Liquid discharge apparatus and print head

Abstract

To provide a liquid discharge apparatus capable of reducing a possibility that miniaturization of a print head becomes difficult.SOLUTION: A liquid discharge apparatus includes a discharge control circuit that outputs a first signal and a second signal, and a print head that discharges liquid according to the first signal and the second signal, in which the print head includes: a first head chip that discharges liquid according to the first signal; a second head chip that discharges liquid according to the second signal; a first flexible wiring substrate that propagates the first signal to the first head chip; a second flexible wiring substrate that propagates the second signal to the second head chip; a substrate to which the first head chip and the second head chip are fixed; and a connector to which the first signal and the second signal are input, where the second flexible wiring substrate is directly coupled to the first flexible wiring substrate, and the second signal propagates through the first flexible wiring substrate, then propagates through the second flexible wiring substrate without passing through the substrate, and is input to the second head chip.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a liquid ejection device and a print head.

Background Art

[0002] Patent Document 1 discloses a print head that ejects liquid, which includes a plurality of flexible wiring boards that propagate signals, a wiring board to which the plurality of flexible wiring boards are connected, and a plurality of ejection parts from which liquid is ejected. A signal for controlling the ejection of liquid input to the print head propagates through each of the wiring board and the plurality of flexible wiring boards and is input to the corresponding ejection part, thereby controlling the ejection of liquid from the ejection part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology described in Patent Document 1, when the number of ejection parts of the print head increases or the number of signals for controlling the ejection of liquid from the print head increases, there is a risk that the wiring board to which the flexible wiring board is connected becomes large, and it may be difficult to miniaturize the print head.

Means for Solving the Problems

[0005] One aspect of the liquid ejection device according to the present invention is an ejection control circuit that outputs a first signal and a second signal, a print head that ejects liquid according to the first signal and the second signal, and includes wherein the print head A first head chip that discharges liquid in response to the first signal, A second head chip that discharges liquid in response to the second signal, A first flexible wiring board that propagates the first signal to the first head chip, A second flexible wiring board that propagates the second signal to the second head chip, A board to which the first head chip and the second head chip are fixed, A connector to which the first signal and the second signal are input, and having, The second flexible wiring board is directly connected to the first flexible wiring board, After propagating through the first flexible wiring board, the second signal propagates through the second flexible wiring board without passing through the board and is input to the second head chip.

[0006] One aspect of the print head according to the present invention is, A print head that discharges liquid in response to a first signal and a second signal, A first head chip that discharges liquid in response to the first signal, A second head chip that discharges liquid in response to the second signal, A first flexible wiring board that propagates the first signal to the first head chip, A second flexible wiring board that propagates the second signal to the second head chip, A board to which the first head chip and the second head chip are fixed, A connector to which the first signal and the second signal are input, comprising, The second flexible wiring board is directly connected to the first flexible wiring board, After propagating through the first flexible wiring board, the second signal propagates through the second flexible wiring board without passing through the board and is input to the second head chip.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 15

Embodiments for Carrying Out the Invention

[0008] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The drawings used are for convenience of explanation. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0009] Further, the liquid ejection device according to the present invention is a printing device that ejects ink as a liquid. Although it will be described by taking an inkjet printer as an example, the liquid ejection device is not limited to an inkjet printer. For example, it may be a colorant ejection device used for manufacturing a color filter such as a liquid crystal display, an electrode material ejection device used for forming electrodes such as an organic EL display and a surface emission display, a biological organic substance ejection device used for manufacturing a biochip, and the like.

[0010] 1. Structure of the liquid ejection device FIG. 1 is a diagram showing a schematic configuration of a liquid ejection device 1. In the liquid ejection device 1 in the present embodiment, a carriage 21 on which a print head 20 that ejects ink as an example of a liquid is mounted reciprocates along a scanning axis, and ink is ejected onto a medium P conveyed along a conveyance direction, thereby forming an image on the medium P. A serial printing type inkjet printer will be exemplified and described. Note that the liquid ejection device 1 is not limited to a serial printing type inkjet printer, and may be a line printing type inkjet printer. As the medium P used for such a liquid ejection device 1, any printing target such as printing paper, a resin film, and a fabric can be used.

[0011] As shown in FIG. 1, the liquid ejection device 1 includes an ink container 2, a control mechanism 10, a carriage 21, a moving mechanism 30, and a conveyance mechanism 40.

[0012] A plurality of types of ink to be ejected onto the medium P are stored in the ink container 2. Examples of the colors of the ink stored in the ink container 2 include black, cyan, magenta, yellow, red, and gray. As the ink container 2 in which such ink is stored, an ink cartridge, a bag-shaped ink pack formed of a flexible film, an ink tank capable of replenishing ink, and the like can be used.

[0013] The control mechanism 10 includes a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory, and controls each element of the liquid ejection device 1 including the print head 20.

[0014] The carriage 21 mounts the print head 20 and is fixed to an endless belt 32 included in the movement mechanism 30. Note that the ink container 2 may be mounted on the carriage 21.

[0015] A control signal Ctrl-H for controlling the print head 20 output by the control mechanism 10, a drive signal COM and a reference voltage signal VBS for driving the print head 20 are input to the print head 20 mounted on the carriage 21. Further, ink stored in the ink container 2 is supplied to the print head 20 via a tube (not shown). Then, the print head 20 ejects the ink supplied from the ink container 2 based on the input control signal Ctrl-H, drive signal COM, and reference voltage signal VBS.

[0016] The movement mechanism 30 includes a carriage motor 31 and an endless belt 32. The carriage motor 31 is driven based on a control signal Ctrl-C input from the control mechanism 10. The endless belt 32 rotates according to the drive of the carriage motor 31. Thereby, the carriage 21 fixed to the endless belt 32 reciprocates along the scanning axis. That is, the carriage 21 reciprocates along the scanning axis intersecting the conveyance direction in which the medium P is conveyed.

[0017] The conveyance mechanism 40 includes a conveyance motor 41 and a conveyance roller 42. The conveyance motor 41 is driven based on a control signal Ctrl-T input from the control mechanism 10. The conveyance roller 42 rotates according to the drive of the conveyance motor 41. Along with the rotation of the conveyance roller 42, the medium P is conveyed in the conveyance direction.

[0018] As described above, the liquid ejection device 1 is interlocked with the conveyance of the medium P by the conveyance mechanism 40 and the reciprocating movement of the carriage 21 by the movement mechanism 30, and the print head 20 mounted on the carriage 21 ejects ink onto the medium P. Thus, the ink ejected by the liquid ejection device 1 lands at an arbitrary position on the surface of the medium P, and a desired image is formed on the medium P.

[0019] 2. Functional Configuration of Liquid Ejection Device Next, the functional configuration of the liquid ejection device 1 will be described. FIG. 2 is a diagram showing the functional configuration of the liquid ejection device 1. As shown in FIG. 2, the liquid ejection device 1 includes a control mechanism 10, a print head 20, a carriage motor 31, and a conveyance motor 41.

[0020] The control mechanism 10 has a drive circuit 50, a reference voltage output circuit 52, and a control circuit 100. The control circuit 100 includes, for example, a processing circuit such as a CPU or an FPGA and a storage circuit such as a semiconductor memory. An image information signal including image data and the like is input to the control circuit 100 from an external device such as a host computer that is communicably connected to the outside of the liquid ejection device 1. The control circuit 100 generates various signals for controlling the liquid ejection device 1 based on the input image information signal, and outputs them to the corresponding components.

[0021] In a specific example, the control circuit 100 grasps the scanning position of the print head 20 mounted on the carriage 21 based on a signal corresponding to the scanning position of the carriage 21 input from a linear encoder or the like (not shown). Then, the control circuit 100 generates and outputs various signals according to the grasped scanning position of the print head 20 and the input image information signal.

[0022] Specifically, the control circuit 100 generates a control signal Ctrl-C for controlling the movement along the scanning axis of the print head 20 according to the scanning position of the print head 20, and outputs it to the carriage motor 31. Thereby, the carriage motor 31 is driven, and the movement and scanning position along the scanning axis of the print head 20 mounted on the carriage 21 are controlled. Also, the control circuit 100 generates a control signal Ctrl-T for controlling the conveyance of the medium P, and outputs it to the conveyance motor 41. Thereby, the conveyance motor 41 is driven, and the movement along the conveyance direction of the medium P is controlled. Note that the control signal Ctrl-C may be signal-converted via a driver circuit (not shown) and then input to the carriage motor 31, and the control signal Ctrl-T may be signal-converted via a driver circuit (not shown) and then input to the conveyance motor 41.

[0023] Also, the control circuit 100 generates, as a control signal Ctrl-H for controlling the print head 20, print data signals SI1 to SIn, a change signal CH, a latch signal LAT, and a clock signal SCK based on the image information signal input from an external device and the scanning position of the print head 20 input from a linear encoder (not shown), and outputs them to the print head 20.

[0024] Also, the control circuit 100 outputs a base drive signal dO, which is a digital signal, to the drive circuit 50 as the control signal Ctrl-H. The drive circuit 50 generates a drive signal COM by digitally / analog-converting the input base drive signal dO and then D-class amplifying the converted analog signal, and outputs it to the print head 20. That is, the base drive signal dO output by the control circuit 100 is a digital signal that defines the waveform of the drive signal COM. Note that the base drive signal dO only needs to be able to define the waveform of the drive signal COM output by the drive circuit 50, and it may be an analog signal.

[0025] The reference voltage output circuit 52 generates a reference voltage signal VBS and outputs it to the print head 20. The reference voltage signal VBS output by this reference voltage output circuit 52 is a signal of a potential that serves as a reference for driving the piezoelectric element 60 described later. For example, it may be a signal that is constant at the ground potential, or it may be a constant DC voltage signal at a potential such as 5.5V or 6V.

