Head unit, and liquid ejection device

Abstract

To provide a head unit that can reduce error operation that is caused by an intrusion of ink mist that may be caused due to increase in currents.SOLUTION: A head unit comprises: a discharging part that includes a piezoelectric element that is driven by a driving signal and discharges liquid in response to driving of the piezoelectric element; a first substrate that transmits the driving signal to the discharging part; a second substrate that is supplied with the first driving signal and transmits the driving signal to the first substrate; and a connection member that electrically connects the first substrate to the second substrate. The connection member includes: a pin header that has a plurality of insertion pins including a first insertion pin and a second insertion pin and a holding part that holds the plurality of insertion pins being insulated from each other; and a pin socket having a plurality of insertion holes as many as the plurality of insertion pins and arranged in correspondence with the plurality of insertion pins respectively. The connection member is inserted into the plurality of insertion holes corresponding to the plurality of insertion pins, so as to electrically connect the first substrate to the second substrate.SELECTED DRAWING: Figure 11

Description

Technical Field

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

Background Art

[0002] A liquid ejection device that ejects liquid onto a medium has a drive element such as a piezoelectric element that is driven based on a drive signal, and controls the drive of the drive element by controlling the supply of the drive signal to the drive element, and also controls the amount of liquid ejected in response to the drive of the drive element, thereby forming desired dots on the medium.

[0003] However, a part of the liquid ejected onto the medium may be atomized before landing on the medium and float inside the liquid ejection device as liquid mist. Also, even after the liquid ejected from the nozzle lands on the medium, the landed liquid may be atomized by the airflow generated as the medium on which the liquid is ejected is conveyed, and float inside the liquid ejection device as liquid mist. Since such liquid mist floating inside the liquid ejection device is extremely minute, it becomes charged due to the Lenard effect. Therefore, the liquid mist is attracted to conductive parts such as wiring patterns that propagate various signals to the print head and terminals that electrically connect the cable and the print head, and as a result, may enter the inside of the print head.

[0004] When liquid mist enters the inside of the print head, the liquid mist is attracted to wiring patterns, terminals, electronic components, etc. provided inside the print head. And when the liquid mist adheres between the wiring patterns and between the terminals, a short-circuit abnormality occurs in the print head, and as a result, there has been a risk of malfunction in the print head and the liquid ejection device.

[0005] Regarding problems that may occur due to liquid intrusion into the interior of such a print head (head unit), for example, Patent Document 1 discloses a liquid ejection device capable of controlling the amount of ink ejected from nozzles by controlling the driving amount of a piezoelectric element by supplying or not supplying a trapezoidal waveform included in a driving signal to the piezoelectric element. Even when a liquid such as ink intrudes into the print head that ejects the liquid, a liquid ejection device that can reduce the risk of malfunction is disclosed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In recent years, in liquid ejection devices, there has been an increasing demand for higher image formation speeds on a medium. Therefore, there is a demand for speeding up the dot formation cycle for forming dots of a desired size on the medium by ejecting liquid. However, to speed up the dot formation cycle, it is necessary to increase the driving amount of the driving element per unit time. Therefore, the amount of current generated along with the driving signal for driving the driving element increases. And when the amount of current generated along with the driving signal increases, from the perspective of current density, the number of wirings for propagating the driving signal increases. As a result, the density of the wirings for propagating the driving signal increases. Such an increase in wiring density increases the possibility of short-circuiting between the wirings due to the adhesion of ink mist when ink mist intrudes into the interior of the head unit. As a result, the possibility of malfunction occurring in the head unit increases.

[0008] However, Patent Document 1 does not describe anything about the malfunction of the head unit due to the intrusion of newly generated ink mist caused by the increase in current accompanying the speeding up of the dot formation speed on the medium, and there is room for improvement. increase, and there is room for improvement.

Means for Solving the Problem

[0009] One aspect of the head unit according to the present invention includes a discharge unit that includes a piezoelectric element driven by a drive signal and discharges a liquid in response to the drive of the piezoelectric element, a first substrate that propagates the drive signal to the discharge unit, a second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate, a connection member that electrically connects the first substrate and the second substrate, and is provided with The connection member includes a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding portion that holds the plurality of insertion pins in a mutually insulated state, and is a pin header, a pin socket having the same number as the plurality of insertion pins and provided corresponding to the plurality of insertion pins and having a plurality of insertion holes, and includes The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding thereto.

[0010] One aspect of the liquid discharge device according to the present invention includes a drive circuit unit having a drive signal output circuit that outputs a drive signal, a head unit that discharges a liquid based on the drive signal, and is provided with The head unit includes a piezoelectric element driven by the drive signal and a discharge unit that discharges a liquid in response to the drive of the piezoelectric element, a first substrate that propagates the drive signal to the discharge unit, a second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate, a connection member that electrically connects the first substrate and the second substrate, and has The connection member A pin header having a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding portion that holds the plurality of insertion pins in an insulated state from each other. A pin socket having the same number as the plurality of insertion pins and provided with a plurality of insertion holes corresponding to the plurality of insertion pins. Including The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding thereto.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The drawings used are for convenience of explanation. It should be noted 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.

[0013] 1. Configuration of the Liquid Discharge Device FIG. 1 is a diagram showing a schematic configuration of the liquid discharge device 1. As shown in FIG. 1, the liquid discharge device 1 in the present embodiment is a line type inkjet printer that forms a desired image on the medium P by discharging ink, which is an example of a liquid, at a desired timing with respect to the medium P conveyed by the medium conveyance unit 40. Here, in the following description, the width direction of the conveyed medium P may be referred to as the main scanning direction, and the direction in which the medium P is conveyed may be referred to as the conveyance direction.

[0014] As shown in FIG. 1, the liquid ejection device 1 includes a liquid container 2, a control unit 10, a liquid ejection unit 20, and a medium conveyance unit 40.

[0015] In the liquid container 2, ink supplied to the liquid ejection unit 20 is stored. Specifically, in the liquid container 2, inks of a plurality of colors ejected onto the medium P, such as inks of colors such as black, cyan, magenta, yellow, red, and gray, are stored. As such a liquid container 2, for example, an ink cartridge, a bag-shaped ink pack formed of a flexible film, an ink tank capable of replenishing ink, or the like can be used.

[0016] The control unit 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. Then, the control unit 10 outputs a control signal for controlling each element of the liquid ejection device 1.

[0017] The liquid ejection unit 20 has a plurality of head modules 21. In the liquid ejection unit 20, the plurality of head modules 21 are arranged side by side so as to be equal to or greater than the width of the medium P along the main scanning direction. That is, the liquid ejection device 1 includes a plurality of head modules 21, and the plurality of head modules 21 are provided side by side along the main scanning direction intersecting the conveyance direction in which the medium P on which ink, an example of the liquid, is ejected is conveyed.

[0018] To each of the plurality of head modules 21 included in the liquid ejection unit 20, a data signal DATA for controlling the operations of the plurality of head modules 21 and a drive signal COM for driving the head module 21 so that ink is ejected from each of the plurality of head modules 21 are input from the control unit 10. Also, ink stored in the liquid container 2 is supplied to each of the plurality of head modules 21 via a tube (not shown) or the like. Then, each of the plurality of head modules 21 ejects the ink supplied from the liquid container 2 based on the input data signal DATA and drive signal COM.

[0019] The medium conveyance unit 40 includes a conveyance motor 41 and a conveyance roller 42. The conveyance motor 41 operates based on a conveyance control signal Ctrl-T input from the control unit 10. The conveyance roller 42 is rotationally driven as the conveyance motor 41 operates. Then, due to the rotational drive of the conveyance roller 42, the medium P is conveyed along the conveyance direction.

[0020] In the liquid ejection apparatus 1 configured as described above, the control unit 10 causes the ink to be ejected from the plurality of head modules 21 included in the liquid ejection unit 20 in conjunction with the conveyance of the medium P by the medium conveyance unit 40. Thereby, the liquid ejection apparatus 1 lands the ink at a desired position on the medium P and forms a desired image on the medium P.

[0021] Here, a specific example of the control of the liquid ejection unit 20 by the control unit 10 will be described. FIG. 2 is a diagram showing the functional configuration of the liquid ejection apparatus 1. Note that in FIG. 2, only the electrical connection between the control unit 10 and the liquid ejection unit 20 is shown, and the illustration of the medium conveyance unit 40 and the liquid container 2 is omitted.

[0022] As shown in FIG. 2, the liquid ejection device 1 includes a control unit 10 and a liquid ejection unit 20. The control unit 10 includes a control circuit 100, a drive circuit unit 50, and a conversion circuit 120. Further, the drive circuit unit 50 includes drive circuits 51-1 to 51-m. Also, the liquid ejection unit 20 has a plurality of head modules 21. And the control unit 10 and each of the plurality of head modules 21 included in the liquid ejection unit 20 are electrically connected by a cable (not shown).

[0023] Here, all of the plurality of head modules 21 have the same configuration. Therefore, in FIG. 2, only the circuit configuration included in one head module 21 is shown, and the illustration of the circuit configurations included in the other head modules 21 is omitted. Also, in the following description, only the operation and functional configuration of one head module 21 will be described, and the description of the operation and functional configuration of the other head modules 21 will be omitted or simplified.

[0024] The control circuit 100 has an integrated circuit such as a CPU or an FPGA. Signals such as image data to be formed on the medium P are input to the control circuit 100 from an external device such as a host computer (not shown). The control circuit 100 outputs a control signal for controlling each element of the liquid ejection device 1 based on the input signals such as image data.

[0025] The control circuit 100 generates a base data signal dDATA that serves as a basis for a data signal DATA output to the liquid ejection unit 20 based on the input signals such as image data, and outputs it to the conversion circuit 120. The conversion circuit 120 converts the base data signal dDATA into a differential signal data signal DATA such as LVDS (Low Voltage Differential Signaling) and outputs it to the head module 21 included in the liquid ejection unit 20. Note that the conversion circuit 120 is the base data signal The data signal DATA obtained by converting the dDATA into differential signals of various high-speed transfer systems such as LVPECL (Low Voltage Positive Emitter Coupled Logic) and CML (Current Mode Logic) other than LVDS may be generated and output to the head module 21. Also, part or all of the input base data signal dDATA may be converted into a single-ended data signal DATA and output to the head module 21.

[0026] Further, the control circuit 100 outputs base drive signals dA1, dB1, and dC1 to the drive circuit 51-1 included in the drive circuit unit 50. The drive circuit 51-1 includes drive signal output circuits 52a, 52b, and 52c having the same circuit configuration.

[0027] The base drive signal dA1 is input to the drive signal output circuit 52a included in the drive circuit 51-1. The drive signal output circuit 52a generates a drive signal COMA1 by performing digital / analog conversion on the input base drive signal dA1 and then performing class-D amplification on the analog signal, and outputs the generated drive signal COMA1 to the head module 21. The base drive signal dB1 is input to the drive signal output circuit 52b included in the drive circuit 51-1. The drive signal output circuit 52b generates a drive signal COMB1 by performing digital / analog conversion on the input base drive signal dB1 and then performing class-D amplification on the analog signal, and outputs the generated drive signal COMB1 to the head module 21. The base drive signal dC1 is input to the drive signal output circuit 52c included in the drive circuit 51-1. The drive signal output circuit 52c generates a drive signal COMC1 by performing digital / analog conversion on the input base drive signal dC1 and then performing class-D amplification on the analog signal, and outputs the generated drive signal COMC1 to the head module 21.

[0028] Here, each of the drive signal output circuits 52a, 52b, and 52c may be configured to generate the drive signals COMA1, COMB1, and COMC1 by amplifying the waveforms defined by the basic drive signals dA1, dB1, and dC1, which are input digital signals, and may be configured to include a class A amplifier circuit, a class B amplifier circuit, or a class AB amplifier circuit, etc., instead of or in addition to the class D amplifier circuit. Also, each of the basic drive signals dA1, dB1, and dC1 may be an analog signal as long as it can define the waveforms of the corresponding drive signals COMA1, COMB1, and COMC1.

[0029] The drive circuit 51-1 also has a reference voltage output circuit 53. The reference voltage output circuit 53 generates a reference voltage signal VBS1 of a constant potential indicating a reference potential of a piezoelectric element 60 (described later) of the head module 21 by stepping up or down a power supply voltage (not shown) used in the liquid ejection device 1, and outputs the signal to the head module 21. The reference voltage signal VBS1 output by the reference voltage output circuit 53 may be a constant signal at ground potential, or may be a constant signal at a potential of 5.5 V or 6 V. Note that a constant potential includes a case where the potential can be considered to be approximately constant when errors such as potential fluctuations caused by the operation of peripheral circuits, potential fluctuations caused by variations in circuit elements, and potential fluctuations caused by temperature characteristics are taken into account.

