The present application is based on, and claims priority from JP Application Serial Number 2023-123136, filed Jul. 28, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus.
JP-A-2022-124599 discloses a liquid ejecting head provided with a piezoelectric element, which includes a resistor with a wire disposed in the vicinity of a pressure chamber, the resistor being designed to change its resistance value in response to a change in temperature so as to detect a temperature of a liquid in the pressure chamber.
The resistor is wired in the vicinity of the pressure chamber and is therefore influenced by noise attributed to a drive current that flows on a driver wire for driving the piezoelectric element. Moreover, according to the technique disclosed in JP-A-2022-124599, the resistor is disposed in a meandering manner. For this reason, resistance of the resistor is increased along with an increase in wiring length. Hence, a value of a current flowing on the resistor is reduced accordingly. As a consequence, the degree of influence of the noise from the drive current on the current flowing on the resistor grows larger. While a larger current may be fed to the resistor in order to relatively reduce the influence of the noise, this method is not desirable in light of a possibility of causing a state of overvoltage. In this regard, there has been a demand for a technique for wiring a resistor in such a way as to reduce a resistance value thereof.
An aspect of the present disclosure provides a liquid ejecting head. This liquid ejecting head includes: a pressure chamber substrate including a first pressure chamber line having a plurality of pressure chambers arranged in a first direction, and a second pressure chamber line having a plurality of pressure chambers arranged in the first direction, the first pressure chamber line and the second pressure chamber line being provided in such a way as to be arranged in a second direction intersecting with the first direction; a plurality of individual electrodes individually provided to the respective pressure chambers of the first pressure chamber line and the second pressure chamber line; at least one common electrode provided in common to the respective pressure chambers of the first pressure chamber line and the second pressure chamber line; piezoelectric bodies provided between the plurality of individual electrodes and the at least one common electrode, respectively, and driven in order to apply a pressure to a liquid inside the plurality of pressure chambers; a first detection resistor formed from an identical material to a material of at least any of the plurality of individual electrodes and the at least one common electrode, and designed to change a resistance value depending on a temperature of the liquid inside the plurality of pressure chambers included in the first pressure chamber line; a second detection resistor formed from the identical material to the material of at least any of the plurality of individual electrodes and the at least one common electrode, and designed to change a resistance value depending on a temperature of the liquid inside the plurality of pressure chambers included in the second pressure chamber line; a wiring board; a first coupling terminal that couples one end of the first detection resistor and one end of the second detection resistor in common to the wiring board; and a second coupling terminal that couples another end of the first detection resistor and another end of the second detection resistor in common to the wiring board.
The liquid ejecting apparatus 1 is an ink jet printer which ejects an ink as an example of a liquid, thereby printing an image on printing paper P being a medium. The medium being a target of ejection of the ink from the liquid ejecting apparatus 1 is not limited only to the printing paper P, but will also be any of plastics, films, fibers, fabrics, leather, metal, glass, wood, ceramics, and so forth.
The liquid ejecting apparatus 1 includes the liquid ejecting head 100 that ejects the liquid, a liquid container 310, a head movement mechanism 320, a transportation mechanism 330, and a control unit 500.
The liquid ejecting head 100 includes nozzles 21 for ejecting the liquid, and ejects the liquid supplied from the liquid container 310 onto the printing paper P. The nozzles 21 are arranged in the y-axis direction. Details of the structure of the liquid ejecting head 100 will be described later.
The liquid container 310 stores the liquid to be ejected from the liquid ejecting head 100. The liquid stored in the liquid container 310 is supplied to the liquid ejecting head 100 through a tube 312 made of a resin. The liquid container 310 is a liquid package in the form of a bag being formed from a flexible film, for example.
The head movement mechanism 320 includes a carriage 322 that mounts the liquid ejecting head 100, a driving belt 324 to which the carriage 322 is fixed, a movement motor 326 and a pulley 327 that reciprocate the driving belt 324 in a main scanning direction. By reciprocating the driving belt 324 in the main scanning direction, the movement motor 326 reciprocates the carriage 322 and the liquid ejecting head 100 in the main scanning direction. The main scanning direction includes +x direction and −x direction. A vertical scanning direction is a direction intersecting with the main scanning direction and includes +y direction and −y direction. In the illustrated example, the liquid is ejected in +z direction from the nozzles 21.