[0026] The print head 20 has head chips 22-1 to 22-n. Each of the head chips 22-1 to 22-n has a drive signal selection circuit 200 and a plurality of ejection units 600, and each of the plurality of ejection units 600 includes a piezoelectric element 60.

[0027] The print data signal SI1, change signal CH, latch signal LAT, and clock signal SCK output by the control circuit 100, the drive signal COM output by the drive circuit 50, and the reference voltage signal VBS output by the reference voltage output circuit 52 are input to the head chip 22-1.

[0028] The clock signal SCK, latch signal LAT, change signal CH, print data signal SI1, and drive signal COM input to the head chip 22-1 are input to the drive signal selection circuit 200. Based on the input clock signal SCK, latch signal LAT, change signal CH, and print data signal SI1, the drive signal selection circuit 200 generates drive signals VOUT corresponding to each of the plurality of piezoelectric elements 60 by selecting or not selecting the signal waveform of the drive signal COM. Then, the drive signal selection circuit 200 individually outputs the generated drive signals VOUT to one end of the corresponding piezoelectric elements 60. A reference voltage signal VBS is commonly supplied to the other ends of the plurality of piezoelectric elements 60. Each of the plurality of piezoelectric elements 60 is driven by the potential difference between the drive signal VOUT individually supplied to one end and the reference voltage signal VBS commonly supplied to the other end. An amount of ink corresponding to the driving of the piezoelectric element 60 is ejected from the head chip 22-1. That is, the head chip 22-1 ejects ink according to signals for controlling ejection including the clock signal SCK, latch signal LAT, change signal CH, print data signal SI1, drive signal COM, and reference voltage signal VBS.

[0029] Here, the head chips 22-2 to 22-n have the same configuration as the head chip 22-1 and perform the same operations, differing only in the input and output signals. That is, for the head chip 22-i (where i is any of 1 to n), a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SIi, a drive signal COM, and a reference voltage signal VBS are input. Then, the drive signal selection circuit 200 of the head chip 22-i generates a drive signal VOUT corresponding to each of the plurality of piezoelectric elements 60 by selecting or not selecting the signal waveform of the drive signal COM based on the input clock signal SCK, latch signal LAT, change signal CH, and print data signal SIi. The drive signal VOUT generated by the drive signal selection circuit 200 is individually supplied to one end of the corresponding piezoelectric element 60. Also, the reference voltage signal VBS is commonly supplied to the other ends of the plurality of piezoelectric elements 60 of the head chip 22-i. Thereby, each of the plurality of piezoelectric elements 60 of the head chip 22-i is driven, and an amount of ink corresponding to the driving of the piezoelectric element 60 is ejected from the head chip 22-i.

[0030] That is, the head chip 22-2 ejects ink according to the signals for controlling ejection including the clock signal SCK, the latch signal LAT, the change signal CH, the print data signal SI2, the drive signal COM, and the reference voltage signal VBS, and the head chip 22-i ejects ink according to the signals for controlling ejection including the clock signal SCK, the latch signal LAT, the change signal CH, the print data signal SIi, the drive signal COM, and the reference voltage signal VBS.

[0031] Here, in the following description, when there is no need to distinguish between the head chips 22-1 to 22-n, they may simply be referred to as the head chip 22. In this case, the description will be made assuming that a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SI, a drive signal COM, and a reference voltage signal VBS are input to the head chip 22.

[0032] As described above, in the liquid ejection device 1 of the present embodiment, the control circuit 100 included in the control mechanism 10 outputs a clock signal SCK, a latch signal LAT, a change signal CH, and a print data signal SI for controlling the ejection of ink from the print head 20. The drive circuit 50 included in the control mechanism 10 outputs a drive signal COM for controlling the ejection of ink from the print head 20. The reference voltage output circuit 52 included in the control mechanism 10 outputs a reference voltage signal VBS for controlling the ejection of ink from the print head 20. That is, the control mechanism 10 outputs a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SI, a drive signal COM, and a reference voltage signal VBS for controlling the ejection of ink from the print head 20. Then, the print head 20 ejects ink in response to the input clock signal SCK, latch signal LAT, change signal CH, print data signal SI, drive signal COM, and reference voltage signal VBS.

[0033] 3. Functional Configuration of Drive Signal Selection Circuit Next, the configuration and operation of the drive signal selection circuit 200 included in the head chip 22 will be described. As described above, the drive signal selection circuit 200 included in the head chip 22 generates a drive signal VOUT by selecting or not selecting the signal waveform included in the drive signal COM based on the clock signal SCK, the print data signal SI, the latch signal LAT, and the change signal CH, and outputs it to the piezoelectric element 60 included in the corresponding ejection unit 600. Therefore, in explaining the configuration and operation of the drive signal selection circuit 200, first, an example of the waveform of the drive signal COM input to the drive signal selection circuit 200 will be described.

[0034] FIG. 3 is a diagram showing an example of the signal waveform of the drive signal COM. As shown in FIG. 3, the drive signal COM includes a trapezoidal waveform Adp arranged in a period td1 from when the latch signal LAT rises until the change signal CH rises, a trapezoidal waveform Bdp arranged in a period td2 from when the change signal CH rises until the change signal CH rises next, and a trapezoidal waveform Cdp arranged in a period td3 from when the change signal CH rises until the latch signal LAT rises.

[0035] The trapezoidal waveform Adp is a signal waveform for driving the piezoelectric element 60 so that a predetermined amount of ink is ejected, and the trapezoidal waveform Bdp is a signal waveform for driving the piezoelectric element 60 so that an amount of ink less than the predetermined amount is ejected. Further, the trapezoidal waveform Cdp is a signal waveform for driving the piezoelectric element 60 to such an extent that no ink is ejected, and is a signal waveform for reducing the possibility of an increase in the ink viscosity in the vicinity of the nozzle orifice corresponding to the piezoelectric element 60 by vibrating the ink in the vicinity of the nozzle orifice. And the trapezoidal waveforms Adp, Bdp, and Cdp are all common signal waveforms with the voltage value Vc at their respective start timings and end timings. That is, each of the trapezoidal waveforms Adp, Bdp, and Cdp starts with the voltage Vc and ends with the voltage Vc.

[0036] Here, in the following description, when the trapezoidal waveform Adp is supplied to the piezoelectric element 60, the amount of the predetermined amount of ink ejected is referred to as a medium amount, and when the trapezoidal waveform Bdp is supplied to the piezoelectric element 60, the amount of ink less than the predetermined amount ejected may be referred to as a small amount. Also, when the trapezoidal waveform Cdp is supplied to the piezoelectric element 60, the operation for vibrating the ink in the vicinity of the nozzle orifice corresponding to the piezoelectric element 60 to prevent an increase in the ink viscosity may be referred to as micro-vibration. Note that the signal waveform of the drive signal COM shown in FIG. 3 is an example and is not limited thereto, and various waveform combinations may be used according to the properties of the ejected ink, the material of the medium P on which the ink lands, and the like.

[0037] Then, the drive signal selection circuit 200 controls the ink ejection amount in the cycle tp by selecting or not selecting the trapezoidal waveforms Adp, Bdp, and Cdp included in the drive signal COM in the cycle tp including the above-described periods td1, td2, and td3. In other words, the dot size formed on the medium P in the cycle tp is controlled. The cycle tp including these periods td1, td2, and td3 is a dot formation cycle for forming dots of a predetermined size on the medium P and corresponds to a ejection cycle for ejecting ink onto the medium P.

[0038] Next, the configuration and operation of the drive signal selection circuit 200 that generates the drive signal VOUT by selecting or not selecting the signal waveforms included in the drive signal COM will be described. FIG. 4 is a diagram showing the configuration of the drive signal selection circuit 200. As shown in FIG. 4, the drive signal selection circuit 200 includes a selection control circuit 210 and a plurality of selection circuits 230 equal in number to the plurality of ejection units 600. In the following description, the head chip 22 will be described assuming that it has m ejection units 600.

[0039] A clock signal SCK, a print data signal SI, a latch signal LAT, and a change signal CH are input to the selection control circuit 210. In addition, a set of a shift register (S / R) 212, a latch circuit 214, and a decoder 216 is provided in the selection control circuit 210 corresponding to each of the m ejection units 600. That is, the drive signal selection circuit 200 includes m shift registers 212, m latch circuits 214, and m decoders 216.

[0040] The print data signal SI is input to the selection control circuit 210 in synchronization with the clock signal SCK. The print data signal SI serially includes 2-bit print data [SIH, SIL] for selecting any one of a large dot LD, a medium dot MD, a small dot SD, and non-recording ND corresponding to each of the m ejection units 600. The print data [SIH, SIL] included in the print data signal SI is held in m shift registers 212 corresponding to the m ejection units 600. Specifically, the m shift registers 212 corresponding to the piezoelectric elements 60 are connected in series with each other, and the serially input print data signal SI is sequentially transferred to the subsequent shift register 212 according to the clock signal SCK. Then, when the print data [SIH, SIL] is held in the corresponding shift register 212, the clock signal SCK stops. As a result, the print data [SIH, SIL] included in the print data signal SI is held in the corresponding shift register 212. In FIG. 4, in order to distinguish the m shift registers 212, they are denoted as the first stage, the second stage,..., the mth stage in order from the upstream side where the print data signal SI is input.