[0030] Here, the drive circuits 51-1 to 51-m included in the drive circuit unit 50 only have different input and output signals, and all have the same configuration. Specifically, the drive circuit 51-m includes circuits corresponding to the drive signal output circuits 52a, 52b, and 52c and a circuit corresponding to the reference voltage output circuit 53, and generates drive signals COMAm, COMBm, and COMCm and a reference voltage signal VBSm based on the base drive signals dAm, dBm, and dCm input from the control circuit 100, and outputs them to the head module 21. Similarly, the drive circuit 51-j (j is any one of 1 to m) includes circuits corresponding to the drive signal output circuits 52a, 52b, and 52c and a circuit corresponding to the reference voltage output circuit 53, and generates drive signals COMAj, COMBj, and COMCj and a reference voltage signal VBSj based on the base drive signals dAj, dBj, and dCj input from the control circuit 100, and outputs them to the head module 21.

[0031] The plurality of head modules 21 included in the liquid discharge unit 20 each include a restoration circuit 220 and discharge modules 23-1 to 23-m.

[0032] The restoration circuit 220 restores the data signal DATA of the differential signal output by the control unit 10 to a single-ended signal, separates it into signals corresponding to each of the discharge modules 23-1 to 23-m, and outputs the separated signals to the corresponding discharge modules 23-1 to 23-m.

[0033] Specifically, the restoration circuit 220 restores and separates the data signal DATA of the differential signal output by the control unit 10 to generate a clock signal SCK1, a print data signal SI1, and a latch signal LAT1 corresponding to the ejection module 23-1. Then, the restoration circuit 220 outputs the generated clock signal SCK1, print data signal SI1, and latch signal LAT1 to the ejection module 23-1. Further, the restoration circuit 220 restores and separates the data signal DATA of the differential signal output by the control unit 10 to generate a clock signal SCKm, a print data signal SIm, and a latch signal LATm corresponding to the ejection module 23-m and outputs them to the ejection module 23-m. Also, the restoration circuit 220 restores and separates the data signal DATA of the differential signal output by the control unit 10 to generate a clock signal SCKj, a print data signal SIj, and a latch signal LATj corresponding to the ejection module 23-j and outputs them to the ejection module 23-j. Note that the clock signal SCK1 corresponding to the ejection module 23-1, the clock signal SCKj corresponding to the ejection module 23-j, and the clock signal SCKm corresponding to the ejection module 23-m output by the restoration circuit 220 may be common signals.

[0034] As described above, the restoration circuit 220 restores the data signal DATA of the differential signal output by the control unit 10 and separates the restored signal into signals corresponding to the ejection modules 23-1 to 23-m. Thereby, the restoration circuit 220 generates clock signals SCK1 to SCKm, print data signals SI1 to SIm, and latch signals LAT1 to LATm corresponding to the respective ejection modules 23-1 to 23-m of the head module 21 and outputs them to the corresponding ejection modules 23-1 to 23-m.

[0035] Here, in view of the fact that the restoration circuit 220 restores and separates the data signal DATA of the differential signal to generate the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm, the reference data signal dDATA that is the basis of the data signal DATA output by the control circuit 100 includes signals corresponding to each of the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm. Also, the data signal DATA output by the conversion circuit 120 includes a differential signal corresponding to the clock signals SCK1 to SCKm, a differential signal corresponding to the print data signals SI1 to SIm, and a differential signal corresponding to the latch signals LAT1 to LATm.

[0036] Note that the conversion circuit 120 may output, as different differential signals, a differential signal corresponding to the clock signals SCK1 to SCKm, a differential signal corresponding to the print data signals SI1 to SIm, and a differential signal corresponding to the latch signals LAT1 to LATm. Also, the conversion circuit 120 may output, as a single-ended signal without converting any of the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm included in the reference data signal dDATA into a differential signal.

[0037] The ejection module 23-1 includes a drive signal selection control circuit 200 and a plurality of ejection units 600. Also, each of the plurality of ejection units 600 includes a piezoelectric element 60. The drive signals COMA1, COMB1, COMC1, the reference voltage signal VBS1, the clock signal SCK1, the print data signal SI1, and the latch signal LAT1 are input into the ejection module 23-1. applied.

[0038] Among the signals input to the ejection module 23-1, the drive signals COMA1, COMB1, COMC1, the clock signal SCK1, the print data signal SI1, and the latch signal LAT1 are input to the drive signal selection control circuit 200 included in the ejection module 23-1. Based on the input clock signal SCK1, print data signal SI1, and latch signal LAT1, the drive signal selection control circuit 200 generates a drive signal VOUT by selecting or not selecting each of the drive signals COMA1, COMB1, COMC1, and supplies the generated drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding ejection unit 600. At this time, a reference voltage signal VBS1 is supplied to the other end of the piezoelectric element 60. Then, the piezoelectric elements 60 included in the plurality of ejection units 600 are driven by the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBS1 supplied to the other end.

[0039] Similarly, the ejection module 23-m includes a drive signal selection control circuit 200 and a plurality of ejection units 600. Each of the plurality of ejection units 600 includes a piezoelectric element 60. The drive signals COMAm, COMBm, COMCm, the reference voltage signal VBSm, the clock signal SCKm, the print data signal Sim, and the latch signal LATm are input to the ejection module 23-m. Among these, the drive signals COMAm, COMBm, COMCm, the clock signal SCKm, the print data signal Sim, and the latch signal LATm are input to the drive signal selection control circuit 200 included in the ejection module 23-m. Based on the input clock signal SCKm, print data signal Sim, and latch signal LATm, the drive signal selection control circuit 200 generates a drive signal VOUT by selecting or not selecting each of the drive signals COMAm, COMBm, COMCm, and supplies the generated drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding ejection unit 600. Also, the reference voltage signal VBSm is commonly supplied to the other ends of the piezoelectric elements 60 included in the plurality of ejection units 600. As a result, the piezoelectric elements 60 included in the plurality of ejection units 600 are driven by the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBSm supplied to the other end.

[0040] Similarly, the ejection module 23-j includes a drive signal selection control circuit 200 and a plurality of ejection units 600. Each of the plurality of ejection units 600 includes a piezoelectric element 60. The drive signals COMAj, COMBj, COMCj, the reference voltage signal VBSj, the clock signal SCKj, the print data signal SIj, and the latch signal LATj are input to the ejection module 23-j. Among these, the drive signals COMAj, COMBj, COMCj, the clock signal SCKj, the print data signal SIj, and the latch signal LATj are input to the drive signal selection control circuit 200 included in the ejection module 23-j. Based on the input clock signal SCKj, print data signal SIj, and latch signal LATj, the drive signal selection control circuit 200 generates a drive signal VOUT by selecting or not selecting each of the drive signals COMAj, COMBj, COMCj, and supplies the generated drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding ejection unit 600. Also, the reference voltage signal VBSj is commonly supplied to the other ends of the piezoelectric elements 60 included in the plurality of ejection units 600. As a result, the piezoelectric elements 60 included in the plurality of ejection units 600 are driven by the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBSj supplied to the other end.

[0041] Then, when the piezoelectric element 60 is driven by the ejection modules 23-1 to 23-m, an amount of ink corresponding to the drive of the piezoelectric element 60 is ejected.

[0042] In the liquid ejection apparatus 1 configured as described above, a drive circuit unit 50 having a drive signal output circuit 52a that outputs drive signals COMA1 to COMAm, a drive signal output circuit 52b that outputs drive signals COMB1 to COMBm, and a drive signal output circuit 52c that outputs drive signals COMC1 to COMCm is an example of a drive circuit unit, and a head module 21 that ejects ink based on the drive signals COMA1 ~COMAm, COMB1~COMBm, COMC1~COMCm is an example of a head unit.

[0043] 2. Functional Configuration of Drive Signal Selection Control Circuit Next, the operation of the drive signal selection control circuit 200 included in the ejection modules 23-1 to 23-m will be described. Here, the ejection modules 23-1 to 23-m only differ in the input signals and have the same configuration. Therefore, in the following description, when there is no need to distinguish the ejection modules 23-1 to 23-m, they may simply be referred to as the ejection module 23. Also, in this case, the drive signals COMA1 to COMAm input to the ejection module 23 are referred to as the drive signal COMA, the drive signals COMB1 to COMBm are referred to as the drive signal COMB, the drive signals COMC1 to COMCm are referred to as the drive signal COMC, the clock signals SCK1 to SCKm are referred to as the clock signal SCK, the print data signals SI1 to SIm are referred to as the print data signal SI, and the latch signals LAT1 to LATm are referred to as the latch signal LAT.

[0044] In explaining the functional configuration of the drive signal selection control circuit 200 included in the ejection module 23, first, an example of the signal waveforms included in the drive signals COMA, COMB, and COMC input to the drive signal selection control circuit 200 will be described.

[0045] FIG. 3 is a diagram showing an example of the signal waveforms of the drive signals COMA, COMB, and COMC. As shown in FIG. 3, the drive signal COMA includes a trapezoidal waveform Adp arranged in a period T from when the latch signal LAT rises until the latch signal LAT rises next, the drive signal COMB includes a trapezoidal waveform Bdp arranged in the period T, and the drive signal COMC includes a trapezoidal waveform Cdp arranged in the period T. Here, the period T from when the latch signal LAT rises until the latch signal LAT rises next corresponds to the dot formation period for forming dots of a desired size on the medium P.

[0046] The trapezoidal waveform Adp is a waveform that, when supplied to one end of the piezoelectric element 60, causes a predetermined amount of ink to be ejected from the ejection unit 600 corresponding to the piezoelectric element 60. The trapezoidal waveform Bdp is a waveform with a smaller voltage amplitude than the trapezoidal waveform Adp. When this trapezoidal waveform Bdp is supplied to one end of the piezoelectric element 60, a smaller amount of ink than the predetermined amount is ejected from the ejection unit 600 corresponding to the piezoelectric element 60. The trapezoidal waveform Cdp is a waveform with a smaller voltage amplitude than the trapezoidal waveforms Adp and Bdp. When this trapezoidal waveform Cdp is supplied to one end of the piezoelectric element 60, the ink near the nozzle orifice is vibrated to such an extent that no ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60. This reduces the risk of an increase in the viscosity of the ink near the nozzle orifice.

[0047] Also, the voltages at the start timing and end timing of each of the trapezoidal waveforms Adp, Bdp, and Cdp are all common at the voltage Vc. That is, the trapezoidal waveforms Adp, Bdp, and Cdp are waveforms that each start at the voltage Vc and end at the voltage Vc.

[0048] Here, in the following description, when the trapezoidal waveform Adp is supplied to one end of the piezoelectric element 60, the amount of ink ejected from the ejection unit 600 corresponding to the piezoelectric element 60 is referred to as a large amount, and when the trapezoidal waveform Bdp is supplied to one end of the piezoelectric element 60, the amount of ink ejected from the ejection unit 600 corresponding to the piezoelectric element 60 is referred to as a small amount. Also, vibrating the ink near the nozzle orifice to such an extent that no ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60 may be referred to as micro-vibration.

[0049] Note that the drive signals COMA, COMB, and COMC may be signals having a waveform in which two or more trapezoidal waveforms are continuous in the period T. In this case, the drive signal selection control circuit 200 has A signal that defines boundaries of two or more trapezoidal waveforms, and a signal that defines switching timings of two or more trapezoidal waveforms may be input. And in this case, in a period T corresponding to a dot formation period, the ejection unit 600 may eject ink a plurality of times, and on the medium P, ink ejected in a plurality of times lands and combines to form one dot. In contrast, in the present embodiment, the drive signals COMA, COMB, and COMC will be described as signals each including one trapezoidal waveform in the period T. Thereby, in the period T, compared with the case where the drive signals COMA, COMB, and COMC include a plurality of trapezoidal waveforms, the period T corresponding to the dot formation period can be shortened, and a higher image formation speed on the medium P can be realized.

[0050] Here, the drive signal COMA is an example of a first drive signal, and the drive signal COMB including a trapezoidal waveform Bdp having a different waveform from the trapezoidal waveform Adp included in the drive signal COMA is an example of a second drive signal. That is, the drive signal COM output from the control unit 10 includes the drive signal COMA and the drive signal COMB having a different waveform from the drive signal COMA.

[0051] Next, the functional configuration and operation of the drive signal selection control circuit 200 will be described with reference to FIGS. 4 to 7. FIG. 4 is a diagram showing the functional configuration of the drive signal selection control circuit 200. As shown in FIG. 4, the drive signal selection control circuit 200 includes a selection control circuit 210 and a plurality of selection circuits 230.

