The present application claims priority from Japanese Patent Application No. 2021-115216 filed on Jul. 12, 2021, the disclosure of which is incorporated herein by reference in its entirety.
The present technology relates to a head system, a liquid discharging device, and a method of discharging liquid, that discharge liquid from nozzles.
There is proposed a liquid drop discharging system including: a control unit; a serially connected plurality of head drive units; and a conveying unit that generates a movement amount signal indicating a movement amount of a print medium. Based on an image signal and discharge timing signal from the control unit, the plurality of head drive units respectively outputs drive signals to a plurality of heads, and cause ink to be discharged from each of the heads. The conveying unit outputs the movement amount signal to the control unit, and, based on the movement amount signal, the control unit generates the discharge timing signal. The head drive units cause ink corresponding to the image signal to be discharged from the heads at a timing indicated by the discharge timing signal.
The image signal and discharge timing signal are sequentially transferred from the head drive unit positioned at one end, of the serially connected plurality of head drive units to the head drive unit positioned at the other end, of the serially connected plurality of head drive units. In the case of the discharge timing signal being transferred after the image signal, there is a risk that volume of the image signal will be larger than that of the discharge timing signal, and that a timepoint when the discharge timing signal is received by the head drive units will be delayed.
The present disclosure, which was made in view of such circumstances, has an object of providing a head system, a liquid discharging device, and a method of discharging liquid, that enable delay in discharge timing to be suppressed.
According to an aspect of the present disclosure, a head system includes: a main controller; a plurality of head units having nozzles; and a plurality of sub-controllers respectively connected to at least one of the plurality of head units. Each of the sub-controllers is serially connected via a wiring. The wiring includes: a first communication path configured to transmit an image signal; and a second communication path configured to transmit a discharge timepoint signal indicating a discharge timepoint when liquid is to be discharged from the nozzles. The second communication path differs from the first communication path. The first communication path is configured to transmit the image signal from the main controller to each of the sub-controllers. The second communication path is configured to transmit the discharge timepoint signal to each of the sub-controllers. Each of the sub-controllers is configured to control one of the head units, to which each of the sub-controllers have been connected, to discharge liquid corresponding to an image indicated by the image signal that has been received through the first communication path from the nozzles of the one of the head unit, at a discharge timepoint indicated by the discharge timepoint signal that has been received through the second communication path.
The present disclosure will be described below based on drawings depicting a printer according to a first embodiment. In
As depicted in
The recording sheet 100 passes over an upper surface of the platen 3. The four ink jet heads 4 are aligned in the conveying direction above the platen 3. Each of the ink jet heads 4 is a so-called line-type head. The ink jet head 4 has ink supplied to it from an ink tank (not illustrated). The four ink jet heads 4 are supplied with inks of different colors.
As depicted in
The controller 7 includes an FPGA, an EEPROM, and a RAM and the like. Note that the controller 7 may include a CPU or an ASIC. The controller 7, which is data-communicably connected to an external device 9 such as a PC, controls each section of the printer 1 based on print data sent from the external device 9.
The controller 7 includes a main controller 7a. The main controller 7a includes a counter 7b and a communication section 7c. The ink jet head 4 includes a plurality of head modules 40. The plurality of head modules 40 is arranged in line in the left-right direction.
The plurality of head modules 40 includes, for example, n head modules, that is, a first head module 40(1) through nth head module 40(n) (where n is a natural number). The first head module 40(1) is positioned furthest to the left, and the nth head module 40(n) is positioned furthest to the right.
The first head module 40(1) through nth head module 40(n) each includes an SoC 41 and a plurality of heads 42. The SoC 41 corresponds to a sub-controller. The head 42 has a plurality of nozzles. The SoC 41 includes a control section 41a, a memory 41b, a counter 41c, and a communication section 41d. The control section 41a controls operation of each SoC 41. The memory 41b is a rewritable nonvolatile memory such as an EPROM or an EEPROM, for example. The SoC 41 of the first head module 40(1) further includes a discharge timepoint generator 41e. The SoCs 41 of the second head module 40(2) through nth head module 40(n) do not include the discharge timepoint generator 41e. Hereafter, the SoCs 41 of the first head module 40(1) through nth head module 40(n) will be called SoC(1) through SoC(n).