[0041] Each of the m latch circuits 214 latches the print data [SIH, SIL] held in the corresponding shift register 212 simultaneously at the rising edge of the latch signal LAT. Then, the print data [SIH, SIL] latched by the latch circuit 214 is input to the corresponding decoder 216. FIG. 5 is a diagram showing an example of the decoded content in the decoder 216. The decoder 216 outputs a selection signal S of a logic level defined by the input print data [SIH, SIL] in each of the periods td1, td2, and td3. For example, when the print data [SIH, SIL]=[1, 0] is input to the decoder 216, the decoder 216 outputs the logic level of the selection signal S as H, L, L levels in the periods td1, td2, and td3.

[0042] The selection signal S output by the decoder 216 is input to the selection circuit 230. The selection circuit 230 is provided corresponding to each of the m ejection units 600. That is, the drive signal selection circuit 200 has m selection circuits 230, the same number as the m ejection units 600. FIG. 6 is a diagram showing the configuration of the selection circuit 230. As shown in FIG. 6, the selection circuit 230 includes an inverter 232 which is a NOT circuit and a transfer gate 234.

[0043] The selection signal S is input to the non-marked positive control terminal of the transfer gate 234. After the logic level is inverted by the inverter 232, it is also input to the marked negative control terminal of the transfer gate 234. Also, a drive signal COM is supplied to the input terminal of the transfer gate 234. When a high-level selection signal S is input, the transfer gate 234 conducts between the input terminal and the output terminal. When a low-level selection signal S is input, the transfer gate 234 does not conduct between the input terminal and the output terminal. That is, when the logic level of the selection signal S is high, the transfer gate 234 outputs the signal waveform included in the drive signal COM from the output terminal. When the logic level of the selection signal S is low, the transfer gate 234 does not output the signal waveform included in the drive signal COM from the output terminal. Then, the drive signal selection circuit 200 outputs the signal output from the output terminal of the transfer gate 234 included in the selection circuit 230 as the drive signal VOUT.

[0044] Here, the operation of the drive signal selection circuit 200 will be described. FIG. 7 is a diagram for explaining the operation of the drive signal selection circuit 200. The print data signal SI is input to the selection control circuit 210 as a serial signal synchronized with the clock signal SCK. Then, the print data signal SI is sequentially transferred in the m shift registers 212 corresponding to the m ejection units 600 in synchronization with the clock signal SCK. After that, when the input of the clock signal SCK stops, the print data [SIH, SIL] corresponding to each of the m ejection units 600 is held in the shift register 212. Note that the print data signal SI is input in order corresponding to the m-th stage, …, the second stage, and the first stage of the shift register 212 of the ejection unit 600.

[0045] When the latch signal LAT rises, each of the latch circuits 214 latches the print data [SIH, SIL] held in the shift register 212 all at once. Note that LT1, LT2, …, LTm shown in FIG. 7 indicate the print data [SIH, SIL] latched by the latch circuits 214 corresponding to the first-stage, second-stage, …, m-th stage shift registers 212.

[0046] Decoder 216 outputs the logic level of the selection signal S in each of the periods td1, td2, and td3 according to the dot size defined by the latched print data [SIH, SIL], as shown in FIG. 5. Then, the selection circuit 230 generates the drive signal VOUT by selecting or not selecting the signal waveform included in the drive signal COM according to the logic level of the selection signal S output by the decoder 216.

[0047] Specifically, when the print data [SIH, SIL] = [1, 1] is input to the decoder 216, the decoder 216 sets the logic level of the selection signal S to H, H, L levels in the periods td1, td2, and td3. As a result, the selection circuit 230 selects the trapezoidal waveform Adp in the period td1, selects the trapezoidal waveform Bdp in the period td2, and does not select the trapezoidal waveform Cdp in the period td3. Consequently, the drive signal selection circuit 200 outputs the drive signal VOUT corresponding to the large dot LD.

[0048] When the drive signal VOUT corresponding to the large dot LD is supplied to the piezoelectric element 60 included in the corresponding ejection unit 600, a medium amount of ink is ejected in the period td1, a small amount of ink is ejected in the period td2, and no ink is ejected in the period td3. Then, the ejected medium amount of ink and the small amount of ink land and bond on the medium P, thereby forming the large dot LD on the medium P.

[0049] Also, when the print data [SIH, SIL] = [1, 0] is input to the decoder 216, the decoder 216 sets the logic level of the selection signal S to H, L, L levels in the periods td1, td2, and td3. As a result, the selection circuit 230 selects the trapezoidal waveform Adp in the period td1, does not select the trapezoidal waveform Bdp in the period td2, and does not select the trapezoidal waveform Cdp in the period td3. Consequently, the drive signal selection circuit 200 outputs the drive signal VOUT corresponding to the medium dot MD.

[0050] When the drive signal VOUT corresponding to the medium dot MD is supplied to the piezoelectric element 60 included in the corresponding ejection unit 600, an intermediate amount of ink is ejected during the period td1, no ink is ejected during the period td2, and no ink is ejected during the period td3. Then, the ejected intermediate amount of ink lands on the medium P, and the medium dot MD is formed on the medium P.

[0051] Also, when print data [SIH, SIL] = [0, 1] is input to the decoder 216, the decoder 216 sets the logic level of the selection signal S to L, H, L levels during the periods td1, td2, and td3. As a result, the selection circuit 230 does not select the trapezoidal waveform Adp during the period td1, selects the trapezoidal waveform Bdp during the period td2, and does not select the trapezoidal waveform Cdp during the period td3. Consequently, the drive signal selection circuit 200 outputs a drive signal VOUT corresponding to the small dot SD.

[0052] When the drive signal VOUT corresponding to the small dot SD is supplied to the piezoelectric element 60 included in the corresponding ejection unit 600, no ink is ejected during the period td1, a small amount of ink is ejected during the period td2, and no ink is ejected during the period td3. Then, the ejected small amount of ink lands on the medium P, and the small dot SD is formed on the medium P.

[0053] Also, when print data [SIH, SIL] = [0, 0] is input to the decoder 216, the decoder 216 sets the logic level of the selection signal S to L, L, H levels during the periods td1, td2, and td3. As a result, the selection circuit 230 does not select the trapezoidal waveform Adp during the period td1, does not select the trapezoidal waveform Bdp during the period td2, and selects the trapezoidal waveform Cdp during the period td3. Consequently, the drive signal selection circuit 200 outputs a drive signal VOUT corresponding to the non - recording ND.

[0054] When the drive signal VOUT corresponding to non-recording ND is supplied to the piezoelectric element 60 included in the corresponding ejection unit 600, no ink is ejected during the period td1, no ink is ejected during the period td2, and no ink is ejected during the period td3. Therefore, no ink is ejected from the ejection unit 600, resulting in non-recording ND where no dots are formed on the medium P. At this time, a drive signal VOUT including a trapezoidal waveform Cdp is input to the corresponding piezoelectric element 60. Therefore, micro-vibration is executed. As a result, the possibility of an increase in the ink viscosity near the nozzle orifice of the corresponding ejection unit 600 is reduced.

[0055] As described above, in the liquid ejection device 1 of the present embodiment, the head chip 22 has a piezoelectric element 60 that is driven by supplying a drive signal COM, and ejects ink, which is an example of a liquid, by driving the piezoelectric element 60.

[0056] 4. Structure of Print Head Next, an example of the structure of the print head 20 will be described. Here, in the following description, the X-axis, Y-axis, and Z-axis that are orthogonal to each other will be illustrated and described. Also, in the following description, the starting point side of the arrow along the illustrated X-axis will be referred to as the -X side, the tip side will be referred to as the +X side, the starting point side of the arrow along the illustrated Y-axis will be referred to as the -Y side, the tip side will be referred to as the +Y side, and the starting point side of the arrow along the illustrated Z-axis may be referred to as the -Z side and the tip side may be referred to as the +Z side. The print head 20 is provided in the liquid ejection device 1 such that the Y-axis corresponds to the scanning axis, the direction from the -X side to the +X side along the X-axis corresponds to the conveyance direction, and ink, which is an example of a liquid, is ejected in the direction from the -Z side to the +Z side along the Z-axis.

[0057] FIG. 8 is a perspective view showing the configuration of the print head 20. As shown in FIG. 8, the print head 20 has a head 310 and a head substrate 320. The head substrate 320 is a plate-shaped rigid wiring board, and for example, a glass epoxy substrate, a glass composite substrate, or the like can be used. The head 310 has head chips 22-1 to 22-n and is located on the -Z side of the head substrate 320. Also, on the +Z side surface of the head 310, an ink ejection surface 311 is located where a plurality of ejection portions 600 each of the head chips 22-1 to 22-n are provided. Ink is ejected from this ink ejection surface 311.

[0058] That is, the print head 20 includes a head chip 22-1 that ejects ink in response to a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SI1, a drive signal COM, and a reference voltage signal VBS, a head chip 22-n that ejects ink in response to a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SIn, a drive signal COM, and a reference voltage signal VBS, and a head chip 22-i that ejects ink in response to a clock signal SCK, a latch signal LAT, a change signal CH, a print data signal SIi, a drive signal COM, and a reference voltage signal VBS.

[0059] Hereinafter, a specific example of the structure of the head 310 and the head substrate 320 included in the print head 20 will be described.

[0060] 4.1 Structure of the Head First, a specific example of the structure of the head 310 will be described. FIG. 9 is a diagram showing an example of the structure of the ink ejection surface 311 of the head 310. As shown in FIG. 9, each of the head chips 22-1 to 22-n includes a nozzle row in which nozzles 651 included in a plurality of ejection portions 600 are arranged in two rows along the Y-axis. And the two nozzle rows included in each of the head chips 22-1 to 22-n are exposed from the ink ejection surface 311. Ink is ejected from each of the plurality of nozzles 651 forming this nozzle row. Also, the head chips 22-1 to 22-n are arranged side by side along the X-axis. That is, the head 310 has head chips 22-1 to 22-n provided such that a plurality of nozzles 651 arranged side by side along the Y-axis are exposed from the ink ejection surface 311. And by the head chips 22-1 to 22-n, on the ink ejection surface 311 of the head 310, 2n rows of nozzle rows arranged side by side are formed along the X-axis.

