21 varies. As a result, the timing and the discharge amount of the ink discharged from the print head 21 may fluctuate and thus discharge accuracy of the ink may be deteriorated.

In the print head control circuit 15 in the first embodiment, since the voltage VDD2 having a stable potential is propagated in the wiring 197-24 adjacent to the wiring 197-23 in which the clock signal SCK is propagated in the cable 19, the wiring 197-24 in which the voltage VDD2 is propagated functions as a shield wiring. Thus, it is possible to reduce a concern that the waveform of the clock signal SCK is distorted in the cable 19.

Similarly, in the print head 21 in the first embodiment, since the voltage VDD2 having a stable potential is input to the terminal 353-24 adjacent to the terminal 353-23 to which the clock signal SCK is input in the connector 350, the terminal 353-24 to which the voltage VDD2 is input functions as a shield terminal. Thus, in the connector 350, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted.

Similarly, in the liquid discharge apparatus 1 in the first embodiment, since the voltage VDD2 having a stable potential is input to the contact section 180-24 adjacent to the contact section 180-23 to which the clock signal SCK is input in the plurality of contact sections 180 at which the cable 19 and the connector 350 are electrically in contact with each other, the contact section 180-24 to which the voltage VDD2 is input functions as a shield. Thus, in the plurality of contact sections 180, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted.

Accordingly, in the liquid discharge apparatus 1, the print head control circuit 15, and the print head 21 in the first embodiment, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted. As a result, it is possible to reduce a concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased.

As illustrated in FIG. 20, the followings are preferable. The wiring 197-23 in which the clock signal SCK is propagated and the wiring 197-22 in which the ground signal GND is propagated are provided in the same cable 19 and are located to be adjacent to each other. The terminal 353-23 to which the clock signal SCK is input and the terminal 353-22 to which the ground signal GND are provided in the same connector 350 and are located to be adjacent to each other. The contact section 180-23 to which the clock signal SCK is input and the contact section 180-22 to which the ground signal GND is input are located to be adjacent to each other. In other words, the wiring 197-23 in which the clock signal SCK is propagated is preferably located between the wiring 197-24 in which the voltage VDD2 is propagated and the wiring 197-22 in which the ground signal GND is propagated, in the cable 19. The terminal 353-23 to which the clock signal SCK is input is preferably located between the terminal 353-24 to which the voltage VDD2 is input and the terminal 353-22 to which the ground signal GND is input, in the connector 350. The contact section 180-23 to which the clock signal SCK is input is preferably located between the contact section 180-24 to which the voltage VDD2 is input and the contact section 180-22 to which the ground signal GND is input.

Thus, both the wiring 197-22 in which the ground signal GND is propagated and the wiring 197-24 in which the voltage VDD2 is propagated function as shield wirings for the wiring 197-23 in which the clock signal SCK is propagated. Thus, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted. Accordingly, it is possible to more reduce the concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased. Similarly, both the terminal 353-22 to which the ground signal GND is input and the terminal 353-24 to which the voltage VDD2 is input function as shields for the terminal 353-23 to which the clock signal SCK is input. Thus, it is possible to more reduce the concern that the waveform of the clock signal SCK is distorted. Similarly, both the contact section 180-22 to which the ground signal GND is input and the contact section 180-24 to which the voltage VDD2 is input function as shields for the contact section 180-23 to which the clock signal SCK is input. Thus, it is possible to more reduce the concern that the waveform of the clock signal SCK is distorted. Accordingly, it is possible to more reduce the concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased. The wiring 197-22 in which the ground signal GND is propagated is an example of a first ground signal propagation wiring in the first embodiment. The terminal 353-22 to which the ground signal GND is input is an example of a first ground terminal in the first embodiment. The contact section 180-22 at which the wiring 197-22 and the terminal 353-22 are electrically in contact with each other is an example of a first ground contact section in the first embodiment.

As illustrated in FIG. 20, the followings are preferable. That is, the wiring 197-24 in which the voltage VDD2 is propagated and the wiring 197-9 in which the voltage VHV is propagated are not located to be adjacent to each other in the direction in which the wiring 197-23 and the wiring 197-11 are aligned. The terminal 353-24 to which the voltage VDD2 is input and the terminal 353-9 to which the voltage VHV is input are not located to be adjacent to each other in the direction in which the terminal 353-23 and the terminal 353-11. The contact section 180-24 to which the voltage VDD2 is input and the contact section 180-9 to which the voltage VHV is input are not located to be adjacent to each other in the direction in which the contact section 180-23 and the contact section 180-11 are aligned.

Further, in this case, the followings are preferable. That is, the wiring 197-9 in which the voltage VHV is propagated and the wiring 197-10 in which the ground signal GND is propagated are located to be adjacent to each other in the direction in which the wiring 197-23 and the wiring 197-11 are aligned. The terminal 353-9 to which the voltage VHV is input and the terminal 353-10 to which the ground signal GND is input are located to be adjacent to each other in the direction in which the terminal 353-23 and the terminal 353-11. The contact section 180-9 to which the voltage VHV is input and the contact section 180-10 to which the ground signal GND is input are located to be adjacent to each other in the direction in which the contact section 180-23 and the contact section 180-11 are aligned.

The voltage VHV has a voltage value larger than the voltages VDD1 and VDD2. Further, the voltage VHV is used as a voltage for amplifying the driving signal COM or a voltage for level shift for making the selection signal S be a signal having a high amplitude logic. Thus, a noise component of having a large voltage value may be superimposed on the voltage VHV. Therefore, when a noise component is superimposed on the voltage VHV, the noise component which is included in the voltage VHV and has a large voltage value may interfere with the signal propagated in the wiring adjacent to the wiring in which the voltage VHV is propagated, the signal input to the terminal adjacent to the terminal to which the voltage VHV is input, and the signal input to the contact section adjacent to the contact section to which the voltage VHV is input. In such a case, when the noise component interferes with the voltage VDD2, the waveform of the clock signal SCK may be distorted, and the discharge accuracy of the liquid discharge apparatus 1 may be decreased.

As illustrated in FIG. 19, if the wiring 197-24 in which the voltage VDD2 is propagated is not provided to be adjacent to the wiring 197-9 in which the voltage VHV is propagated, the terminal 353-24 to which the voltage VDD2 is input is not provided to be adjacent to the terminal 353-9 to which the voltage VHV is input, and the contact section 180-24 to which the voltage VDD2 is input is not provided to be adjacent to the contact section 180-9 to which the voltage VHV is input, it is possible to reduce a concern that the voltage VHV interferes with the voltage VDD2 being a signal having a stable potential. Further, if the wiring 197-10 in which the ground signal GND is propagated is provided to be adjacent to the wiring 197-9 in which the voltage VHV is propagated, the terminal 353-10 to which the ground signal GND is input is provided to be adjacent to the terminal 353-9 to which the voltage VHV is input, and the contact section 180-10 to which the ground signal GND is input is provided to be adjacent to the contact section 180-9 to which the voltage VHV is input, the wiring 197-10, the terminal 353-10, and the contact section 180-10 function as the shield. As a result, it is possible to reduce a concern that the voltage VHV interferes with other signals including the voltage VDD2. The wiring 197-10 in which the ground signal GND is propagated is an example of a second ground signal propagation wiring in the first embodiment. The terminal 353-10 to which the ground signal GND is input via the wiring 197-10 is an example of a second ground terminal in the first embodiment. The contact section 180-10 at which the wiring 197-10 and the terminal 353-10 are electrically in contact with each other is an example of a second ground contact section in the first embodiment.

