Liquid ejection device and head drive circuit

Abstract

The present application provides a liquid ejection device and a head driving circuit, which efficiently releases heat generated by a driving circuit, and includes a substrate having a first through-hole, a first driving circuit, a second driving circuit, and a third driving circuit, a metal frame, and a first screw inserted through the first through-hole and mounting the metal frame to the substrate. The first driving circuit outputs a first driving signal for driving a first piezoelectric element to cause an ejection head to eject a first ejection amount of liquid. The second driving circuit outputs a second driving signal for driving the first piezoelectric element to cause the ejection head to eject a second ejection amount of liquid. The third driving circuit outputs a third driving signal for driving the first piezoelectric element to cause the ejection head to not eject liquid. The first driving circuit, the second driving circuit, and the third driving circuit are arranged in order of the first driving circuit, the second driving circuit, and the third driving circuit in a direction on the substrate. The first through-hole is located between the first driving circuit and the second driving circuit in the direction.

Description

Technical Field

[0001] This invention relates to a liquid ejection device and a head drive circuit. Background Technology

[0002] In liquid ejection devices that form images or documents on a medium by ejecting ink as a liquid, a known configuration includes a drive element that is provided corresponding to each of a plurality of nozzles for ejecting liquid, and ink is ejected from the corresponding nozzle by driving the drive element. In such liquid ejection devices, the drive element is provided corresponding to each of the plurality of nozzles. Therefore, the drive circuit needs to output a drive signal including a current sufficient to drive multiple drive elements simultaneously. In particular, in liquid ejection devices using piezoelectric elements as drive elements, from an electrical point of view, the piezoelectric element is a capacitive load like a capacitor; therefore, from the viewpoint of driving the piezoelectric element with high precision, it is necessary to supply sufficient current to the piezoelectric element.

[0003] However, the drive circuit of the driving element generates significant heat due to the output of a drive signal containing a large current. When the heat generated in such a drive circuit affects the ejected liquid, the physical properties of the liquid may change. Furthermore, when the heat generated in the drive circuit affects the electronic components within the drive circuit, the characteristics of those components may also change. In other words, the heat generated in the drive circuit may reduce the stability of its operation and may also cause changes in the physical properties of the liquid, thus reducing the ejection characteristics of the liquid in the liquid ejection device. Therefore, various heat dissipation structures for efficiently releasing the heat from the drive circuit are being researched in liquid ejection devices.

[0004] For example, Patent Document 1 discloses the following technology: a liquid ejection device, in which a circuit board with multiple drive circuits is housed in a housing, the drive circuits output drive signals to drive piezoelectric elements as drive elements, by arranging the drive circuits with high heat generation among the multiple drive circuits near the air inlet of the housing, thereby improving the heat release efficiency of the drive circuits and improving the stability of the operation of the drive circuits.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-099835

[0006] In response to the market demand for increasingly faster ink ejection speeds in recent years, liquid ejection devices have been developed to increase the amount of ink ejected with a single drive waveform, based on the viewpoint that the drive waveform included in the drive signal of the drive element should have a shorter cycle, and that even with a shorter cycle, sufficient dot size can be formed. Consequently, the amount of current generated as the drive signal is transmitted increases, leading to an increase in heat generation in the drive circuit. The heat dissipation method described in Patent Document 1 is insufficient to address this increase in heat generation in the drive circuit; further improvements are required from the viewpoint of more efficiently dissipating the heat generated in the drive circuit. Summary of the Invention

[0007] One aspect of the liquid ejection device according to the present invention comprises:

[0008] The nozzle ejects liquid in response to the actuation of the first piezoelectric element;

[0009] The substrate has a first through hole;

[0010] The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate;

[0011] A metal frame is mounted on the substrate; and

[0012] A first screw is inserted through the first through hole to mount the metal frame onto the substrate.

[0013] The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid.

[0014] The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid.

[0015] The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid.

[0016] The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit.

[0017] The first through hole is located between the first driving circuit and the second driving circuit in the one direction.

[0018] One aspect of the head drive circuit according to the present invention is a head drive circuit for driving a jet head that ejects liquid in response to the driving of a first piezoelectric element, comprising:

[0019] The substrate has a first through hole;

[0020] The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate;

[0021] A metal frame is mounted on the substrate; and

[0022] A first screw is inserted through the first through hole to mount the metal frame onto the substrate.

[0023] The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid.

[0024] The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid.