[0061] Next, a specific example of the structure of the head chips 22-1 to 22-n will be described. FIG. 10 is a diagram showing an example of the structure of the head chip 22. FIG. 10 is a cross-sectional view when the head chip 22 is cut along the X-axis so as to include a plurality of ejection portions 600 arranged in two rows along the Y-axis.

[0062] As shown in FIG. 10, the head chip 22 has a nozzle plate 510, a flow path forming substrate 520, a pressure chamber substrate 530, a protection substrate 540, a compliance portion 550, a diaphragm 560, a case 570, a semiconductor device 410, and a piezoelectric element 60.

[0063] On the nozzle plate 510, nozzles 651 from which ink is ejected are arranged in two rows along the Y-axis. The flow path forming substrate 520 defines individual flow paths 614, communication flow paths 615, and a reservoir 616. The pressure chamber substrate 530 defines a pressure chamber 613. The case 570 defines a reservoir 612 and a liquid inlet 611.

[0064] The ink stored in the ink container 2 is supplied to the head chip 22 through the liquid inlet 611. The ink supplied to the head chip 22 reaches the nozzle 651 through the ink flow path 610 which includes the reservoirs 612, 616, the individual flow paths 614, the pressure chambers 613, and the communication flow paths 615. Then, the ink reaching the nozzle 651 is discharged as the piezoelectric element 60 is driven.

[0065] Specifically, the ink flow path 610 is defined by laminating the flow path forming substrate 520, the pressure chamber substrate 530, and the case 570 along the Z-axis. The ink introduced from the liquid inlet 611 is stored in the reservoir 612 defined by the case 570 and the reservoir 616 defined by the flow path forming substrate 520. The reservoirs 612, 616 are provided in common for each of the plurality of nozzles 651 provided on the nozzle plate 510. The ink stored in the reservoirs 612, 616 is supplied to the pressure chambers 613 provided individually corresponding to each of the plurality of nozzles 651 through the individual flow paths 614 provided individually corresponding to each of the plurality of nozzles 651. Then, when pressure is applied to the ink supplied to the pressure chamber 613, the ink stored in the pressure chamber 613 is discharged from the nozzle 651 through the communication flow path 615.

[0066] That is, the ink flow path 610 includes the liquid inlet 611 and the reservoirs 612, 616 provided in common for the plurality of nozzles 651, and the individual flow paths 614, the pressure chambers 613, and the communication flow paths 615 which branch from the reservoir 616 and are provided individually corresponding to each of the plurality of nozzles 651.

[0067] The diaphragm 560 is located on the -Z side of the pressure chamber substrate 530 and is provided to seal the pressure chamber 613. A piezoelectric element 60 is provided on the -Z side of the diaphragm 560. The piezoelectric element 60 is composed of a piezoelectric body and a pair of electrodes formed on both surfaces of the piezoelectric body. Then, according to the potential difference generated between the pair of electrodes of the piezoelectric element 60, the piezoelectric body of the piezoelectric element 60 is displaced. That is, the piezoelectric element 60 is driven by the potential difference generated between the pair of electrodes. With the driving of the piezoelectric element 60, the diaphragm 560 provided with the piezoelectric element 60 is deformed. Then, the internal pressure of the pressure chamber 613 changes due to the deformation of the diaphragm 560. As a result, pressure is applied to the ink supplied to the pressure chamber 613, and the ink stored in the pressure chamber 613 is ejected from the nozzle 651.

[0068] The nozzle plate 510 is fixed to the flow path forming substrate 520 on the +Z side such that each of the plurality of nozzles 651 formed in the nozzle plate 510 communicates with a corresponding communication flow path 615 formed in the flow path forming substrate 520.

[0069] A compliance part 550 is fixed to the +Z side of the flow path forming substrate 520. The compliance part 550 is located on the +Z side of the reservoir 616 and the individual flow path 614 and includes a sealing film 551 and a support 552. The sealing film 551 is a flexible film-like member that seals the +Z side of the reservoir 616 and the individual flow path 614. The support 552 supports the outer peripheral edge of the sealing film 551 in a frame shape. With the compliance part 550 configured as described above, the head chip 22 is protected, and the fluctuation of the pressure applied with ink inside the reservoir 616 and inside the communication flow path 615 is reduced.

[0070] The semiconductor device 410 is COF (Chip On Film) mounted on the flexible wiring board 400. The semiconductor device 410 includes the drive signal selection circuit 200 described above. Then, the drive signal VOUT output by the drive signal selection circuit 200 included in the semiconductor device 410 propagates through the flexible wiring board 400 and is supplied to one of the pair of electrodes of the piezoelectric element 60. At this time, the reference voltage signal VBS that has propagated through the flexible wiring board 400 is supplied to the other of the pair of electrodes of the piezoelectric element 60. The piezoelectric element 60 drives according to the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBS supplied to the other end. Due to the driving of this piezoelectric element 60, the diaphragm 560 is displaced, and an amount of ink corresponding to the displacement of the diaphragm 560 is ejected from the nozzle 651.

[0071] Also, the flexible wiring board 400 on which the semiconductor device 410 is mounted is electrically connected to the head substrate 320 to be described later. Thereby, signals input to the print head 20, namely, the print data signal SI, the change signal CH, the latch signal LAT, the clock signal SCK, and the drive signal COM, are input to the semiconductor device 410 via the flexible wiring board 400. Note that the semiconductor device 410 is not limited to the case of being COF mounted on the flexible wiring board 400. For example, it may be mounted on the diaphragm 560 or on a wiring board (not shown) included in the head chip 22.

[0072] As described above, the head 310 has the head chips 22-1 to 22-n. And signals for controlling the ejection of ink from each of the head chips 22-1 to 22-n are input to each of the head chips 22-1 to 22-n via the corresponding flexible wiring board 400. Thereby, ink is ejected from each of the head chips 22.

[0073] Here, in the following description, the flexible printed circuit board 400 that propagates various signals to the head chip 22-1 is referred to as the flexible printed circuit board 400-1, the flexible printed circuit board 400 that propagates various signals to the head chip 22-n is referred to as the flexible printed circuit board 400-n, and the flexible printed circuit board 400 that propagates various signals to the head chip 22-i may be referred to as the flexible printed circuit board 400-i. In other words, the print head 20 includes a flexible printed circuit board 400-1 that propagates a print data signal SI1, a change signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage signal VBS to the head chip 22-1, a flexible printed circuit board 400-n that propagates a print data signal SIn, a change signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage signal VBS to the head chip 22-n, and a flexible printed circuit board 400-i that propagates a print data signal SIi, a change signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage signal VBS to the head chip 22-i.

[0074] Also, in the head chip 22, a configuration including a piezoelectric element 60, a diaphragm 560, a pressure chamber 613, an individual flow path 614, a communication flow path 615, and a nozzle 651 corresponds to the discharge unit 600 described above.

[0075] 4.2 Structure of the head substrate Next, the configuration of the head substrate 320 will be described. FIG. 11 is a diagram showing an example of the configuration of the head substrate 320. As shown in FIG. 11, the head substrate 320 includes surfaces 321 and 322, and sides 323, 324, 325, and 326. The head substrate 320 is positioned such that sides 323 and 324 face each other along the X-axis, side 323 is on the -X side, side 324 is on the +X side, sides 325 and 326 face each other along the Y-axis, side 325 is on the -Y side, side 326 is on the +Y side, and surface 321 is on the +Z side and surface 322 is on the -Z side, and is provided on the print head 20. Then, the head 310 described above is fixed to the surface 321 side of the head substrate 320. That is, the print head 20 has a head substrate 320 to which the head chips 22-1 to 22-n are fixed.

[0076] On the surface 322 of the head substrate 320, electrode groups 330-1 to 330-n are provided. The electrode group 330-1 includes p electrodes TM1 arranged in parallel along the Y-axis, the electrode group 330-n includes p electrodes TM n arranged in parallel along the Y-axis, and the electrode group 330-i includes p electrodes TM i arranged in parallel along the Y-axis. Also, each of the electrode groups 330-1 to 330-n is arranged in order of the electrode group 330-1, the electrode group 330-2,..., the electrode group 330-n from the -X side to the +X side along the X-axis.

[0077] Here, in the following description, when the p electrodes TM1 included in the electrode group 330-1 are distinguished and described, they may be referred to as electrode TM1[1], electrode TM1[2],..., electrode TM1[p] in order from the side 325 to the side 326. Similarly, when the p electrodes TM n included in the electrode group 330-n are distinguished and described, they may be referred to as electrode TM n[1], electrode TM n[2],..., electrode TM n[p] in order from the side 325 to the side 326. When the p electrodes TM i included in the electrode group 330-i are distinguished and described, they may be referred to as electrode TM i[1], electrode TM i[2],..., electrode TM i[p] in order from the side 325 to the side 326.

[0078] Further, the head substrate 320 includes through holes 340-1 to 340-n that penetrate through surface 322 and surface 321. Each of the through holes 340-1 to 340-n is an elongated hole having a rectangular shape or an oval shape with a major axis along the Y-axis and a minor axis along the X-axis. Each of the through holes 340-1 to 340-n is arranged in order from the -X side to the +X side along the X-axis as through hole 340-1, through hole 340-2, …, through hole 340-n. Specifically, when looking at the head substrate 320 along the Y-axis, through hole 340-1 is located between electrode group 330-1 and electrode group 330-2, through hole 340-2 is located between electrode group 330-2 and electrode group 330-3 when looking at the head substrate 320 along the Y-axis, and through hole 340-i is located between electrode group 330-i and electrode group 330-(i + 1) when looking at the head substrate 320 along the Y-axis. Also, through hole 340-n is located between electrode group 330-n and side 324 when looking at the head substrate 320 along the Y-axis.