1.8. Advantageous Effects

As described above, in the print head control circuit 15 in the first embodiment, the clock signal SCK and the voltage VDD2 propagated in the same cable 19 are provided to be adjacent to each other. Specifically, the wiring 197-23 for propagating the clock signal SCK and the wiring 197-24 in which the voltage VDD2 is propagated are located to be adjacent to each other in the direction in which the wiring 197-23 and the wiring 197-11 are aligned.

The voltage VDD2 is a signal propagated in the wiring different from the wiring for the voltage VDD1 supplied to the driving signal selection circuit 200 and is supplied to the temperature abnormality detection circuit 250 that generates the abnormality signal XHOT. The driving signal selection circuit 200 controls the supply of the driving signal COM to the piezoelectric element 60. That is, the driving signal selection circuit 200 operates at a high speed in accordance with a discharge rate of the ink discharged from the nozzle. Thus, noise depending on the operation of the driving signal selection circuit 200 may be superimposed on the voltage VDD1 supplied to the driving signal selection circuit 200. The voltage VDD1 supplied to the driving signal selection circuit 200 is fed back via the wiring in which the ground signal GND is propagated. That is, when the noise caused by the operation of the driving signal selection circuit 200 is superimposed on the voltage VDD1, a current caused by the voltage VDD1 on which the noise is superimposed flows in the wiring in which the ground signal GND is propagated.

On the contrary, the temperature abnormality detection circuit 250 diagnoses whether or not temperature abnormality occurs in the print head 21 and outputs the abnormality signal XHOT. Therefore, when the temperature of the print head 21 is within a normal temperature range, the logical level does not change. Thus, the voltage VDD2 supplied to the temperature abnormality detection circuit 250 is a signal having a potential more stable than the voltage VDD1 and the ground signal GND.

Since the wiring 197-24 in which the voltage VDD2 having a stable potential as described above is propagated and the wiring 197-23 for propagating the clock signal SCK are located to be adjacent to each other in the direction in which the wiring 197-23 and the wiring 197-11 are aligned, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted in the cable 19. Thus, variations in a timing at which the various control signals such as the print data signal SI, which are supplied in synchronization with the clock signal SCK and is input to the print head are reduced. As a result, variations in a discharge timing and a discharge amount of the ink discharged from the plurality of nozzles are reduced. Accordingly, discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is improved.

Similarly, in the print head 21 in the first embodiment, the terminal 353-23 to which the clock signal SCK is input and the terminal 353-24 to which the voltage VDD2 is input are located to be adjacent to each other in the direction in which the terminal 353-23 and the terminal 353-11 are aligned. In the liquid discharge apparatus 1 in the first embodiment, the contact section 180-23 to which the clock signal SCK is input and the contact section 180-24 to which the voltage VDD2 is input are located to be adjacent to each other in the direction in which the contact section 180-23 and the contact section 180-11 are aligned. With such a configuration, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted. Thus, variations in a timing at which the various control signals such as the print data signal SI, which are supplied in synchronization with the clock signal SCK and is input to the print head are reduced. As a result, variations in a discharge timing and a discharge amount of the ink discharged from the plurality of nozzles are reduced. Accordingly, discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is improved.

2. Second Embodiment

Next, a liquid discharge apparatus 1, a print head control circuit 15, and a print head 21 according to a second embodiment will be described. When the liquid discharge apparatus 1, the print head control circuit 15, and the print head 21 in the second embodiment are described, components similar to those in the first embodiment are denoted by the same reference signs, and descriptions thereof will not be repeated or will be briefly made.

FIG. 21 is a schematic diagram illustrating an internal configuration of the liquid discharge apparatus 1 in the second embodiment when viewed from the Y-direction. As illustrated in FIG. 21, in the second embodiment, the liquid discharge apparatus 1 includes a main substrate 11, cables 19a and 19b, and a print head 21. That is, the liquid discharge apparatus 1 in the second embodiment is different from that in the first embodiment in that the main substrate 11 and the print head 21 are electrically coupled to each other by the two cables 19a and 19b, and thus various signals are propagated in the cables 19a and 19b. In addition, the liquid discharge apparatus 1 in the second embodiment is different from that in the first embodiment in that the main substrate 11 includes a connector 12a to which one end of the cable 19a is attached and a connector 12b to which one end of the cable 19b is attached, and the print head 21 includes a connector 350 to which the other end of the cable 19a is attached and a connector 360 to which the other end of the cable 19b is attached.

Here, in the liquid discharge apparatus 1 in the second embodiment, a configuration in which a control mechanism 10 that outputs various signals for controlling an operation of the print head 21 and the cables 19a and 19b for propagating the various signals for controlling the operation of the print head 21 are provided is an example of a print head control circuit 15 that controls the operation of the print head 21 in the second embodiment.

The cables 19a and 19b have a configuration similar to that of the cable 19 in the first embodiment except that the numbers of terminals 195 and 196 and wirings 197 are different. Therefore, detailed descriptions of the configuration of the cables 19a and 19b will not be repeated. In the following descriptions, a terminal 195-k provided in the cables 19a and 19b is referred to as a terminal 195a-k and a terminal 195b-k. A terminal 196-k is referred to as a terminal 196a-k and a terminal 196b-k. A wiring 197-k is referred to as a wiring 197a-k and a wiring 197b-k. A contact section 180-k is referred to as a contact section 180a-k and a contact section 180b-k. The terminals 195a-k and 195b-k are electrically coupled to connectors 12a and 12b, respectively. The terminals 196a-k and 196b-k are electrically coupled to the connectors 350 and 360 via the contact sections 180a-k and 180b-k, respectively.

In the second embodiment, descriptions will be made on the assumption that the print head 21 includes six driving signal selection circuits 200-1 to 200-6. Thus, six print data signals SI1 to SI6 respectively corresponding to the six driving signal selection circuits 200-1 to 200-6, six driving signals COM1 to COM6, and six reference voltage signals CGND1 to CGND6 are input to the print head 21 in the second embodiment.

FIG. 22 is a perspective view illustrating a configuration of the print head 21 in the second embodiment. As illustrated in FIG. 22, the print head 21 includes a head 310 and a substrate 320. An ink discharge surface 311 on which the plurality of discharge sections 600 are formed is located on a lower surface of the head 310 in the Z-direction.

The substrate 320 has a surface 321 and a surface 322 facing the surface 321 and has a substantially rectangular shape formed by a side 323, a side 324 (facing the side 323 in the X-direction), a side 325, and a side 326 (facing the side 325 in the Y-direction).

The connectors 350 and 360 are provided on the substrate 320. The connector 350 is provided along the side 323 on the surface 321 side of the substrate 320. The connector 360 is provided along the side 323 on the surface 322 side of the substrate 320.

A configuration of the connectors 350 and 360 will be described with reference to FIG. 23. FIG. 23 is a diagram illustrating the configuration of the connectors 350 and 360 in the second embodiment. The connector 350 includes a housing 351, a cable attachment section 352 formed in the housing 351, and a plurality of terminals 353. The plurality of terminals 353 is aligned in parallel along the side 323. Specifically, 26 terminals 353 are provided along the side 323 to be aligned. Here, the 26 terminals 353 are referred to as terminals 353-1, 353-2, . . . , and 353-26 in order from the side 325 toward the side 326 in a direction along the side 323. The cable attachment section 352 is located on the substrate 320 side of the plurality of terminals 353 in the Z-direction. The cable 19a is attached to the cable attachment section 352. When the cable 19a is attached to the cable attachment section 352, terminals 196a-1 to 196a-26 in the cable 19a are electrically coupled to the terminals 353-1 to 353-26 in the connector 350, respectively. As illustrated in FIG. 18, in the connector 350, the plurality of terminals 353 may be located on the substrate 320 side of the cable attachment section 352 in the Z-direction.