The communication section 7c and each of the communication sections 41d are serially connected by a first wiring 50. The communication section 7c transmits to the communication section 41d of SoC(1) an image signal included in the print data. The communication section 41d of SoC(1) transfers the image signal to the communication section 41d of SoC(2), and the communication section 41d of SoC(2) transfers the image signal to the communication section 41d of SoC(3). In this way, the image signal is sequentially transferred to the communication section 41d of SoC(n).
The image signal includes: an identifier of each of SoC(1) through SoC(n); and print information associated with each identifier. The control sections 41a of SoC(1) through SoC(n) acquire from the received image signal image information associated with their own identifier.
The conveying rollers 5, 6 include an unillustrated motor, and a rotating shaft of the motor is provided with an encoder 8. The encoder 8 corresponds to a detecting unit. The encoder 8, the discharge timepoint generator 41e, and SoC(2) through SoC(n) are serially connected by a second wiring 60. The encoder 8 detects rotational position of the motor as the detection value, and outputs the detected rotational position of the motor as the detection value to the discharge timepoint generator 41e.
The discharge timepoint generator 41e generates a discharge timepoint signal when ink is to be discharged by the head 42 of each of the first head module 40(1) through nth head module 40(n), based on a detection value with which the discharge timepoint generator 41e has been inputted. The discharge timepoint generator 41e transmits to SoC(2) through SoC(n) a discharge timepoint signal indicating the generated discharge timepoints. That is, the discharge timepoint signal is transmitted from the discharge timepoint generator 41e to each of the SoCs 41 other than SoC(1), through the second wiring 60. The discharge timepoint signal includes: an identifier of each of SoC(2) through SoC(n); and a count value which is associated with each identifier, and that indicates a timepoint when ink is to be discharged from the head 42. SoC(1) acquires the discharge timepoint signal from the discharge timepoint generator 41e, and SoC(2) through SoC(n) receive the discharge timepoint signal. SoC(1) through SoC(n) acquire from the acquired or received discharge timepoint signal the count value associated with their own identifier.
SoC(1) through SoC(n) cause ink corresponding to acquired image information to be discharged from the head 42 when a value of the counter 41c has reached the acquired count value, that is, when the value of the counter 41c has reached a discharge timepoint indicated by the discharge timepoint signal.
The printer 1 according to the first embodiment includes: the first wiring 50 that serially connects the main controller 7a and plurality of SoCs 41; and the second wiring 60 that differs from the first wiring 50. The first wiring 50 is used in transmission of the image signal, and the second wiring 60 is used in transmission of the discharge timepoint signal. Volume of the image signal is larger than that of the discharge timepoint signal. However, since a different communication path from that of the image signal is used in transmission of the discharge timepoint signal, delay of the discharge timepoint signal can be suppressed.
The SoC 41 including the discharge timepoint generator 41e is not limited to SoC(1). Any of SoC(2) through SoC(n) may include the discharge timepoint generator 41e, instead of SoC(1). A circuit including a discharge timepoint generator may be separately provided between the encoder 8 and SoC(1), rather than the discharge timepoint generator 41e being provided in SoC(1). In this case, the discharge timepoint signal is transmitted from the circuit to SoC(1) through the second wiring 60. Note that in order to suppress that wiring between the encoder 8 and discharge timepoint generator 41e gets lengthy, the discharge timepoint generator 41e is preferably included in the head module 40 closest to the encoder 8.