[0079] Further, the head substrate 320 includes a plurality of fixing portions 350 used for fixing the head 310. The plurality of fixing portions 350 are through holes that penetrate through surface 322 and surface 321 of the head substrate 320. Then, the head 310 is fixed to the head substrate 320 by screws (not shown) inserted through the fixing portions 350. Note that the fixing portions 350 are not limited to through holes formed in the head substrate 320, and for example, a configuration in which the head 310 is fixed to the head substrate 320 by fitting may be used. Also, the fixing portions 350 may be any configuration used for fixing the head 310, and may be used as a reference point for the fixing position when fixing the head 310 to the head substrate 320.

[0080] In addition, a connector 360 is mounted on the head substrate 320. The connector 360 is provided along the side 323 on the surface 322 of the head substrate 320. A cable (not shown) such as a flexible flat cable for electrically connecting the control mechanism 10 and the print head 20 is connected to the connector 360. As a result, various signals including the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS output by the control mechanism 10 are input to the print head 20. That is, the print head 20 has a connector 360 to which the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS are input.

[0081] Here, in the following description, when it is not necessary to distinguish the electrode groups 330-1 to 330-n, they may be referred to as the electrode group 330. At this time, the electrode group 330 will be described as having p electrodes TM arranged in parallel along the Y-axis. When distinguishing the p electrodes TM included in the electrode group 330, they may be referred to as electrode TM[1], electrode TM[2],..., electrode TM[p] from the side 325 side to the side 326 side. Also, in the following description, when it is not necessary to distinguish the through holes 340-1 to 340-n, they may be referred to as the through hole 340.

[0082] 4.3 Electrical connection between the head substrate and the head chip In the print head 20 configured as described above, a specific example of the electrical connection between the head chips 22-1 to 22-n included in the head 310 and the head substrate 320 will be described. As described above, the head chip 22 and the head substrate 320 are electrically connected via the flexible wiring substrate 400. Therefore, when describing a specific example of the electrical connection between the head chips 22-1 to 22-n and the head substrate 320, first, a specific example of the structure of the flexible wiring substrate 400 will be described.

[0083] FIG. 12 is a diagram showing an example of the structure of the flexible printed circuit board 400. Here, in describing the structure of the flexible printed circuit board 400, x-axis, y-axis, and z-axis that are independent of the above-described X-axis, Y-axis, and Z-axis and are orthogonal to each other are used. At this time, the starting point side of the arrow along the illustrated x-axis is referred to as the -x side, the tip side is referred to as the +x side, the starting point side of the arrow along the illustrated y-axis is referred to as the -y side, the tip side is referred to as the +y side, and the starting point side of the arrow along the illustrated z-axis may be referred to as the -z side and the tip side as the +z side. Further, in FIG. 12, a part of the configuration formed on the +x side surface of the flexible printed circuit board 400 and the wiring pattern formed on the flexible printed circuit board 400 are illustrated by solid lines, and a part of the configuration formed on the -x side surface of the flexible printed circuit board 400 is illustrated by broken lines.

[0084] As shown in FIG. 12, a semiconductor device 410 including a drive signal selection circuit 200 is COF-mounted on the +x side surface of the flexible printed circuit board 400. The flexible printed circuit board 400 also includes a plurality of wirings 482, 484, 486 and p terminals 421, 422, 423. The flexible printed circuit board 400 is connected to the head chip 22 on the +z side and to the head substrate 320 on the -z side.

[0085] The plurality of wirings 482 are located on the -z side of the semiconductor device 410, and one end thereof is electrically connected to the semiconductor device 410. The plurality of wirings 482 propagate any one of a plurality of signals including print data signals SI1 to SIn, a change signal CH, a latch signal LAT, a clock signal SCK, and a drive signal COM input to the drive signal selection circuit 200 included in the semiconductor device 410. In other words, the print data signal SI1 propagates through any one of the plurality of wirings 482, the print data signal SIn propagates through a different one of the plurality of wirings 482, the print data signal SIi propagates through a different one of the plurality of wirings 482, the change signal CH propagates through a different one of the plurality of wirings 482, the latch signal LAT propagates through a different one of the plurality of wirings 482, the clock signal SCK propagates through a different one of the plurality of wirings 482, and the drive signal COM propagates through a different one of the plurality of wirings 482.

[0086] In this case, the plurality of signals including the print data signals SI1 to SIn, the change signal CH, the latch signal LAT, the clock signal SCK, and the drive signal COM are not limited to being propagated by a single wiring 482, and may be propagated by two or more wirings 482.

[0087] The plurality of wirings 486 are located on the +z side of the semiconductor device 410, one end is electrically connected to the semiconductor device 410, and the other end is electrically connected to the corresponding ejection portion 600. The plurality of wirings 486 propagate the drive signal VOUT output from the drive signal selection circuit 200 included in the semiconductor device 410 to the corresponding ejection portion 600.

[0088] Some of the plurality of wirings 484 are located on the -y side of the plurality of wirings 482 and the plurality of wirings 486, and some different ones of the plurality of wirings 484 are located on the +y side of the plurality of wirings 482 and the plurality of wirings 486. The plurality of wirings 484 propagate the reference voltage signal VBS commonly input to each of the plurality of ejection portions 600.

[0089] The p terminals 421 are located on the -z side of the semiconductor device 410 on the +x side surface of the flexible wiring board 400 and are arranged side by side along the y-axis. Here, in the following description, when the p terminals 421 are separately described, they may be referred to as terminals 421[1], terminals 421[2],..., terminals 421[p] in order from the +y side to the -y side.

[0090] The p terminals 422 are located on the -z side of the p terminals 421 on the +x side surface of the flexible wiring board 400 and are arranged side by side along the y-axis. Here, in the following description, when the p terminals 422 are separately described, they may be referred to as terminals 422[1], terminals 422[2],..., terminals 422[p] in order from the +y side to the -y side.

[0091] The p terminals 423 are arranged side by side along the y-axis on the -x side surface of the flexible wiring board 400, and are positioned so as to overlap at least a part of the corresponding terminal 421 when viewed along the x-axis. Here, in the following description, when the p terminals 423 are to be described separately, they may be referred to as terminal 423[1], terminal 423[2],..., terminal 423[p] in order from the +y side to the -y side. Also, when viewed along the x-axis, the p terminals 423 are positioned such that terminal 421[1] and terminal 423[1] overlap at least in part, terminal 421[p] and terminal 423[p] overlap at least in part, and terminal 421[k] (k is any one of 1 to p) and terminal 423[k] overlap at least in part.

[0092] Then, terminal 421[1], terminal 422[1], and terminal 423[1] are electrically connected to a common wiring 482 or wiring 484, terminal 421[p], terminal 422[p], and terminal 423[p] are electrically connected to a common wiring 482 or wiring 484, and terminal 421[k], terminal 422[k], and terminal 423[k] are electrically connected to a common wiring 482 or wiring 484.

[0093] As described above, the flexible wiring boards 400-1 to 400-n included in the print head 20 of the present embodiment each have a double-sided structure including a plurality of wirings 482, 484, 486, p terminals 421, 422 formed on the +x side surface, and p terminals 423 formed on the -x side surface.

[0094] Next, a specific example of the electrical connection between the head chips 22-1 to 22-n and the head substrate 320 using the flexible printed circuit board 400 will be described. FIG. 13 is a diagram for explaining a specific example of the electrical connection between the head chips 22-1 to 22-n and the head substrate 320. As described above, each of the head chips 22-1 to 22-n is positioned such that a plurality of ejection portions 600 each of the head chips 22-1 to 22-n are arranged side by side along the Y-axis, and each of the head chips 22-1 to 22-n is arranged in the order of head chip 22-1, head chip 22-2,..., head chip 22-n from the -X side to the +X side along the X-axis.

[0095] The head chip 22-1 is electrically connected to the head substrate 320 via the flexible printed circuit board 400-1. Specifically, the flexible printed circuit board 400-1 is inserted through the through hole 340-1. One end of the flexible printed circuit board 400-1 inserted through the through hole 340-1 is electrically connected to the head chip 22-1, and the other end of the flexible printed circuit board 400-1 inserted through the through hole 340-1 is electrically connected to the head substrate 320. Thereby, the head chip 22-1 and the head substrate 320 are electrically connected, and the head chip 22-1 and the flexible printed circuit board 400-1 are fixed to the head substrate 320.

[0096] Also, the head chip 22-n is electrically connected to the head substrate 320 via the flexible printed circuit board 400-n. Specifically, the flexible printed circuit board 400-n is inserted through the through hole 340-n. One end of the flexible printed circuit board 400-n inserted through the through hole 340-n is electrically connected to the head chip 22-n, and the other end of the flexible printed circuit board 400-n inserted through the through hole 340-n is electrically connected to the head substrate 320. Thereby, the head chip 22-n and the head substrate 320 are electrically connected, and the head chip 22-n and the flexible printed circuit board 400-n are fixed to the head substrate 320.

[0097] Further, the head chip 22-i is electrically connected to the head substrate 320 via the flexible wiring board 400-i. Specifically, the flexible wiring board 400-i is inserted through the through-hole 340-i. One end of the flexible wiring board 400-i inserted through the through-hole 340-i is electrically connected to the head chip 22-i, and the other end of the flexible wiring board 400-i inserted through the through-hole 340-i is electrically connected to the head substrate 320. Thereby, the head chip 22-i and the head substrate 320 are electrically connected, and the head chip 22-i and the flexible wiring board 400-i are fixed to the head substrate 320.