The connector 360 includes a housing 361, a cable attachment section 362 formed in the housing 361, and a plurality of terminals 363. The plurality of terminals 363 is aligned in parallel along the side 323. Specifically, 26 terminals 363 are provided along the side 323 to be aligned. Here, the 26 terminals 363 are referred to as terminals 363-1, 363-2, . . . , and 363-26 in order from the side 325 toward the side 326 in a direction along the side 323. The cable attachment section 362 is located on the substrate 320 side of the plurality of terminals 363 in the Z-direction. The cable 19b is attached to the cable attachment section 362. When the cable 19b is attached to the cable attachment section 362, terminals 196b-1 to 196b-26 in the cable 19b are electrically coupled to the terminals 363-1 to 363-26 in the connector 360, respectively.

Next, details of a signal which are propagated in each of the cables 19a and 19b and is input to the print head 21 will be described with reference to FIGS. 24 and 25. As illustrated in FIGS. 24 and 25, in the print head control circuit 15 of the liquid discharge apparatus 1 in the second embodiment, the wiring 197a-21 for propagating the clock signal SCK and the wiring 197a-15 for propagating the abnormality signal XHOT are provided to be aligned. The wiring 197a-21 for propagating the clock signal SCK and the wiring 197b-21 in which the voltage VDD2 is propagated are located to overlap each other in a direction intersecting the direction in which the wiring 197a-21 and the wiring 197a-15 are aligned. In the print head 21 of the liquid discharge apparatus 1 in the second embodiment, the terminal 353-21 to which the clock signal SCK is input and the terminal 353-15 to which the abnormality signal XHOT is input are provided to be aligned. The terminal 353-21 to which the clock signal SCK is input and the terminal 363-21 to which the voltage VDD2 are located to overlap each other in a direction intersecting the direction in which the terminal 353-21 and the terminal 353-15 are aligned. In the liquid discharge apparatus 1 in the second embodiment, the contact section 180a-21 to which the clock signal SCK is input and the contact section 180b-15 to which the abnormality signal XHOT is input are provided to be aligned. The contact section 180a-21 to which the clock signal SCK is input and the contact section 190b-21 to which the voltage VDD2 is input are located to overlap each other in a direction intersecting the direction in which the contact section 180a-21 and the contact section 180a-15 are provided to be aligned.

FIG. 24 is a diagram illustrating details of a signal propagated in the cable 19a in the second embodiment. As illustrated in FIG. 24, the cable 19a includes wirings for propagating driving signals COM1 to COM6, wirings for propagating reference voltage signals CGND1 to CGND6, wirings for propagating a temperature signal TH, a latch signal LAT, a clock signal SCK, a change signal CH, a print data signal SI1, and an abnormality signal XHOT, a wiring for propagating the voltage VHV, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM1 to COM6 and the reference voltage signals CGND1 to CGND6 are input from the terminals 195a-1 to 195a-12 to the cable 19a and are propagated in the wiring 197a-1 to 197a-12, respectively. Then, the driving signals COM1 to COM6 and the reference voltage signals CGND1 to CGND6 are input to the terminals 353-1 to 353-12 of the connector 350 via the terminals 196a-1 to 196a-12 and the contact sections 180a-1 to 180a-12, respectively.

The latch signal LAT is input from the terminal 195a-23 to the cable 19a and is propagated in the wiring 197a-23. Then, the latch signal LAT is input to the terminal 353-23 of the connector 350 via the terminal 196a-23 and the contact section 180a-23.

The clock signal SCK is input from the terminal 195a-21 to the cable 19a and is propagated in the wiring 197a-21. Then, the clock signal SCK is input to the terminal 353-21 of the connector 350 via the terminal 196a-21 and the contact section 180a-21. Here, the wiring 197a-21 in which the clock signal SCK is propagated is an example of a first propagation wiring in the second embodiment. The terminal 353-21 to which the clock signal SCK is input is an example of a first terminal in the second embodiment. The contact section 180a-21 at which the wiring 197a-21 and the terminal 353-21 are electrically in contact with each other is an example of a first contact section in the second embodiment.

The change signal CH is input from the terminal 195a-19 to the cable 19a and is propagated in the wiring 197a-19. Then, the change signal CH is input to the terminal 353-19 of the connector 350 via the terminal 196a-19 and the contact section 180a-19.

The print data signal SI1 is input from the terminal 195a-17 to the cable 19a and is propagated in the wiring 197a-17. The print data signal SI1 is input to the terminal 353-17 of the connector 350 via the terminal 196a-17 and the contact section 180a-17.

The abnormality signal XHOT is input to the terminal 353-15 of the connector 350 and is input to the cable 19a via the contact section 180a-15 and the terminal 196a-15. The abnormality signal XHOT is propagated in the wiring 197a-15 and is input to the main substrate 11 from the terminal 195a-15. Here, the wiring 197a-15 for propagating the abnormality signal XHOT is an example of a second propagation wiring in the second embodiment. The terminal 353-15 to which the abnormality signal XHOT is input is an example of a second terminal in the second embodiment. The contact section 180a-15 at which the wiring 197a-15 and the terminal 353-15 are electrically in contact with each other is an example of a second contact section in the second embodiment.

The temperature signal TH is input to the terminal 353-25 of the connector 350 and is input to the cable 19a via the contact section 180a-25 and the terminal 196a-25. The temperature signal TH is propagated in the wiring 197a-25, and then is input from the terminal 195a-25 to the main substrate 11.

The voltage VHV is input from the terminal 195a-13 to the cable 19a and is propagated in the wiring 197a-13. Then, the voltage VHV is input to the terminal 353-13 of the connector 350 via the terminal 196a-13 and the contact section 180a-13. Here, the voltage VHV is an example of a third voltage signal in the second embodiment. The wiring 197a-13 for propagating the voltage VHV is an example of a fifth propagation wiring in the second embodiment. The terminal 353-13 to which the voltage VHV is input is an example of a fifth terminal in the second embodiment. The contact section 180a-13 at which the wiring 197a-13 and the terminal 353-13 are electrically in contact with each other is an example of a fifth contact section in the second embodiment.

The ground signal GND is input from each of the terminals 195a-14, 195a-16, 195a-18, 195a-20, 195a-22, 195a-24, and 195a-26 to the cable 19a and is propagated in each of the wirings 197a-14, 197a-16, 197a-18, 197a-20, 197a-22, 197a-24, and 197a-26. Then, the ground signal GND is input to each of the terminals 353-14, 353-16, 353-18, 353-20, 353-22, 353-24, and 353-26 of the connector 350 via each of the terminals 196a-14, 196a-16, 196a-18, 196a-20, 196a-22, 196a-24, and 196a-26 and each of the contact sections 180a-14, 180a-16, 180a-18, 180a-20, 180a-22, 180a-24, and 180a-26.