[0025] The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid.

[0026] The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit.

[0027] The first through hole is located between the first driving circuit and the second driving circuit in the one direction. Attached Figure Description

[0028] Figure 1 This is a diagram showing a simplified configuration of a liquid ejection device.

[0029] Figure 2 This is a diagram showing a simplified configuration of the ejection unit.

[0030] Figure 3 This is a diagram showing an example of the signal waveforms of the drive signals COMA, COMB, and COMC.

[0031] Figure 4 This is a diagram illustrating the functional structure of the drive signal selection circuit.

[0032] Figure 5 This is a diagram illustrating an example of the decoded content in the decoder.

[0033] Figure 6 This is a diagram showing an example of the configuration of a selection circuit corresponding to an ejector section.

[0034] Figure 7 This is a diagram used to illustrate the operation of the drive signal selection circuit.

[0035] Figure 8 This is a diagram showing the configuration of the drive circuit.

[0036] Figure 9 This is a diagram showing the structure of the liquid ejection module.

[0037] Figure 10 This is a diagram illustrating an example of the structure of the ejection module.

[0038] Figure 11 This is a diagram showing an example of a cross-section of the ejection module.

[0039] Figure 12 This is a diagram illustrating an example of the structure of a head-driving module.

[0040] Figure 13 This is a diagram showing an example of a cross-sectional structure of a wiring board for arranging multiple drive circuits.

[0041] Figure 14 This is a diagram illustrating an example of the configuration of the first layer of a wiring substrate.

[0042] Figure 15 This is a diagram showing an example of a wiring pattern disposed on the second layer of a wiring substrate.

[0043] Figure 16 This is a diagram showing an example of a wiring pattern disposed on the third layer of a wiring substrate.

[0044] Figure 17 This is a diagram showing an example of a wiring pattern disposed on the fourth layer of a wiring substrate.

[0045] Figure 18 This is a diagram showing an example of the configuration of the first layer of the wiring substrate according to the second embodiment.

[0046] Figure 19 This is a diagram showing an example of a wiring pattern disposed on the second layer of the wiring substrate in the second embodiment.

[0047] Figure 20 This is a diagram showing an example of a wiring pattern disposed on the third layer of the wiring substrate in the second embodiment.

[0048] Figure 21 This is a diagram showing an example of a wiring pattern disposed on the fourth layer of the wiring substrate in the second embodiment.

[0049] Figure 22 This is a diagram showing an example of the configuration of the first layer of the wiring substrate according to the third embodiment.

[0050] Figure 23 This is a diagram showing an example of a wiring pattern disposed on the second layer of the wiring substrate in the third embodiment.

[0051] Figure 24 This is a diagram showing an example of a wiring pattern disposed on the third layer of the wiring substrate in the third embodiment.

[0052] Figure 25 This is a diagram showing an example of a wiring pattern disposed on the fourth layer of the wiring substrate in the third embodiment.

[0053] Figure 26 This is a diagram illustrating an example of the configuration of the first layer of a wiring substrate in a modified embodiment of the third embodiment.

