Head unit, and liquid ejection device

Abstract

To provide a head unit that can reduce the risk that the head unit may be enlarged in size due to increase of amounts of currents.SOLUTION: A head unit comprises: a discharging part that includes a piezoelectric element that is driven by a first driving signal and discharges liquid in response to driving of the piezoelectric element; a switching circuit that switches whether the first driving signal is supplied to the piezoelectric element or not on the basis of a discharging control signal; a first substrate that transmits the first driving signal and the discharging control signal to the switching circuit; a second substrate that is supplied with the first driving signal and the discharging control signal and transmits the first driving signal and the discharging control signal to the first substrate; a first connection member including a first conductive part that electrically connects the first substrate to the second substrate; and a second connection member including a second conductive part that electrically connects the first substrate to the second substrate, where the cross sectional area of the first conductive part are larger than the cross sectional area of the second conductive part.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 forms desired dots on the medium by controlling the amount of liquid ejected in response to the drive of the drive element.

[0003] For example, in Patent Document 1, a drive signal including a plurality of trapezoidal waveforms in series is propagated to a liquid ejection unit via a flexible flat cable (FFC), and in the liquid ejection unit, the drive amount of a piezoelectric element as a drive element is controlled by switching whether to supply the trapezoidal waveform included in the drive signal to the piezoelectric element, and a liquid ejection device that controls the amount of ink ejected from a nozzle is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] 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 a higher dot formation cycle for forming dots of a desired size on the medium by ejecting liquid. However, to increase 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. Such an increase in the amount of current generated along with the driving signal promotes the enlargement of the wiring, cable, and connector through which the driving signal propagates. Therefore, there has been a risk that the head unit for ejecting the medium would become larger. Regarding the problem that such an increase in the amount of current generated along with the high-speed image formation speed may increase the amount of current and there is a risk that the head unit may become larger as a result, Patent Document 1 has no description, and there was room for improvement in the liquid ejection device described in Patent Document 1 in this regard.

Means for Solving the Problems

[0006] One aspect of the head unit according to the present invention is including a piezoelectric element driven by a first driving signal, and a discharge unit that discharges liquid in response to the driving of the piezoelectric element; a switching circuit that switches whether or not to supply the first driving signal to the piezoelectric element based on a discharge control signal; a first substrate that propagates the first driving signal and the discharge control signal to the switching circuit; a second substrate to which the first driving signal and the discharge control signal are supplied and that propagates the first driving signal and the discharge control signal to the first substrate; a first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; a second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; and is provided with the cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion.

[0007] One aspect of the liquid ejection device according to the present invention is A drive circuit unit having a first drive signal output circuit that outputs a first drive signal; A discharge control unit that outputs a discharge control signal; A head unit that discharges liquid based on the first drive signal and the discharge control signal; Comprising; The head unit is Including a piezoelectric element driven by the first drive signal, and a discharge unit that discharges liquid in response to the drive of the piezoelectric element; A switching circuit that switches whether to supply the first drive signal to the piezoelectric element based on the discharge control signal; A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit; A second substrate to which the first drive signal and the discharge control signal are supplied and that propagates the first drive signal and the discharge control signal to the first substrate; A first connection member including a first conductive part that electrically connects the first substrate and the second substrate; A second connection member including a second conductive part that electrically connects the first substrate and the second substrate; Having; The cross-sectional area of the first conductive part is larger than the cross-sectional area of the second conductive part.

Brief Description of the Drawings

[0008]

Figure 1

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The drawings used are for convenience of explanation. Note that the embodiments described below are those of the present invention described in the claims It does not unduly limit the content of the disclosure. Also, not all of the configurations described below are essential components of the present invention.

[0010] 1. Configuration of the liquid ejection device FIG. 1 is a diagram showing a schematic configuration of a liquid ejection device 1. As shown in FIG. 1, the liquid ejection device 1 in the present embodiment is a line-type inkjet printer that forms a desired image on a medium P by ejecting ink, which is an example of a liquid, at a desired timing onto the medium P conveyed by a 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.

[0011] 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.

[0012] The liquid container 2 stores ink supplied to the liquid ejection unit 20. Specifically, the liquid container 2 stores inks of a plurality of types of colors ejected onto the medium P, for example, inks of colors such as black, cyan, magenta, yellow, red, and gray. 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, etc. can be used.

[0013] 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.

[0014] 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 along the main scanning direction so as to be equal to or greater than the width of the medium P. That is, the liquid ejection apparatus 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 that intersects the conveyance direction in which the medium P on which ink, which is an example of the liquid, is ejected is conveyed.

[0015] To each of the plurality of head modules 21 included in the liquid ejection unit 20, a data signal DATA for controlling the operation 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. Further, 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.

[0016] 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, the medium P is conveyed along the conveyance direction by the rotational drive of the conveyance roller 42.

[0017] In the liquid ejection apparatus 1 configured as described above, the control unit 10 causes the plurality of head modules 21 included in the liquid ejection unit 20 to eject ink 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.

[0018] Here, a specific example of the control of the liquid ejection unit 20 by the control unit 10 will be described. It is as follows. FIG. 2 is a diagram showing the functional configuration of the liquid ejection device 1. In FIG. 2, only the electrical connection between the control unit 10 and the liquid ejection unit 20 is illustrated, and the illustration of the medium conveyance unit 40 and the liquid container 2 is omitted.

[0019] 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).

[0020] 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 illustrated, and the illustration of the circuit configuration included in 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 other head modules 21 will be omitted or simplified.

[0021] 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.

[0022] The control circuit 100 generates a base data signal dDATA that serves as the basis for the data signal DATA output to the liquid ejection unit 20 based on signals such as input image data, and outputs it to the conversion circuit 120. The conversion circuit 120 converts the base data signal dDATA into a data signal DATA of a differential signal 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 may generate a data signal DATA obtained by converting the base data signal dDATA into a differential signal of various high-speed transfer methods such as LVPECL (Low Voltage Positive Emitter Coupled Logic) or CML (Current Mode Logic) other than LVDS, and output it to the head module 21. Alternatively, 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.

[0023] Further, the control circuit 100 outputs base drive signals dA1, dB1, and dC1 to a 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.

[0024] The base drive signal dA1 is input to a drive signal output circuit 52a included in the drive circuit 51-1. The drive signal output circuit 52a performs digital / analog conversion on the base drive signal dA1 input thereto, and then performs class D amplification on the analog signal to generate a drive signal COMA1, and outputs the generated drive signal COMA1 to the head module 21. The base drive signal dB1 is input to a drive signal output circuit 52b included in the drive circuit 51-1. The drive signal output circuit 52b performs digital / analog conversion on the base drive signal dB1 input thereto, and then performs class D amplification on the analog signal to generate a drive signal COMB1, and outputs the generated drive signal COMB1 to the head module 21. The base drive signal dC1 is input to a drive signal output circuit 52c included in the drive circuit 51-1. The drive signal output circuit 52c performs digital / analog conversion on the input basic drive signal dC1, and then performs class D amplification on the analog signal to generate a drive signal COMC1.

[0025] Here, each of the drive signal output circuits 52a, 52b, and 52c receives an input digital It is sufficient that the drive signals COMA1, COMB1, and COMC1 can be generated by amplifying the waveforms defined by the basic drive signals dA1, dB1, and dC1, respectively, and the circuit 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 a 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.

[0026] 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.