Next, details of a signal propagated in the cable 19b will be described with reference to FIG. 25. FIG. 25 is a diagram illustrating details of a signal propagated in a cable 19b in the second embodiment. As illustrated in FIG. 25, the cable 19b includes wirings for propagating the driving signals COM1 to COM6, wirings for propagating the reference voltage signals CGND1 to CGND6, wirings for propagating print data signals SI2 to SI6, wirings for propagating voltages VDD1 and VDD2, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM1 to COM6 and the reference voltage signals CGND1 to CGND6 are input to the cable 19b from the terminals 195b-1 to 195b-12 and are propagated in the wirings 197b-1 to 197b-12, respectively. Then, the driving signals COM1 to COM6 and the reference voltage signals CGND1 to CGND6 are input to the terminals 363-1 to 363-12 of the connector 360 via the terminals 196b-1 to 196b-12 and the contact sections 180b-1 to 180b-12, respectively.

The print data signals S12 to S16 are input from the terminals 195b-24, 195b-22, 195b-20, 195b-18, and 195b-16 to the cable 19b, and are propagated in the wirings 197b-24, 197b-22, 197b-20, 197b-18, and 197b-16, respectively. Then, the print data signals S12 to S16 are input to the terminals 363-24, 363-22, 363-20, 363-18, and 363-16 of the connector 360 via the terminals 196b-24, 196b-22, 196b-20, 196b-18, and 196b-16 and the contact sections 180b-24, 180b-22, 180b-20, 180b-18, and 180b-16, respectively.

The voltage VDD1 is input from the terminal 195b-26 to the cable 19b and is propagated in the wiring 197b-26. Then, the voltage VDD1 is input to the terminal 363-26 of the connector 360 via the terminal 196b-26 and the contact section 180b-26. Here, the voltage VDD1 is an example of a first voltage signal in the second embodiment. The wiring 197b-26 for propagating the voltage VDD1 is an example of a third propagation wiring in the second embodiment. The terminal 363-26 to which the voltage VDD1 is input is an example of a third terminal in the second embodiment. The contact section 180b-26 at which the wiring 197b-26 and the terminal 363-26 are electrically in contact with each other is an example of a third contact section in the second embodiment.

The voltage VDD2 is input from the terminal 195b-21 to the cable 19b and is propagated in the wiring 197b-21. Then, the voltage VDD2 is input to the terminal 363-21 of the connector 360 via the terminal 196b-21 and the contact section 180b-21. Here, the voltage VDD2 is an example of a second voltage signal in the second embodiment. The wiring 197b-21 for propagating the voltage VDD2 is an example of a fourth propagation wiring in the second embodiment. The terminal 363-21 to which the voltage VDD2 is input is an example of a fourth terminal in the second embodiment. The contact section 180b-26 at which the wiring 197b-21 and the terminal 363-21 are electrically in contact with each other is an example of a fourth contact section in the second embodiment.

The ground signal GND is input to the cable 19a from each of the terminals 195b-13, 195b-15, 195b-17, 195b-19, 195b-23, and 195b-25 and is propagated in each of the wirings 197b-13, 197b-15, 197b-17, 197b-19, 197b-23, and 197b-25. Then, the ground signal GND is input to each of the terminals 363-13, 363-15, 363-17, 363-19, 363-23, and 363-25 of the connector 360 via each of the terminals 196b-13, 196b-15, 196b-17, 196b-19, 196b-23, and 196b-25 and each of the contact sections 180b-13, 180b-15, 180b-17, 180b-19, 180b-23, and 180b-25.

In the liquid discharge apparatus 1 in the second embodiment, as illustrated in FIGS. 24 and 25, the clock signal SCK is propagated in the wiring 197a-21 of the cable 19a. The voltage VDD2 being a signal having a stable potential is propagated in the wiring 197b-21 of the cable 19b. That is, in the print head control circuit 15, the wiring 197a-21 for propagating the clock signal SCK and the wiring 197b-21 for propagating the voltage VDD2 are located to overlap each other in a direction intersecting the direction in which the wiring 197a-21 and the wiring 197a-15 are aligned. In other words, the wiring 197a-21 for propagating the clock signal SCK and the wiring 197b-21 for propagating the voltage VDD2 are provided in the cables 19a and 19b different from each other and are located to face each other.

Similarly, in the print head 21, the terminal 353-21 to which the clock signal SCK is input and the terminal 353-21 to which the voltage VDD2 is input are located to overlap each other in which the terminal 353-21 and the terminal 353-15 are aligned. In other words, the clock signal SCK is input to the terminal 353-21 of the connector 350. The voltage VDD2 being a signal having a stable potential is input to the terminal 363-21 of the connector 360. That is, the terminal 353-21 to which the clock signal SCK is input and the terminal 363-21 to which the voltage VDD2 is input are provided in the connectors 350 and 360 different from each other and are located to face each other.

Similarly, in the liquid discharge apparatus 1, the contact section 180a-21 to which the clock signal SCK is input and the contact section 180b-21 to which the voltage VDD2 is input are located to overlap each other in a direction intersecting the direction in which the contact section 180a-21 and the contact section 180a-15 are aligned. In other words, the clock signal SCK is input to the contact section 180a-21 among the plurality of contact sections 180a at which the cable 19a and the connector 350 are electrically in contact with each other. The voltage VDD2 being a signal having a stable potential is input to the contact section 180b-21 in the contact section 180b at which the cable 19b and the connector 360 are electrically in contact with each other. That is, the contact section 180a-21 to which the clock signal SCK is input and the contact section 180b-21 to which the voltage VDD2 is input are provided in the plurality of contact sections 180a and 180b at which the different cables 19a and 19b and the different connectors 350 and 360 are electrically in contact with each other and are located to face each other.

As described above, even when the clock signal SCK and the voltage VDD2 are propagated in the wirings provided in the different cables 19 and are input via the terminals provided in the different connectors, it is possible to exhibit effects similar to those in the first embodiment.

Here, the phrase of being located to face each other may have the meaning that the substrate 320, a housing 351 of the connector 350, a housing 361 of the connector 360, or the like is interposed between the wiring 197a-k and the wiring 197b-k, between the terminal 353-k and the terminal 363-k, and between the contact section 180a-k and the contact section 180b-k, in addition to the meaning that a space is provided between the wiring 197a-k and the wiring 197b-k, between the terminal 353-k and the terminal 363-k, and between the contact section 180a-k and the contact section 180b-k. In other words, the phrase of being located to face each other means that another wiring 197 is not located between the wiring 197a-k and the wiring 197b-k, other terminals 353 and 363 are not located between the terminal 353-k and the terminal 363-k, and another contact section 180 is not located between the contact section 180a-k and the contact section 180b-k, when viewed from a specific direction.

That is, when the wiring 197a-21 in which the clock signal SCK is propagated and the wiring 197b-21 in which the voltage VDD2 having a stable potential is propagated are provided in the cables 19a and 19b different from each other, the wiring 197a-21 is located in the vicinity of the wiring 197b-21. In other words, the shortest distance between the wiring 197a-21 provided in the cable 19a and the wiring 197b-21 provided in the cable 19b is shorter than the shortest distance between the wiring 197a-21 provided in the cable 19a and the wiring provided in the cable 19b other than the wiring 197b-21.

When the terminal 353-21 to which the clock signal SCK is input and the terminal 363-21 to which the voltage VDD2 having a stable potential is input are provided in the connectors 350 and 360 different from each other, the terminal 353-21 is located in the vicinity of the terminal 363-21. In other words, the shortest distance between the terminal 353-21 provided in the connector 350 and the terminal 363-21 provided in the connector 360 is shorter than the shortest distance between the terminal 353-21 and the terminal 363 provided in the connector 360 other than the terminal 363-21.