[0098] Also, the flexible wiring board 400-1 is directly connected to the flexible wiring board 400-2, and the flexible wiring board 400-j (j is any one of 2 to (n-1)) is directly connected to both the flexible wiring board 400-(j-1) and the flexible wiring board 400-(j+1), and the flexible wiring board 400-n is directly connected to the flexible wiring board 400-(n-1). That is, the flexible wiring boards 400-1 to 400-n are adjacent flexible wiring boards 400, and specifically, they are directly connected to the flexible wiring boards 400 inserted through adjacent through-holes 340.

[0099] Here, being directly connected means that the flexible wiring boards 400-1 to 400-n are connected without passing through the head substrate 320 to which the head chip 22-i and the flexible wiring board 400-i are fixed, and includes the case where the flexible wiring boards 400-1 to 400-n are connected via a bonding material such as solder or a conductive adhesive.

[0100] A specific example of the connection between the flexible printed circuit board 400 and the head substrate 320 and the direct connection between adjacent flexible printed circuit boards 400 will be described. Here, in the following description, the p terminals 421 formed on the flexible printed circuit board 400-1 may be referred to as p terminals 421-1, the p terminals 422 may be referred to as p terminals 422-1, and the p terminals 423 may be referred to as p terminals 423-1. When distinguishing the p terminals 421-1, they are referred to as terminal 421-1[1], terminal 421-1[2],..., terminal 421-1[p] in order from the +y side to the -y side. When distinguishing the p terminals 422-1, they are referred to as terminal 422-1[1], terminal 422-1[2],..., terminal 422-1[p] in order from the +y side to the -y side. When distinguishing the p terminals 423-1, they may be referred to as terminal 423-1[1], terminal 423-1[2],..., terminal 423-1[p] in order from the +y side to the -y side.

[0101] Similarly, the p terminals 421 formed on the flexible printed circuit board 400-n may be referred to as p terminals 421-n, the p terminals 422 may be referred to as p terminals 422-n, and the p terminals 423 may be referred to as p terminals 423-n. When distinguishing the p terminals 421-n, they are referred to as terminal 421-n[1], terminal 421-n[2],..., terminal 421-n[p] in order from the +y side to the -y side. When distinguishing the p terminals 422-n, they are referred to as terminal 422-n[1], terminal 422-n[2],..., terminal 422-n[p] in order from the +y side to the -y side. When distinguishing the p terminals 423-n, they may be referred to as terminal 423-n[1], terminal 423-n[2],..., terminal 423-n[p] in order from the +y side to the -y side.

[0102] Similarly, the p terminals 421 formed on the flexible printed circuit board 400-i may be referred to as p terminals 421-i, the p terminals 422 may be referred to as p terminals 422-i, and the p terminals 423 may be referred to as p terminals 423-i. When distinguishing the p terminals 421-i, they are referred to as terminal 421-i[1], terminal 421-i[2],..., terminal 421-i[p] in order from the +y side to the -y side. When distinguishing the p terminals 422-i, they are referred to as terminal 422-i[1], terminal 422-i[2],..., terminal 422-i[p] in order from the +y side to the -y side. When distinguishing the p terminals 423-i, they may be referred to as terminal 423-i[1], terminal 423-i[2],..., terminal 423-i[p] in order from the +y side to the -y side.

[0103] FIG. 14 is a diagram for explaining the details of the connection between the flexible printed circuit board 400-i and the head substrate 320. In FIG. 14, among the plurality of terminals 421-i, the plurality of terminals 422-i, and the plurality of terminals 423-i of the flexible printed circuit board 400-i, the terminals 421-i[k], terminals 422-i[k], and terminals 423-i[k] that are electrically connected to the common wiring 482 or wiring 484 are illustrated as representatives. Also, in the following description, the flexible printed circuit board 400 is provided in the liquid ejection device 1 such that the direction from the -x side to the +x side along the x-axis shown in FIG. 12 becomes the direction from the -X side to the +X side along the X-axis, the direction from the -y side to the +y side along the y-axis shown in FIG. 12 becomes the direction from the -Y side to the +Y side along the Y-axis, and the direction from the -z side to the +z side along the z-axis shown in FIG. 12 becomes the direction from the -Z side to the +Z side along the Z-axis, and the explanation will be made accordingly.

[0104] As shown in FIG. 14, the terminal 421-i[k] formed on the flexible wiring board 400-i is electrically connected to the corresponding electrode TMi[k] included in the electrode group 330-i. At this time, the terminal 421-i[k] and the electrode TMi[k] are mechanically and electrically directly connected by solder, laser bonding, a conductive adhesive, or the like. The terminal 422-i[k] formed on the flexible wiring board 400-i is electrically connected to the terminal 423-(i-1)[k] formed on the flexible wiring board 400-(i-1). At this time, the terminal 422-i[k] and the terminal 423-(i-1)[k] are mechanically and electrically directly connected by solder, laser bonding, a conductive adhesive, or the like. The terminal 423-i[k] formed on the flexible wiring board 400-i is electrically connected to the terminal 422-(i+1)[k] formed on the flexible wiring board 400-(i+1). At this time, the terminal 423-i[k] and the terminal 422-(i+1)[k] are mechanically and electrically directly connected by solder, laser bonding, a conductive adhesive, or the like. Thereby, the flexible wiring board 400-i is mechanically and electrically directly connected to the adjacent flexible wiring boards 400-(i-1) and 400-(i+1).

[0105] At this time, in the print head 20 of the present embodiment, the electrode TMi[k], the terminal 421-i[k] connected to the electrode TMi[k], the terminal 423-i[k] overlapping at least a part of the terminal 421-i[k] via the flexible wiring board 400-i, and the terminal 422-(i + 1)[k] connected to the terminal 423-i[k] are arranged substantially linearly along the Z-axis. In the following description, the point where the electrode TMi[k] is connected to the terminal 421-i[k] and the point where the terminal 423-i[k] is connected to the terminal 422-(i + 1)[k] may be collectively referred to as the connection point cpi[k]. Similarly, the electrode TM(i - 1)[k], the terminal 421-(i - 1)[k] connected to the electrode TM(i - 1)[k], the terminal 423-(i - 1)[k] overlapping at least a part of the terminal 421-(i - 1)[k] via the flexible wiring board 400-(i - 1), and the terminal 422-i[k] connected to the terminal 423-(i - 1)[k] are arranged substantially linearly along the Z-axis. In the following description, the point where the electrode TM(i - 1)[k] is connected to the terminal 421-(i - 1)[k] and the point where the terminal 423-(i - 1)[k] is connected to the terminal 422-i[k] may be collectively referred to as the connection point cp(i - 1)[k]. That is, the flexible wiring board 400-(i - 1) and the flexible wiring board 400-i are directly connected at the connection points cp(i - 1)[1] to cp(i - 1)[p], and the flexible wiring board 400-i and the flexible wiring board 400-(i + 1) are directly connected at the connection points cpi[1] to cpi[p].

[0106] And in the print head 20 configured as described above, the flexible printed circuit board 400-(i-1) and the flexible printed circuit board 400-i are directly connected at the connection points cp(i-1)[1] to cp(i-1)[p], so that the wiring 482 or the wiring 484 to which the terminals 421-(i-1)[k], the terminals 422-(i-1)[k], and the terminals 423-(i-1)[k] of the flexible printed circuit board 400-(i-1) are electrically connected, and the wiring 482 or the wiring 484 to which the terminals 421-i[k], the terminals 422-i[k], and the terminals 423-i[k] of the flexible printed circuit board 400-i are electrically connected are electrically connected. Similarly, the flexible printed circuit board 400-i and the flexible printed circuit board 400-(i + 1) are directly connected at the connection points cpi[1] to cpi[p], so that the wiring 482 or the wiring 484 to which the terminals 421-i[k], the terminals 422-i[k], and the terminals 423-i[k] of the flexible printed circuit board 400-i are electrically connected, and the wiring 482 or the wiring 484 to which the terminals 421-(i + 1)[k], the terminals 422-(i + 1)[k], and the terminals 423-(i + 1)[k] of the flexible printed circuit board 400-(i + 1) are electrically connected are electrically connected. That is, in the print head 20 of the present embodiment, the wirings 482 and 484 respectively provided in the flexible printed circuit boards 400-1 to 400-n are electrically and mechanically directly connected to each other.

[0107] In addition, in the print head 20 of the present embodiment, the terminal 422-1[k] of the flexible printed circuit board 400-1 may be connected to, for example, an electrode (not shown) of the head substrate 320. Thereby, signals for controlling the ejection of ink including the print data signals SI1 to SIn, the change signal CH, the latch signal LAT, the clock signal SCK, the drive signal COM, and the reference voltage signal VBS input to the connector 360 are input to the flexible printed circuit board 400-1.

[0108] Next, a specific example of signal propagation in the print head 20 configured as described above will be described. FIG. 15 is a diagram showing an example of signal propagation in the print head 20. As shown in FIG. 15, the signal input to the print head 20 via the connector 360 propagates through each of the signal propagation paths SR1 to SRp and is input to the head chips 22-1 to 22-n. At this time, each of the signal propagation paths SR1 to SRp is configured by the wirings 482 and 484 included in each of the flexible wiring boards 400-1 to 400-n being electrically and mechanically directly connected to each other. That is, each of the signal propagation paths SR1 to SRp includes the wirings 482 and 484 included in each of the flexible wiring boards 400-1 to 400-n.