[0027] Here, the driving circuits 51-1 to 51-m of the driving circuit unit 50 have the same configuration, except that the input signals and output signals are different. Specifically, the driving circuit 51-m includes a circuit equivalent to the driving signal output circuits 52a, 52b, and 52c, and a circuit equivalent to the reference voltage output circuit 53, and generates driving signals COMAm, COMBm, and COMCm and a reference voltage signal VBSm based on the basic driving signals dAm, dBm, and dCm input from the control circuit 100, and outputs them to the head module 21. Similarly, the driving circuit 51-j (j is any one of 1 to m) includes a circuit equivalent to the driving signal output circuits 52a, 52b, and 52c, and a circuit equivalent to the reference voltage output circuit 53, and generates driving signals COMAj, COMBj, and COMCj and a reference voltage signal VBSj based on the basic driving signals dAj, dBj, and dCj input from the control circuit 100, and outputs them to the head module 21.

[0028] The plurality of head modules 21 included in the liquid ejection unit 20 each include a restoration circuit 220 and ejection modules 23-1 to 23-m.

[0029] The restoration circuit 220 restores the data signal DATA of the differential signal output by the control unit 10 into a single-ended signal, separates it into signals corresponding to each of the ejection modules 23-1 to 23-m, and outputs the separated signals to the corresponding ejection modules 23-1 to 23-m.

[0030] 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 output by the restoration circuit 220, the clock signal SCKj corresponding to the ejection module 23-j, and the clock signal SCKm corresponding to the ejection module 23-m may be common signals.

[0031] 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 each of the ejection modules 23-1 to 23-m included in the head module 21 and outputs them to the corresponding ejection modules 23-1 to 23-m.

[0032] 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 base 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. Further, 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.

[0033] 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. Further, 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 base data signal dDATA into a differential signal.

[0034] The ejection module 23-1 includes a drive signal selection control circuit 200 and a plurality of ejection units 600. Further, 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 to the ejection module 23-1.

[0035] 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.

[0036] 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 6 00. 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.

[0037] 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, a reference voltage signal VBSj, a clock signal SCKj, a print data signal SIj, and a 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. 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 based on the input clock signal SCKj, print data signal SIj, and latch signal LATj, and supplies the generated drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding ejection unit 600. 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.

[0038] 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.

[0039] In the liquid ejection device 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 control circuit 100 that outputs a base data signal dDATA serving as a basis for clock signals SCK1 to SCKm, print data signals SI1 to SIm, and latch signals LAT1 to LATm is an example of a discharge control unit. A head module 21 that ejects ink based on the drive signals COMA1 to COMAm, COMB1 to COMBm, COMC1 to COMCm, the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm based on the base data signal dDATA is an example of a head unit.

[0040] 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 between 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.

[0041] 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.

[0042] FIG. 3 is a diagram showing an example of the signal waveforms of 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. 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.

[0043] 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. Also, 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. Thereby, the possibility of an increase in the viscosity of the ink near the nozzle orifice is reduced.

[0044] 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.

[0045] 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 may be referred to as a small amount. Also, vibrating the ink near the nozzle orifice so that no ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60 may be referred to as fine vibration.

[0046] 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, a signal that defines the boundary of two or more trapezoidal waveforms and that defines the switching timing of two or more trapezoidal waveforms may be input to the drive signal selection control circuit 200. And, in this case, in the period T corresponding to the 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. On the other hand, in the present embodiment, the drive signals COMA, COMB, and COMC will be described as signals including one trapezoidal waveform in the period T. Thereby, in the period T, the period T corresponding to the dot formation period can be made shorter compared to the case where the drive signals COMA, COMB, and COMC include a plurality of trapezoidal waveforms, and the image formation speed on the medium P can be increased.

[0047] 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.

[0048] The selection control circuit 210 receives a print data signal SI, a latch signal LAT, and a clock signal SCK. Also, 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 the same number of sets of n shift registers 212, n latch circuits 214, and n decoders 216 as the total number of ejection units 600. 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, the n-stage shift registers 212 corresponding to the ejection unit 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.

[0049]

[0050] Each of the n latch circuits 214 latches the 2-bit print data [SIH, SIL] held in each of the n shift registers 212 simultaneously at the rising edge of the latch signal LAT.

[0051] 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.

[0052] ​FIG. 5 is a diagram showing the decoding content in the decoder 216. The decoder 216 outputs selection signals S1, S2, and 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, and S3 as L, H, and L levels to the corresponding selection circuit 230 at the period T.

[0053] The selection circuit 230 is provided corresponding to each of the ejection units 600. That is, the number of the selection circuits 230 included in the drive signal selection control circuit 200 is the same n as the total number of the corresponding ejection units 600.

[0054] 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, and 232c which are NOT circuits, and transfer gates 234a, 234b, and 234c.

[0055] The selection signal S1 is input to the non-marked positive control terminal in the transfer gate 234a, while being logically inverted by the inverter 232a and input to the marked negative control terminal in 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.

[0056] 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, a drive signal COMB is supplied to the input terminal of the transfer gate 234b. And the transfer gate 234b conducts between the input terminal and the output terminal when the input selection signal S2 is at the H level, and does not conduct between the input terminal and the output terminal when the input selection signal S2 is at the L level.

[0057] Also, the selection signal S3 is input to the non - marked positive control terminal of the transfer gate 234c, while being logically inverted by the inverter 232c and input to the marked negative control terminal of the transfer gate 234c. Also, a drive signal COMC is supplied to the input terminal of the transfer gate 234c. And the transfer gate 234c conducts between the input terminal and the output terminal when the input selection signal S3 is at the H level, and does not conduct between the input terminal and the output terminal when the input selection signal S3 is at the L level.

[0058] 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.

[0059] With reference to FIG. 7, the operation of the drive signal selection control circuit 200 will be described. 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 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.

[0060] 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. In FIG. 7, LT1, LT2, …, LTn indicate 2-bit print data [SIH, SIL] latched by the latch circuits 214 corresponding to the shift registers 212 of the 1st stage, 2nd stage, …, n-th stage.

[0061] The decoder 216 outputs the logic levels of the selection signals S1, S2, and S3 in the content shown in FIG. 5 in the period T according to the dot size defined by the latched 2-bit print data [SIH, SIL].

[0062] Specifically, when the print data [SIH, SIL] is [1, 1], the decoder 216 sets the selection signal S1 to the H level, the selection signal S2 to the L level, and the selection signal S3 to the L level in the period T. In this case, the selection circuit 230 selects the trapezoidal waveform Adp in the period T, and as a result, the drive signal VOUT corresponding to the “large dot LD” is output.

[0063] Also, when the print data [SIH, SIL] is [1, 0], the decoder 216 sets the selection signal S1 to the L level, the selection signal S2 to the H level, and the selection signal S3 to the L level at the period T. In this case, the selection circuit 230 selects the trapezoidal waveform Bdp at the period T, and as a result, the drive signal VOUT corresponding to the "small dot SD" is output.

[0064] 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 select any of the trapezoidal waveforms Adp, Bdp, and Cdp at the period T, and as a result, the drive signal VOUT corresponding to the "non-ejection ND" is output. Here, the drive signal VOUT corresponding to the non-ejection ND is a constant voltage waveform at the voltage Vc. When none of the trapezoidal waveforms Adp, Bdp, and Cdp is selected as the drive signal VOUT the voltage Vc immediately before 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, and Cdp, this voltage Vc is supplied to the piezoelectric element 60 as the drive signal VOUT.

[0065] 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, the drive signal VOUT corresponding to the "fine vibration BSD" is output.