Similarly, when the contact section 180a-21 to which the clock signal SCK is input and the contact section 180b-21 to which the voltage VDD2 having a stable potential is input are provided in the plurality of contact sections 180a at which the cable 19a and the connector 350 are electrically in contact with each other and the plurality of contact sections 180b which is different from the plurality of contact sections 180a and at which the cable 19b and the connector 360 are electrically in contact with each other, the contact section 180a-21 is located in the vicinity of the contact section 180b-21. In other words, the shortest distance between the contact section 180a-21 in the plurality of contact sections 180a at which the cable 19a and the connector 350 are electrically in contact with each other, and the contact section 180b-21 in the plurality of contact sections 180b at which the cable 19b and the connector 360 are electrically in contact with each other is shorter than the shortest distance between the contact section 180a-21 and the contact section 180b in the plurality of contact sections 180b other than the contact section 180b-21.

In the liquid discharge apparatus 1 in the second embodiment, the descriptions are made on the assumption that the wiring 197a-k of the cable 19a and the wiring 197b-k of the cable 19b are located to face each other, the terminal 353-k of the connector 350 and the terminal 363-k of the connector 360 are located to face each other, and the contact section 180a-k and the contact section 180b-k are located to face each other. However, the embodiment is not limited thereto.

As illustrated in FIGS. 24 and 25, the wiring 197a-21 in which the clock signal SCK is propagated and the wiring 197a-22 in which the ground signal GND is propagated are preferably located to be adjacent to each other in a direction intersecting the direction in which the wiring 197a-21 and the wiring 197a-15 are aligned. In other words, preferably, the wiring 197a-21 in which the clock signal SCK is propagated and the wiring 197a-22 in which the ground signal GND is propagated are provided in the same cable 19a and are located to be adjacent to each other. The terminal 353-21 to which the clock signal SCK and the terminal 353-22 to which the ground signal GND is input are preferably located to be adjacent to each other in a direction intersecting the direction in which the terminal 353-21 and the terminal 353-15 are aligned. In other words, preferably, the terminal 353-21 to which the clock signal SCK is input and the terminal 353-22 to which the ground signal GND is input are provided in the same connector 350 and are located to be adjacent to each other. The contact section 180a-21 to which the clock signal SCK is input and the contact section 180a-22 to which the ground signal GND is input are preferably located to be adjacent to each other in a direction intersecting the direction in which the contact section 180a-21 and the contact section 180a-15 are aligned.

Thus, the wiring 197a-22 in which the ground signal GND functions as a shield wiring for the wiring 197a-21 in which the clock signal SCK is propagated. Accordingly, it is possible to reduce a concern that the waveform of the clock signal SCK is distorted. As a result, it is possible to further reduce a concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased. Similarly, the terminal 353-22 to which the ground signal GND is input functions as a shield for the terminal 353-21 to which the clock signal SCK is input. Thus, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted. As a result, it is possible to further reduce the concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased. Similarly, the contact section 180a-22 to which the ground signal GND is input functions as a shield for the contact section 180a-21 to which the clock signal SCK is input. Thus, it is possible to reduce the concern that the waveform of the clock signal SCK is distorted. As a result, it is possible to further reduce the concern that discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is decreased. The wiring 197a-22 in which the ground signal GND is propagated is an example of a first ground signal propagation wiring in the second embodiment. The terminal 353-22 to which the ground signal GND is input is an example of a first ground terminal in the second embodiment. The contact section 180a-22 at which the wiring 197a-22 and the terminal 353-22 are electrically in contact with each other is an example of a first ground contact section in the second embodiment.

As illustrated in FIGS. 24 and 25, preferably, the wiring 197b-21 in which the voltage VDD2 is propagated and the wiring 197a-13 in which the voltage VHV is propagated do not overlap each other in a direction perpendicular to the direction in which the wiring 197a-21 and the wiring 197a-15 are aligned. In other words, preferably, the wiring 197b-21 in which the voltage VDD2 is propagated and the wiring 197a-13 in which the voltage VHV is propagated are provided in the cables 19a and 19b different from each other and are not located to face each other. Preferably, the terminal 363-21 to which the voltage VDD2 is input and the terminal 353-13 to which the voltage VHV is input do not overlap each other in a direction perpendicular to the direction in which the terminal 353-21 and the terminal 353-15 are aligned. In other words, preferably, the terminal 363-21 to which the voltage VDD2 is input and the terminal 353-13 to which the voltage VHV is input are provided in the connectors 360 and 350 different from each other and are not located to face each other. Preferably, the contact section 180b-21 to which the voltage VDD2 is input and the contact section 180a-13 to which the voltage VHV is input do not overlap each other in a direction perpendicular to the direction in which the contact section 180a-21 and the contact section 180a-15 are aligned. In other words, preferably, the contact section 180b-21 to which the voltage VDD2 is input and the contact section 180a-13 to which the voltage VHV is input are provided in the plurality of contact sections 180a at which the cable 19a and the connector 350 are electrically in contact with each other, and the plurality of contact sections 180b which is different from the plurality of contact sections 180a and at which the cable 19b different from the cable 19a and the connector 360 different from the connector 350 are electrically in contact with each other, and are not located to face each other.

Further, in this case, the wiring 197a-13 in which the voltage VHV is propagated and the wiring 197b-13 in which the ground signal GND is propagated are preferably located to overlap each other in a direction intersecting the direction in which the wiring 197a-21 and the wiring 197a-15 are aligned. In other words, preferably, the wiring 197a-13 in which the voltage VHV is propagated and the wiring 197b-13 in which the ground signal GND is propagated are provided in the cables 19a and 19b different from each other and are located to face each other. The terminal 353-13 to which the voltage VHV is input and the terminal 363-13 to which the ground signal GND is input are preferably located to overlap each other in the direction intersecting the direction in which the terminal 353-21 and the terminal 353-15 are aligned. In other words, preferably, the terminal 353-13 to which the voltage VHV is input and the terminal 363-13 to which the ground signal GND is input are provided in the connectors 350 and 360 different from each other and are located to face each other. The contact section 180a-13 to which the voltage VHV is input and the contact section 180b-13 to which the ground signal GND is input are preferably located to overlap each other in the direction intersecting the direction in which the contact section 180a-21 and the contact section 180a-15 are aligned. In other words, preferably, the contact section 180a-13 to which the voltage VHV is input and the contact section 180b-13 to which the ground signal GND is input are provided in the plurality of contact sections 180a at which the cable 19a and the connector 350 are electrically in contact with each other and the plurality of contact sections 180b which is different from the plurality of contact sections 180a and at which the cable 19b different from the cable 19a and the connector 360 different from the connector 350 are electrically in contact with each other, and are located to face each other.

Thus, similar to the first embodiment, it is possible to reduce a concern that a noise component which has a large voltage value and has a possibility of being superimposed on the voltage VHV interferes with the wirings in which other signals including the voltage VDD2 are propagated and with the terminals to which other signals including the voltage VDD2 are input. The wiring 197b-13 in which the ground signal GND is propagated is an example of a second ground signal propagation wiring in the second embodiment. The terminal 363-13 to which the ground signal GND is input is an example of a second ground terminal in the second embodiment. The contact section 180b-13 at which the wiring 197b-13 and the terminal 363-13 are electrically in contact with each other is an example of a second ground contact section in the second embodiment.

As described above, in the print head control circuit 15 and the liquid discharge apparatus 1 in the second embodiment, even when the wiring 197a-21 in which the clock signal SCK is propagated and the wiring 197b-21 in which the voltage VDD2 having a stable potential is propagated are located in the different cables 19a and 19b to face each other, it is possible to reduce the concern that the waveform of the clock signal SCK propagated in the cable 19a is distorted. Thus, similar to the first embodiment, variations in a timing at which the various control signals such as the print data signal SI, which are supplied in synchronization with the clock signal SCK and is input to the print head are reduced. As a result, variations in a discharge timing and a discharge amount of the ink discharged from the plurality of nozzles are reduced. Accordingly, discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is improved.