[0054] Explanation of reference numerals in the attached figures

[0055] 1 Liquid ejection device; 2 Control unit; 3 Liquid container; 4 Conveying unit; 5 Ejection unit; 10 Head drive module; 20 Liquid ejection module; 23 Ejection module; 30 Wiring components; 31 Frame; 33 Assembly base plate; 34 Flow path structure; 35 Head base plate; 37 Distribution flow path; 39 Fixing plate; 41 Conveyor motor; 42 Conveyor roller; 50-1~50-j drive signal output circuit; 52, 52a, 52b, 52c drive circuit; 53 Reference voltage output circuit; 60 Piezoelectric element; 100 Control circuit; 101 Integrated circuit; 120 Conversion circuit; 200 Drive signal selection circuit; 201 Integrated 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 Transmission gates; 311 Opening; 313 Substrate insertion part; 315 Holding component; 330 Connection part; 341 Inlet part; 343 Through hole; 351 Opening; 352, 353, 355 Cutouts; 371 Opening; 373 Inlet part; 388 Wiring component; 391 Opening; 500 Integrated circuit; 510 Modulation circuit; 512, 513 Adder; 514 Comparator; 515 Inverter; 516 Integrator attenuator; 517 Attenuator; 520 Gate drive circuit; 521, 522 Gate driver; 550 Amplifier circuit; 560 Demodulation circuit; 570, 572 feedback circuit; 590 power supply circuit; 600 ejection section; 610 vibrating plate; 611 lead electrode; 620 malleable substrate; 621 sealing film; 622 fixing substrate; 623 nozzle plate; 623a liquid jet surface; 630 connecting plate; 641 protective substrate; 642 flow path forming substrate; 643 through hole; 644 protective space; 660 outer shell; 661 inlet channel; 662 connection port; 665 recess; 710 heat sink; 711 bottom; 712, 713 sides; 714 opening; 715-717 protrusions; 718 finned section; 720 heat-conducting component assembly; 730, 740, 750, 760 heat-conducting components; 770 cooling fan; 780 screw. ; 800 Drive circuit board; 810 Wiring board; 811-814 Edges; 820 Through hole; 831 First layer; 832 Second layer; 833 Third layer; 834 Fourth layer; 835 Fifth layer; 840 Insulating layer; C1-C5 Capacitors; CB Pressure chamber; CN1, CN2 Connection part; D1 Diode; FC Wiring component; L1 Inductor; Ln1, Ln2 Nozzle array; M1, M2 Transistor; MN Manifold; N Nozzle; P Dielectric; R1-R6 Resistors; RA, RB Supply connection channel; RK1, RK2 Pressure chamber connection channel; RR Nozzle connection channel; RX Connection connection channel; Su1, Su2 Flow path board; WA1-WA6, WB1-WB6, WC1-WC6 Wiring. Detailed Implementation

[0056] The preferred embodiments of the present invention will now be described using the accompanying drawings. The drawings are provided for ease of explanation. It should be noted that the embodiments described below are not intended to unduly limit the scope of the invention as defined in the claims. Furthermore, not all of the components described below are necessarily essential elements of the present invention.

[0057] 1. First Implementation Method

[0058] 1.1 Composition of the liquid ejection device

[0059] Figure 1 This is a diagram showing a simplified configuration of the liquid ejection device 1. Figure 1 As shown, the liquid ejection device 1 is a so-called line inkjet printer that forms a desired image on a medium P by ejecting ink from a medium P conveyed by the transport unit 4 at a desired timing. Here, in the following description, the direction in which the medium P is transported is sometimes referred to as the transport direction, and the width direction of the transported medium P is referred to as the main scanning direction.

[0060] like Figure 1 As shown, the liquid ejection device 1 includes a control unit 2, a liquid container 3, a conveying unit 4, and multiple ejection units 5.

[0061] The control unit 2 includes processing circuits such as a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), and storage circuits such as semiconductor memory. Based on image data supplied from an external device such as a host (not shown) located outside the liquid ejection device 1, the control unit 2 outputs signals controlling various elements of the liquid ejection device 1.

[0062] The liquid container 3 stores ink, which is one example of a liquid, that is supplied to the ejection unit 5. Specifically, the liquid container 3 stores ink of various colors that are ejected to the medium P, such as black, cyan, magenta, yellow, red, and gray ink.

[0063] The conveying unit 4 includes a conveying motor 41 and a conveying roller 42. A conveying control signal Ctrl-T output by the control unit 2 is input to the conveying unit 4. Then, based on the input conveying control signal Ctrl-T, the conveying motor 41 operates, and as the conveying motor 41 operates, the conveying roller 42 is driven to rotate, thereby conveying the medium P along the conveying direction.

[0064] Multiple ejection units 5 each have a head drive module 10 and a liquid ejection module 20. An image information signal IP output from the control unit 2 is input to the ejection unit 5, and ink stored in the liquid container 3 is supplied. Then, based on the image information signal IP input from the control unit 2, the head drive module 10 controls the operation of the liquid ejection module 20. According to the control of the head drive module 10, the liquid ejection module 20 ejects the ink supplied from the liquid container 3 to the medium P.

[0065] The liquid ejection device 1 in the first embodiment constitutes a so-called line inkjet printer, in which liquid ejection modules 20, each of a plurality of ejection units 5, are arranged and positioned along the main scanning direction to be wider than the width of the medium P, thereby enabling the ejection of ink to the entire area in the width direction of the transported medium P. It should be noted that the liquid ejection device 1 is not limited to a line inkjet printer.