The transportation mechanism 330 includes three transportation rollers 332, a transportation rod 334 attaching the transportation rollers 332, and a transportation motor 336. The printing paper P is transported in the vertical scanning direction by causing the transportation motor 336 to rotate the transportation rod 334.
The piezoelectric element 150 is a driving element for applying a pressure to the liquid in the after-mentioned pressure chamber of the liquid ejecting head 100.
The temperature detection unit 410 is formed from resistance wiring used for temperature detection. In the present specification, the resistance wiring used for detecting the temperature will be referred to as a detection resistor. Details of the temperature detection unit 410 will be described later.
The temperature detection circuit 450 estimates the temperature of the liquid in the pressure chamber by using a characteristic of an electric resistance value of the resistance wiring made of a metal, a semiconductor, and the like, which varies with the temperature.
The temperature detection circuit 450 includes a power supply unit 451 and a resistance measurement unit 452. The power supply unit 451 is a constant-current circuit, for example. The power supply unit 451 feeds a constant current to the temperature detection unit 410 in accordance with control by a temperature management unit 550. The resistance measurement unit 452 acquires a resistance value of the detection resistor of the temperature detection unit 410 based on a current value of the constant current fed from the power supply unit 451 to the temperature detection unit 410, and voltage values at two ends of the detection resistor included in the temperature detection unit 410. The resistance measurement unit 452 outputs the acquired resistance value of the detection resistor of the temperature detection unit 410 to the temperature management unit 550. The resistance measurement unit 452 will also be referred to as a “resistance value acquisition unit”.
The control unit 500 controls the entire liquid ejecting apparatus 1. The control unit 500 is a microcomputer that includes a central processing unit (CPU) 501 and a memory 502. Various programs to be executed by the CPU 501 are stored in the memory 502. Meanwhile, a conversion table TB to be described later is stored in the memory 502. The CPU 501 executes the programs stored in the memory 502, thus functioning as a head control unit 520 and the temperature management unit 550. Here, the control unit 500 may be realized by one or more processing circuits of a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and the like instead of the CPU.
The head control unit 520 controls a reciprocating operation of the carriage 322 along the main scanning direction and a transporting operation of the printing paper P along the vertical scanning direction. Moreover, the head control unit 520 controls ejection of the liquid onto the printing paper P by driving the piezoelectric element 150. In the present embodiment, the head control unit 520 determines a drive waveform for driving the piezoelectric element 150 based on the temperature of the liquid in the pressure chamber acquired from the temperature management unit 550, and drives the piezoelectric element 150 with a drive signal having the determined drive waveform. Accordingly, it is possible to drive the piezoelectric element 150 in accordance with the temperature of the liquid in the pressure chamber. The head control unit 520 will also be referred to as a “drive waveform determination unit”.
The temperature management unit 550 acquires a temperature in the vicinity of the pressure chamber by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the conversion table TB. In the present embodiment, the temperature of the liquid in the pressure chamber can be detected by using the temperature in the vicinity of the pressure chamber thus acquired. For example, the acquired temperature in the vicinity of the pressure chamber may be treated as the temperature of the liquid in the pressure chamber. Alternatively, a value derived from the acquired temperature in the vicinity of the pressure chamber in accordance with a predetermined method may be treated as the temperature of the liquid in the pressure chamber. The conversion table TB includes information that represents a correspondence relation between the electric resistance value of the detection resistor and the temperature. The temperature management unit 550 outputs the acquired temperature of the liquid in the pressure chamber to the head control unit 520. Here, the temperature management unit 550 may compute the temperature of the liquid in the pressure chamber by using the resistance value of the detection resistor of the temperature detection unit 410 and a temperature computation formula that is stored in a storage unit 584 in advance. The temperature management unit 550 will also be referred to as a “temperature acquisition unit”.
The detailed configuration of the liquid ejecting head 100 will be described with reference to
As illustrated in
The pressure chamber substrate 10, the communication substrate 15, the nozzle substrate 20, the compliance substrate 25, the protection substrate 30, the case member 40, the vibration plate 130, and the piezoelectric elements 150 are lamination members. The liquid ejecting head 100 is formed by laminating these lamination members. A direction to laminate the lamination members constituting the liquid ejecting head 100 will also be referred to as a “direction of lamination”. In the present embodiment, the direction of lamination coincides with the z-axis direction. With respect to a predetermined reference position, +z direction side will also be referred to as a “lower side” while −z direction side will also be referred to as an “upper side”.