Similarly, in the print head 21 in the second embodiment, since the terminal 353-21 to which the clock signal SCK is input and the terminal 363-21 to which the voltage VDD2 is input are located in the different connectors 350 and 360 to face each other, it is possible to reduce the concern that the waveform of the clock signal SCK input to the connector 350 is distorted. Thus, similar to the first embodiment, variations in a timing at which the various control signals such as the print data signal SI, which are supplied in synchronization with the clock signal SCK and is input to the print head are reduced. As a result, variations in a discharge timing and a discharge amount of the ink discharged from the plurality of nozzles are reduced. Accordingly, discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is improved.

Similarly, in the liquid discharge apparatus 1 in the second embodiment, the contact section 180a-21 to which the clock signal SCK is input and the contact section 180b-21 to which the voltage VDD2 is input are located in the different contact sections 180a 180b which are respectively and electrically in contact with the different cables 19a and 19b and the different connectors 350 and 360. With such a configuration, it is possible to reduce the concern that the waveform of the clock signal SCK at the contact section 180a is distorted. Thus, similar to the first embodiment, variations in a timing at which the various control signals such as the print data signal SI, which are supplied in synchronization with the clock signal SCK and is input to the print head are reduced. As a result, variations in a discharge timing and a discharge amount of the ink discharged from the plurality of nozzles are reduced. Accordingly, discharge accuracy of the ink discharged from the liquid discharge apparatus 1 is improved.

3. Third Embodiment

Next, a liquid discharge apparatus 1, a print head control circuit 15, and a print head 21 according to a third embodiment will be described. When the liquid discharge apparatus 1, the print head control circuit 15, and the print head 21 in the third embodiment are described, components similar to those in the first embodiment and the second embodiment are denoted by the same reference signs, and descriptions thereof will not be repeated or will be briefly made.

FIG. 26 is a block diagram illustrating an electrical configuration of the liquid discharge apparatus 1 in the third embodiment. As illustrated in FIG. 26, a control circuit 100 in the third embodiment is different from that in the first embodiment in that the control circuit 100 generates two latch signals LAT1 and LAT2 for defining a discharge timing of the print head 21, two change signals CH1 and CH2 for defining a waveform switching timing of the driving signal COM, and two clock signals SCK1 and SCK2 for defining a timing at which a print data signal SI is input, and outputs the generated signals to the print head 21.

FIG. 27 is a schematic diagram illustrating an internal configuration of the liquid discharge apparatus 1 in the third embodiment when viewed from the Y-direction. As illustrated in FIG. 27, the liquid discharge apparatus 1 in the third embodiment includes a main substrate 11, cables 19a, 19b, 19c, and 19d, and a print head 21. That is, the liquid discharge apparatus 1 in the third embodiment is different from that in the first embodiment in that the main substrate 11 and the print head 21 are electrically coupled to each other by the four cables 19a, 19b, 19c, and 19d, and various signals are propagated in the cables 19a, 19b, 19c, and 19d. The liquid discharge apparatus 1 in the third embodiment is different from that in the first embodiment in that the main substrate 11 includes a connector 12a to which one end of the cable 19a is attached, a connector 12b to which one end of the cable 19b is attached, a connector 12c to which one end of the cable 19c is attached, and a connector 12d to which one end of the cable 19d is attached, and the print head 21 includes a connector 350 to which the other end of the cable 19a is attached, a connector 360 to which the other end of the cable 19b is attached, a connector 370 to which the other end of the cable 19c is attached, and a connector 380 to which the other end of the cable 19d is attached.

Here, in the liquid discharge apparatus 1 in the third embodiment, a configuration in which a control mechanism 10 that outputs various signals for controlling an operation of the print head 21 and the cables 19a, 19b, 19c, and 19d for propagating the various signals for controlling the operation of the print head 21 are provided is an example of a print head control circuit 15 that controls the operation of the print head 21 in the third embodiment.

The cables 19a, 19b, 19c, and 19d have a configuration similar to that of the cable 19 in the first embodiment except that the numbers of terminals 195 and 196 and wirings 197 are different. Therefore, detailed descriptions of the configuration of the cables 19a, 19b, 19c, and 19d will not be repeated. In the following descriptions, a terminal 195-k provided in the cables 19a, 19b, 19c, and 19d is referred to as terminals 195a-k, 195b-k, 195c-k, and 195d-k. A terminal 196-k is referred to as terminals 196a-k, 196b-k, 196c-k, and 196d-k. A wiring 197-k is referred to as wirings 197a-k, 197b-k, 197c-k, and 197d-k. A contact section 180-k is referred to as contact sections 180a-k, 180b-k, 180c-k, and 180d-k. The terminals 195a-k, 195b-k, 195c-k, and 195b-k are electrically coupled to the connectors 12a, 12b, 12c, and 12d, respectively. The terminals 196a-k, 196b-k, 196c-k, and 196d-k are electrically coupled to the connectors 350, 360, 370, and 380 via the contact sections 180a-k, 180b-k, 180c-k, and 180d-k, respectively.

In the third embodiment, descriptions will be made on the assumption that the print head 21 includes ten driving signal selection circuits 200-1 to 200-10. Thus, 10 print data signals SI1 to SI10 respectively corresponding to the ten driving signal selection circuits 200-1 to 200-10, 10 driving signals COM1 to COM10, and 10 reference voltage signals CGND1 to CGND10 are input to the print head 21 in the third embodiment.

FIG. 28 is a perspective view illustrating a configuration of the print head 21 in the third embodiment. As illustrated in FIG. 28, the print head 21 includes a head 310 and a substrate 320. An ink discharge surface 311 on which the plurality of discharge sections 600 are formed is located on a lower surface of the head 310 in the Z-direction.

The connectors 350, 360, 370, and 380 are provided on the substrate 320. The connector 350 is provided along the side 323 on the surface 321 side of the substrate 320. The connector 360 is provided along the side 323 on the surface 322 side of the substrate 320. Here, the third embodiment is different from the second embodiment in that the number of a plurality of terminals included in each of the connector 350 and the connector 360 is 20. Other components of the connectors 350 and 360 are similar to those illustrated in FIG. 23. Therefore, detailed descriptions of the connectors 350 and 360 in the third embodiment will not be repeated. In the third embodiment, 20 terminals 353 provided in the connector 350 to be aligned are referred to as terminals 353-1, 353-2, and 353-20 in order from the side 325 toward the side 326 in a direction along the side 323. 20 terminals 363 provided in the connector 360 to be aligned are referred to as terminals 363-1, 363-2, . . . , and 363-20 in order from the side 325 toward the side 326 in a direction along the side 323.

The connector 370 is provided along the side 324 on the surface 321 side of the substrate 320. The connector 380 is provided along the side 324 on the surface 322 side of the substrate 320.