[0066] 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 deselects the drive signals COMA, COMB, and COMC, thereby generating a drive signal VOUT corresponding to each of the plurality of ejection units 600 and outputting the drive signal VOUT to the corresponding ejection unit 600. That is, the drive signal selection control circuit 200 switches whether to supply the drive signals COMA, COMB, and COMC to the piezoelectric element 60 as the drive signal VOUT based on the print data signal SI, the latch signal LAT, and the clock signal SCK. This drive signal selection control circuit 200 is an example of a switching circuit, and any one of the print data signal SI, the latch signal LAT, and the clock signal SCK that defines the operation of the drive signal selection control circuit 200 is an example of an ejection control signal. Further, at least one of the drive signals COMA and COMB that drives the piezoelectric element 60 included in the ejection unit 600 so that ink is ejected from the ejection unit 600 is an example of a first drive signal, and the drive signal COMC that drives the piezoelectric element 60 included in the ejection unit 600 so that ink is not ejected from the ejection unit 600 is an example of a second drive signal.

[0067] Also, as shown in FIG. 2, the drive signal COMA is output by the drive signal output circuit 52a included in the drive circuit unit 50, the drive signal COMB is output by the drive signal output circuit 52b included in the drive circuit unit 50, and the drive signal COMC is output by the drive signal output circuit 52c included in the drive circuit unit 50. At least one of the drive signal output circuit 52a that outputs the drive signal COMA and the drive signal output circuit 52b that outputs the drive signal COMB is an example of a first drive signal output circuit, and the drive signal output circuit 52c that outputs the drive signal COMC is an example of a second drive signal output circuit.

[0068] 3. Structure of 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 as the +X side, the starting side of the arrow indicating the Y direction as the -Y side, the tip side as the +Y side, and the starting side of the arrow indicating the Z direction as the -Z side, the tip side as the +Z side.

[0069] As shown in FIG. 8, the head module 21 includes a housing 31, an aggregate substrate 33, a flow path structure 34, a head substrate 35, a flow path distribution unit 37, and a fixing plate 39. And the flow path structure 34, the head substrate 35, the flow path distribution unit 37, and the fixing plate 39 are located in the direction along the Z direction, from the -Z side to the +Z side, and are stacked in the order of the fixing plate 39, the flow path distribution unit 37, the head substrate 35, and the flow path structure 34. At the same time, 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. The aggregate substrate 33 stands upright while being held by the housing 31 on the +Z side of the housing 31, and thus the head module 21 is configured.

[0070] 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 fixing plate 39, and a part of them is located so as to be exposed to the outside of the head module 21. FIG. 8 illustrates the 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.

[0071] 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.

[0072] 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 on the assumption 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 there is no need to distinguish between the nozzle N1 and the nozzle N2, it may simply be referred to as the nozzle N.

[0073] 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.

[0074] On the flow path forming substrate 642, pressure chambers CB1 partitioned by a plurality of partition walls by anisotropic etching from one 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 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 it is not necessary 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 with an opening area smaller than that of the pressure chamber CB.

[0075] 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 -Z side surface of the nozzle plate 623 where the nozzle N opens may be referred to as the liquid ejection surface 623a.

[0076] 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 located. 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 independently 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, corresponding to each of the pressure chambers CB1 and CB2. That is, on the communication plate 630, n / 2 nozzles N1 arranged in parallel and A row of nozzle connection passages RR1 corresponding to the pressure chamber CB1, a row of pressure chamber connection passages RK1, and n / 2 nozzles N2 arranged in parallel therewith, a row of nozzle connection passages RR2 corresponding to the pressure chamber CB2, and a row of pressure chamber connection passages RK2 are provided.

[0077] Further, the communication plate 630 includes manifolds MN1 and MN2. The manifold MN1 includes a supply connection passage RA1 and a connection passage RX1. The supply connection passage RA1 is provided to penetrate the communication plate 630 in the Z direction, and the connection passage RX1 is provided to open to the nozzle plate 623 side of the communication plate 630 without penetrating the communication plate 630 in the Z direction and extends to the middle in the Z direction. Similarly, the manifold MN2 includes a supply connection passage RA2 and a connection passage RX2. The supply connection passage RA2 is provided to penetrate the communication plate 630 in the Z direction, and the connection passage RX2 is provided to open to the nozzle plate 623 side of the communication plate 630 without penetrating the communication plate 630 in the Z direction and extends to the middle in the Z direction. And the connection passage RX1 included in the manifold MN1 is communicated with the corresponding pressure chamber CB1 through the pressure chamber connection passage RK1, and the connection passage RX2 included in the manifold MN2 is communicated with the corresponding pressure chamber CB2 through the pressure chamber connection passage RK2.

[0078] 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 be simply 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 be simply 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 be simply referred to as the supply connection passage RA, and when there is no need to distinguish between the connection passage RX1 and the connection passage RX2, it may be simply referred to as the connection passage RX.

[0079] 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 and 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 common electrode which is the other electrode.

[0080] Also, on the +Z side surface of the flow path forming substrate 642, a protective substrate 641 having substantially the same size as the flow path forming substrate 642 is joined. The protective substrate 641 forms a holding portion 644 which is a space for protecting the piezoelectric element 60. Further, the protective substrate 641 is provided with a through hole 643 penetrating along the Z direction. The end 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 of the lead electrode 611 exposed within this through hole 643.

[0081] Also, a case 660 which 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 its -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 of the protective substrate 641 joined to the flow path forming substrate 642. And with the flow path forming substrate 642 etc. accommodated in the recess 665, the -Z side opening surface of the recess 665 is sealed by the communication plate 630. Thereby, on the outer peripheral portion of the flow path forming substrate 642, supply communication paths RB1 and supply communication paths 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.

[0082] Further, on the surface of the communication plate 630 where the supply communication path RA and the connection communication path RX open, a compliance substrate 620 is provided. By this compliance substrate 620, the openings of the supply communication path RA and the connection communication path RX are sealed. 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 such as stainless steel.

[0083] Also, the case 660 is provided with an introduction path 661 for supplying ink to the manifold MN. Further, the case 660 is provided with a connection port 662 through which the wiring member 388 is inserted and communicates with the through hole 643 of the protection substrate 641. The connection port 662 is an opening penetrating along the Z direction.

[0084] 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 COF (Chip On Film) mounted.

[0085] 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 and COMB, and ejects ink in response to the drive of the piezoelectric element 60.

[0086] 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 that penetrate the fixing plate 39 in the Z direction. Six ejection modules 23 are fixed to the fixing plate 39 such that the liquid ejection surfaces 623a included in the six ejection modules 23 are exposed from the respective six exposed openings 391.

[0087] The flow path distribution unit 37 is located on the +Z side of the ejection module 23. Four introduction connection parts 373 are provided on the +Z side surface of the flow path distribution unit 37. The four introduction connection parts 373 are flow path pipes that protrude in the +Z direction along the Z direction from the +Z side surface of the flow path distribution unit 37, and communicate with flow path holes (not shown) formed on the -Z side surface of the flow path structure 34 described later. Also, on the -Z side surface of the flow path distribution unit 37, flow path pipes (not shown) that communicate with the corresponding introduction connection parts 373 among the four introduction connection parts 373 are located. The flow path pipes (not shown) located on the -Z side surface of the flow path distribution unit 37 are connected to the introduction paths 661 each of the six ejection modules 23 has. Further, the flow path distribution unit 37 has six openings 371 that penetrate in the Z direction. Wiring members 388 each of the six ejection modules 23 has are inserted through the six openings 371.