[0066] Next, a brief description of the structure of the ejection unit 5 will be given. Figure 2 This is a diagram showing a simplified configuration of the ejection unit 5. (See diagram for example.) Figure 2 As shown, the ejection unit 5 includes a head drive module 10 and a liquid ejection module 20. Furthermore, in the ejection unit 5, the head drive module 10 and the liquid ejection module 20 are electrically connected via a wiring component 30.

[0067] The wiring component 30 is a flexible component used to electrically connect the head drive module 10 and the liquid ejection module 20, such as a flexible printed circuit board (FPC) or a flexible flat cable (FFC). It should be noted that the head drive module 10 and the liquid ejection module 20 may also be connected electrically without an FPC or FFC, for example, via a B2B (Board to Board) connector. Alternatively, they may be electrically connected via a combination of a B2B connector and an FPC or FFC.

[0068] The head drive module 10 has a control circuit 100, drive signal output circuits 50-1 to 50-m and a conversion circuit 120.

[0069] The control circuit 100 includes a CPU, FPGA, etc. The image information signal IP output by the control unit 2 is input to the control circuit 100. Based on the input image information signal IP, the control circuit 100 outputs signals to control each element of the ejection unit 5.

[0070] The control circuit 100 generates a basic data signal dDATA based on the image information signal IP to control the operation of the liquid ejection module 20, and outputs it to the conversion circuit 120. The conversion circuit 120 converts the basic data signal dDATA into a differential signal such as LVDS (Low Voltage Differential Signaling), and outputs it as the data signal DATA to the liquid ejection module 20. It should be noted that the conversion circuit 120 can also convert the basic data signal dDATA into a differential signal using a high-speed transmission method other than LVDS, such as LVPECL (Low Voltage Positive Emitter Coupled Logic) or CML (Current Mode Logic), and output it as the data signal DATA to the liquid ejection module 20. In addition, it can also output part or all of the input basic data signal dDATA as a single-ended data signal DATA to the liquid ejection module 20.

[0071] Additionally, the control circuit 100 outputs basic drive signals dA1, dB1, and dB1 to the drive signal output circuit 50-1. The drive signal output circuit 50-1 includes drive circuits 52a, 52b, and 52c. The basic drive signal dA1 is input to drive circuit 52a. After performing digital-to-analog conversion on the input basic drive signal dA1, drive circuit 52a amplifies it using Class D amplification to generate drive signal COMA1, which is then output to the liquid ejection module 20. The basic drive signal dB1 is input to drive circuit 52b. After performing digital-to-analog conversion on the input basic drive signal dB1, drive circuit 52b amplifies it using Class D amplification to generate drive signal COMB1, which is then output to the liquid ejection module 20. The basic drive signal dB1 is input to drive circuit 52c. After performing digital-to-analog conversion on the input basic drive signal dB1, drive circuit 52c amplifies it using Class D amplification to generate drive signal COMC1, which is then output to the liquid ejection module 20.

[0072] Here, the driving circuits 52a, 52b, and 52c only need to amplify the waveforms defined by the input basic driving signals dA1, dB1, and dC1 to generate driving signals COMA1, COMB1, and COMC1, respectively. They can replace Class D amplifier circuits, or include Class A, Class B, or Class AB amplifier circuits in addition to Class D amplifier circuits. Furthermore, the basic driving signals dA1, dB1, and dC1 only need to define the waveforms of the corresponding driving signals COMA1, COMB1, and COMC1, and can also be analog signals.

[0073] Additionally, the drive signal output circuit 50-1 includes a reference voltage output circuit 53. The reference voltage output circuit 53 generates a reference voltage signal VBS1 representing a constant potential of the reference potential of the piezoelectric element 60 (described later) in the liquid ejection module 20, and outputs it to the liquid ejection module 20. This reference voltage signal VBS1 can be, for example, a ground potential, or a constant potential such as 5.5V or 6V. Here, a constant potential includes a potential that is considered approximately constant after considering various variations such as potential variations caused by the operation of peripheral circuits, potential variations caused by deviations of circuit components, and potential variations caused by the temperature characteristics of circuit components.

[0074] The drive signal output circuits 50-2 to 50-m differ only in the input and output signals; they have the same configuration as drive signal output circuit 50-1. Specifically, drive signal output circuits 50-j (j being any one of 1 to m) include circuits equivalent to drive circuits 52a, 52b, and 52c, and a circuit equivalent to reference voltage output circuit 53. Based on the basic drive signals dAj, dBj, and dCj input from control circuit 100, they generate drive signals COMAj, COMBj, and COMCj, and a reference voltage signal VBSj, which are then output to the liquid ejection module 20.