The pressure chamber substrate 10 is formed from a single-crystal silicon substrate. Alternatively, the pressure chamber substrate 10 may be formed from a metal material such as stainless steel (SUS) and a nickel (Ni), a ceramic material such as zirconia (ZrO2) and alumina (Al2O3), a glass ceramic material, or an oxide material such as magnesium oxide (MgO) and lanthanum aluminate (LaAlO3).
As illustrated in
As illustrated in
As illustrated in
As illustrated in
The compliance substrate 25 is disposed around the nozzle substrate 20. As illustrated in
As illustrated in
The protection substrate 30 is provided in order to protect the piezoelectric element 150 and to increase strength of the pressure chamber substrate 10 and the vibration plate 130. The protection substrate 30 is provided with recesses 33 and a through hole 39. Each recess 33 is a recess that is open on the +z side. The recess 33 is not coupled to the flow channel for the liquid. For this reason, the liquid does not circulate in the recesses 33. The through hole 39 is a through hole that penetrates the protection substrate 30 in the z-axis direction. The wiring board 200 is inserted into the through hole 39.
As illustrated in
As illustrated in
The vibration plate 130 is laminated on the upper side of the pressure chamber substrate 10 at a position overlapping the pressure chambers 12 when viewed in the direction of lamination. The vibration plate 130 includes a flexible layer 131 and a protection layer 133. The flexible layer 131 is formed on the pressure chamber substrate 10. The flexible layer 131 is formed from silicon dioxide (SiO2), for example. The protection layer 133 is formed on the flexible layer 131. The protection layer 133 is an insulating film formed from zirconium oxide (ZrO2), for example.
The piezoelectric elements 150 are disposed on the upper side of the pressure chamber substrate 10 together with the vibration plate 130. To be more precise, each piezoelectric element 150 is disposed above the vibration plate 130 inside the recess 33 provided to the protection substrate 30. The piezoelectric element 150 vibrates the vibration plate 130, thereby applying the pressure to the liquid in the pressure chamber 12. When the pressure is applied to the liquid in the pressure chamber 12, the liquid is ejected from the nozzle 21 through the nozzle communication port 19.
The first electrode 151 is an individual electrode to be individually provided to each of the pressure chambers 12. The first electrode 151 is formed from a conductive material such as gold (Au), platinum (Pt), iridium (Ir), titanium (Ti), and tungsten (W). The first electrode 151 is disposed at such a position that overlaps the corresponding pressure chamber 12 on the surface on the upper side of the vibration plate 130 when viewed in the direction of lamination. As illustrated in
As illustrated in
The piezoelectric body 155 is disposed in such a way as to extend in the direction of arrangement (the y-axis direction) of the pressure chambers 12. The piezoelectric body 155 is formed from a lead zirconate titanate (PZT), for example. Instead, the piezoelectric body 155 may be formed from a different material such as potassium sodium diniobate and barium titanate. The piezoelectric body 155 is formed in a thickness in a range from 1000 nm to 4000 nm, for example.
As illustrated in
Each second electrode 153 is a common electrode to be provided to the pressure chambers 12 in common. As illustrated in
The first electrodes 151 and the second electrodes 153 are electrically coupled to a driving circuit 201 provided to the wiring board 200 (see
As illustrated in
As illustrated in
As illustrated in
The coupling portion 172c is a portion disposed in the vicinity of an end portion on the −y side of the extending portion 172b and extends from the extending portion 172b toward the wiring board 200. The coupling portion 172c extends in a direction having a predetermined inclination with respect to the x axis. For example, the coupling portion 172c extends in an axial direction in a case of turning the x axis clockwise at 20 degrees within the xy plane. An end portion of the coupling portion 172c is coupled to the wiring board 200. Accordingly, an end portion of the second electrode 153 being the common electrode is electrically coupled to the wiring board 200.
The coupling portion 172d is a portion disposed in the vicinity of an end portion on the +y side of the extending portion 172b and extends from the extending portion 172b toward the wiring board 200. The coupling portion 172d extends in the same direction as the coupling portion 172c. An end portion of the coupling portion 172d is coupled to the wiring board 200. Accordingly, another end portion of the second electrode 153 being the common electrode is electrically coupled to the wiring board 200.