[0052] The selection control circuit 210 receives a print data signal SI, a latch signal LAT, and a clock signal SCK. In addition, the selection control circuit 210 is provided with a set of a shift register (S / R) 212, a latch circuit 214, and a decoder 216 corresponding to each of the n ejection units 600. That is, the drive signal selection control circuit 200 includes a set of n shift registers 212, latch circuits 214, and decoders 216 that is the same as the total number of the ejection units 600.

[0053] Specifically, the print data signal SI is a signal synchronized with the clock signal SCK, and is a total 2n-bit signal including 2-bit print data [SIH, SIL] for selecting any one of "large dot LD", "small dot SD", "non-ejection ND", and "fine vibration BSD" for each of the n ejection units 600. The print data signal SI is held in the shift register 212 for every 2-bit print data [SIH, SIL] included in the print data signal SI corresponding to the ejection unit 600. Specifically, n-stage shift registers 212 corresponding to the ejection units 600 are connected in series to each other, and the serially input print data signal SI is sequentially transferred to the subsequent stage according to the clock signal SCK. In FIG. 4, for the purpose of distinguishing the shift registers 212, they are denoted as the 1st stage, 2nd stage, …, nth stage in order from the upstream side where the print data signal SI is input.

[0054] Each of the n latch circuits 214 latches the 2-bit print data [SIH, SIL] held in each of the n shift registers 212 all at once at the rising edge of the latch signal LAT.

[0055] Each of the n decoders 216 decodes the 2-bit print data [SIH, SIL] latched by each of the n latch circuits 214. Then, the decoder 216 outputs selection signals S1, S2, S3 every period T defined by the latch signal LAT.

[0056] FIG. 5 is a diagram showing the decoding content in the decoder 216. The decoder 216 outputs selection signals S1, S2, S3 according to the latched 2-bit print data [SIH, SIL]. For example, when the 2-bit print data [SIH, SIL] is [1, 0], the decoder 216 outputs the logical levels of the selection signals S1, S2, S3 as L, H, L levels to the corresponding selection circuit 230 in the period T.

[0057] The selection circuit 230 is provided corresponding to each of the ejection units 600. That is, the number of selection circuits 230 included in the drive signal selection control circuit 200 is the same n as the total number of corresponding ejection units 600.

[0058] FIG. 6 is a diagram showing the configuration of the selection circuit 230 corresponding to one of the ejection units 600. As shown in FIG. 6, the selection circuit 230 includes inverters 232a, 232b, 232c which are NOT circuits, and transfer gates 234a, 234b, 234c.

[0059] The selection signal S1 is input to the non-marked positive control terminal of the transfer gate 234a, while being logically inverted by the inverter 232a and input to the marked negative control terminal of the transfer gate 234a. Also, the drive signal COMA is supplied to the input terminal of the transfer gate 234a. Then, when the input selection signal S1 is at the H level, the transfer gate 234a conducts between the input terminal and the output terminal, and when the input selection signal S1 is at the L level, the transfer gate 234a does not conduct between the input terminal and the output terminal.

[0060] Also, the selection signal S2 is input to the non-marked positive control terminal of the transfer gate 234b, while being logically inverted by the inverter 232b and input to the marked negative control terminal of the transfer gate 234b. Also, the drive signal COMB is supplied to the input terminal of the transfer gate 234b. Then, when the input selection signal S2 is at the H level, the transfer gate 234b conducts between the input terminal and the output terminal, and when the input selection signal S2 is at the L level, the transfer gate 234b does not conduct between the input terminal and the output terminal.

[0061] Also, the selection signal S3 is input to the non-marked positive control terminal in the transfer gate 234c, while being logically inverted by the inverter 232c and input to the marked negative control terminal in the transfer gate 234c. Further, a drive signal COMC is supplied to the input terminal of the transfer gate 234c. Then, when the input selection signal S3 is at the H level, the transfer gate 234c conducts between the input terminal and the output terminal, and when the input selection signal S3 is at the L level, the transfer gate 234c does not conduct between the input terminal and the output terminal.

[0062] And the output terminals of the transfer gates 234a, 234b, and 234c are commonly connected. Thereby, signals obtained by selecting or not selecting the drive signals COMA, COMB, and COMC are supplied to the commonly connected output terminals of the transfer gates 234a, 234b, and 234c by switching the transfer gates 234a, 234b, and 234c between conduction and non-conduction. The signal supplied to the commonly connected output terminals of the transfer gates 234a, 234b, and 234c corresponds to the drive signal VOUT.

[0063] The operation of the drive signal selection control circuit 200 will be described with reference to FIG. 7. FIG. 7 is a diagram for explaining the operation of the drive signal selection control circuit 200. The print data signal SI is serially input in synchronization with the clock signal SCK and sequentially transferred in the shift register 212 corresponding to the ejection unit 600. Then, when the input of the clock signal SCK stops, each shift register 212 holds the 2-bit print data [SIH, SIL] corresponding to each of the ejection units 600. Note that the print data signal SI is input in order corresponding to the ejection units 600 of the n-th stage, …, 2nd stage, and 1st stage of the shift register 212.

[0064] Then, when the latch signal LAT rises, each of the latch circuits 214 latches the 2-bit print data [SIH, SIL] held in the shift register 212 all at once. It does. In FIG. 7, LT1, LT2, …, LTn represent 2-bit print data [SIH, SIL] latched by latch circuits 214 corresponding to the 1st, 2nd, …, nth stage shift registers 212.

[0065] Decoder 216 outputs the logic levels of selection signals S1, S2, S3 in period T according to the dot size defined by the latched 2-bit print data [SIH, SIL], as shown in FIG. 5.

[0066] Specifically, when the print data [SIH, SIL] is [1, 1], decoder 216 sets selection signal S1 to the H level, selection signal S2 to the L level, and selection signal S3 to the L level in period T. In this case, selection circuit 230 selects trapezoidal waveform Adp in period T, and as a result, a drive signal VOUT corresponding to "large dot LD" is output.

[0067] Also, when the print data [SIH, SIL] is [1, 0], decoder 216 sets selection signal S1 to the L level, selection signal S2 to the H level, and selection signal S3 to the L level in period T. In this case, selection circuit 230 selects trapezoidal waveform Bdp in period T, and as a result, a drive signal VOUT corresponding to "small dot SD" is output.

[0068] Also, when the print data [SIH, SIL] is [0, 1], the decoder 216 sets the selection signal S1 to the L level, the selection signal S2 to the L level, and the selection signal S3 to the L level at the period T. In this case, the selection circuit 230 does not generate any of the trapezoidal waveforms Adp, Bdp, Cdp at the period T, and as a result, a drive signal VOUT corresponding to "non-ejection ND" is output. Here, the drive signal VOUT corresponding to non-ejection ND has a constant voltage waveform at the voltage Vc. When none of the trapezoidal waveforms Adp, Bdp, Cdp is selected as the drive signal VOUT, the immediately preceding voltage Vc is held by the capacitance component of the piezoelectric element 60. Therefore, since the selection circuit 230 does not select any of the trapezoidal waveforms Adp, Bdp, Cdp, this voltage Vc is supplied to the piezoelectric element 60 as the drive signal VOUT.

[0069] Also, when the print data [SIH, SIL] is [0, 0], the decoder 216 sets the selection signal S1 to the L level, the selection signal S2 to the L level, and the selection signal S3 to the H level at the period T. In this case, the selection circuit 230 selects the trapezoidal waveform Cdp at the period T, and as a result, a drive signal VOUT corresponding to "fine vibration BSD" is output.

[0070] As described above, based on the print data signal SI, the latch signal LAT, and the clock signal SCK, the drive signal selection control circuit 200 selects or does not select the drive signals COMA, COMB, COMC, thereby generating a drive signal VOUT corresponding to each of the plurality of ejection units 600 and outputting it to the corresponding ejection unit 600. That is, based on the print data signal SI, the latch signal LAT, and the clock signal SCK, the drive signal selection control circuit 200 switches whether to supply the drive signals COMA, COMB, COMC to the piezoelectric element 60 as the drive signal VOUT.

[0071] Also, as shown in FIG. 2, the driving signal COMA is output by the driving signal output circuit 52a included in the driving circuit unit 50, the driving signal COMB is output by the driving signal output circuit 52b included in the driving circuit unit 50, and the driving signal COMC is output by the driving signal output circuit 52c included in the driving circuit unit 50. At least one of the driving signal output circuit 52a that outputs this driving signal COMA and the driving signal output circuit 52b that outputs the driving signal COMB is an example of a driving signal output circuit.

[0072] 3. Structure of the liquid ejection head Next, the structure of the head module 21 will be described. FIG. 8 is an exploded perspective view of the head module 21. In FIG. 8, arrows indicating the X direction, Y direction, and Z direction perpendicular to each other are illustrated. Also, in the following description, the starting side of the arrow indicating the X direction may be referred to as the -X side, the tip side may be referred to as the +X side, the starting side of the arrow indicating the Y direction may be referred to as the -Y side, the tip side may be referred to as the +Y side, and the starting side of the arrow indicating the Z direction may be referred to as the -Z side, and the tip side may be referred to as the +Z side.

[0073] As shown in FIG. 8, the head module 21 includes a housing 31, a collective substrate 33, a flow path structure 34, a head substrate 35, a flow path distribution unit 37, and a fixing plate 39. Then, the flow path structure 34, the head substrate 35, the flow path distribution unit 37, and the fixing plate 39 are located in the order of the fixing plate 39, the flow path distribution unit 37, the head substrate 35, and the flow path structure 34 from the -Z side to the +Z side in the direction along the Z direction, and the housing 31 is located around the flow path structure 34, the head substrate 35, the flow path distribution unit 37, and the fixing plate 39 so as to support them, and the collective substrate 33 stands upright in a state of being held by the housing 31 on the +Z side of the housing 31, whereby the head module 21 is configured.

[0074] Also, as shown in FIG. 8, the head module 21 has a plurality of ejection modules 23. The plurality of ejection modules 23 are located between the flow path distribution unit 37 and the fixed plate 39 and are positioned such that a part thereof is exposed outside the head module 21. FIG. 8 illustrates a case where the head module 21 has six ejection modules 23. In the following description, when it is necessary to distinguish each of the six ejection modules 23, they may be referred to as ejection modules 23-1 to 23-6. Note that the number of ejection modules 23 included in the head module 21 is not limited to six.

[0075] In explaining the details of the configuration of the head module 21 in the present embodiment, first, a specific example of the configuration of the ejection module 23 included in the head module 21 will be described. FIG. 9 is an exploded perspective view of the ejection module 23, and FIG. 10 is a cross-sectional view when the ejection module 23 shown in FIG. 9 is cut along line A-a. Here, the line A-a shown in FIG. 9 is a virtual line segment that passes through the introduction path 661 included in the ejection module 23 and passes through the nozzles N1 and N2.

[0076] As shown in FIGS. 9 and 10, the ejection module 23 has a plurality of nozzles N1 arranged in parallel and a plurality of nozzles N2 arranged in parallel. The total number of the plurality of nozzles N1 and the plurality of nozzles N2 included in this ejection module 23 is n, which is the same number as the ejection part 600 included in the ejection module 23. In the present embodiment, the description will be made assuming that the number of nozzles N1 and nozzles N2 included in the ejection module 23 is the same. That is, the ejection module 23 has n / 2 nozzles N1 and n / 2 nozzles N2. In the following description, when it is not necessary to distinguish between the nozzles N1 and N2, they may simply be referred to as nozzles N.

[0077] As shown in FIGS. 9 and 10, the ejection module 23 has a wiring member 388, a case 660, a protection substrate 641, a flow path forming substrate 642, a communication plate 630, a compliance substrate 620, and a nozzle plate 623. And each member included in the ejection module 23 is laminated along the Z direction and joined by an adhesive or the like.

[0078] On the flow path forming substrate 642, pressure chambers CB1 partitioned by a plurality of partition walls by anisotropic etching from one surface side are arranged in parallel corresponding to the nozzles N1, and pressure chambers CB2 partitioned by a plurality of partition walls by anisotropic etching from one surface side are arranged in parallel corresponding to the nozzles N2. That is, on the flow path forming substrate 642, a row of pressure chambers CB1 arranged in parallel corresponding to n / 2 nozzles N1 and a row of pressure chambers CB2 arranged in parallel corresponding to n / 2 nozzles N2 are provided. Here, in the following description, when there is no need to distinguish between the pressure chamber CB1 and the pressure chamber CB2, it may simply be referred to as the pressure chamber CB. Further, on the flow path forming substrate 642, a supply path or the like for imparting a flow path resistance to the ink flowing into the pressure chamber CB may be provided on one end side of the pressure chamber CB, which has a smaller opening area than the pressure chamber CB.