[0109] Specifically, the signal propagation path SR1 is configured to include a wiring 482 or a wiring 484 to which the terminals 421[1], 422[1], and 423[1] included in each of the flexible wiring boards 400-1 to 400-n are commonly connected, and the signal propagation path SRk is configured to include a wiring 482 or a wiring 484 to which the terminals 421[k], 422[k], and 423[k] included in each of the flexible wiring boards 400-1 to 400-n are commonly connected.

[0110] The first control signal, which is any one of the signals for controlling the ejection of ink including the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS input to the print head 20 via the connector 360, propagates through the wiring 482 or wiring 484 of the flexible printed circuit board 400-1 that constitutes part of the signal propagation path SR1. Then, the first control signal branches at the connection point cp1[1], one of the branches is input to the head chip 22-1, and the other branch propagates through the wiring 482 or wiring 484 of the flexible printed circuit board 400-2 that constitutes part of the signal propagation path SR1. Thereafter, the first control signal branches at each of the connection points cp2[1] to cpn[1], one of the branches is input to each of the corresponding head chips 22-2 to 22-n, and the other branch propagates through the wiring 482 or wiring 484 of the flexible printed circuit boards 400-3 to 400-n that constitute part of the signal propagation path SR1.

[0111] As a result, the first control signal, which is any one of the signals for controlling the ejection of ink including the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS, is input to each of the head chips 22-1 to 22-n. That is, after propagating through the flexible printed circuit board 400-1, the first control signal propagates through the flexible printed circuit boards 400-2 to 400-n without passing through the head substrate 320 and is input to the head chips 22-2 to 22-n.

[0112] Also, a second control signal, which is any one of the signals for controlling the ejection of ink including print data signals SI1 to SIn, a change signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage signal VBS, input to the print head 20 via the connector 360, propagates through the wiring 482 or the wiring 484 of the flexible printed circuit board 400-1 that forms part of the signal propagation path SRk. Then, the second control signal branches at the connection point cp1[k], and one of the branched signals is input to the head chip 22-1, while the other branched signal propagates through the wiring 482 or the wiring 484 of the flexible printed circuit board 400-2 that forms part of the signal propagation path SRk. Thereafter, the second control signal branches at each of the connection points cp2[k] to cpn[k], and one of the branched signals is input to each of the corresponding head chips 22-2 to 22-n, while the other branched signal propagates through the wiring 482 or the wiring 484 that each of the flexible printed circuit boards 400-3 to 400-n forming part of the signal propagation path SRk has.

[0113] As a result, a second control signal, which is any one of the signals for controlling the ejection of ink including print data signals SI1 to SIn, a change signal CH, a latch signal LAT, a clock signal SCK, a drive signal COM, and a reference voltage signal VBS, is input to each of the head chips 22-1 to 22-n. That is, after propagating through the flexible printed circuit board 400-1, the second control signal propagates through the flexible printed circuit boards 400-2 to 400-n without passing through the head substrate 320 and is input to the head chips 22-2 to 22-n.

[0114] As described above, in the print head 20 of the present embodiment, all of the signals for controlling the ejection of ink from the head chips 22-2 to 22-n, including the print data signals SI2 to SIn, the change signal CH, the latch signal LAT, the clock signal SCK, the drive signal COM, and the reference voltage signal VBS, input to the head chips 22-2 to 22-n, propagate through the flexible printed circuit board 400-1 and then propagate through the corresponding flexible printed circuit boards 400-2 to 400-n without passing through the head substrate 320 and are input to the corresponding head chips 22-2 to 22-n.

[0115] Here, the head chip 22-1 included in the print head 20 is an example of a first head chip, the flexible printed circuit board 400-1 connected to the head chip 22-1 is an example of a first flexible printed circuit board, and any one of the clock signal SCK, latch signal LAT, change signal CH, print data signal SI1, drive signal COM, and reference voltage signal VBS input to the head chip 22-1 via the flexible printed circuit board 400-1 is an example of a first signal. Also, the head chip 22-2 is an example of a second head chip, the flexible printed circuit board 400-2 connected to the head chip 22-2 is an example of a second flexible printed circuit board, and any one of the clock signal SCK, latch signal LAT, change signal CH, print data signal SI2, drive signal COM, and reference voltage signal VBS input to the head chip 22-2 via the flexible printed circuit board 400-2 is an example of a second signal, and the clock signal SCK, latch signal LAT, change signal CH, print data signal SI2, drive signal COM, and reference voltage signal VBS input to the head chip 22-2 via the flexible printed circuit board 400-2 are an example of a plurality of ejection control signals.

[0116] Then, via the flexible printed circuit boards 400-1 to 400-n, the head substrate 320 to which the head chips 22-1 to 22-n are fixed is an example of a substrate, and the connector 360 provided on the head substrate 320 and to which the clock signal SCK, latch signal LAT, change signal CH, print data signals SI1 to SIn, drive signal COM, and reference voltage signal VBS are input is an example of a connector.

[0117] 5. Operational Effects In the liquid ejection device 1 and the print head 20 configured as described above, the clock signal SCK, latch signal LAT, change signal CH, print data signal SI2, drive signal COM, and reference voltage signal VBS input to the head chip 22-2 are propagated through the flexible wiring board 400-1 electrically connected to the head chip 22-1, and then propagated through the flexible wiring board 400-2 electrically connected to the head chip 22-2 without passing through the head substrate 320, and input to the head chip 22-2. Thereby, the number of wiring patterns formed on the head substrate 320 can be reduced. As a result, miniaturization of the head substrate 320 and the print head 20 including the head substrate 320 can be achieved.

[0118] In particular, like the print head 20 of the liquid ejection device 1 of the present embodiment, when the head substrate 320 has through holes 340-1 to 340-n and various signals are propagated to the head chips 22-1 to 22-n by the flexible wiring boards 400-1 to 400-n inserted through the through holes 340-1 to 340-n, it is necessary to route the wiring patterns through which the signals input to the head chips 22-1 to 22-n propagate, avoiding the through holes 340-1 to 340-n, on the head substrate 320. In that case, the wiring patterns provided on the head substrate 320 become complicated, and in particular, there is a risk that the size of the head substrate 320 in the direction along the Y axis where the major diameters of the through holes 340-1 to 340-n extend increases.

[0119] On the other hand, in the liquid ejection device 1 and the print head 20 of the present embodiment, the signal input to the head chip 22-2 is propagated through the flexible wiring board 400-2 electrically connected to the head chip 22-2 without passing through the head substrate 320 and input to the head chip 22-2, so that it is not necessary to form a wiring pattern avoiding the through holes 340-1 to 340-n. As a result, the risk of the wiring pattern being routed complicatedly on the head substrate 320 is reduced. As a result, even when the head substrate 320 has the through holes 340-1 to 340-n, miniaturization of the head substrate 320 and the print head 20 including the head substrate 320 can be achieved.

[0120] 6. Modification Example In the liquid ejection device 1 of the present embodiment described above, it has been described that all of the clock signal SCK, latch signal LAT, change signal CH, print data signals SI2 to SIn, drive signal COM, and reference voltage signal VBS input to the head chips 22-2 to 22-n are propagated through the flexible wiring board 400-1 and then input to the corresponding head chip 22 without passing through the head substrate 320. However, at least one of the clock signal SCK, latch signal LAT, change signal CH, print data signals SI2 to SIn, drive signal COM, and reference voltage signal VBS may be input to the corresponding head chip 22 without passing through the head substrate 320 after being propagated through the flexible wiring board 400-1, and thus, the same operational effects can be achieved.

[0121] In this case, among the clock signal SCK, latch signal LAT, change signal CH, print data signals SI2 to SIn, drive signal COM, and reference voltage signal VBS, a signal that is commonly supplied to the head chips 22-1 to 22-n, and any one of the clock signal SCK, latch signal LAT, change signal CH, drive signal COM, and reference voltage signal VBS is prioritized over the print data signals SI2 to SIn that are individually input to the head chips 22-1 to 22-n, and after being propagated through the flexible wiring board 400-1, it is preferably configured to be input to the corresponding head chip 22 without passing through the head substrate 320. This reduces the possibility of the wirings 482 and 484 formed on each of the flexible wiring boards 400-1 to 400-n becoming complicated.

[0122] In addition, in the liquid ejection device 1 and the print head 20 of the present embodiment described above, the terminal 422-1[k] of the flexible wiring board 400-1 is connected to an electrode (not shown) of the head board 320, and the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS input to the connector 360, which are signals for controlling the ejection of ink, are input to the flexible wiring board 400-1 via the electrode. However, the terminal 422-1[k] of the flexible wiring board 400-1 may be directly connected to the connector 360.

[0123] That is, any one or all of the signals for controlling the ejection of ink, including the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS input to the connector 360, may be input to the corresponding head chips 22-1 to 22-n via the flexible wiring board 400-1 without propagating through the head board 320. In other words, any one or all of the signals for controlling the ejection of ink, including the print data signals SI1 to SIn, change signal CH, latch signal LAT, clock signal SCK, drive signal COM, and reference voltage signal VBS input to the connector 360, may be input to the head chips 22-1 to 22-n without propagating through the head board 320.

[0124] As a result, the possibility of the head board 320 becoming larger due to the influence of the wiring pattern provided on the head board 320 is further reduced, and as a result, further miniaturization of the head board 320 and the print head 20 including the head board 320 can be achieved.

[0125] As described above, the embodiments and modification examples have been explained. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist thereof. For example, it is also possible to appropriately combine the above embodiments.