As illustrated in
The individual electrodes 171 and the common electrode 172 are formed from a conductive material such as gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), and aluminum (Al). The individual electrodes 171 and the common electrode 172 are formed on the same layer. However, the individual electrodes 171 are not electrically coupled to the common electrode 172. Thus, it is possible to simplify a manufacturing process and to reduce costs as compared to a case of forming the individual electrodes 171 and the common electrode 172 on different layers.
The coupling portion 172c of the common electrode 172 in the first pressure chamber line L1 will also be referred to as a “third coupling terminal”. The coupling portion 172c of the common electrode 172 in the second pressure chamber line L2 will also be referred to as a “fourth coupling terminal”. The coupling portion 172d of the common electrode 172 in the first pressure chamber line L1 will also be referred to as a “fifth coupling terminal”. The coupling portion 172d of the common electrode 172 in the second pressure chamber line L2 will also be referred to as a “sixth coupling terminal”. The individual electrode 171 in the first pressure chamber line L1 will also be referred to as a “seventh coupling terminal”. The individual electrode 171 in the second pressure chamber line L2 will also be referred to as an “eighth coupling terminal”.
The wiring board 200 is formed from a flexible printed circuit (FPC) board, for example.
As illustrated in
As illustrated in
As illustrated in
As illustrated in
The first detection resistor 411 and the second detection resistor 412 are disposed on the same layer as the first electrode 151 in the direction of lamination. The first detection resistor 411 and the second detection resistor 412 are formed from the same material as that of the first electrode 151. As with the first electrode 151, the first detection resistor 411 and the second detection resistor 412 are formed from a material such as gold (Au), platinum (Pt), iridium (Ir), titanium (Ti), and tungsten (W). Each of these materials is a material having conductivity with its electric resistance value exhibiting a temperature dependency at the same time.
The first detection resistor 411 and the second detection resistor 412 are formed together with the first electrode 151 in a process of forming the first electrode 151. However, the first detection resistor 411 and the second detection resistor 412 are not electrically coupled to the first electrode 151. Thus, it is possible to simplify a manufacturing process and to reduce costs as compared to a case of forming the first detection resistor 411 and the second detection resistor 412 on a different layer from the first electrode 151.
As illustrated in
The first detection lead electrode 415 and the second detection lead electrode 416 are disposed on the same layer as the individual electrodes 171 and the common electrode 172 in the direction of lamination. The first detection lead electrode 415 and the second detection lead electrode 416 are formed from the same material as that of the individual electrodes 171 and the common electrode 172. The first detection lead electrode 415 and the second detection lead electrode 416 are formed together with the individual electrodes 171 and the common electrode 172 in a process of forming the individual electrodes 171 and the common electrode 172. However, the first detection lead electrode 415 and the second detection lead electrode 416 are not electrically coupled to the individual electrodes 171 and the common electrode 172. By adopting the above-described configuration, it is possible to simplify a manufacturing process and to reduce costs as compared to a case of forming the first detection lead electrode 415 and the second detection lead electrode 416 on a different layer from the individual electrodes 171 and the common electrode 172.
As with the individual electrodes 171 and the common electrode 172 being partially disposed on the piezoelectric body 155 (see
As illustrated in
In the present embodiment, the first detection resistor 411 and the second detection resistor 412 are coupled in parallel in order to reduce combined resistance of the first detection resistor 411 and the second detection resistor 412. For example, a resistance value of the first detection resistor 411 will be defined as R1 and a resistance value of the second detection resistor 412 will be defined as R2. Combined resistance Rtp when coupling the first detection resistor 411 and the second detection resistor 412 in parallel is equal to R1·R2/(R1+R2). Here, resistance values of the first detection lead electrode 415 and the second detection lead electrode 416 are not taken into consideration in order to facilitate technical understanding.
An assumption is made to couple the first detection resistor 411 and the second detection resistor 412 in series. Here, the serial coupling is equivalent to coupling the one end of the first detection resistor 411 and the one end of the second detection resistor 412 individually to the wiring board 200 and coupling the other end of the first detection resistor 411 and the other end of the second detection resistor 412 to each other. The other end of the first detection resistor 411 and the other end of the second detection resistor 412 are not coupled to the wiring board 200. In this case, combined resistance Rts of the first detection resistor 411 and the second detection resistor 412 is equal to R1+R2.