A configuration of the connectors 370 and 380 will be described with reference to FIG. 29. FIG. 29 is a diagram illustrating the configuration of the connectors 370 and 380 in the third embodiment. The connector 370 includes a housing 371, a cable attachment section 372 formed in the housing 371, and a plurality of terminals 373. The plurality of terminals 373 is provided to be aligned along the side 324. Specifically, 20 terminals 373 are provided to be aligned along the side 324. Here, the 20 terminals 373 are referred to as terminals 373-1, 373-2, . . . , and 373-20 in order from the side 325 toward the side 326 in a direction along the side 324. The cable attachment section 372 is located on the substrate 320 side of the plurality of terminals 373 in the Z-direction. The cable 19c is attached to the cable attachment section 372. When the cable 19c is attached to the cable attachment section 372, the terminals 196c-1 to 196c-20 in the cable 19c are electrically coupled to the terminals 373-1 to 373-20 in the connector 370, respectively. Similar to FIG. 18, in the connector 370, the plurality of terminals 373 may be located on the substrate 320 side of the cable attachment section 372 in the Z-direction.

The connector 380 includes a housing 381, a cable attachment section 382 formed in the housing 381, and a plurality of terminals 383. The plurality of terminals 383 is provided to be aligned along the side 324. Specifically, 20 terminals 383 are provided to be aligned along the side 324. Here, the 20 terminals 383 are referred to as terminals 383-1, 383-2, . . . , and 383-20 in order from the side 325 toward the side 326 in a direction along the side 324. The cable attachment section 382 is located on the substrate 320 side of the plurality of terminals 383 in the Z-direction. The cable 19d is attached to the cable attachment section 382. When the cable 19d is attached to the cable attachment section 382, the terminals 196d-1 to 196d-20 in the cable 19d are electrically coupled to the terminals 383-1 to 383-20 in the connector 380, respectively.

Next, details of a signal which are propagated in each of the cables 19a, 19b, 19c, and 19d and is input to the print head 21 will be described with reference to FIGS. 30 to 33.

FIG. 30 is a diagram illustrating details of a signal propagated in the cable 19a in the third embodiment. As illustrated in FIG. 30, the cable 19a includes wirings for propagating driving signals COM1 to COM5, wirings for propagating reference voltage signals CGND1 to CGND5, wirings for propagating a temperature signal TH, a latch signal LAT1, a clock signal SCK1, a change signal CH1, and a print data signal SI1, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM1 to COM5 and the reference voltage signals CGND1 to CGND5 are input from the terminals 195a-1 to 195a-10 to the cable 19a and are propagated in the wiring 197a-1 to 197a-10, respectively. Then, the driving signals COM1 to COM5 and the reference voltage signals CGND1 to CGND5 are input to the terminals 353-1 to 353-10 of the connector 350 via the terminals 196a-1 to 196a-10 and the contact sections 180a-1 to 180a-10, respectively.

The latch signal LAT1 is input from the terminal 195a-17 to the cable 19a and is propagated in the wiring 197a-17. Then, the latch signal LAT is input to the terminal 353-17 of the connector 350 via the terminal 196a-17 and the contact section 180a-17.

The clock signal SCK1 is input from the terminal 195a-15 to the cable 19a and is propagated in the wiring 197a-15. Then, the clock signal SCK1 is input to the terminal 353-15 of the connector 350 via the terminal 196a-15 and the contact section 180a-15.

The change signal CH1 is input from the terminal 195a-13 to the cable 19a and is propagated in the wiring 197a-13. Then, the change signal CH1 is input to the terminal 353-13 of the connector 350 via the terminal 196a-13 and the contact section 180a-13.

The print data signal SI1 is input from the terminal 195a-11 to the cable 19a and is propagated in the wiring 197a-11. Then, the print data signal SI1 is input to the terminal 353-11 of the connector 350 via the terminal 196a-11 and the contact section 180a-11.

The temperature signal TH is input to the terminal 353-19 of the connector 350 and then is input to the cable 19a via the contact section 180a-19 and the terminal 196a-19. The temperature signal TH is propagated in the wiring 197a-19 and then is input from the terminal 195a-19 to the main substrate 11.

The ground signal GND is input to the cable 19a from each of the terminals 195a-12, 195a-14, 195a-16, 195a-18, and 195a-20 and is propagated in each of the wirings 197a-12, 197a-14, 197a-16, 197a-18, and 197a-20. Then, the ground signal GND is input to each of the terminals 353-12, 353-14, 353-16, 353-18, and 353-20 of the connector 350 via each of the terminals 196a-12, 196a-14, 196a-16, 196a-18, and 196a-20 and each of the contact sections 180a-12, 180a-14, 180a-16, 180a-18, and 180a-20.

FIG. 31 is a diagram illustrating details of a signal propagated in the cable 19b in the third embodiment. As illustrated in FIG. 31, the cable 19b includes wirings for propagating the driving signals COM1 to COM5, wirings for propagating the reference voltage signals CGND1 to CGND5, wirings for propagating print data signals SI2 to S15, a wiring for propagating a voltage VDD1, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM1 to COM5 and the reference voltage signals CGND1 to CGND5 are input from the terminals 195b-1 to 195b-10 to the cable 19b and are propagated in the wiring 197b-1 to 197b-10, respectively. Then, the driving signals COM1 to COM5 and the reference voltage signals CGND1 to CGND5 are input to the terminals 363-1 to 363-10 of the connector 360 via the terminals 196b-1 to 196b-10 and the contact sections 180b-1 to 180b-10, respectively.

The print data signals S12 to S15 are input to the cable 19b from the terminals 195b-18, 195b-16, 195b-14, and 195b-12 and are propagated in the wirings 197b-18, 197b-16, 197b-14, and 197b-12, respectively. Then, the print data signals S12 to S15 are input to the terminals 363-18, 363-16, 363-14, and 363-12 of the connector 360 via the terminals 196b-18, 196b-16, 196b-14, and 196b-12 and the contact sections 180b-18, 180b-16, 180b-14, and 180b-12, respectively.

The voltage VDD1 is input from the terminal 195b-20 to the cable 19b and is propagated in the wiring 197b-20. Then, the voltage VDD1 is input to the terminal 363-20 of the connector 360 via the terminal 196b-20 and the contact section 180b-20. The voltage VDD1 is an example of a first voltage signal in the third embodiment. The wiring 197b-20 in which the voltage VDD1 is propagated is an example of a third propagation wiring in the third embodiment. The terminal 363-20 to which the voltage VDD1 is input is an example of a third terminal in the third embodiment. The contact section 180b-20 at which the wiring 197b-20 and the terminal 363-20 are electrically in contact with each other is an example of a third contact section in the third embodiment.

The ground signal GND is input to the cable 19b from each of the terminals 195b-11, 195b-13, 195b-15, 195b-17, and 195b-19 and is propagated in each of the wirings 197b-11, 197b-13, 197b-15, 197b-17, and 197b-19. Then, the ground signal GND is input to each of the terminals 363-11, 363-13, 363-15, 363-17, and 363-19 of the connector 360 via each of the terminals 196b-11, 196b-13, 196b-15, 196b-17, and 196b-19 and each of the contact sections 180b-11, 180b-13, 180b-15, 180b-17, and 180b-19.

FIG. 32 is a diagram illustrating details of a signal propagated in the cable 19c in the third embodiment. As illustrated in FIG. 32, the cable 19c includes wirings for propagating driving signals COM6 to COM10, wirings for propagating reference voltage signals CGND6 to CGND10, wirings for propagating an abnormality signal XHOT, a latch signal LAT2, a clock signal SCK2, a change signal CH2, and a print data signal SI10, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM6 to COM10 and the reference voltage signals CGND6 to CGND10 are input to the cable 19c from the terminals 195c-1 to 195c-10 and are propagated in the wiring 197c-1 to 197c-10, respectively. Then, the driving signals COM6 to COM10 and the reference voltage signals CGND6 to CGND10 are input to the terminals 373-1 to 373-10 of the connector 370 via the terminals 196c-1 to 196c-10 and the contact sections 180c-1 to 180c-10, respectively.