The present disclosure will be described below based on a drawing depicting a printer 1 according to a second embodiment. Configurations of the second embodiment that are similar to in the first embodiment will be assigned with the same symbols as in the first embodiment, and their detailed descriptions omitted.
The printer 1 according to the second embodiment differs from that of the first embodiment in not including the second wiring 60. Moreover, whereas in the first embodiment, SoC(1) included the discharge timepoint generator 41e, in the second embodiment, SoC(n) includes the discharge timepoint generator 41e.
The communication section 7c and each of the communication sections 41d are serially connected by the first wiring 50. The first wiring 50 is a communication cable capable of bidirectional communication. The first wiring 50 has a first communication path 51 and a second communication path 52.
The first communication path 51 has: a first transmission start terminal positioned at one of ends of the first wiring 50 and connected to the main controller 7a; and a first transmission finish terminal positioned at the other of the ends of the first wiring 50 and connected to SoC(n). The second communication path 52 has: a second transmission start terminal positioned at the other of the ends of the first wiring 50 and connected to SoC(n); and a second transmission finish terminal positioned at the one of the ends of the first wiring 50 and connected to the main controller 7a.
The first communication path 51 is a path directed from the main controller 7a to SoC(n), and the second communication path 52 is a path directed from SoC(n) to the main controller 7a.
The image signal is sequentially transmitted to the first transmission start terminal, SoC(1) through SoC(n−1), the first transmission finish terminal, and SoC(n) from the main controller 7a, through the first communication path 51. Moreover, the discharge timepoint signal is sequentially transmitted to the second transmission start terminal, SoC(n−1) through SoC(1), the second transmission finish terminal, and the main controller 7a from SoC(n), through the second communication path 52.
The encoder 8, discharge timepoint generator 41e, SoC(1) through SoC(n−1), and main controller 7a are serially connected by the second communication path 52. The encoder 8 detects rotational position of the motor, and outputs the detected rotational position of the motor to the discharge timepoint generator 41e.
The discharge timepoint generator 41e generates a discharge timepoint when ink is to be discharged by the head 42 of each of the first head module 40(1) through nth head module 40(n), based on a detection value with which the discharge timepoint generator 41e has been inputted. The discharge timepoint generator 41e uses the second communication path 52 to transmit to SoC(1) through SoC(n−1) a discharge timepoint signal indicating the generated discharge timepoints. The discharge timepoint signal includes: an identifier of each of SoC(1) through SoC(n); and a count value which is associated with each identifier, and that indicates a timepoint when ink is to be discharged from the head 42. SoC(n) acquires the discharge timepoint signal from the discharge timepoint generator 41e, and SoC(1) through SoC(n−1) receive the discharge timepoint signal. SoC(1) through SoC(n) acquire from the acquired or received discharge timepoint signal the count value associated with their own identifier.
SoC(1) through SoC(n) cause ink corresponding to acquired image information to be discharged from the head 42 when a value of the counter 41c has reached the acquired count value, that is, when the value of the counter 41c has reached the discharge timepoint indicated by the discharge timepoint signal.
In the printer 1 according to the second embodiment, the communication cable capable of bidirectional communication is used for transmission of the image signal and the discharge timepoint signal, so increase in the number of wirings can be suppressed. Moreover, since a transferring direction of the image signal and a transferring direction of the discharge timepoint signal are reversed with respect to each other, it becomes possible for transfer of the discharge timepoint signal to be performed without waiting for completion of transfer of the image signal.
In the above description, the first communication path 51 and second communication path 52 are separate wirings. However, not only the separate wirings but also a single wiring can be used. For example, as depicted in
The present disclosure will be described below based on drawings depicting a printer 1 according to a third embodiment. Configurations of the printer 1 according to the third embodiment that are similar to in the second embodiment will be assigned with the same symbols as in the second embodiment, and their detailed descriptions omitted.