[0079] The nozzle plate 623 is located on the -Z side of the flow path forming substrate 642. The nozzle plate 623 is provided with a nozzle row Ln1 formed by n / 2 nozzles N1 and a nozzle row Ln2 formed by n / 2 nozzles N2. Here, in the following description, the surface on the -Z side of the nozzle plate 623 where the nozzle N opens may be referred to as the liquid ejection surface 623a.

[0080] On the -Z side of the flow path forming substrate 642 and on the +Z side of the nozzle plate 623, a communication plate 630 is positioned. The communication plate 630 is provided with a nozzle communication path RR1 that communicates the pressure chamber CB1 and the nozzle N1, and a nozzle communication path RR2 that communicates the pressure chamber CB2 and the nozzle N2. Further, the communication plate 630 is provided with a pressure chamber communication path RK1 that communicates the end of the pressure chamber CB1 and a manifold MN1 described later, and a pressure chamber communication path RK2 that communicates the end of the pressure chamber CB2 and a manifold MN2 described later, which are independently provided corresponding to each of the pressure chambers CB1 and CB2. That is, the communication plate 630 is provided with a row of nozzle communication paths RR1 corresponding to n / 2 parallel nozzles N1 and the pressure chamber CB1, and a row of pressure chamber communication paths RK1, and a row of nozzle communication paths RR2 corresponding to n / 2 parallel nozzles N2 and the pressure chamber CB2, and a row of pressure chamber communication paths RK2.

[0081] Also, the communication plate 630 includes the manifolds MN1 and MN2. The manifold MN1 includes a supply communication path RA1 and a connection communication path RX1. The supply communication path RA1 is provided penetrating the communication plate 630 in the Z direction, and the connection communication path RX1 is provided opening to the nozzle plate 623 side of the communication plate 630 without penetrating the communication plate 630 in the Z direction and extending to the middle in the Z direction. Similarly, the manifold MN2 includes a supply communication path RA2 and a connection communication path RX2. The supply communication path RA2 is provided penetrating the communication plate 630 in the Z direction, and the connection communication path RX2 is provided opening to the nozzle plate 623 side of the communication plate 630 without penetrating the communication plate 630 in the Z direction and extending to the middle in the Z direction. Then, the connection communication path RX1 included in the manifold MN1 is communicated with the corresponding pressure chamber CB1 by the pressure chamber communication path RK1, and the connection communication path RX2 included in the manifold MN2 is communicated with the corresponding pressure chamber CB2 by the pressure chamber communication path RK2.

[0082] Here, in the following description, when there is no need to distinguish between the nozzle connection passage RR1 and the nozzle connection passage RR2, it may simply be referred to as the nozzle connection passage RR. Also, when there is no need to distinguish between the manifold MN1 and the manifold MN2, it may simply be referred to as the manifold MN, when there is no need to distinguish between the supply connection passage RA1 and the supply connection passage RA2, it may simply be referred to as the supply connection passage RA, and when there is no need to distinguish between the connection connection passage RX1 and the connection connection passage RX2, it may simply be referred to as the connection connection passage RX.

[0083] On the +Z side surface of the flow path forming substrate 642, the diaphragm 610 is positioned. Also, on the +Z side surface of the diaphragm 610, piezoelectric elements 60 are formed in two rows corresponding to the nozzles N1, N2. One electrode of the piezoelectric element 60 and the piezoelectric layer are formed for each pressure chamber CB, and the other electrode is configured as a common electrode common to the pressure chambers CB. Then, a drive signal VOUT is supplied from the drive signal selection control circuit 200 to one electrode of the piezoelectric element 60, and a reference voltage signal VBS is supplied to the other electrode, which is the common electrode.

[0084] Also, on the +Z side surface of the flow path forming substrate 642, a protection substrate 641 having substantially the same size as the flow path forming substrate 642 is joined. The protection substrate 641 forms a holding portion 644, which is a space for protecting the piezoelectric element 60. Also, the protection substrate 641 is provided with a through hole 643 that penetrates along the Z direction. The end portion of the lead electrode 611 drawn from the electrode of the piezoelectric element 60 extends so as to be exposed within this through hole 643. A wiring member 388 is electrically connected to the end portion of the lead electrode 611 exposed within this through hole 643.

[0085] In addition, a case 660 that defines a part of a manifold MN communicating with a plurality of pressure chambers CB is fixed to the protective substrate 641 and the communication plate 630. The case 660 has substantially the same shape as the communication plate 630 in plan view, is joined to the protective substrate 641, and is also joined to the communication plate 630. Specifically, the case 660 has a recess 665 on the -Z side surface with a depth in which the flow path forming substrate 642 and the protective substrate 641 are accommodated. This recess 665 has an opening area wider than the surface where the protective substrate 641 is joined to the flow path forming substrate 642. Then, with the flow path forming substrate 642 and the like accommodated in the recess 665, the opening surface on the -Z side of the recess 665 is sealed by the communication plate 630. Thereby, on the outer peripheral portion of the flow path forming substrate 642, a supply communication path RB1 and a supply communication path RB2 are defined by the case 660, the flow path forming substrate 642, and the protective substrate 641. Here, when there is no need to distinguish between the supply communication path RB1 and the supply communication path RB2, it may simply be referred to as the supply communication path RB.

[0086] In addition, a compliance substrate 620 is provided on the surface of the communication plate 630 where the supply communication path RA and the connection communication path RX open. The compliance substrate 620 seals the openings of the supply communication path RA and the connection communication path RX. Such a compliance substrate 620 has a sealing film 621 and a fixed substrate 622. The sealing film 621 is formed of a flexible thin film or the like, and the fixed substrate 622 is formed of a hard material such as metal like stainless steel.

[0087] In addition, the case 660 is provided with an introduction path 661 for supplying ink to the manifold MN. The case 660 is also provided with a connection port 662 through which a wiring member 388 is inserted in communication with the through hole 643 of the protective substrate 641. The connection port 662 is an opening penetrating along the Z direction.

[0088] The wiring member 388 is a flexible substrate for electrically connecting the ejection module 23 and a head substrate 35 described later, and is, for example, a flexible substrate such as an FPC (Flexible Printed Circuits). On this wiring member 388, a drive signal selection control circuit 200 composed of, for example, an integrated circuit is mounted by COF (Chip On Film).

[0089] In the ejection module 23 configured as described above, a drive signal VOUT output from the drive signal selection control circuit 200 and a reference voltage signal VBS are supplied to the piezoelectric element 60 via the wiring member 388. The piezoelectric element 60 is driven by a change in the potential of the drive signal VOUT. As the piezoelectric element 60 is driven, the diaphragm 610 deforms in the vertical direction, and the internal pressure of the pressure chamber CB changes. Due to this change in the internal pressure of the pressure chamber CB, the ink stored inside the pressure chamber CB is ejected from the corresponding nozzle N. In the ejection module 23 configured as described above, the configuration including the nozzle N, the nozzle communication passage RR, the pressure chamber CB, the piezoelectric element 60, and the diaphragm 610 corresponds to the ejection unit 600. That is, the ejection unit 600 includes the piezoelectric element 60 driven by the drive signal VOUT based on the drive signals COMA, COMB, and ejects ink in response to the drive of the piezoelectric element 60.

[0090] Returning to FIG. 8, the fixing plate 39 is located on the -Z side of the ejection module 23. The fixing plate 39 has six exposed openings 391 penetrating the fixing plate 39 in the Z direction. And six ejection modules 23 are fixed to the fixing plate 39 so that the liquid ejection surfaces 623a included in the six ejection modules 23 are exposed from the respective six exposed openings 391.

[0091] The flow path distribution unit 37 is located on the +Z side of the ejection module 23. The + of the flow path distribution unit 37 On the surface on the Z side, four connection parts 373 for introduction are provided. The four connection parts 373 for introduction are flow path tubes that protrude in the +Z direction along the Z direction from the surface on the +Z side of the flow path distribution part 37, and communicate with flow path holes (not shown) formed on the surface on the -Z side of a flow path structure body 34 described later. Also, on the surface on the -Z side of the flow path distribution part 37, there are located flow path tubes (not shown) that communicate with the corresponding connection parts 373 for introduction among the four connection parts 373 for introduction. The flow path tubes (not shown) located on the surface on the -Z side of this flow path distribution part 37 are connected to the introduction paths 661 each of the six discharge modules 23 has. Further, the flow path distribution part 37 has six openings 371 that penetrate in the Z direction. Wiring members 388 each of the six discharge modules 23 has are inserted into the six openings 371.

[0092] The head substrate 35 is located on the +Z side of the flow path distribution part 37. The head substrate 35 is provided with a connector CN1 that is electrically connected to an assembly substrate 33 described later, and a cable FC. Also, four openings 351 and two cutouts 353 are formed in the head substrate 35. Wiring members 388 that the discharge modules 23-2 to 23-5 have are inserted into the four openings 351. And each of the wiring members 388 of the discharge modules 23-2 to 23-5 that have passed through the four openings 351 is electrically connected to the head substrate 35 by solder or the like. Also, a wiring member 388 that the discharge module 23-1 has passes through one of the two cutouts 353, and a wiring member 388 that the discharge module 23-6 has passes through the other of the two cutouts 353. And each of the wiring members 388 that the discharge modules 23-1 and 23-6 that have passed through each of the two cutouts 353 have is electrically connected to the head substrate 35 by solder or the like. That is, the head substrate 35 branches the signals input via the connector CN1 and the cable FC corresponding to each of the discharge modules 23-1 to 23-6, and outputs the signals output by each of the discharge modules 23-1 to 23-6 to the assembly substrate 33 described later via the connector CN1 and the cable FC.

[0093] In addition, four notches 355 are formed at the four corners of the head substrate 35. Four introduction connection parts 373 of the flow path distribution part 37 located on the -Z side of the head substrate 35 pass through the four notches 355. Then, the four introduction connection parts 373 that have passed through the notches 355 are connected to the flow path structure 34 located on the +Z side of the head substrate 35.

[0094] The flow path structure 34 is located on the +Z side of the head substrate 35. The flow path structure 34 has a flow path plate Su1 and a flow path plate Su2 laminated along the Z direction. The flow path plate Su1 and the flow path plate Su2 are joined to each other by an adhesive or the like with the flow path plate Su1 positioned on the +Z side and the flow path plate Su2 positioned on the -Z side. Such flow path plates Su1 and Su2 are formed, for example, by injection molding of resin.

[0095] In addition, the flow path structure 34 has four supply connection parts 341 which are flow path tubes protruding toward the +Z side along the Z direction on the +Z side surface. The four supply connection parts 341 communicate with a flow path hole (not shown) formed on the -Z side surface of the flow path structure 34 of the flow path structure 34 via an ink flow path formed inside the flow path structure 34. Further, a through hole 343 penetrating along the Z direction is formed in the flow path structure 34. A connector CN1 and a cable FC provided on the head substrate 35 are inserted through the through hole 343. Note that inside the flow path structure 34, in addition to the ink flow path that connects the supply connection parts 341 and the flow path hole (not shown) formed on the -Z side surface, a filter or the like for catching foreign matter contained in the ink may be provided.

[0096] The housing 31 is positioned so as to cover the periphery of the flow path structure 34, the head substrate 35, the flow path distribution part 37, and the fixing plate 39, and supports the flow path structure 34, the head substrate 35, the flow path distribution part 37, and the fixing plate 39. The housing 31 has four supply holes 311, a collective substrate insertion part 313, and holding members 315, 317.

[0097] Each of the four supply holes 311 has inserted therein four supply connection parts 341 of the flow path structure 34. Then, ink is supplied from the liquid container 2 to the four supply connection parts 341 that have passed through the four supply holes 311 via a tube or the like (not shown).

[0098] The holding members 315 and 317 sandwich and hold the assembly substrate 33 in a state where a part of the assembly substrate 33 passes through the assembly substrate insertion part 313. Connectors CN1 and 330 are provided on the assembly substrate 33. Various signals such as a data signal DATA, drive signals COMA, COMB, COMC, a reference voltage signal VBS, and other power supply voltages output by the control unit 10 are input to the connector 330. The connector CN1 passes through the assembly substrate insertion part 313 of the housing 31 together with the assembly substrate 33 and is electrically connected to the connector CN2 of the head substrate 35. Further, a cable FC of the head substrate 35 is electrically connected to the assembly substrate 33. Thereby, the assembly substrate 33 and the head substrate 35 are electrically connected. Details of the electrical connection between the assembly substrate 33 and the head substrate 35 will be described later.

[0099] In the head module 21 configured as described above, the liquid container 2 and the supply connection part 341 communicate with each other via a tube or the like (not shown), so that the ink stored in the liquid container 2 is supplied to the head module 21. Then, the ink supplied to the head module 21 is guided to a flow path hole (not shown) formed on the -Z side surface of the flow path structure 34 via the ink flow path formed inside the flow path structure 34. The ink guided to the flow path hole (not shown) formed on the -Z side surface of the flow path structure 34 is supplied to the four introduction connection parts 373 of the flow path distribution part 37.