As described above, the combined resistance Rtp when the first detection resistor 411 and the second detection resistor 412 are coupled in parallel is lower than the combined resistance Rts when the first detection resistor 411 and the second detection resistor 412 are not coupled in parallel.
A reason why it is desirable to reduce the combined resistance of the first detection resistor 411 and the second detection resistor 412 is as follows. The first detection resistor 411 and the second detection resistor 412 are disposed in the vicinity of the pressure chamber 12 in order to detect the temperature of the ink in the pressure chamber 12. Accordingly, the first detection resistor 411 and the second detection resistor 412 are influenced by noise attributed to currents that flow on the individual electrodes 171 and the common electrode 172 being the drive wiring of the piezoelectric elements 150. While a larger current may be fed to the detection resistor in order to relatively reduce the influence of the noise, this method is not desirable in light of a possibility of causing a state of overvoltage. Accordingly, in the present embodiment, the combined resistance of the first detection resistor 411 and the second detection resistor 412 is reduced so that the value of the current flowing on the first detection resistor 411 and the second detection resistor 412 can be increased as compared to that in the aspect of coupling the first detection resistor 411 and the second detection resistor 412 in series. In this way, the influence of the noise attributed to the drive current on the piezoelectric element 150 is reduced.
Meanwhile, as illustrated in
In the meantime, in the present embodiment, a distance in the direction of arrangement (the y-axis direction) between the first detection lead electrode 415 and the coupling portion 172c in the first pressure chamber line L1 is set shorter than a distance in the direction of arrangement between the first detection lead electrode 415 and the coupling portion 172c in the second pressure chamber line L2. A distance in the direction of arrangement between the second detection lead electrode 416 and the coupling portion 172d in the first pressure chamber line L1 is set longer than a distance in the direction of arrangement between the second detection lead electrode 416 and the coupling portion 172d in the second pressure chamber line L2. On the one end portion side (the −y side) in the direction of arrangement of the first pressure chamber line L1, the distance between the first detection lead electrode 415 and the coupling portion 172c of the common electrode 172 in the first pressure chamber line L1 is short. Accordingly, on the other end portion side (the +y side) in the direction of arrangement of the first pressure chamber line L1, the distance between the second detection lead electrode 416 and the coupling portion 172d is set long. Adoption of the above-described configuration reduces a difference between a magnitude of electromagnetic induction noise on the first detection lead electrode 415 attributed to the common electrode 172 and a magnitude of electromagnetic induction noise on the second detection lead electrode 416 attributed to the common electrode 172. That is to say, it is possible to maintain balance between the influence of the noise on the first detection lead electrode 415 and the influence of the noise on the second detection lead electrode 416.
Meanwhile, a length in a direction (a direction of extension) in which the first detection lead electrode 415 extends is larger than a length in the direction of extension of the coupling portion 172c in the first pressure chamber line L1 and larger than a length in the direction of extension of the coupling portion 172c in the second pressure chamber line L2. Here, in the example illustrated in
The length in the direction of extension of the coupling portion 172c in the first pressure chamber line L1 and the length in the direction of extension of the coupling portion 172c in the second pressure chamber line L2 are not set to unnecessarily large lengths. Thus, the influence of induction noise on the first detection lead electrode 415 is reduced.
The Embodiment has explained the example in which the temperature management unit 550 acquires the temperature of the ink in the pressure chamber 12 by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the conversion table TB stored in the memory 502 in advance.
There is also a case of driving only one of the first pressure chamber line L1 and the second pressure chamber line L2 in the liquid ejecting head 100. In this regard, the memory 502 may store a first conversion table TB1 and a second conversion table TB2 in advance instead of the conversion table TB. The first conversion table TB1 includes information that represents correspondence between the resistance value of the detection resistor of the temperature detection unit 410 and the temperature when driving the first pressure chamber line L1 and the second pressure chamber line L2. The second conversion table TB2 includes information that represents correspondence between the resistance value of the detection resistor of the temperature detection unit 410 and the temperature when driving one of the first pressure chamber line L1 and the second pressure chamber line L2.