A signal other than the discharge timepoint signal is transmitted from the head module 40 to the main controller 7a, through the second communication path 52. As a signal other than the discharge timepoint signal, there may be cited, for example, a signal indicating that reception of the image signal has been completed, or a signal indicating environmental temperature of the head module 40.
In
In the memory 41b of the head module 40, “98” is stored as a threshold value of the count value. The threshold value is predetermined based on a prediction that has been made of the reception timepoint of the discharge timepoint signal into the head module 40. For example, if the predicted reception timepoint is “99 onwards”, then “98” which is earlier than “99” will be set as the threshold value.
If the count value reaches the threshold value “98” or more (S2: YES), then the SoC 41 executes prohibition processing prohibiting transmission of a signal other than the discharge timepoint signal (S3), and judges whether or not the discharge timepoint signal has been received (S4). If the discharge timepoint signal has not been received (S4: NO), then the SoC 41 returns processing to step S4. Note that the reception timepoint of the discharge timepoint signal is not necessarily fixed, and, as depicted in
If the discharge timepoint signal has been received (S4: YES), then the SoC 41 transmits the discharge timepoint signal (S5) and resets the counter 41c (S6). As depicted in
There is a risk that if the second communication path 52 is used by a signal other than the discharge timepoint signal, then said signal will be transmitted at the same timing as the discharge timepoint signal and a delay will occur in reception of the discharge timepoint signal in the head module 40. In the third embodiment, by prohibition processing prohibiting transmission of a signal other than the discharge timepoint signal being started prior to transmission of the discharge timepoint signal, that is, by the discharge timepoint signal being transmitted during the period K1 of prohibition processing and a signal other than the discharge timepoint signal being transmitted during the period K2 which is a different period from the period K1 and in which prohibition processing has been ended, occurrence of delay in reception of the discharge timepoint signal can be suppressed.
The present disclosure will be described below based on drawings depicting a printer 1 according to a fourth embodiment. Configurations of the printer 1 according to the fourth embodiment that are similar to in the third embodiment will be assigned with the same symbols as in the third embodiment, and their detailed descriptions omitted.
“Reception”, “transmission”, and “communication state” in
As depicted in
If the discharge timepoint signal has been received (S13: YES), then the SoC 41 transmits the discharge timepoint signal (S14) and ends prohibition processing (S15). A period from when the prohibition signal is received to when the discharge timepoint signal is transmitted is the period K1, and a period from when the discharge timepoint signal is transmitted to when the prohibition signal is received is the period K2.
In the fourth embodiment, by the prohibition signal being transmitted by the discharge timepoint generator 41e and by prohibition processing prohibiting transmission of a signal other than the discharge timepoint signal being started prior to transmission of the discharge timepoint signal, that is, by the discharge timepoint signal being transmitted during the period K1 of prohibition processing and a signal other than the discharge timepoint signal being transmitted during the period K2 which is a different period from the period K1 and in which prohibition processing has been ended, the discharge timepoint signal can be received by the SoC 41 during the period K1, and occurrence of delay in reception of the discharge timepoint signal can be suppressed.
The embodiments disclosed on this occasion are in all respects exemplifications, and should not be considered limiting. The technological features described in each of the embodiments can be combined with each other.
Number | Date | Country | Kind |
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2021-115216 | Jul 2021 | JP | national |
Number | Name | Date | Kind |
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10661560 | Nakajima | May 2020 | B2 |
20040046830 | Mitsuzawa | Mar 2004 | A1 |
20180345696 | Kodaira | Dec 2018 | A1 |
Number | Date | Country |
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2001-277658 | Oct 2001 | JP |
2004-25551 | Jan 2004 | JP |
2009241379 | Oct 2009 | JP |
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2009128351 | Oct 2009 | WO |
Entry |
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Notice of Reasons for Refusal dated Dec. 26, 2023 received from the Japanese Patent Office in corresponding application JP 2021-115216 together with English language translation. |
Number | Date | Country | |
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20230010691 A1 | Jan 2023 | US |