[0100] The ink supplied to the flow path distribution unit 37 through the four introduction connection parts 373 is distributed corresponding to each of the six ejection modules 23 in an ink flow path (not shown) formed inside the flow path distribution unit 37, and then supplied to the introduction path 661 included in the corresponding ejection module 23. Then, the ink supplied to the ejection module 23 through the introduction path 661 is stored in the pressure chamber CB included in the ejection unit 600.

[0101] Also, the control unit 10 and the head module 21 are electrically connected by a cable (not shown). Then, various signals including drive signals COMA, COMB, COMC, a reference voltage signal VBS, and a data signal DATA are input to the head module 21 from the control unit 10 through the cable. The various signals including the drive signals COMA, COMB, COMC, the reference voltage signal VBS, and the data signal DATA input to the head module 21 propagate through the assembly substrate 33 and the head substrate 35 and are supplied to the ejection module 23. Then, in the ejection module 23, drive signals VOUT based on the drive signals COMA, COMB, COMC corresponding to each of the n and the ejection unit 600 and the data signal DATA are generated and supplied to the piezoelectric element 60 included in the corresponding ejection unit 600. As a result, the piezoelectric element 60 is driven based on the drive signal VOUT. Then, the ink stored in the pressure chamber CB included in the ejection unit 600 is ejected according to the drive of the piezoelectric element 60.

[0102] 4. Electrical Connection between the Assembly Substrate and the Head Substrate Here, in the head module 21, a specific example of the propagation path of various signals including the electrical connection between the assembly substrate 33 and the head substrate 35, and the clock signal SCK, the print data signal SI, and the latch signal LAT, and the drive signals COMA, COMB, COMC will be described. FIG. 11 is a diagram showing an example of the electrical connection between the assembly substrate 33 and the head substrate 35 when the head module 21 is viewed from the direction along the Z direction, FIG. 12 is a diagram showing an example of the electrical connection between the assembly substrate 33 and the head substrate 35 when the head module 21 is viewed from the direction along the Y direction, and FIG. 13 is a diagram showing the view when the head module 21 is viewed from the direction along the X direction It is a diagram showing an example of the electrical connection between the integrated substrate 33 and the head substrate 35 in a case.

[0103] As shown in FIGS. 11 to 13, the head substrate 35 has a surface 35a and a surface 35b. And the head substrate 35 extends along a plane formed by the X direction and the Y direction for the surfaces 35a and 35b, and is positioned such that the surface 35a is on the +Z side and the surface 35b is on the -Z side. At the central part of the head substrate 35, four openings 351 penetrating the surface 35a and the surface 35b are formed side by side along the X direction. Further, cutouts 353 are formed on each of the +X side of the four openings 351 formed side by side and the -X side of the four openings 351 formed side by side. That is, on the head substrate 35, two cutouts 353 and four openings 351 are formed in the direction along the X direction, and four openings 351 are formed between the two cutouts 353.

[0104] And, as described above, the head substrate 35 is electrically connected to six ejection modules 23 via a wiring member 388 that passes through the two cutouts 353 and the four openings 351 formed in the head substrate 35. That is, the head substrate 35 propagates drive signals COMA, COMB, COMC, a print data signal SI, a latch signal LAT, and a clock signal SCK to an ejection unit 600 included in the ejection module 23. This head substrate 35 is an example of a first substrate.

[0105] Also, on the -Y side of the four openings 351 positioned side by side along the X direction, connectors CN1, CN2, a cable FC, and the integrated substrate 33 are positioned.

[0106] The integrated substrate 33 has a surface 33a and a surface 33b. The integrated substrate 33 extends along a plane formed by the X direction and the Z direction for both the surface 33a and the surface 33b, and is positioned such that the surface 33a is on the +Y side and the surface 33b is on the -Y side. That is, the integrated substrate 33 and the head substrate 35 are positioned so that the surface 33a of the integrated substrate 33 intersects the surface 35a of the head substrate 35. Two connectors 330 are provided on the integrated substrate 33. Along the side of the integrated substrate 33 on the +Z side, one connector 330 is provided on the surface 33a and the other connector 330 is provided on the surface 33b. A cable (not shown) that is electrically connected to the control unit 10 is attached to these two connectors 330. Here, as the cable attached to the connector 330, for example, a flexible flat cable (FFC: Flexible Flat Cable) is used.

[0107] The cable FC, and the connectors CN1 and CN2 electrically connect the integrated substrate 33 and the head substrate 35.

[0108] One end of the cable FC is electrically connected to the surface 35a of the head substrate 35, and the other end is electrically connected to the surface 33a of the integrated substrate 33. Then, the cable FC supplies the signal propagated through the integrated substrate 33 to the head substrate 35. As such a cable FC, for example, a flexible printed circuit (FPC: Flexible Printed Circuit) in which a plurality of propagation wirings are formed is used. Generally, an FPC is formed by forming a copper foil with a thickness of 10 μm to 20 μm on a base material such as a pet film or a polyimide film with a thickness of 10 μm to 50 μm, and performing an etching process or the like on the copper foil to form a wiring pattern with a thickness of 30 μm to 150 μm on the base material. And the FPC is configured by protecting the wiring pattern formed on the substrate with a film such as a polyimide film or a solder resist with a thickness of 10 μm to 50 μm. That is, the FPC has a fine wiring pattern with a cross-sectional area of 0.0003 to 0.0025 mm 2 formed at a high density.

[0109] Such an FPC, in addition to the above-described base material, wiring pattern, and coating, includes an adhesive for bonding them, and has a very thin thickness generally of 100 μm or less. Therefore, it can be bent and can electrically connect the substrate to be connected with a high degree of freedom. Furthermore, as described above, the FPC can form a high-density wiring pattern, and even when bent, the change rate of the electrical characteristics of the wiring pattern is small. Therefore, it is possible to transmit many signals with a high degree of reliability.

[0110] As described above, the cable FC includes a wiring pattern for electrically connecting the integrated substrate 33 and the head substrate 35. Here, the cable FC may electrically connect the head substrate 35 and the integrated substrate 33 by being connected to the head substrate 35 and the integrated substrate 33 by, for example, solder or the like, or may electrically connect the head substrate 35 and the integrated substrate 33 by being electrically connected to the head substrate 35 and the integrated substrate 33 via a connector (not shown).

[0111] The connector CN1 is electrically connected to the surface 33b of the integrated substrate 33. Also, the connector CN2 is located on the -Y side of the integrated substrate 33 and is electrically connected to the surface 35a of the head substrate 35. Then, by fitting the connector CN1 and the connector CN2 together, the connector CN1 and the connector CN2 are electrically connected, and the integrated substrate 33 provided with the connector CN1 and the head substrate 35 provided with the connector CN2 are electrically connected. That is, the connectors CN1 and CN2 are directly fitted together without passing through a cable or the like to electrically connect the integrated substrate 33 and the head substrate 35.

[0112] Here, a specific example of the structures of the connectors CN1 and CN2 will be described. In this embodiment, the description will be given assuming that the connector CN1 is a male connector of the right angle type and the connector CN2 is a female connector of the straight type. However, the connector CN1 may be a female connector and the connector CN2 may be a male connector. Also, the connector CN1 may be of the straight type and the connector CN2 may be of the right angle type. Furthermore, the assembly substrate 33 and the head substrate 35 may be stack-connected. In this case, both of the connectors CN1 and CN2 may be of the straight type.

[0113] An example of the structure of the connector CN1 will be described with reference to FIGS. 14 to 16. In describing the structure of the connector CN1 with reference to FIGS. 14 to 16, FIGS. 14 to 16 illustrate arrows indicating the P1 direction, the Q1 direction, and the R1 direction that are perpendicular to each other. Also, in the following description, the starting side of the arrow indicating the P1 direction may be referred to as the -P1 side and the tip side may be referred to as the +P1 side, the starting side of the arrow indicating the Q1 direction may be referred to as the -Q1 side and the tip side may be referred to as the +Q1 side, and the starting side of the arrow indicating the R1 direction may be referred to as the -R1 side and the tip side may be referred to as the +R1 side.

[0114] FIG. 14 is a diagram showing an example of the structure of the connector CN1 when viewed from the direction along the Q1 direction, FIG. 15 is a diagram showing an example of the structure of the connector CN1 when viewed from the direction along the R1 direction, and FIG. 16 is a diagram showing an example of the structure of the connector CN1 when viewed from the direction along the P1 direction.

[0115] As shown in FIGS. 14 to 16, the connector CN1 includes insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p, substrate connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p, and a holding member 420.

[0116] The insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p are rectangular connection pins having conductivity with one side being the width pw, and each extends from the side surface on the -R1 side of the connector CN1 toward the -R1 side. Note that the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p may be connection pins on a cylinder having conductivity with a diameter of the width pw.

[0117] In the direction along the P1 direction, the insertion pins 410a-1 to 410a-p are arranged at equal intervals, separated by a pitch distance ph1 in the order of the insertion pins 410a-1, 410a-2,..., 410a-p from the -P1 side to the +P1 side. The insertion pins 410b-1 to 410b-p are located on the -Q1 side of the insertion pins 410a-1 to 410a-p arranged along the P1 direction, and in the direction along the P1 direction, they are arranged at equal intervals, separated by a pitch distance ph1 in the order of the insertion pins 410b-1, 410b-2,..., 410b-p from the -P1 side to the +P1 side. Here, being arranged at equal intervals separated by the pitch distance ph1 includes cases where it can be regarded as equal intervals including variations and the like.

[0118] Also, the insertion pin 410a-1 and the insertion pin 410b-1 are arranged separated by a pitch distance ph2 in the direction along the Q1 direction, the insertion pin 410a-p and the insertion pin 410b-p are arranged separated by a pitch distance ph2 in the direction along the Q1 direction, and the insertion pin 410a-i (where i is any of 1 to p) and the insertion pin 410b-i are arranged separated by a pitch distance ph2 in the direction along the Q1 direction.

[0119] Here, in the connector CN1 of the present embodiment, the shortest distance between the insertion pin 410a-i and the insertion pin 410a-i + 1 adjacent to the insertion pin 410a-i is preferably 1 mm or more, and the cross-sectional areas of the insertion pin 410a-i and the insertion pin 410a-i + 1 are 0.1 mm 2It is preferably as described above. Further, it is preferable that the insertion pins 410a-i and 410a-i+1 are positioned such that the shortest distance between the insertion pin 410a-i and the insertion pin 410a-i+1 is at least three times the width pw of the insertion pin 410a-i and the insertion pin 410a-i+1.

[0120] In the connector CN1, as an example where the arrangement and dimensions of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p satisfy the above conditions, the pitch distance ph1 and the pitch distance ph2 are 2.54 mm, and the width pw of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p is 0.635 mm. In this case, the shortest distance between the insertion pin 410a-i and the insertion pin 410a-i+1 adjacent to the insertion pin 410a-i is "2.54 mm - 0.635 mm = 1.905 mm", and the cross-sectional area of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p is "0.635 mm × 0.635 mm = 0.403 mm 2 ". Note that the pitch distance ph1 and the pitch distance ph2 are not limited to 2.54 mm, and the width pw of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p is not limited to 0.635 mm.

[0121] The board connection terminals 411a-1 to 411a-p and 411b-1 to 411b-p are conductive members provided on the side surface of the +Q1 side of the connector CN1 and extending so as to protrude toward the +Q1 side along the Q1 direction. When the board connection terminals 411a-1 to 411a-p and 411b-1 to 411b-p are inserted into the assembly board 33 and connected to the assembly board 33 by solder or the like, the connector CN1 is electrically connected to the assembly board 33.

[0122] The substrate connection terminals 411a-1 to 411a-p are provided corresponding to each of the insertion pins 410a-1 to 410a-p. And each of the substrate connection terminals 411a-1 to 411a-p and each of the insertion pins 410a-1 to 410a-p are electrically connected via the internal electrodes 413a-1 to 413a-p. Specifically, the substrate connection terminal 411a-1 is electrically connected to the insertion pin 410a-1 via the internal electrode 413a-1, the substrate connection terminal 411a-p is electrically connected to the insertion pin 410a-p via the internal electrode 413a-p, and the substrate connection terminal 411a-i is electrically connected to the insertion pin 410a-i via the internal electrode 413a-i.

[0123] The substrate connection terminals 411b-1 to 411b-p are provided corresponding to each of the insertion pins 410b-1 to 410b-p. And each of the substrate connection terminals 411b-1 to 411b-p and each of the insertion pins 410b-1 to 410b-p are electrically connected via the internal electrodes 413b-1 to 413b-p. Specifically, the substrate connection terminal 411b-1 is electrically connected to the insertion pin 410b-1 via the internal electrode 413b-1, the substrate connection terminal 411b-p is electrically connected to the insertion pin 410b-p via the internal electrode 413b-p, and the substrate connection terminal 411b-i is electrically connected to the insertion pin 410b-i via the internal electrode 413b-i.