[0088] The head substrate 35 is located on the +Z side of the flow path distribution section 37. The head substrate 35 is provided with a connector CN1 that is electrically connected to the collective substrate 33 described later, and a cable FC. Further, four openings 351 and two notches 353 are formed in the head substrate 35. Wiring members 388 included in the ejection modules 23-2 to 23-5 are inserted through the four openings 351. Then, the respective wiring members 388 of the ejection modules 23-2 to 23-5 that have passed through the four openings 351 are electrically connected to the head substrate 35 by soldering or the like. Also, a wiring member 388 included in the ejection module 23-1 passes through one of the two notches 353, and a wiring member 388 included in the ejection module 23-6 passes through the other of the two notches 353. Then, the respective wiring members 388 of the ejection modules 23-1 and 23-6 that have passed through the respective two notches 353 are electrically connected to the head substrate 35 by soldering 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 ejection modules 23-1 to 23-6, and outputs the signals output from each of the ejection modules 23-1 to 23-6 to the collective substrate 33 described later via the connector CN1 and the cable FC. In addition, four notches 355 are formed at the four corners of the head substrate 35. Four introduction connection portions 373 included in the flow path distribution section 37 located on the -Z side of the head substrate 35 pass through the four notches 355. Then, the four introduction connection portions 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.

[0089]

[0090] ​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.

[0091] Also, 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. The connector CN1 and the cable FC provided on the head substrate 35 are inserted into the through hole 343. In addition, inside the flow path structure 34, in addition to the ink flow path that connects the supply connection part 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.

[0092] 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.

[0093] Each of the four supply holes 311 has inserted therein the four supply connection parts 341 that the flow path structure 34 has. Then, ink is supplied from the liquid container 2 to the four supply connection parts 341 passing through the four supply holes 311 via a tube or the like (not shown).

[0094] The holding members 315 and 317 sandwich and hold the assembly substrate 33 in a state where a part of the assembly substrate 33 is inserted through the assembly substrate insertion portion 313. Connectors CN1 and 330 are provided on the assembly substrate 33. Various signals such as the data signal DATA output by the control unit 10, the drive signals COMA, COMB, COMC, the reference voltage signal VBS, and other power supply voltages are input to the connector 330. The connector CN1 is inserted through the assembly substrate insertion portion 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. The details of the electrical connection between the assembly substrate 33 and the head substrate 35 will be described later.

[0095] In the head module 21 configured as described above, the liquid container 2 and the supply connection portion 341 communicate with each other through a tube or the like (not shown), and 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 through the ink flow path formed inside the flow path structure 34 to a flow path hole (not shown) formed on the -Z side surface of the flow path structure 34 of 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 portions 373 of the flow path distribution portion 37.

[0096] The ink supplied to the flow path distribution portion 37 through the four introduction connection portions 373 is distributed corresponding to each of the six ejection modules 23 in the ink flow path (not shown) formed inside the flow path distribution portion 37, and then supplied to the introduction path 661 of 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 portion 600.

[0097] The control unit 10 and the head module 21 are electrically connected by a cable (not shown). Various signals including drive signals COMA, COMB, COMC, a reference voltage signal VBS, and a data signal DATA are input from the control unit 10 to the head module 21 via 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 collective substrate 33 and the head substrate 35 and are supplied to the ejection module 23. In the ejection module 23, drive signals VOUT are generated based on the drive signals COMA, COMB, COMC corresponding to each of the n ejection units 600 and the data signal DATA, and are supplied to the piezoelectric elements 60 included in the corresponding ejection units 600. As a result, the piezoelectric elements 60 are driven based on the drive signals VOUT. Then, the ink stored in the pressure chamber CB included in the ejection unit 600 is ejected according to the driving of the piezoelectric elements 60.

[0098] 4. Electrical Connection between the Collective 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 collective 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 collective 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 collective 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 an example of the electrical connection between the collective substrate 33 and the head substrate 35 when the head module 21 is viewed from the direction along the X direction.

[0099] As shown in FIGS. 11 to 13, the head substrate 35 has a surface 35a and a surface 35b. The head substrate 35 extends along a plane formed by the X direction and the Y direction for both the surface 35a and the surface 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 portion 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 respectively on the +X side of the four openings 351 formed side by side and on 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.

[0100] Then, via the wiring member 388 passing through the two cutouts 353 and the four openings 351 formed in the head substrate 35 as described above, the head substrate 35 is electrically connected to six ejection modules 23. That is, the head substrate 35 transmits drive signals COMA, COMB, COMC, print data signal SI, latch signal LAT, and clock signal SCK to the drive signal selection control circuit 2 00 mounted on the wiring member 388 of the ejection module 23 by COF. This head substrate 35 is an example of the first substrate.

[0101] Further, on the -Y side of the four openings 351 arranged side by side along the X direction, connectors CN1, CN2, a cable FC, and an integrated substrate 33 are located.

[0102] 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 such that the surface 33a of the integrated substrate 33 intersects with 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. Cables (not shown) that are electrically connected to the control unit 10 are 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.

[0103] The cable FC, and the connectors CN1 and CN2 electrically connect the integrated substrate 33 and the head substrate 35.

[0104] 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) on 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 coating such as a polyimide film or a solder resist with a thickness of 10 μm to 50 μm. That is, on the FPC, fine wiring patterns with a cross-sectional area of 0.0003 to 0.0025 mm 2 are formed at high density.

[0105] Such an FPC, in addition to the base material, wiring pattern, and coating described above, includes an adhesive for bonding them, and generally has a thickness of 100 μm or less, which is very thin. Therefore, it can be bent and the substrate to be connected can be electrically connected with a high degree of freedom. Furthermore, as described above, an 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 level of reliability.

[0106] As described above, the cable FC includes a wiring pattern for electrically connecting the collective substrate 33 and the head substrate 35. Here, the cable FC may electrically connect the head substrate 35 and the collective substrate 33 by being connected to the head substrate 35 and the collective substrate 33 by, for example, solder or the like. Alternatively, the cable FC may electrically connect the head substrate 35 and the collective substrate 33 by being electrically connected to the head substrate 35 and the collective substrate 33 via a connector (not shown). Here, the cable FC that electrically connects the collective substrate 33 and the head substrate 35 is an example of a second connection member, and the wiring pattern included in the cable FC is an example of a second conductive portion.

[0107] The connector CN1 is electrically connected to the surface 33b of the collective substrate 33. Further, the connector CN2 is located on the -Y side of the collective substrate 33 and is electrically connected to the surface 35a of the head substrate 35. When the connector CN1 and the connector CN2 are fitted to each other, the connector CN1 and the connector CN2 are electrically connected, and 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 connectors CN1 and CN2 are directly fitted to each other without passing through a cable or the like, thereby electrically connecting the collective substrate 33 and the head substrate 35. That is, the connectors CN1 and CN2 are directly fitted to each other without passing through a cable or the like, thereby electrically connecting the collective substrate 33 and the head substrate 35.

[0108] 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. Further, 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.

[0109] 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 show 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.

[0110] 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.

[0111] 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.

[0112] The insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p are rectangular connection pins having conductivity with one side having a width of 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 width pw.

[0113] 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 side by side in 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 a pitch distance ph1, includes cases where it can be regarded as equal intervals including variations and the like.

[0114] 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 (i is any one 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.

[0115] 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.

[0116] 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 distances ph1 and 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.

[0117] 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 project 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 collective board 33 and connected to the collective board 33 by solder or the like, the connector CN1 is electrically connected to the collective board 33.

[0118] 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.

[0119] 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.