When driving the first pressure chamber line L1 and the second pressure chamber line L2, the temperature management unit 550 can acquire the temperature of the ink in the pressure chamber 12 by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the first conversion table TB1. When driving one of the first pressure chamber line L1 and the second pressure chamber line L2, the temperature management unit 550 can acquire the temperature of the ink in the pressure chamber 12 by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the second conversion table TB2. The temperature management unit 550 will also be referred to as a correspondence relation acquisition unit. The first conversion table TB1 will also be referred to as a first correspondence relation. The second conversion table TB2 will also be referred to as a second correspondence relation.
Even when driving one of the first pressure chamber line L1 and the second pressure chamber line L2, the resistance measurement unit 452 acquires the combined resistance of the temperature detection unit 410 including the first detection resistor 411 and the second detection resistor 412. Accordingly, it is possible to improve temperature detection accuracy by using any of the first conversion table TB1 and the second conversion table TB2 prepared in advance.
The Other Embodiment 1 has described the example of using the first conversion table TB1 being an example of the first correspondence relation and the second conversion table TB2 being an example of the second correspondence relation in order to acquire the temperature of the ink in the pressure chamber 12. Nonetheless, a first computation formula F1 and a second computation formula F2 may be used in order to acquire the temperature of the ink in the pressure chamber 12. The first computation formula F1 is a computation formula for computing the temperature of the ink based on the resistance value of the detection resistor of the temperature detection unit 410 in the case of driving the first pressure chamber line L1 and the second pressure chamber line L2. The second computation formula F2 is a computation formula for computing the temperature of the ink based on the resistance value of the detection resistor of the temperature detection unit 410 in the case of driving one of the first pressure chamber line L1 and the second pressure chamber line L2. The first computation formula F1 and the second computation formula F2 are stored in the memory 502 in advance. The first computation formula F1 will also be referred to as the “first correspondence relation”. The second computation formula F2 will also be referred to as the “second correspondence relation”.
When driving the first pressure chamber line L1 and the second pressure chamber line L2, the temperature management unit 550 can acquire the temperature of the ink in the pressure chamber 12 by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the first computation formula F1. When driving one of the first pressure chamber line L1 and the second pressure chamber line L2, the temperature management unit 550 can acquire the temperature of the ink in the pressure chamber 12 by using the resistance value of the detection resistor of the temperature detection unit 410 acquired from the resistance measurement unit 452 and using the second computation formula F2. It is possible to improve temperature detection accuracy by using any of the first computation formula F1 and the second computation formula F2 prepared in advance.
Meanwhile, the second detection lead electrode 416 and a fourth detection lead electrode 418, which are coupled in parallel, couple the end portion on the +y side of the first detection resistor 411 and the end portion on the +y side of the second detection resistor 412 in a lump to the wiring board 200 in the vicinity of the end portions on the +y side of the first pressure chamber line L1 and the second pressure chamber line L2. The third detection lead electrode 417 will also be referred to as a “first parallel coupling terminal”. The fourth detection lead electrode 418 will also be referred to as a “second parallel coupling terminal”.
Combined resistance of the first detection lead electrode 415 and the third detection lead electrode 417 coupled in parallel is lower than the resistance when using the first detection lead electrode 415 alone (see
Meanwhile, widths of the first detection resistor 411 and the second detection resistor 412 in the longitudinal direction (the x-axis direction) of the pressure chamber 12 may be set larger than those in the example illustrated in
Meanwhile, a single common electrode (a third common electrode) corresponding to both the first pressure chamber line L1 and the second pressure chamber line L2 may be provided instead of individually providing the second electrodes 153 to the first pressure chamber line L1 and the second pressure chamber line L2. In other words, the two second electrodes 153 in
The Embodiment has described the example in which the individual electrodes 171, the coupling portions 172c, and the coupling portions 172d extend in the same direction (see
The present disclosure is not limited to the above-described embodiments and can be realized by various configurations within a range not departing from the gist of the present disclosure. For example, the technical features in the embodiments corresponding to technical features in respective aspects described in the chapter of the summary of the present disclosure may be exchanged or combined as appropriate in order to solve all or part of the above-mentioned problems or to realize all or part of the above-mentioned advantageous effects. Meanwhile, the technical features therein may be deleted as appropriate as long as the relevant technical features are not described as indispensable features in the present specification.