[0124] Also, the substrate connection terminals 411a-1 to 411a-p are arranged in the order of the substrate connection terminals 411a-1, 411a-2, …, 411a-p from the -P1 side to the +P1 side in the direction along the P1 direction, and the substrate connection terminals 411b-1 to 411b-p are located on the +R1 side of the substrate connection terminals 411a-1, 411a-2, …, 411a-p arranged in the direction along the P1 direction, and are arranged in the order of the substrate connection terminals 411b-1, 411b-2, …, 411b-p from the -P1 side to the +P1 side in the direction along the P1 direction. And the substrate connection terminal 411a-1 and the substrate connection terminal 411b-1 are arranged side by side in the direction along the R1 direction, the substrate connection terminal 411a-p and the substrate connection terminal 411b-p are arranged side by side in the direction along the R1 direction, and the substrate connection terminal 411a-i and the substrate connection terminal 411b-i are arranged side by side in the direction along the R1 direction.

[0125] The holding member 420 holds the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p and the substrate connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p, and also functions as an insulating member that insulates between the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p and between the substrate connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p.

[0126] As such a holding member 420, it is preferable to use a polybutylene terephthalate (PBT) resin. In the liquid ejection device 1, a part of the ink ejected from the ejection unit 600 may be atomized before landing on the medium P and float as ink mist inside the liquid ejection device 1. Since such ink mist floating inside the liquid ejection device 1 is very minute, it is charged by the Lenard effect. Therefore, there is a high possibility that the ink mist floating inside the liquid ejection device 1 adheres to the vicinity of the connector of the head module 21 where various signals propagate, which is in the vicinity of the ejection unit 600 where the ink is ejected.

[0127] In particular, in the liquid ejection device 1, inks with various physical properties can be used depending on the type and application of the medium. Therefore, it is required that the characteristics of the connectors included in the head module 21 are hardly changed even when various types of solvents adhere thereto. By using a PBT resin, which has excellent insulation performance, a low water absorption rate, and excellent oil resistance and solvent resistance, as the holding member 420 of the connector CN1 included in the head module 21, even when the ink used in the liquid ejection device 1 adheres to the connector CN1, the possibility of the characteristics of the holding member 420 changing is reduced. Accordingly, the possibility of the characteristics of the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p and the board connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p held by the holding member 420 changing is also reduced. As a result, the stability of various signals propagated by the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p and the board connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p is improved. That is, since the holding member 420 of the connector CN1 contains a PBT resin, the reliability of various signals propagated by the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p and the board connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p is improved. The reliability of various signals is improved.

[0128] The connector CN1 configured as described above is a so-called pin header having insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p including insertion pins 410a-i and 410a-i+1, and a holding member 420 that holds the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p in a state of being insulated from each other. The connector CN1 is provided on the assembly substrate 33 such that each of the P1 direction, Q1 direction, and R1 direction shown in FIGS. 14 to 16 is along each of the X direction, Y direction, and Z direction shown in FIGS. 11 to 13. Here, the insertion pin 410a-i is an example of a first insertion pin, the insertion pin 410a-i+1 is an example of a second insertion pin, the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p including the insertion pins 410a-i and 410a-i+1 are an example of a plurality of insertion pins, and the holding member 420 is an example of a holding portion.

[0129] Next, an example of the structure of the connector CN2 will be described with reference to FIGS. 17 to 19. In describing the structure of the connector CN2 with reference to FIGS. 17 to 19, FIGS. 17 to 19 illustrate arrows indicating the P2 direction, Q2 direction, and R2 direction that are perpendicular to each other. Also, in the following description, the starting side of the arrow indicating the P2 direction may be referred to as the -P2 side and the tip side as the +P2 side, the starting side of the arrow indicating the Q2 direction may be referred to as the -Q2 side and the tip side as the +Q2 side, and the starting side of the arrow indicating the R2 direction may be referred to as the -R2 side and the tip side as the +R2 side.

[0130] FIG. 17 is a diagram showing an example of the structure of the connector CN2 when viewed in the direction along the Q2 direction, FIG. 18 is a diagram showing an example of the structure of the connector CN2 when viewed in the direction along the R2 direction, and FIG. 19 is a diagram showing an example of the structure of the connector CN2 when viewed in the direction along the P2 direction.

[0131] As shown in FIGS. 17 to 19, the connector CN2 has insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p, board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p, and a holding member 460.

[0132] The insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p are recesses that open on the side surface of the +R2 side of the connector CN2 and are formed from the opening along the R2 direction toward the -R1 side. Inside each recess formed as the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p, a conductive member (not shown) is provided.

[0133] The insertion holes 450a-1 to 450a-p are arranged at equal intervals, separated by a pitch distance ps1, in the order of insertion holes 450a-1, 450a-2,..., 450a-p from the -P2 side to the +P2 side in the direction along the P2 direction. The insertion holes 450b-1 to 450b-p are arranged at equal intervals, separated by a pitch distance ps1, in the order of insertion holes 450b-1, 450b-2,..., 450b-p from the -P2 side to the +P2 side in the direction along the P2 direction on the -Q2 side of the insertion holes 450a-1 to 450a-p arranged along the P2 direction. Here, being arranged at equal intervals separated by the pitch distance ps1 includes cases where it can be regarded as equal intervals including variations and the like.

[0134] Also, the insertion hole 450a-1 and the insertion hole 450b-1 are arranged separated by a pitch distance ps2 in the direction along the Q2 direction, the insertion hole 450a-p and the insertion hole 450b-p are arranged separated by a pitch distance ps2 in the direction along the Q2 direction, and the insertion hole 450a-i and the insertion hole 450b-i are arranged separated by a pitch distance ps2 in the direction along the Q2 direction.

[0135] The board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p are each It is a conductive member provided on the side surface of the -R2 side of the connector CN2 and extending so as to protrude toward the -R2 side along the R2 direction. When these substrate connection terminals 451a-1 to 451a-p and 451b-1 to 451b-p are inserted into the head substrate 35 and connected to the head substrate 35 by solder or the like, the connector CN2 is electrically connected to the head substrate 35.

[0136] The substrate connection terminals 451a-1 to 451a-p are provided corresponding to the respective insertion holes 450a-1 to 450a-p, and are electrically connected to a conductive portion (not shown) provided inside each of the insertion holes 450a-1 to 450a-p. Specifically, the substrate connection terminal 451a-1 is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450a-1, the substrate connection terminal 451a-p is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450a-p, and the substrate connection terminal 451a-i is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450a-i.

[0137] Also, the substrate connection terminals 451b-1 to 451b-p are provided corresponding to the respective insertion holes 450b-1 to 450b-p, and are electrically connected to a conductive portion (not shown) provided inside each of the insertion holes 450b-1 to 450b-p. Specifically, the substrate connection terminal 451b-1 is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450b-1, the substrate connection terminal 451b-p is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450b-p, and the substrate connection terminal 451b-i is electrically connected to a conductive portion (not shown) provided inside the insertion hole 450b-i.

[0138] The substrate connection terminals 451a-1 to 451a-p are arranged in the order of the substrate connection terminals 451a-1, 451a-2, …, 451a-p from the -P2 side to the +P2 side in the direction along the P2 direction, and the substrate connection terminals 451b-1 to 451b-p are arranged in the order of the substrate connection terminals 451b-1, 451b-2, …, 451b-p from the -P2 side to the +P2 side in the direction along the P2 direction. The substrate connection terminal 451a-1 and the substrate connection terminal 451b-1 are arranged side by side in the direction along the Q2 direction, the substrate connection terminal 451a-p and the substrate connection terminal 451b-p are arranged side by side in the direction along the Q2 direction, and the substrate connection terminal 451a-i and the substrate connection terminal 451b-i are arranged side by side in the direction along the Q2 direction.

[0139] The holding member 460 holds the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and the substrate connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p, and also functions as an insulating member that insulates between the conductive members provided inside each of the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and between the substrate connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p.

[0140] Such a holding member 460 preferably also contains PBT resin, similar to the holding member 420 of the connector CN1. Thereby, even when ink adheres to the connector CN2, the possibility of a change in the properties of the holding member 460 is reduced, and the possibility of a change in the properties of the insertion holes 450a-1 to 540a-p, 450b-1 to 450b-p and the board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p held by the holding member 460 is also reduced. As a result, the stability of the conductive members formed inside the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and various signals propagated through the board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p is improved. That is, by using PBT resin as the holding member 460 of the connector CN2, the reliability of the conductive members formed inside the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and the signals propagated through the board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p is improved.

[0141] The connector CN2 configured as described above has 2p pieces, the same number as the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p of the connector CN1, and is a so-called pin socket having insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p provided corresponding to the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p of the connector CN1. And the connector CN2 is provided on the head board 35 such that each of the P2 direction, Q2 direction, and R2 direction shown in FIGS. 17 to 19 is in a direction along each of the X direction, Y direction, and Z direction shown in FIGS. 11 to 13. Here, the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p are an example of a plurality of insertion holes.

[0142] Returning to FIGS. 11 to 13, the connector CN1 provided on the collective substrate 33 and the connector CN2 provided on the head substrate 35 are arranged along the Z direction such that the connector CN1 is located on the +Z side and the connector CN2 is located on the -Z side. Then, the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p of the connector CN1 are inserted into the insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p of the connector CN2, thereby electrically connecting the connector CN1 and the connector CN2. As a result, the collective substrate 33 provided with the connector CN1 and the head substrate 35 provided with the connector CN2 are electrically connected. That is, the connector CN1, which is a pin header, and the connector CN2, which is a pin socket, constitute a connection member.

[0143] Specifically, the insertion pin 410a-1 of the connector CN1 is inserted into the insertion hole 450a-1 of the connector CN2. Thereby, the insertion pin 410a-1 and the conductive member formed inside the insertion hole 450a-1 are electrically connected. Accordingly, the board connection terminal 411a-1 that is electrically connected to the insertion pin 410a-1 is electrically connected to the board connection terminal 451a-1 that is electrically connected to the conductive member formed inside the insertion hole 450a-1. As a result, the collective substrate 33 that is electrically connected via the board connection terminal 411a-1 and the head substrate 35 that is electrically connected via the board connection terminal 451a-1 are electrically connected.

[0144] Similarly, the insertion pin 410a-i of the connector CN1 is inserted into the insertion hole 450a-i of the connector CN2. Thereby, the insertion pin 410a-i and the conductive member formed inside the insertion hole 450a-i are electrically connected. Accordingly, the board connection terminal 411a-i that is electrically connected to the insertion pin 410a-i is electrically connected to the board connection terminal 451a-i that is electrically connected to the conductive member formed inside the insertion hole 450a-i. As a result, the collective substrate 33 that is electrically connected via the board connection terminal 411a-i and the head substrate 35 that is electrically connected via the board connection terminal 451a-i are electrically connected.

[0145] In addition, the insertion pins 410b-i of the connector CN1 are inserted into the insertion holes 450b-i of the connector CN2. As a result, the insertion pins 410b-i and the conductive members formed inside the insertion holes 450b-i are electrically connected. Therefore, the board connection terminals 411b-i that are electrically connected to the insertion pins 410b-i are electrically connected to the board connection terminals 451b-i that are electrically connected to the conductive members formed inside the insertion holes 450b-i. As a result, the collective board 33 that is electrically connected via the board connection terminals 411b-i and the head board 35 that is electrically connected via the board connection terminals 451b-i are electrically connected.

[0146] Next, a propagation path through which various signals propagate in the collective board 33 and the head board 35 that are electrically connected as described above will be described. Various signals including the drive signals COMA, COMB, COMC, and the data signal DATA output by the control unit 10 propagate through a cable (not shown) connected to the connector 330 of the collective board 33 and are supplied to the collective board 33.

[0147] Among the drive signals COMA, COMB, COMC, and the data signal DATA input to the collective board 33, the data signal DATA propagates through the collective board 33 and is input to a restoration circuit 220 provided on the collective board 33. The restoration circuit 220 generates and outputs a plurality of clock signals SCK, a plurality of print data signals SI, and a plurality of latch signals LAT corresponding to the plurality of ejection modules 23 by restoring the input data signal DATA. The collective board 33 propagates the clock signals SCK, the print data signals SI, and the latch signals LAT generated by this restoration circuit 220, and the drive signals COMA, COMB, COMC input via the connector 330, to the head board 35.