[0126] The present invention includes a configuration that is substantially the same as the configuration described in the embodiments (for example, a configuration having the same functions, methods, and results, or a configuration having the same objectives and effects). The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiments are replaced. The present invention also includes a configuration that exhibits the same operational effects as the configuration described in the embodiments or a configuration that can achieve the same objective. The present invention also includes a configuration in which known techniques are added to the configuration described in the embodiments.

[0127] The following content is derived from the above-described embodiments.

[0128] One aspect of the liquid ejection device is a discharge control circuit that outputs a first signal and a second signal, a print head that ejects liquid in response to the first signal and the second signal, and the print head includes a first head chip that ejects liquid in response to the first signal, a second head chip that ejects liquid in response to the second signal, a first flexible wiring board that propagates the first signal to the first head chip, a second flexible wiring board that propagates the second signal to the second head chip, a substrate to which the first head chip and the second head chip are fixed, a connector to which the first signal and the second signal are input, and the second flexible wiring board is directly connected to the first flexible wiring board, and the second signal propagates through the first flexible wiring board, then propagates through the second flexible wiring board without passing through the substrate, and is input to the second head chip.

[0129] According to this liquid ejection device, after the second signal propagates through the first flexible wiring board, it propagates through the second flexible wiring board without passing through the board and is input to the second head chip, thereby reducing the wiring patterns formed on the board. As a result, the risk of the board becoming larger is reduced, and miniaturization of the print head can be achieved.

[0130] In one aspect of the liquid ejection device described above, the second head chip ejects liquid according to a plurality of ejection control signals including the second signal, all of the plurality of ejection control signals may propagate through the second flexible wiring board without passing through the board after propagating through the first flexible wiring board and be input to the second head chip.

[0131] According to this liquid ejection device, a plurality of ejection control signals including the second signal propagate through the first flexible wiring board, then propagate through the second flexible wiring board without passing through the board, and are input to the second head chip, thereby further reducing the wiring patterns formed on the board. As a result, the risk of the board becoming larger is further reduced, and further miniaturization of the print head can be achieved.

[0132] In one aspect of the liquid ejection device described above, the second signal may be input to the second head chip without propagating through the board.

[0133] According to this liquid ejection device, the wiring patterns formed on the board can be further reduced. As a result, the risk of the board becoming larger is further reduced, and further miniaturization of the print head can be achieved.

[0134] In one aspect of the liquid ejection device described above, the second head chip ejects liquid according to a plurality of ejection control signals including the second signal, the plurality of ejection control signals are input from the connector, All of the plurality of ejection control signals may be input to the second head chip without propagating through the substrate.

[0135] According to this liquid ejection device, the wiring pattern formed on the substrate can be further reduced. As a result, the possibility of the substrate becoming larger is further reduced, and further miniaturization of the print head can be achieved.

[0136] In one aspect of the liquid ejection device, The second flexible wiring board may have a double-sided structure.

[0137] In one aspect of the liquid ejection device, The first flexible wiring board and the second flexible wiring board may be fixed to the substrate.

[0138] One aspect of the print head is A print head that ejects liquid according to a first signal and a second signal, A first head chip that ejects liquid according to the first signal, A second head chip that ejects liquid according to the second signal, A first flexible wiring board that propagates the first signal to the first head chip, A second flexible wiring board that propagates the second signal to the second head chip, A substrate to which the first head chip and the second head chip are fixed, A connector to which the first signal and the second signal are input, Comprising The second flexible wiring board is directly connected to the first flexible wiring board, The second signal propagates through the second flexible wiring board without passing through the substrate after propagating through the first flexible wiring board, and is input to the second head chip.

[0139] According to this print head, after the second signal propagates through the first flexible wiring board, it propagates through the second flexible wiring board without passing through the board and is input to the second head chip, thereby reducing the wiring patterns formed on the board. As a result, the possibility of the board becoming large is reduced, and miniaturization of the print head can be achieved.

[0140] In one aspect of the above print head, the second head chip discharges liquid according to a plurality of ejection control signals including the second signal, all of the plurality of ejection control signals may propagate through the second flexible wiring board without passing through the board after propagating through the first flexible wiring board and be input to the second head chip.

[0141] According to this print head, a plurality of ejection control signals including the second signal propagate through the first flexible wiring board, then propagate through the second flexible wiring board without passing through the board, and are input to the second head chip, thereby further reducing the wiring patterns formed on the board. As a result, the possibility of the board becoming large is further reduced, and further miniaturization of the print head can be achieved.

[0142] In one aspect of the above print head, the second signal may be input to the second head chip without propagating through the board.

[0143] According to this print head, the wiring patterns formed on the board can be further reduced. As a result, the possibility of the board becoming large is further reduced, and further miniaturization of the print head can be achieved.

[0144] In one aspect of the above print head, the second head chip discharges liquid according to a plurality of ejection control signals including the second signal, the plurality of ejection control signals are input from the connector, All of the plurality of ejection control signals may be input to the second head chip without propagating through the substrate.

[0145] According to this print head, the number of wiring patterns formed on the substrate can be further reduced. As a result, the possibility of the substrate becoming larger is further reduced, and further miniaturization of the print head can be achieved.

[0146] In one aspect of the print head, The second flexible wiring board may have a double-sided structure.

[0147] In one aspect of the print head, The first flexible wiring board and the second flexible wiring board may be fixed to the substrate.

Description of Reference Numerals

[0148] 1... Liquid ejection device, 2... Ink container, 10... Control mechanism, 20... Print head, 21... Carriage, 22, 22-1 to 22-n... Head chips, 30... Moving mechanism, 31... Carriage motor, 32... Endless belt, 40... Conveying mechanism, 41... Conveying motor, 42... Conveying roller, 50... Drive circuit, 52... Reference voltage output circuit, 60... Piezoelectric element, 100... Control circuit, 200... Drive signal selection circuit, 210... Selection control circuit, 212... Shift register, 214... Latch circuit, 216... Decoder, 230... Selection circuit, 232... Inverter, 234... Transfer gate, 310... Head, 311... Ink ejection surface, 320... Head substrate, 321, 322... Surfaces, 323 to 326... Sides, 330, 330-1 to 330-n... Electrode groups, 340, 340-1 to 340-n... Through holes, 350... Fixed part, 360... Connector, 400, 400-1 to 400-n... Flexible printed circuit board, 410... Semiconductor device, 421, 422, 423... Terminals, 482, 484, 486... Wiring, 510... Nozzle plate, 520... Flow path forming substrate, 530... Pressure chamber substrate, 540... Protection substrate, 550... Compliance part, 551... Sealing film, 552... Support, 560... Diaphragm, 570... Case, 600... Ejection part, 610... Ink flow path, 611... Liquid inlet, 612... Reservoir, 613... Pressure chamber, 614... Individual flow path, 615... Communication flow path, 616... Reservoir, 651... Nozzle, P... Medium

Claims

1. A discharge control circuit that outputs a first signal and a second signal, A print head that discharges liquid according to the first signal and the second signal, comprising: The print head is A first head chip that discharges liquid according to the first signal, A second head chip that discharges liquid according to the second signal, A first flexible wiring board that propagates the first signal to the first head chip, A second flexible wiring board that propagates the second signal to the second head chip, A substrate to which the first head chip and the second head chip are fixed, A connector to which the first signal and the second signal are input, having The second flexible wiring board is directly connected to the first flexible wiring board, The second signal propagates through the second flexible wiring board and is input to the second head chip without passing through the substrate after propagating through the first flexible wiring board. A liquid discharge device characterized by this.

2. The second head chip discharges liquid according to a plurality of discharge control signals including the second signal, All of the plurality of discharge control signals propagate through the second flexible wiring board and are input to the second head chip without passing through the substrate after propagating through the first flexible wiring board. The liquid discharge device according to claim 1, characterized by this.

3. The second signal is input to the second head chip without passing through the substrate. The liquid discharge device according to claim 1, characterized by this.

4. The second head chip discharges liquid according to a plurality of discharge control signals including the second signal, The plurality of ejection control signals are input from the connector, all of the plurality of ejection control signals are input to the second head chip without propagating through the substrate, The liquid ejection device according to claim 3, wherein:

5. The second flexible printed circuit board has a double-sided structure, The liquid ejection device according to claim 1, wherein:

6. The first flexible printed circuit board and the second flexible printed circuit board are fixed to the substrate, The liquid ejection device according to any one of claims 1 to 5, wherein:

7. A print head that ejects liquid according to a first signal and a second signal, a first head chip that ejects liquid according to the first signal; a second head chip that ejects liquid according to the second signal; a first flexible printed circuit board that propagates the first signal to the first head chip; a second flexible printed circuit board that propagates the second signal to the second head chip; a substrate to which the first head chip and the second head chip are fixed; a connector to which the first signal and the second signal are input; comprising: The second flexible printed circuit board is directly connected to the first flexible printed circuit board, The second signal propagates through the second flexible printed circuit board without passing through the substrate after propagating through the first flexible printed circuit board, and is input to the second head chip. The print head is characterized in that:

8. The second head chip ejects liquid according to a plurality of ejection control signals including the second signal, All of the plurality of ejection control signals are propagated through the first flexible wiring board, then propagated through the second flexible wiring board without passing through the board, and input to the second head chip. The print head according to claim 7, characterized in that.

9. The second signal is input to the second head chip without passing through the board. The print head according to claim 7, characterized in that.

10. The second head chip ejects liquid according to a plurality of ejection control signals including the second signal. The plurality of ejection control signals are input from the connector. All of the plurality of ejection control signals are input to the second head chip without passing through the board. The print head according to claim 9, characterized in that.

11. The second flexible wiring board has a double-sided structure. The print head according to claim 7, characterized in that.

12. The first flexible wiring board and the second flexible wiring board are fixed to the board. The print head according to any one of claims 7 to 11, characterized in that.

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