(1) An aspect of the present disclosure provides a liquid ejecting head. This liquid ejecting head includes: a pressure chamber substrate including a first pressure chamber line having a plurality of pressure chambers arranged in a first direction, and a second pressure chamber line having a plurality of pressure chambers arranged in the first direction, the first pressure chamber line and the second pressure chamber line being provided in such a way as to be arranged in a second direction intersecting with the first direction; a plurality of individual electrodes individually provided to the respective pressure chambers of the first pressure chamber line and the second pressure chamber line; at least one common electrode provided in common to the respective pressure chambers of the first pressure chamber line and the second pressure chamber line; piezoelectric bodies provided between the plurality of individual electrodes and the at least one common electrode, respectively, and driven in order to apply a pressure to a liquid inside the plurality of pressure chambers; a first detection resistor formed from an identical material to a material of at least any of the plurality of individual electrodes and the at least one common electrode, and designed to change a resistance value depending on a temperature of the liquid inside the plurality of pressure chambers included in the first pressure chamber line; a second detection resistor formed from the identical material to the material of at least any of the plurality of individual electrodes and the at least one common electrode, and designed to change a resistance value depending on a temperature of the liquid inside the plurality of pressure chambers included in the second pressure chamber line; a wiring board; a first coupling terminal that couples one end of the first detection resistor and one end of the second detection resistor in common to the wiring board; and a second coupling terminal that couples another end of the first detection resistor and another end of the second detection resistor in common to the wiring board.
According to this aspect, respective first ends of the first detection resistor to detect the temperature of the first pressure chamber line and of the second detection resistor to detect the temperature of the second pressure chamber line are coupled in common to the wiring board, while respective second ends thereof are coupled in common to the wiring board. That is to say, the first detection resistor and the second detection resistor are coupled in parallel. Accordingly, it is possible to establish wiring of the first detection resistor and the second detection resistor in such a way as to reduce the combined resistance of the first detection resistor and the second detection resistor lower than that in the aspect of coupling the first detection resistor and the second detection resistor in series.
(2) In the liquid ejecting head according to above aspect, the at least one common electrode may include a first common electrode corresponding to the first pressure chamber line and a second common electrode corresponding to the second pressure chamber line, and the liquid ejecting head may further include a third coupling terminal that couples a portion of the first common electrode to the wiring board, and a fourth coupling terminal that couples a portion of the second common electrode to the wiring board.
According to this aspect, by providing the common electrodes individually to the first pressure chamber line and the second pressure chamber line, it is possible to prevent consumption of unnecessary electric power when driving only one of the first pressure chamber line and the second pressure chamber line.
(3) In the liquid ejecting head according to above aspect, the liquid ejecting head may further include: a fifth coupling terminal that couples another portion of the first common electrode to the wiring board; and a sixth coupling terminal that couples another portion of the second common electrode to the wiring board.
(4) In the liquid ejecting head according to above aspect, a distance in the first direction between the first coupling terminal and the third coupling terminal may be shorter than a distance in the first direction between the first coupling terminal and the fourth coupling terminal, and a distance in the first direction between the second coupling terminal and the fifth coupling terminal may be longer than a distance in the first direction between the second coupling terminal and the sixth coupling terminal.
According to this aspect, the distance between the first coupling terminal and the fourth coupling terminal is longer than the distance between the first coupling terminal and the third coupling terminal at the one end portion side in the first direction. Therefore, by setting the distance between the second coupling terminal and the fifth coupling terminal shorter than the distance between the second coupling terminal and the sixth coupling terminal at the other end portion side in the first direction, it is possible to maintain the balance between the influence of the electromagnetic induction noise on the first coupling terminal and the influence of the electromagnetic induction noise on the second coupling terminal.
(5) In the liquid ejecting head according to above aspect, a width in the first direction of the first coupling terminal may be larger than a width in the first direction of the third coupling terminal.
According to this aspect, the width of the first coupling terminal that couples the first resistor and the second resistor to the wiring board in common is increased so as to widen the cross-sectional area of the first coupling terminal. Thus, it is possible to reduce the resistance value of the first coupling terminal.
(6) In the liquid ejecting head according to above aspect, the liquid ejecting head may further include: a first parallel coupling terminal that is coupled in parallel with the first coupling terminal, and couples the one end of the first detection resistor and the one end of the second detection resistor in common to the wiring board; and a second parallel coupling terminal that is coupled in parallel with the second coupling terminal, and couples the other end of the first detection resistor and the other end of the second detection resistor in common to the wiring board.