[0148] The collective substrate 33 and the head substrate 35 are electrically connected by connectors CN1, CN2 and cable FC. Specifically, connector CN1 is electrically connected to the surface 33b of the collective substrate 33 and is fitted into connector CN2 that is electrically connected to the surface 35a of the head substrate 35, thereby electrically connecting the collective substrate 33 and the head substrate 35. One end of cable FC is electrically connected to the surface 33a of the collective substrate 33, and the other end is electrically connected to the surface 35a of the head substrate 35, thereby electrically connecting the collective substrate 33 and the head substrate 35. That is, connectors CN1, CN2 and cable FC are electrically connected to different surfaces of the collective substrate 33.

[0149] Among the clock signal SCK, print data signal SI, and latch signal LAT propagated through the collective substrate 33 and the drive signals COMA, COMB, COMC, the clock signal SCK, print data signal SI, and latch signal LAT, which include a large number of signals and are thus propagated through a large number of signal lines, have a voltage value smaller than that of the drive signals COMA, COMB. Therefore, the amount of current generated during propagation is also small. The clock signal SCK, print data signal SI, and latch signal LAT, which have such a small amount of current and are propagated through a large number of signal lines, are propagated from the collective substrate 33 to the head substrate 35 via the cable FC in which the wiring pattern is formed at a high density. That is, the clock signal SCK, print data signal SI, and latch signal LAT with a small maximum value of current are propagated from the collective substrate 33 to the head substrate 35 via the wiring pattern included in the cable FC.

[0150] Also, the drive signals COMA, COMB, which have a large voltage value and thus can generate a large current, are propagated from the collective substrate 33 to the head substrate 35 via the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p, which have a larger cross-sectional area of the propagation path than the plurality of wiring patterns of the cable FC. That is, the maximum value of the current flowing through the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p is larger than the maximum value of the current flowing through the plurality of wiring patterns of the cable FC.

[0151] Specifically, the drive signal COMA that can generate a large current is propagated from the collective substrate 33 to the head substrate 35 via any of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p of the connector CN1. The drive signal COMB that can generate a large current is propagated from the collective substrate 33 to the head substrate 35 via insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p that are different from the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p through which the drive signal COMA is propagated among the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p of the connector CN1.

[0152] Here, the drive signal COMC supplied to the collective substrate 33 drives the piezoelectric element 60 so that ink is not ejected from the ejection unit 600. Therefore, compared with the drive signals COMA and COMB that drive the piezoelectric element 60 so that ink is ejected from the ejection unit 600, the voltage amplitude is small. Therefore, the amount of current generated when the drive signal COMC is propagated is smaller than the amount of current generated when the drive signals COMA and COMB are propagated. Such a drive signal COMC is preferably propagated through the wiring pattern included in the cable FC. That is, among the drive signals COMA, COMB, and COMC output by the drive circuit unit 50, the drive signals COMA and COMB with a large amount of current generated when propagated are propagated through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p with a large cross-sectional area, and are not propagated through the wiring pattern included in the cable FC with a small cross-sectional area. The drive signal COMC with a small amount of current generated when propagated is preferably propagated through the wiring pattern included in the cable FC with a small cross-sectional area and is not propagated through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p with a large cross-sectional area.

[0153] Since the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p have a large cross-sectional area, when a signal with a small current is propagated using the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p, there is a risk of exceeding the specifications. As a result, it may inhibit the miniaturization of the connectors CN1 and CN2 and the miniaturization of the head module 21. Therefore, by propagating the drive signal COMC with a small current through the wiring pattern included in the cable FC with a small cross-sectional area, the risk of the connectors CN1 and CN2 becoming larger is reduced, and as a result, the miniaturization of the head module 21 becomes possible.

[0154] Here, whether to propagate the drive signal COMC through the wiring pattern included in the cable FC with a small cross-sectional area or through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p with a large cross-sectional area may be appropriately changed depending on the amount of current generated when the drive signal COMC is propagated. Specifically, when the number of ejection portions 600 of the ejection module 23 is equal to or more than a predetermined number, it is estimated that the amount of current generated when the drive signal COMC is propagated increases. In such a case, when the drive signal COMC is propagated through the wiring pattern included in the cable FC with a small cross-sectional area, it becomes necessary to propagate the drive signal COMC using many wiring patterns included in the cable FC, and as a result, the cable FC becomes larger. Therefore, when the number of ejection portions 600 of the ejection module 23 is equal to or more than a predetermined number, the drive signal COMC is preferably propagated through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p with a large cross-sectional area.

[0155] On the other hand, when the number of ejection units 600 included in the ejection module 23 is less than a predetermined number, it is estimated that the amount of current generated when the drive signal COMC is propagated is reduced. In such a case, if the drive signal COMC is propagated through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p having a large cross-sectional area, there is a risk of exceeding the specifications. Therefore, when the number of ejection units 600 included in the ejection module 23 is less than a predetermined number, the drive signal COMC is preferably propagated through the wiring patterns included in the cable FC having a small cross-sectional area.

[0156] Then, the clock signal SCK, the print data signal SI, and the latch signal LAT propagated to the head substrate 35 via the connectors CN1 and CN2 and the cable FC, and the drive signals COMA, COMB, and COMC are branched on the head substrate 35 so as to correspond to the plurality of ejection modules 23, and then input to each of the plurality of ejection modules 23 via the wiring member 388. Then, the drive signal selection control circuit 200 mounted with COF on the wiring member 388 generates drive signals VOUT corresponding to the plurality of ejection units 600, and the generated drive signals VOUT are supplied to the piezoelectric elements 60 included in the corresponding ejection units 600. As a result, the piezoelectric elements 60 are driven, and an amount of ink corresponding to the drive of the piezoelectric elements 60 is ejected from the nozzles N.

[0157] Here, the assembly substrate 33 is an example of the second substrate.

[0158] 5. Operational Effects The head module included in the liquid ejection device 1 in the present embodiment configured as described above 21 includes a connector CN1 which is a so-called pin header having insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p, and a connector CN2 which is a so-called pin socket having insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p corresponding to each of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p. Then, when the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p are inserted into the corresponding insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p, the connector CN1 and the connector CN2 are directly connected, whereby the collective substrate 33 and the head substrate 35 are electrically connected. As a result, for example, compared with the case where the collective substrate 33 and the head substrate 35 are electrically connected using a flexible wiring such as an FPC or an FFC, or the case where the collective substrate 33 and the head substrate 35 are electrically connected using a board-to-board (BtoB) connector with terminals arranged at high density, the effective cross-sectional area of the propagation path through which the drive signals COMA and COMB propagate can be increased, and the terminal pitch between the connectors CN1 and CN2 can be secured widely.

[0159] As a result, even when the current amount accompanying the drive signals COMA and COMB increases due to an increase in the image forming speed, the impedance generated in the propagation path can be reduced, the waveform accuracy of the drive signals COMA and COMB can be enhanced, and even when ink mist adheres to the propagation path through which the drive signals COMA and COMB propagate, the risk of a short circuit abnormality occurring due to the ink mist is reduced.

[0160] In particular, in the head module 21 of the present embodiment, each of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p is inserted into each of the corresponding insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p, whereby the connector CN1 and the connector CN2 are electrically connected. Therefore, between the insertion pin 410a-i and the insertion pin 410a-i+1, there are located the outer shells constituting the insertion hole 450a-i and the outer shells constituting the insertion hole 450a-i+1. The outer shells constituting the insertion hole 450a-i and the outer shells constituting the insertion hole 450a-i+1 isolate the insertion pin 410a-i and the insertion pin 410a-i+1. As a result, even when ink mist adheres to the insertion pin 410a-i and the insertion pin 410a-i+1, the risk of a short-circuit abnormality occurring between the insertion pin 410a-i and the insertion pin 410a-i+1 due to the ink mist is reduced.

[0161] As described above, in the liquid ejection device 1 of the present embodiment, the head module 21 includes a connector CN1 that is a pin header having insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p, and a connector CN2 that is a pin socket having insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p corresponding to each of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p. Each of the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p is inserted into each of the corresponding insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p, whereby even when the amount of current generated when the drive signals COMA and COMB are propagated increases due to the electrical connection of the connector CN1 and the connector CN2 to electrically connect the collective substrate 33 and the head substrate 35, the waveform accuracy of the drive signals COMA and COMB can be enhanced, and the risk of malfunction occurring in the head module 21 due to the intrusion of ink mist can be reduced.

[0162] In addition, for the head module 21 included in the liquid ejection device 1 in the present embodiment, the shortest distance between the insertion pins 410a-i and the insertion pin 410a-i+1 positioned adjacent to the insertion pins 410a-i is 1 mm or more, and the shortest distance between the insertion pins 410a-i and the insertion pin 410a-i+1 is set to be three times or more the width pw of the insertion pin 410a-i when viewed from a direction orthogonal to the direction in which the insertion pins 410a-i and the insertion pin 410a-i+1 are arranged. By doing so, even when ink mist adheres to the insertion pins 410a-i and the insertion pin 410a-i+1 there is a reduced risk of a short-circuit abnormality occurring between the insertion pins 410a-i and the insertion pin 410a-i+1 due to the ink mist. Therefore, the risk of malfunction occurring in the head module 21 due to the intrusion of ink mist is further reduced.

[0163] In addition, for the head module 21 included in the liquid ejection device 1 in the present embodiment, by setting the cross-sectional area of the insertion pin 410a-i to 0.1 mm 2 it is possible to further reduce the impedance component generated in the propagation path through which the drive signals COMA and COMB propagate. Therefore, the waveform accuracy of the drive signals COMA and COMB can be improved.

[0164] Although the embodiments have been described above, 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-described embodiments.

[0165] The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations having the same functions, methods, and results, or configurations having the same objectives and effects). In addition, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that exhibit the same operational effects as the configurations described in the embodiments or configurations that can achieve the same objectives. The present invention also includes configurations in which known techniques are added to the configurations described in the embodiments.

[0166] The following content is derived from the above-described embodiments.

[0167] One aspect of the head unit is a discharge unit that includes a piezoelectric element driven by a drive signal and discharges liquid in response to the drive of the piezoelectric element; a first substrate that propagates the drive signal to the discharge unit; a second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate; a connection member that electrically connects the first substrate and the second substrate; and includes The connection member is a pin header having a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding unit that holds the plurality of insertion pins in an insulated state from each other; a pin socket having the same number of insertion holes as the plurality of insertion pins and provided corresponding to the plurality of insertion pins; and includes The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding thereto.

[0168] According to this head unit, a connection member for electrically connecting a first substrate and a second substrate includes a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding portion for holding the plurality of insertion pins in a state of being insulated from each other, that is, a pin header, and a pin socket having the same number as the plurality of insertion pins and provided corresponding to the plurality of insertion pins. The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the corresponding plurality of insertion holes. Thereby, compared with the case of electrically connecting the first substrate and the second substrate using a flexible wiring such as an FPC or an FFC, or the case of electrically connecting the first substrate and the second substrate using a board-to-board (BtoB) connector with terminals arranged at high density, the effective cross-sectional area of the propagation path through which the drive signal propagates from the first substrate to the second substrate can be increased, and a wider terminal pitch of the plurality of insertion pins including the first insertion pin and the second insertion pin can be ensured. As a result, even when the current amount associated with the drive signal increases due to an increase in the image forming speed, the impedance generated in the propagation path through which the drive signal propagates can be reduced, the waveform accuracy of the drive signal can be improved, and even when ink mist adheres to the propagation path through which the drive signal propagates, the risk of a short circuit abnormality caused by the ink mist is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced. Even when ink mist adheres to the propagation path through which the drive signal propagates, the risk of a short circuit abnormality caused by the ink mist is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0169] Furthermore, in the head unit, each of the plurality of insertion pins is inserted into each of the corresponding plurality of insertion holes, whereby the first substrate and the second substrate are electrically connected. That is, between the plurality of insertion pins, an outer shell constituting the plurality of insertion holes is located. The plurality of insertion pins are isolated from each other by the outer shell constituting the plurality of insertion holes. As a result, even when ink mist adheres to the plurality of insertion pins, the risk of a short circuit abnormality occurring between the plurality of insertion pins due to the ink mist is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0170] In one aspect of the head unit, The holding part may contain polybutylene terephthalate.

[0171] According to this head unit, by using polybutylene terephthalate, which has excellent insulation performance, low water absorption rate, and excellent oil resistance and solvent resistance, as the holding part, the holding part can stably hold a plurality of insertion pins even in a head unit that discharges various inks. As a result, the signal accuracy propagated by the plurality of insertion pins is improved.

[0172] In one aspect of the head unit, The first insertion pin and the second insertion pin are adjacent to each other, and the shortest distance between the first insertion pin and the second insertion pin may be 1 mm or more.