The abnormality signal XHOT is input to the terminal 373-12 of the connector 370 and is input to the cable 19c via the contact section 180c-12 and the terminal 196c-12. The abnormality signal XHOT is propagated in the wiring 197c-12, and then is input from the terminal 195c-12 to the main substrate 11. Here, the wiring 197c-12 for propagating the abnormality signal XHOT is an example of a second propagation wiring in the third embodiment. The terminal 373-12 to which the abnormality signal XHOT is input is an example of a second terminal in the third embodiment. The contact section 180c-12 at which the wiring 197c-12 and the terminal 373-12 are electrically in contact with each other is an example of a second contact section in the third embodiment.

The latch signal LAT2 is input from the terminal 195c-14 to the cable 19c and is propagated in the wiring 197c-14. Then, the latch signal LAT2 is input to the terminal 373-14 of the connector 370 via the terminal 196c-14 and the contact section 180c-14.

The clock signal SCK2 is input from the terminal 195c-16 to the cable 19c and is propagated in the wiring 197c-16. Then, the clock signal SCK2 is input to the terminal 373-16 of the connector 370 via the terminal 196c-16 and the contact section 180c-16. Here, the wiring 197c-16 in which the clock signal SCK2 is propagated is an example of a first propagation wiring in the third embodiment. The terminal 373-16 to which the clock signal SCK2 is an example of a first terminal in the third embodiment. The contact section 180c-16 at which the wiring 197c-16 and the terminal 373-16 are electrically in contact with each other is an example of a first contact section in the third embodiment.

The change signal CH2 is input from the terminal 195c-18 to the cable 19c and is propagated in the wiring 197c-18. Then, the change signal CH2 is input to the terminal 373-18 of the connector 370 via the terminal 196c-18 and the wiring 180c-18.

The print data signal SI10 is input to the cable 19c from the terminal 195c-20 and is propagated in the wiring 197c-20. Then, the print data signal SI10 is input to the terminal 373-20 of the connector 370 via the terminal 196c-20 and the wiring 180c-20.

The ground signal GND is input to the cable 19c from each of the terminals 195c-11, 195c-13, 195c-15, 195c-17, and 195c-19 and is propagated in each of the wirings 197c-11, 197c-13, 197c-15, 197c-17, and 197c-19. Then, the ground signal GND is input to each of the terminals 373-11, 373-13, 373-15, 373-17, and 373-19 of the connector 370 via each of the terminals 196c-11, 196c-13, 196c-15, 196c-17, and 196c-19 and each of the contact sections 180c-11, 180c-13, 180c-15, 180c-17, and 180c-19.

FIG. 33 is a diagram illustrating details of a signal propagated in the cable 19d in the third embodiment. As illustrated in FIG. 33, the cable 19d includes wirings for propagating the driving signals COM6 to COM10, wirings for propagating the reference voltage signals CGND6 to CGND10, wirings for propagating print data signals SI6 to SI9, wirings for propagating voltages VHV and VDD2, and a plurality of wirings for propagating a plurality of ground signals GND.

Specifically, the driving signals COM6 to COM10 and the reference voltage signals CGND6 to CGND10 are input from the terminals 195d-1 to 195d-10 to the cable 19d and are propagated in the wiring 197d-1 to 197d-10, respectively. Then, the driving signals COM6 to COM10 and the reference voltage signals CGND6 to CGND10 are input to the terminals 383-1 to 383-10 of the connector 380 via the terminals 196d-1 to 196d-10 and the contact sections 180d-1 to 180d-10, respectively.

The print data signals S16 to S19 are input to the cable 19d from the terminals 195d-13, 195d-15, 195d-17, and 195d-19 and are propagated in the wirings 197d-13, 197d-15, 197d-17, and 197d-19, respectively. The print data signals S16 to S19 are input to the terminals 383-13, 383-15, 383-17, and 383-19 of the connector 380 via the terminals 196d-13, 196d-15, 196d-17, and 196d-19 and the contact sections 180d-13, 180d-15, 180d-17, and 180d-19, respectively.

The voltage VHV is input from the terminal 195d-11 to the cable 19d and is propagated in the wiring 197d-11. Then, the voltage VHV is input to the terminal 383-11 of the connector 380 via the terminal 196d-11 and the contact section 180d-11. Here, the voltage VHV is an example of a third voltage signal in the third embodiment. The wiring 197d-11 for propagating the voltage VHV is an example of a fifth propagation wiring in the third embodiment. The terminal 383-11 to which the voltage VHV is input is an example of a fifth terminal in the third embodiment. The contact section 180d-11 at which the wiring 197d-11 and the terminal 383-11 are electrically in contact with each other is an example of a fifth contact section in the third embodiment.

The voltage VDD2 is input from the terminal 195d-16 to the cable 19d and is propagated in the wiring 197d-16. Then, the voltage VDD2 is input to the terminal 383-16 of the connector 380 via the terminal 196d-16 and the contact section 180d-16. Here, the voltage VDD2 is an example of a second voltage signal in the third embodiment. The wiring 197d-16 for propagating the voltage VDD2 is an example of a fourth propagation wiring in the third embodiment. The terminal 383-16 to which the voltage VDD2 is input is an example of a fourth terminal in the third embodiment. The contact section 180d-16 at which the wiring 197d-16 and the terminal 383-16 are electrically in contact with each other is an example of a fourth contact section in the third embodiment.

The ground signal GND is input to the cable 19d from each of the terminals 195d-12, 195d-14, 195d-18, and 195d-20 and is propagated in each of the wirings 197d-12, 197d-14, 197d-18, and 197d-20. Then, the ground signal GND is input to each of the terminals 383-12, 383-14, 383-18, and 383-20 of the connector 380 via each of the terminals 196d-12, 196d-14, 196d-18, and 196d-20 and each of the contact sections 180d-12, 180d-14, 180d-18, and 180d-20.

As described above, in the liquid discharge apparatus 1, the print head 21, and the print head control circuit 15 in the third embodiment, the wiring 197c-16 in which the clock signal SCK2 is propagated and the wiring 197d-16 in which the voltage VDD2 is propagated are provided in the cables 19c and 19d different from each other and are located to face each other. The terminal 373-16 to which the clock signal SCK2 is input and the terminal 383-16 to which the voltage VDD2 is input are provided in the connectors 370 and 380 different from each other and are located to face each other. Thus, effects similar to those in the first embodiment and the second embodiment are also exhibited in the liquid discharge apparatus 1, the print head 21, and the print head control circuit 15 in the third embodiment.

Hitherto, the embodiments and the modification examples are described. However, the present disclosure is not limited to the above embodiments, and various forms can be made in a range without departing from the gist thereof. For example, combinations of the above embodiments can be appropriately made.

The present disclosure includes configurations which are substantially the same as the configurations described in the above embodiments (for example, configurations having the same functions, methods, and results or configurations having the same purposes and effects). The present disclosure includes configurations in which non-essential components of the configurations described in the embodiments are replaced. The present disclosure includes configurations having the same advantageous effects as those of the configurations described in the embodiments or includes configurations capable of achieving the same object. The present disclosure includes configurations in which a known technique is added to the configurations described in the embodiments.

Number	Date	Country	Kind
2018-174371	Sep 2018	JP	national
2019-036739	Feb 2019	JP	national

PRINT HEAD CONTROL CIRCUIT, PRINT HEAD, AND LIQUID DISCHARGE APPARATUS

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