According to this aspect, the combined resistance of the first coupling terminal and the first parallel coupling terminal can be reduced more than the resistance of the first coupling terminal when using the first coupling terminal alone. The combined resistance of the second coupling terminal and the second parallel coupling terminal can be reduced more than the resistance of the second coupling terminal when using the second coupling terminal alone.
(7) In the liquid ejecting head according to above aspect, the liquid ejecting head may further include: a plurality of seventh coupling terminals that couple the plurality of individual electrodes corresponding, respectively, to the plurality of pressure chambers included in the first pressure chamber line to the wiring board, respectively; and a plurality of eighth coupling terminals that couple the plurality of individual electrodes corresponding, respectively, to the plurality of pressure chambers included in the second pressure chamber line to the wiring board, respectively.
According to this aspect, it is possible to prevent consumption of unnecessary electric power when driving only one of the first pressure chamber line and the second pressure chamber line.
(8) In the liquid ejecting head according to above aspect, a width in the first direction of the first coupling terminal may be larger than a width in the first direction of the seventh coupling terminals.
According to this aspect, the width of the first coupling terminal that couples the first resistor and the second resistor in common to the wiring board so as to widen the cross-sectional area of the first coupling terminal. Thus, it is possible to reduce the resistance value of the first coupling terminal.
(9) In the liquid ejecting head according to above aspect, a length in a direction of extension of the first coupling terminal may be larger than a length in a direction of extension of the third coupling terminal and larger than a length in a direction of extension of the fourth coupling terminal.
According to this aspect, it is possible to reduce the influence of induction noise on the first coupling terminal without forming the third coupling terminal and the fourth coupling terminal unnecessarily long.
(10) In the liquid ejecting head according to above aspect, the at least one common electrode may include a third common electrode that corresponds to both the first pressure chamber line and the second pressure chamber line, and the liquid ejecting head may further include a ninth coupling terminal that couples a portion of the third common electrode to the wiring board.
(11) Another aspect of the present disclosure provides a liquid ejecting apparatus. This liquid ejecting apparatus includes: the liquid ejecting head according to above aspect; a resistance value acquisition unit that acquires a resistance value of combined resistance of the first detection resistor and the second detection resistor through the first coupling terminal and the second coupling terminal; and a temperature acquisition unit that acquires a temperature near the pressure chambers based on the resistance value acquired by the resistance value acquisition unit.
According to this aspect, it is possible to reduce the influence of the noise and to improve temperature detection accuracy.
(12) In the liquid ejecting apparatus according to above aspect, the liquid ejecting apparatus may further include: a drive waveform determination unit that determines a drive waveform to be applied to the plurality of individual electrodes based on the temperature acquired by the temperature acquisition unit.
According to this aspect, it is possible to drive the piezoelectric element depending on the temperature.
(13) In the liquid ejecting apparatus according to above aspect, the liquid ejecting apparatus may further include: a first correspondence relation that represents correspondence between the temperature and the resistance value when driving the first pressure chamber line and the second pressure chamber line; and a second correspondence relation that represents correspondence between the temperature and the resistance value when driving one of the first pressure chamber line and the second pressure chamber line, the temperature acquisition unit may acquire the temperature near the pressure chambers based on the resistance value acquired by the resistance value acquisition unit and on the first correspondence relation when driving the first pressure chamber line and the second pressure chamber line, and the temperature acquisition unit may acquire the temperature near the pressure chambers based on the resistance value acquired by the resistance value acquisition unit and on the second correspondence relation when driving one of the first pressure chamber line and the second pressure chamber line.
According to this aspect, even when driving one of the first pressure chamber line and the second pressure chamber line, the resistance value acquisition unit acquires the combined resistance of the first detection resistor and the second detection resistor. Thus, it is possible to improve temperature detection accuracy by using any of the first correspondence relation and the second correspondence relation.
The present disclosure can be realized not only in the above-described aspect as the liquid ejecting apparatus, but also in various aspects including a liquid ejecting system, a multifunction machine including a liquid ejecting apparatus, and so forth.
Number | Date | Country | Kind |
---|---|---|---|
2023-123136 | Jul 2023 | JP | national |