[0120] Also, the substrate connection terminals 411a-1 to 411a-p are arranged in the order of 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 on the +R1 side of the substrate connection terminals 411a-1, 411a-2,..., 411a-p arranged in the direction along the P1 direction, and in the direction along the P1 direction, from the -P1 side to the +P1 side, the substrate They are arranged in order of the connection terminals 411b-1, 411b-2, …, 411b-p. The board connection terminal 411a-1 and the board connection terminal 411b-1 are arranged side by side in the direction along the R1 direction, the board connection terminal 411a-p and the board connection terminal 411b-p are arranged side by side in the direction along the R1 direction, and the board connection terminal 411a-i and the board connection terminal 411b-i are arranged side by side in the direction along the R1 direction.

[0121] The holding member 420 holds 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, 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 board connection terminals 411a-1 to 411a-p, 411b-1 to 411b-p.

[0122] 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 near the ejection unit 600 where the ink is ejected.

[0123] 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 P. Therefore, it is required that the characteristics of the connectors of the head module 21 are not likely to change even when various types of solvents adhere thereto. By using a PBT resin as the holding member 420 of the connector CN1 of the head module 21, which has excellent insulation performance, low water absorption rate, and excellent oil resistance and solvent resistance, 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, by including the PBT resin in the holding member 420 of the connector CN1, 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.

[0124] 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 the insertion pin 410a-i and the insertion pin 410a-i+1, and a holding member 420 that holds the insertion pins 410a-1 to 410a-p, 410b-1 to 410b-p in an insulated state from each other. The connector CN1 is provided on the assembly board 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.

[0125] 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 show arrows indicating the P2 direction, Q2 direction, and R2 direction that are orthogonal to each other. Also, in the following description, the starting side of the arrow indicating the P2 direction is referred to as the -P2 side, the tip side is referred to as the +P2 side, the starting side of the arrow indicating the Q2 direction is referred to as the -Q2 side, the tip side is referred to as the +Q2 side, and the starting side of the arrow indicating the R2 direction shown may be referred to as the -R2 side, and the tip side may be referred to as the +R2 side.

[0126] FIG. 17 is a diagram showing an example of the structure of the connector CN2 when viewed from a direction along the Q2 direction, FIG. 18 is a diagram showing an example of the structure of the connector CN2 when viewed from a direction along the R2 direction, and FIG. 19 is a diagram showing an example of the structure of the connector CN2 when viewed from a direction along the P2 direction.

[0127] As shown in FIGS. 17 to 19, the connector CN2 includes 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.

[0128] The insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p are recesses that open on the +R2 side surface of the connector CN2 and are formed from the opening along the R2 direction toward the -R1 side. Inside each of the recesses formed as the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p, a conductive member (not shown) is provided.

[0129] The insertion holes 450a-1 to 450a-p are arranged at equal intervals, separated by a pitch distance ps1, in the order of the 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 located on the -Q2 side of the insertion holes 450a-1 to 450a-p arranged along the P2 direction, and are arranged at equal intervals, separated by a pitch distance ps1, in the order of the insertion holes 450b-1, 450b-2, …, 450b-p from the -P2 side to the +P2 side in the direction along the P2 direction. Here, being arranged at equal intervals with a separation of the pitch distance ps1 includes cases where it can be regarded as equal intervals including variations and the like.

[0130] 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.

[0131] The board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p are conductive members 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 the board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p are inserted into the head board 35 and connected to the head board 35 by solder or the like, the connector CN2 is electrically connected to the head board 35.

[0132] The board 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 conductive parts (not shown) provided inside each of the insertion holes 450a-1 to 450a-p. Specifically, the board connection terminal 451a-1 is electrically connected to a conductive part (not shown) provided inside the insertion hole 450a-1, the board connection terminal 451a-p is electrically connected to a conductive part (not shown) provided inside the insertion hole 450a-p, and the board connection terminal 451a-i is electrically connected to a conductive part (not shown) provided inside the insertion hole 450a-i.

[0133] Also, the board 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 conductive parts (not shown) provided inside each of the insertion holes 450b-1 to 450b-p. Specifically, the board connection terminal 451b-1 is electrically connected to a conductive part (not shown) provided inside the insertion hole 450b-1, the board connection terminal 451b-p is electrically connected to a conductive part (not shown) provided inside the insertion hole 450b-p, and the board connection terminal 451b-i is electrically connected to a conductive part (not shown) provided inside the insertion hole 450b-i.

[0134] And the board connection terminals 451a-1 to 451a-p are arranged in the order of the board 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 board connection terminals 451b-1 to 451b-p are arranged in the order of the board connection terminals 451b-1, 451b-2, …, 451b-p from the -P2 side to the +P2 side in the direction along the P2 direction. And the board connection terminal 451a-1 and the board connection terminal 451b-1 are arranged side by side in the direction along the Q2 direction, the board connection terminal 451a-p and the board connection terminal 451b-p are arranged side by side in the direction along the Q2 direction, and the board connection terminal 451a-i and the board connection terminal 451b-i are arranged side by side in the direction along the Q2 direction.

[0135] The holding member 460 holds the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and the board 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 board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p.

[0136] Such a holding member 460 also preferably 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 characteristics of the holding member 460 is reduced, and the possibility of a change in the characteristics 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 various signals propagated through the conductive members formed inside the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and 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 signals propagated through the conductive members formed inside the insertion holes 450a-1 to 450a-p, 450b-1 to 450b-p and the board connection terminals 451a-1 to 451a-p, 451b-1 to 451b-p is improved.

[0137] The connector CN2 configured as described above has 2p pins, the same number as the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p of the connector CN1, and has insertion holes 450a-1 to 450a-p and 450b-1 to 450b-p provided corresponding to the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p of the connector CN1, which is a so-called pin socket. And the connector CN2 is provided on the head substrate 35 such that each of the P2 direction, Q2 direction, and R2 direction shown in FIGS. 17 to 19 is along each of the X direction, Y direction, and Z direction shown in FIGS. 11 to 13.

[0138] 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 such that the connector CN1 is located on the +Z side and the connector CN2 is located on the -Z side along the Z direction. 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, whereby the connector CN1 and the connector CN2 are electrically connected. 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.

[0139] 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. Therefore, the substrate connection terminal 411a-1 electrically connected to the insertion pin 410a-1 is electrically connected to the substrate connection terminal 451a-1 electrically connected to the conductive member formed inside the insertion hole 450a-1. As a result, the collective substrate 33 electrically connected via the substrate connection terminal 411a-1 and the head substrate 35 electrically connected via the substrate connection terminal 451a-1 are electrically connected.

[0140] Similarly, the insertion pins 410a-i of the connector CN1 are inserted into the insertion holes 450a-i of the connector CN2. As a result, the insertion pins 410a-i and the conductive members formed inside the insertion holes 450a-i are electrically connected. Therefore, the board connection terminals 411a-i that are electrically connected to the insertion pins 410a-i are electrically connected to the board connection terminals 451a-i that are electrically connected to the conductive members formed inside the insertion holes 450a-i. As a result, the collective board 33 that is electrically connected via the board connection terminals 411a-i and the head board 35 that is electrically connected via the board connection terminals 451a-i are electrically connected.

[0141] Also, 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.

[0142] Here, the connectors CN1 and CN2 that electrically connect the head board 35 and the collective board 33 are an example of a first connection member, and the insertion pins 410b-i included in the connector CN1 are an example of a first conductive portion.

[0143] Next, the propagation paths through which various signals propagate in the collective board 33 and the head board 35 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.

[0144] Among the drive signals COMA, COMB, COMC, and the data signal DATA input to the integrated substrate 33, the data signal DATA propagates through the integrated substrate 33 and is input to the restoration circuit 220 provided on the integrated substrate 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 integrated substrate 33 propagates the clock signal SCK, the print data signal SI, and the latch signal LAT generated by this restoration circuit 220, and the drive signals COMA, COMB, COMC input via the connector 330 to the head substrate 35.