[0173] According to this head unit, by setting the shortest distance between the adjacent first insertion pin and the second insertion pin to 1 mm or more, even when ink mist adheres to at least one of the first insertion pin and the second insertion pin, the risk of a short-circuit abnormality occurring between the first insertion pin and the second insertion pin is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0174] In one aspect of the head unit, The cross-sectional area of at least one of the first insertion pin and the second insertion pin may be 0.1 mm 2 or more.

[0175] According to this head unit, by setting the cross-sectional area of at least one of the first insertion pin and the second insertion pin to 0.1 mm 2 or more, the impedance of the first insertion pin and the second insertion pin can be reduced. As a result, the accuracy of the signal propagated by the first insertion pin and the second insertion pin can be improved.

[0176] In one aspect of the head unit, The shortest distance between the first insertion pin and the second insertion pin may be equal to or greater than three times the width of the first insertion pin when viewed in a direction orthogonal to the direction in which the first insertion pin and the second insertion pin are aligned.

[0177] According to this head unit, by setting the shortest distance between the first insertion pin and the second insertion pin to be equal to or greater than three times the width of the first insertion pin, even when ink mist adheres to the first insertion pin, the risk of a short - circuit abnormality occurring between the first insertion pin and the adjacent insertion pin is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced. 。

[0178] In one aspect of the head unit, the drive signal supplied to the ejection unit includes a first drive signal and a second drive signal having a waveform different from that of the first drive signal. The first insertion pin propagates the first drive signal. The second insertion pin may propagate the second drive signal.

[0179] One aspect of the liquid ejection device is a drive circuit unit having a drive signal output circuit that outputs a drive signal, a head unit that ejects liquid based on the drive signal, and includes the head unit includes a piezoelectric element driven by the drive signal, and a discharge unit that discharges liquid in response to the drive of the piezoelectric element, a first substrate that propagates the drive signal to the discharge unit, a second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate, a connection member that electrically connects the first substrate and the second substrate, and has the connection member is a pin header having a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding unit that holds the plurality of insertion pins in an insulated state from each other. A pin socket having the same number as the plurality of insertion pins and provided with a plurality of insertion holes corresponding to the plurality of insertion pins, including, The connecting member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding to the plurality of insertion pins.

[0180] According to this liquid ejection device, the head unit includes a pin header having a connecting member that electrically connects a first substrate and a second substrate, the connecting member including a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding unit that holds the plurality of insertion pins in an insulated state from each other, and a pin socket having the same number as the plurality of insertion pins and provided with a plurality of insertion holes corresponding to the plurality of insertion pins. The connecting member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding to the plurality of insertion pins. As a result, compared with the case of electrically connecting the first substrate and the second substrate using a flexible wiring such as an FPC or an FFC, or the case of electrically connecting the first substrate and the second substrate using a board-to-board (BtoB) connector with terminals arranged at high density, the effective cross-sectional area of the propagation path through which the drive signal propagates from the first substrate to the second substrate can be increased, and a wide terminal pitch can be ensured for the plurality of insertion pins including the first insertion pin and the second insertion pin. As a result, even when the amount of current generated with the drive signal increases due to an increase in the image forming speed, the impedance generated in the propagation path through which the drive signal propagates can be reduced, the waveform accuracy of the drive signal can be improved, and even when ink mist adheres to the propagation path through which the drive signal propagates, the risk of a short-circuit abnormality occurring due to the ink mist is reduced. Therefore, the risk of malfunction occurring in the head unit due to the intrusion of ink mist can be reduced.

[0181] Furthermore, in the head unit, each of the plurality of insertion pins is inserted into each of the corresponding plurality of insertion holes, whereby the first substrate and the second substrate are electrically connected. That is, between the plurality of insertion pins, the outer shell constituting the plurality of insertion holes is located. By the outer shell constituting the plurality of insertion holes, the plurality of insertion pins are isolated from each other. As a result, even when ink mist adheres to the plurality of insertion pins, the ink mist reduces the risk of a short-circuit abnormality occurring between the plurality of insertion pins. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0182] In one aspect of the liquid ejection device, The holding portion may contain polybutylene terephthalate.

[0183] According to this liquid ejection device, by using polybutylene terephthalate, which has excellent insulation performance, a small water absorption rate, and excellent oil resistance and solvent resistance, as the holding portion, the holding portion can stably hold the plurality of insertion pins even in a head unit that ejects a wide variety of inks. As a result, the signal accuracy propagated by the plurality of insertion pins is improved.

[0184] In one aspect of the liquid ejection device, The first insertion pin and the second insertion pin are located adjacent to each other, and the shortest distance between the first insertion pin and the second insertion pin may be 1 mm or more.

[0185] According to this liquid ejection device, by setting the shortest distance between the first insertion pin and the second insertion pin located adjacent to each other to 1 mm or more, even when ink mist adheres to at least one of the first insertion pin and the second insertion pin, the risk of a short-circuit abnormality occurring between the first insertion pin and the second insertion pin is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0186] In one aspect of the liquid ejection device, The cross-sectional area of at least one of the first insertion pin and the second insertion pin may be 0.1 mm 2 or more.

[0187] According to this liquid ejection device, by setting the cross-sectional area of at least one of the first insertion pin and the second insertion pin to 0.1 mm 2 or more, the impedance of the first insertion pin and the second insertion pin can be reduced. As a result, the accuracy of the signal propagated by the first insertion pin and the second insertion pin can be improved.

[0188] In one aspect of the liquid ejection device, the shortest distance between the first insertion pin and the second insertion pin may be 3 times or more the width of the first insertion pin when viewed from a direction orthogonal to the direction in which the first insertion pin and the second insertion pin are arranged.

[0189] According to this liquid ejection device, by setting the shortest distance between the first insertion pin and the second insertion pin to 3 times or more the width of the first insertion pin, even when ink mist adheres to the first insertion pin, the risk of a short-circuit abnormality occurring between the first insertion pin and the adjacent insertion pin is reduced. Therefore, the risk of malfunction in the head unit due to the intrusion of ink mist can be reduced.

[0190] In one aspect of the liquid ejection device, the drive signal supplied to the ejection unit includes a first drive signal and a second drive signal having a waveform different from that of the first drive signal, the first insertion pin propagates the first drive signal, and the second insertion pin may propagate the second drive signal.

[0191] In one aspect of the liquid ejection device, a plurality of the head units are provided, and the plurality of head units may be arranged side by side along a direction intersecting the conveyance direction in which the medium on which the liquid is ejected is conveyed.

Explanation of reference numerals

[0192] 1... Liquid ejection device, 2... Liquid container, 10... Control unit, 20... Liquid ejection unit, 21... Head module, 23... Ejection module, 31... Housing, 33... Aggregate substrate, 33a, 33b... Surfaces, 34... Flow path structure, 35... Head substrate, 35a, 35b... Surfaces, 37... Flow path distribution section, 39... Fixed plate, 40... Medium conveyance unit, 41... Conveyance motor, 42... Conveyance roller, 50... Drive circuit unit, 51-1~51-m... Drive circuits, 52a, 52b, 52c... Drive signal output circuits, 53... Reference voltage output circuit, 60... Piezoelectric element, 100... Control circuit, 120... Conversion circuit, 200... Drive signal selection control circuit, 210... Selection control circuit, 212... Shift register, 214... Latch circuit, 216... Decoder, 220... Restoration circuit, 230... Selection circuit, 232a, 232b, 232c... Inverters, 234a, 234b, 234c... Transfer gates, 311... Supply hole, 313... Aggregate substrate insertion section, 315, 317... Holding members, 330... Connector, 341... Supply connection section, 343... Through hole, 351... Opening, 353, 355... Notches, 371... Opening, 373... Introduction connection section, 388... Wiring member, 391... Exposed opening, 410a-1~410a-p, 410b-1~410b-p... Insertion pins, 411a-1~411a-p, 411b-1~411b-p... Substrate connection terminals, 413a-1~413a-p, 413b-1~413b-p... Internal electrodes, 420... Holding member, 450a-1~450a-p, 450b-1~450b-p... Insertion holes, 451a-1~451a-p, 451b-1~451b-p... Substrate connection terminals, 460... Holding member, 600... Ejection section, 610... Diaphragm, 611... Lead electrode, 620... Compliance substrate, 621... Sealing film, 622... Fixed substrate, 623... Nozzle plate, 623a... Liquid injection surface, 630... Communication plate, 641... Protection substrate, 642... Flow path forming substrate, 643... Through hole, 644... Holding section, 660... Case, 661... Introduction path, 662... Connection port, 665... Recess, CB... Pressure chamber, CN1, CN2... Connectors, FC... Cable, Ln1, Ln2... Nozzle rows, MN... Manifold, N... Nozzle, ND... Non-ejection, P... Medium, RA, RB... Supply communication paths, RK1, RK2... Pressure chamber communication paths, RR... Nozzle communication path, RX... Connection communication path, Su1, Su2... Flow path plates

Claims

1. A discharge unit including a piezoelectric element driven by a drive signal, the discharge unit discharging a liquid in response to driving of the piezoelectric element; A first substrate that propagates the drive signal to the discharge unit; A second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate; A connection member that electrically connects the first substrate and the second substrate; Comprising: The connection member Includes a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding unit that holds the plurality of insertion pins in an insulated state from each other, and a pin header provided on one of the first substrate and the second substrate; A plurality of insertion holes having the same number as the plurality of insertion pins and provided corresponding to the plurality of insertion pins, and a pin socket provided on the other of the first substrate and the second substrate; Including: The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of insertion holes corresponding thereto. A head unit characterized by the above.

2. The holding unit includes polybutylene terephthalate. The head unit according to claim 1, characterized by the above.

3. The first insertion pin and the second insertion pin are adjacent to each other, and the shortest distance between the first insertion pin and the second insertion pin is 1 mm or more. The head unit according to claim 1 or 2, characterized by the above.

4. The cross-sectional area of at least one of the first insertion pin and the second insertion pin is 0.1 mm ２ or more. The head unit according to any one of claims 1 to 3, characterized by the above.

5. The shortest distance between the first insertion pin and the second insertion pin is 3 times or more the width of the first insertion pin when viewed from a direction orthogonal to the direction in which the first insertion pin and the second insertion pin are arranged. The head unit according to any one of claims 1 to 4, characterized by the above.

6. The drive signal supplied to the discharge unit includes a first drive signal and a second drive signal having a different waveform from the first drive signal. The first insertion pin propagates the first drive signal. The second insertion pin propagates the second drive signal. The head unit according to any one of claims 1 to 5, characterized by the above.

7. A drive circuit unit having a drive signal output circuit that outputs a drive signal; A head unit that discharges a liquid based on the drive signal; Comprising: The head unit Includes a piezoelectric element driven by the drive signal, and a discharge unit that discharges a liquid in response to driving of the piezoelectric element. a first substrate that propagates the drive signal to the ejection unit; a second substrate to which the drive signal is supplied and that propagates the drive signal to the first substrate; a connection member that electrically connects the first substrate and the second substrate; and includes: The connection member includes a plurality of insertion pins including a first insertion pin and a second insertion pin, and a holding unit that holds the plurality of insertion pins in an insulated state from each other, and a pin header provided on one of the first substrate and the second substrate; a plurality of insertion holes that are the same number as the plurality of insertion pins and are provided corresponding to the plurality of insertion pins, and a pin socket provided on the other of the first substrate and the second substrate; and includes: The connection member electrically connects the first substrate and the second substrate by inserting the plurality of insertion pins into the plurality of corresponding insertion holes. A liquid ejection device characterized by the above.

8. The holding unit includes polybutylene terephthalate. The liquid ejection device according to claim 7, characterized in that.

9. The first insertion pin and the second insertion pin are adjacent to each other, and the shortest distance between the first insertion pin and the second insertion pin is 1 mm or more. The liquid ejection device according to claim 7 or 8, characterized in that.

10. The cross-sectional area of at least one of the first insertion pin and the second insertion pin is 0.1 mm ２ or more. The liquid ejection device according to any one of claims 7 to 9, characterized in that.

11. The shortest distance between the first insertion pin and the second insertion pin is 3 times or more the width of the first insertion pin when viewed from a direction orthogonal to the direction in which the first insertion pin and the second insertion pin are arranged. The liquid ejection device according to any one of claims 7 to 10, characterized in that.

12. The drive signal supplied to the ejection unit includes a first drive signal and a second drive signal having a different waveform from the first drive signal. The first insertion pin propagates the first drive signal. The second insertion pin propagates the second drive signal. The liquid ejection device according to any one of claims 7 to 11, characterized in that.

13. A plurality of the head units are provided. The plurality of head units are arranged side by side along a direction intersecting a conveyance direction in which a medium for ejecting liquid is conveyed. The liquid ejection device according to any one of claims 7 to 12, characterized in that.

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