[0145] The integrated substrate 33 and the head substrate 35 are electrically connected by connectors CN1, CN2 and a cable FC. Specifically, the connector CN1 is electrically connected to the surface 33b of the integrated substrate 33 and is fitted into the connector CN2 electrically connected to the surface 35a of the head substrate 35, thereby electrically connecting the integrated substrate 33 and the head substrate 35. One end of the cable FC is electrically connected to the surface 33a of the integrated substrate 33, and the other end is electrically connected to the surface 35a of the head substrate 35, thereby electrically connecting the integrated substrate 33 and the head substrate 35. That is, the connectors CN1, CN2 and the cable FC are electrically connected to different surfaces of the integrated substrate 33. connected.

[0146] Among the clock signal SCK, print data signal SI, and latch signal LAT propagated through the integrated substrate 33 and the drive signals COMA, COMB, and 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 and 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 integrated 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 integrated substrate 33 to the head substrate 35 via the wiring pattern included in the cable FC.

[0147] Also, the drive signals COMA and COMB, which have a large voltage value and can thus generate a large current, are propagated from the integrated substrate 33 to the head substrate 35 via the insertion pins 410a-1 to 410a-p and 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 and 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.

[0148] Specifically, the drive signal COMA, which can generate a large current, is propagated from the integrated 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, and the drive signal COMB, which can generate a large current, is propagated from the integrated substrate 33 to the head substrate 35 via the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p 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.

[0149] Here, the drive signal COMC supplied to the integrated 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 propagates is smaller than the amount of current generated when the drive signals COMA and COMB propagate. Such a drive signal COMC with a small amount of current 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 propagating 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 propagating 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.

[0150] 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 amount of current is propagated using the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p, there is a risk of over-specification. As a result, there is a risk of hindering 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 amount of 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. As a result, the miniaturization of the head module 21 becomes possible.

[0151] Here, whether the drive signal COMC is propagated 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 according to the amount of current generated when the drive signal COMC is propagated. Specifically, when the number of discharge units 600 included in the discharge 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, if the drive signal COMC is propagated through the wiring pattern included in the cable FC with a small cross-sectional area, it is necessary to propagate the drive signal COMC using many wiring patterns included in the cable FC. As a result, the cable FC becomes larger. Therefore, when the number of discharge units 600 included in the discharge 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.

[0152] On the other hand, when the number of discharge units 600 included in the discharge module 23 is less than a predetermined number, it is estimated that the amount of current generated when the drive signal COMC is propagated decreases. 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 with a large cross-sectional area, there is a risk of excessive specifications. Therefore, when the number of discharge units 600 included in the discharge module 23 is less than a predetermined number, the drive signal COMC is preferably propagated through the wiring pattern included in the cable FC with a small cross-sectional area.

[0153] Then, the clock signal SCK, print data signal SI, and 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 a 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 the COF on the wiring member 388 generates a drive signal VOUT corresponding to a plurality of ejection units 600, and the generated drive signal VOUT is supplied to the piezoelectric element 60 included in the corresponding ejection unit 600. As a result, the piezoelectric element 60 is driven, and an amount of ink corresponding to the drive of the piezoelectric element 60 is ejected from the nozzle N.

[0154] Here, the integrated substrate 33 is an example of the second substrate, the surface 33b of the integrated substrate 33 is an example of the first surface, and the surface 33a of the integrated substrate 33 is an example of the second surface.

[0155] 5. Operational Effects In recent years, in the liquid ejection device 1, there has been an increasing demand for increasing the image formation speed, which is the speed at which a desired image is formed on the medium P. As one method for realizing such an increase in the image formation speed, as shown in FIG. 3 and the like of the present embodiment, the drive circuit unit 50 included in the control unit 10 transfers a drive signal COMA including only a trapezoidal waveform Adp for ejecting a large amount of ink and a drive signal COMB including only a trapezoidal waveform Bdp for ejecting a small amount of ink to the head module 21 at the same time. In the ejection module 23 of the head module 21, a method of controlling the dot size formed on the medium P by switching whether to supply the drive signal COMA to the piezoelectric element 60 or the drive signal COMB to the piezoelectric element 60 at the period T is conceivable. As a result, compared with the method of forming dots on the medium P by selecting a trapezoidal waveform supplied to the piezoelectric element from a drive signal including a plurality of trapezoidal waveforms in order as described in Japanese Patent Application Laid-Open No. 2016-179586 and ejecting ink in multiple times based on the selected trapezoidal waveform, it is possible to shorten the time required for the propagation of the trapezoidal waveform. As a result, the period T defined by the drive signal can be shortened, and an increase in the image formation speed in the liquid ejection device 1 can be realized.

[0156] However, when realizing an increase in the image formation speed by using a method of transferring a drive signal COMA including only a trapezoidal waveform Adp for ejecting a large amount of ink and a drive signal COMB including only a trapezoidal waveform Bdp for ejecting a small amount of ink to the head module 21 at the same time, it is preferable that the drive signal COMA drives the piezoelectric element 60 so that a large amount of ink can be ejected with a small number of trapezoidal waveforms Adp, and the drive signal COMB drives the piezoelectric element 60 so that a small amount of ink can be ejected with a small number of trapezoidal waveforms Bdp. Therefore, it is necessary to increase the voltage values of the trapezoidal waveforms Adp and Bdp. As a result, the amount of current generated when the trapezoidal waveforms Adp and Bdp are propagated also increases.

[0157] As the current increases when such trapezoidal waveforms Adp and Bdp propagate, the drive signals COMA and COMB including the trapezoidal waveforms Adp and Bdp are required to propagate through a propagation path having a sufficient cross-sectional area from the perspective of current density. In particular, in the connection member that connects between substrates in the head module 21, unlike the wiring pattern formed on the substrate, it is difficult to individually form the cross-sectional area according to the amount of current of the propagated signal. Therefore, the drive signals COMA and COMB with a large amount of current may be propagated through a plurality of propagation paths from the perspective of ensuring a sufficient cross-sectional area. As a result, there has been a problem that the connection member that connects between substrates in the head module 21 becomes large-sized.

[0158] In response to such a problem, in the liquid ejection device 1 of the present embodiment, the head module 21 includes a cable FC including a wiring pattern that electrically connects the collective substrate 33 and the head substrate 35, and connectors CN1 and CN2 that electrically connect the collective substrate 33 and the head substrate 35 and include insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p having a larger cross-sectional area than the wiring pattern included in the cable FC. In other words, in the head module 21, the collective substrate 33 and the head substrate 35 are electrically connected by a plurality of connection methods having different cross-sectional areas of the conductive portions through which the signal propagates. Thereby, it becomes possible to select the voltage value of the signal propagating between the collective substrate 33 and the head substrate 35 and the current value generated when the signal propagates according to the cross-sectional area of the propagation path through which the signal propagates. Thereby, when the current value generated when the signal propagates between the collective substrate 33 and the head substrate 35 is small, by propagating the signal through a plurality of wiring patterns included in the cable FC having a small cross-sectional area, it is possible to reduce the possibility that the number of wiring patterns included in the cable FC significantly increases and the cable FC becomes large-sized. Therefore, it is possible to reduce the possibility that the amount of current accompanying the drive signal increases due to the increase in the image formation speed and the head unit becomes large-sized due to the increase in the amount of current.

[0159] In the liquid ejection device 1 of this embodiment, the head module 21 propagates the driving signals COMA and COMB, which have a large voltage value, through the insertion pins 410a-1 to 410a-p and 410b-1 to 410b-p, which have a large cross-sectional area, and propagates the clock signal SCK, the print data signal SI, and the latch signal LAT, which have a small voltage value, through the wiring pattern included in the cable FC. The liquid ejection device 1 has several thousand ejection parts 600, and therefore the clock signal SCK, the print data signal SI, and the latch signal LAT, which have a large voltage value, contain a lot of information. By propagating the clock signal SCK, the print data signal SI, and the latch signal LAT, which contain such a lot of information, through the wiring pattern included in the cable FC, which can form a high-density wiring pattern, it becomes possible to propagate the clock signal SCK, the print data signal SI, and the latch signal LAT in parallel without increasing the size of the cable FC, and it becomes possible to further increase the image formation speed.

[0160] Although the embodiments have been described above, the present invention is not limited to these embodiments, and can be embodied in various forms without departing from the spirit and scope of the present invention. For example, the above-described embodiments can be appropriately combined.

[0161] The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purpose and effect). 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 have the same effects as the configurations described in the embodiments or that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0162] The following can be derived from the above-described embodiment.

[0163] One aspect of the head unit is an ejection section including a piezoelectric element driven by a first drive signal, the ejection section ejecting liquid in response to the driving of the piezoelectric element; A switching circuit that switches whether to supply the first drive signal to the piezoelectric element based on the ejection control signal; A first substrate that propagates the first drive signal and the ejection control signal to the switching circuit; A second substrate to which the first drive signal and the ejection control signal are supplied and that propagates the first drive signal and the ejection control signal to the first substrate; A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; Comprising; The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion.

[0164] According to this head unit, there are a first connection member including a first conductive portion that electrically connects a first substrate and a second substrate, and a second connection member including a second conductive portion that electrically connects the first substrate and the second substrate, and the cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion. That is, in the head unit, the first substrate and the second substrate are electrically connected by a plurality of connection methods with different cross-sectional areas of the conductive portions. Thereby, according to the voltage value of the signal propagating between the first substrate and the second substrate and the current value generated when the signal propagates, it is possible to select a propagation path through which the signal propagates according to the cross-sectional area. As a result, when the current value generated when the signal propagates between the first substrate and the second substrate is large, by propagating the signal using a plurality of second conductive portions with a small cross-sectional area, it is possible to reduce the risk of the second connection portion including the second conductive portion becoming large. Therefore, even when the amount of current generated along with the drive signal increases due to an increase in the image formation speed, it is possible to reduce the risk of the head unit becoming large along with the increase in the amount of current.

[0165] In one aspect of the head unit, The first drive signal is propagated from the second substrate to the first substrate via the first conductive portion, The ejection control signal may be propagated from the second substrate to the first substrate via the second conductive portion.

[0166] According to this head unit, by propagating a first drive signal with a large voltage value from the second substrate to the first substrate through a first conductive portion with a large cross-sectional area, the second conductive portion included in the second connection portion does not significantly increase. Therefore, the risk of the second connection portion including the second conductive portion becoming large is reduced. Further, by propagating a discharge control signal with a small voltage value from the second substrate to the first substrate through a second conductive portion with a small cross-sectional area, the risk of the first connection portion having the first conductive portion becoming large due to excessive specifications caused by the discharge control signal with a small voltage propagating from the second substrate to the first substrate through the first conductive portion with a large cross-sectional area is also reduced. Therefore, the risk of the head unit becoming large is further reduced.

[0167] In one aspect of the head unit, The maximum value of the current flowing through the first conductive portion may be larger than the maximum value of the current flowing through the second conductive portion. It may be large.

[0168] According to this head unit, a signal with a large current value propagates through the first conductive portion with a large cross-sectional area, and a signal with a small current value propagates through the second conductive portion with a small cross-sectional area. Thus, the second conductive portion included in the second connection portion does not significantly increase. Therefore, the risk of the second connection portion including the second conductive portion becoming large is reduced. Further, the risk of the first connection portion having the first conductive portion becoming large due to excessive specifications is also reduced. Therefore, the risk of the head unit becoming large is further reduced.

[0169] In one aspect of the head unit, A second drive signal for driving the piezoelectric element may be supplied to the second substrate so that liquid is not discharged from the discharge portion.

[0170] In one aspect of the head unit, The first drive signal propagates through the first conductive portion and does not propagate through the second conductive portion. The second drive signal may propagate through the second conductive portion and not propagate through the first conductive portion.

[0171] In one aspect of the head unit, The first connection member is connected to the first surface of the second substrate, The second connection member may be connected to a second surface different from the first surface of the second substrate.

[0172] According to this head unit, since the second substrate is positioned between the first connection member and the second connection member, the signal propagated from the second substrate to the first substrate via the first connection member and the signal propagated from the second substrate to the first substrate via the second connection member are less likely to interfere with each other. Therefore, the stability of the operation of the head unit is improved.

[0173] One aspect of the liquid ejection device is, A drive circuit unit having a first drive signal output circuit that outputs a first drive signal, A discharge control unit that outputs a discharge control signal, A head unit that discharges liquid based on the first drive signal and the discharge control signal, Comprising, The head unit is, Including a piezoelectric element driven by the first drive signal, and a discharge unit that discharges liquid in response to the drive of the piezoelectric element, A switching circuit that switches whether to supply the first drive signal to the piezoelectric element based on the discharge control signal, A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit, A second substrate to which the first drive signal and the discharge control signal are supplied and that propagates the first drive signal and the discharge control signal to the first substrate, A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate, A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate, Having, The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion.

[0174] According to this liquid ejection device, the head unit has a first connection member including a first conductive portion that electrically connects the first substrate and the second substrate, and a second connection member including a second conductive portion that electrically connects the first substrate and the second substrate, and the cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion. That is, in the head unit, the first substrate and the second substrate are electrically connected by a plurality of different connection methods with different cross-sectional areas of the conductive portions. Thereby, according to the voltage value of the signal propagating between the first substrate and the second substrate and the current value generated when the signal propagates, it is possible to select the propagation path through which the signal propagates according to the cross-sectional area. Thereby, when the current value generated when the signal propagates between the first substrate and the second substrate is large, by propagating the signal using a plurality of second conductive portions with a small cross-sectional area, it is possible to reduce the risk of the second connection member including the second conductive portion becoming large. Therefore, even when the amount of current generated along with the drive signal increases due to an increase in the image formation speed, it is possible to reduce the risk of the head unit becoming large along with the increase in the amount of current.

[0175] In one aspect of the liquid ejection device, the first drive signal is propagated from the second substrate to the first substrate via the first conductive portion, and the ejection control signal may be propagated from the second substrate to the first substrate via the second conductive portion.

[0176] According to this liquid ejection device, by propagating the first drive signal with a large voltage value from the second substrate to the first substrate via the first conductive portion with a large cross-sectional area, the second conductive portion included in the second connection portion does not increase significantly, and thus the risk of the second connection portion including the second conductive portion becoming large is reduced. Further, by propagating the ejection control signal with a small voltage value from the second substrate to the first substrate via the second conductive portion with a small cross-sectional area, the risk of the first connection portion having the first conductive portion becoming large due to excessive specifications caused by the ejection control signal with a small voltage value propagating from the second substrate to the first substrate via the first conductive portion with a large cross-sectional area is also reduced. Therefore, the risk of the head unit becoming large is further reduced.

[0177] In one aspect of the liquid ejection device, The maximum value of the current flowing through the first conductive portion may be greater than the maximum value of the current flowing through the second conductive portion.

[0178] According to this liquid ejection device, a signal with a large current value is propagated through the first conductive portion with a large cross-sectional area, and a signal with a small current value is propagated through the second conductive portion with a small cross-sectional area. Thus, without a significant increase in the second conductive portion included in the second connection portion, the risk of the second connection portion including the second conductive portion becoming large is reduced. Further, the risk of the first connection portion having the first conductive portion becoming large due to excessive specifications is also reduced. Therefore, the risk of the head unit becoming large is further reduced.

[0179] In one aspect of the liquid ejection device, The drive circuit unit has a second drive signal output circuit that outputs a second drive signal for driving the piezoelectric element so that liquid is not ejected from the ejection portion. The second drive signal may be supplied to the second substrate.

[0180] In one aspect of the liquid ejection device, The first drive signal propagates through the first conductive portion and does not propagate through the second conductive portion. The second drive signal may propagate through the second conductive portion and not propagate through the first conductive portion.

[0181] In one aspect of the liquid ejection device, The first drive signal output circuit and the second drive signal output circuit may have the same circuit configuration.

[0182] According to this liquid ejection device, in the drive circuit unit, by making the first drive signal output circuit and the second drive signal output circuit have the same circuit configuration, the circuit layout in the drive circuit unit becomes easy.

[0183] In one aspect of the liquid ejection device, The first connection member is connected to the first surface of the second substrate, The second connection member may be connected to a second surface different from the first surface of the second substrate.

[0184] According to this liquid ejection device, since the second substrate is positioned between the first connection member and the second connection member, the signal propagated from the second substrate to the first substrate via the first connection member and the signal propagated from the second substrate to the first substrate via the second connection member are less likely to interfere with each other. Therefore, the stability of the operation of the head unit is improved.

[0185] In one aspect of the liquid ejection device, a plurality of the head units are provided, the plurality of head units may be arranged side by side along a direction intersecting with the conveyance direction in which the medium for ejecting the liquid is conveyed.

Explanation of reference numerals

[0186] 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... Media conveyance unit, 41... Conveyance motor, 42... Conveyance roller, 50... Drive circuit unit, 51-1 to 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... Cutouts, 371... Opening, 373... Introduction connection section, 388... Wiring member, 391... Exposed opening, 410a-1 to 410a-p, 410b-1 to 410b-p... Insertion pins, 411a-1 to 411a-p, 411b-1 to 411b-p... Substrate connection terminals, 413a-1 to 413a-p, 413b-1 to 413b-p... Internal electrodes, 420... Holding member, 450a-1 to 450a-p, 450b-1 to 450b-p... Insertion holes, 451a-1 to 451a-p, 451b-1 to 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... Media, 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 first drive signal, the discharge unit discharging liquid in response to driving of the piezoelectric element; A switching circuit that switches whether or not to supply the first drive signal to the piezoelectric element based on a discharge control signal; A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit; A second substrate to which the first drive signal and the discharge control signal are supplied, the second substrate propagating the first drive signal and the discharge control signal to the first substrate; A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; Comprising; The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion; A second drive signal for driving the piezoelectric element so that liquid is not discharged from the discharge unit is supplied to the second substrate; A head unit characterized by this.

2. The first drive signal propagates through the first conductive portion and does not propagate through the second conductive portion; The second drive signal propagates through the second conductive portion and does not propagate through the first conductive portion; The head unit according to claim 1, characterized by this.

3. The first connection member is connected to a first surface of the second substrate; The second connection member is connected to a second surface different from the first surface of the second substrate; The head unit according to claim 1 or 2, characterized by this.

4. A discharge unit including a piezoelectric element driven by a first drive signal, the discharge unit discharging liquid in response to driving of the piezoelectric element; A switching circuit that switches whether or not to supply the first drive signal to the piezoelectric element based on a discharge control signal; A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit; A second substrate to which the first drive signal and the discharge control signal are supplied, the second substrate propagating the first drive signal and the discharge control signal to the first substrate; A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; Comprising; The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion; The first connection member is connected to a first surface of the second substrate; The second connection member is connected to a second surface different from the first surface of the second substrate; A head unit characterized by this.

5. The first drive signal is propagated from the second substrate to the first substrate through the first conductive portion. The discharge control signal is propagated from the second substrate to the first substrate through the second conductive portion. The head unit according to any one of claims 1 to 4, characterized in that.

6. The maximum value of the current flowing through the first conductive portion is larger than the maximum value of the current flowing through the second conductive portion. The head unit according to any one of claims 1 to 5, characterized in that.

7. A drive circuit unit having a first drive signal output circuit that outputs a first drive signal; A discharge control unit that outputs a discharge control signal; A head unit that discharges liquid based on the first drive signal and the discharge control signal; Comprising: The head unit is Including a piezoelectric element driven by the first drive signal, and a discharge unit that discharges liquid in response to the drive of the piezoelectric element; A switching circuit that switches whether to supply the first drive signal to the piezoelectric element based on the discharge control signal; A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit; A second substrate to which the first drive signal and the discharge control signal are supplied and that propagates the first drive signal and the discharge control signal to the first substrate; A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; Having The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion. The drive circuit unit has a second drive signal output circuit that outputs a second drive signal for driving the piezoelectric element so that liquid is not discharged from the discharge unit. The second drive signal is supplied to the second substrate. A liquid discharge device, characterized in that.

8. The first drive signal propagates through the first conductive portion and does not propagate through the second conductive portion. The second drive signal propagates through the second conductive portion and does not propagate through the first conductive portion. The liquid discharge device according to claim 7, characterized in that.

9. The first drive signal output circuit and the second drive signal output circuit have the same circuit configuration. The liquid discharge device according to claim 7 or 8, characterized in that.

10. The first connection member is connected to the first surface of the second substrate. The second connection member is connected to a second surface different from the first surface of the second substrate. The liquid ejection device according to any one of claims 7 to 9, characterized in that...

11. A drive circuit unit having a first drive signal output circuit that outputs a first drive signal; A discharge control unit that outputs a discharge control signal; A head unit that discharges liquid based on the first drive signal and the discharge control signal; Comprising: The head unit is: Including a piezoelectric element driven by the first drive signal, and a discharge unit that discharges liquid in response to the drive of the piezoelectric element; A switching circuit that switches whether to supply the first drive signal to the piezoelectric element based on the discharge control signal; A first substrate that propagates the first drive signal and the discharge control signal to the switching circuit; A second substrate to which the first drive signal and the discharge control signal are supplied and that propagates the first drive signal and the discharge control signal to the first substrate; A first connection member including a first conductive portion that electrically connects the first substrate and the second substrate; A second connection member including a second conductive portion that electrically connects the first substrate and the second substrate; Having: The cross-sectional area of the first conductive portion is larger than the cross-sectional area of the second conductive portion; The first connection member is connected to a first surface of the second substrate; The second connection member is connected to a second surface different from the first surface of the second substrate. The liquid ejection device, characterized in that...

12. The first drive signal is propagated from the second substrate to the first substrate via the first conductive portion; The discharge control signal is propagated from the second substrate to the first substrate via the second conductive portion. The liquid ejection device according to any one of claims 7 to 11, characterized in that...

13. The maximum value of the current flowing through the first conductive portion is larger than the maximum value of the current flowing through the second conductive portion. The liquid ejection device according to any one of claims 7 to 12, characterized in that...

14. Comprising a plurality of the head units; The plurality of head units are arranged side by side along a direction intersecting with the conveyance direction in which the medium through which liquid is discharged is conveyed. The liquid ejection device according to any one of claims 7 to 13, characterized in that...

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