[0075] Here, the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j have the same configuration. In the following description, unless there is a need for distinction, they will sometimes be simply referred to as drive circuit 52. In this case, the description will focus on drive circuit 52 generating drive signal COM based on the basic drive signal do and outputting it to liquid ejection module 20. However, when describing the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j separately, the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 will sometimes be referred to as drive circuits 52a1, 52b1, and 52c1, and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j will sometimes be referred to as drive circuits 52aj, 52bj, and 52cj.

[0076] The liquid ejection module 20 has a recovery circuit 220 and ejection modules 23-1 to 23-m.

[0077] The restoration circuit 220 restores the data signal DATA into a single-ended signal, separates it into signals corresponding to the ejection modules 23-1 to 23-m, and outputs them to the corresponding ejection modules 23-1 to 23-m.

[0078] Specifically, the restoration circuit 220 restores and separates the data signal DATA to generate a clock signal SCK1, a printing data signal SI1, and a latch signal LAT1 corresponding to the ejection module 23-1, and outputs them to the ejection module 23-1. Additionally, the restoration circuit 220 restores and separates the data signal DATA to generate a clock signal SCKj, a printing data signal SIj, and a latch signal LATj corresponding to the ejection module 23-j, and outputs them to the ejection module 23-j.

[0079] As described above, the restoration circuit 220 restores the differential signal DATA output by the head drive module 10 into a single-ended signal, and then separates the restored signal into signals corresponding to the ejection modules 23-1 to 23-m for output. Thus, the restoration circuit 220 generates clock signals SCK1 to SCKm, printing data signals SI1 to SIm, and latch signals LAT1 to LATm corresponding to each of the ejection modules 23-1 to 23-m, and outputs them to the corresponding ejection modules 23-1 to 23-m. It should be noted that any one of the clock signals SCK1 to SCKm, printing data signals SI1 to SIm, and latch signals LAT1 to LATm output by the restoration circuit 220 corresponding to each of the ejection modules 23-1 to 23-m can also be a common signal for all of the ejection modules 23-1 to 23-m.

[0080] Here, given that the restoration circuit 220 generates clock signals SCK1~SCKm, printing data signals SI1~SIm, and latch signals LAT1~LATm by restoring and separating the data signal DATA, the data signal DATA output by the control circuit 100 is a differential signal corresponding to the clock signals SCK1~SCKm, printing data signals SI1~SIm, and latch signals LAT1~LATm. Furthermore, the basic data signal dDATA, which forms the basis of the data signal DATA, includes signals corresponding to each of the clock signals SCK1~SCKm, printing data signals SI1~SIm, and latch signals LAT1~LATm. That is, the control circuit 100 outputs the basic data signal dDATA as a signal to control the operation of the ejection modules 23-1~23-m of the liquid ejection module 20.

[0081] The ejection module 23-1 includes a drive signal selection circuit 200 and a plurality of ejection sections 600. Furthermore, each of the plurality of ejection sections 600 includes a piezoelectric element 60. That is, the ejection module 23-1 has the same number of piezoelectric elements 60 as the plurality of ejection sections 600.

[0082] Drive signals COMA1, COMB1, COMC1, a reference voltage signal VBS1, a clock signal SCK1, a printing data signal SI1, and a latch signal LAT1 are input to the ejection module 23-1. These signals are then fed into the drive signal selection circuit 200 of the ejection module 23-1. Based on the input clock signal SCK1, printing data signal SI1, and latch signal LAT1, the drive signal selection circuit 200 selects or deselects the drive signals COMA1, COMB1, and COMC1 to generate a drive signal VOUT, which is then supplied to one end of the piezoelectric element 60 in the corresponding ejection section 600. Simultaneously, the reference voltage signal VBS1 is supplied to the other end of the piezoelectric element 60. The piezoelectric element 60 is then 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. As a result, ink is ejected from the corresponding ejection section 600.

[0083] Similarly, the ejection module 23-j has a drive signal selection circuit 200 and a plurality of ejection sections 600. Furthermore, each of the plurality of ejection sections 600 includes a piezoelectric element 60. That is, the ejection module 23-j has the same number of piezoelectric elements 60 as the plurality of ejection sections 600.

[0084] Drive signals COMAj, COMBj, COMCj, a reference voltage signal VBSj, a clock signal SCKj, a printing data signal SIj, and a latch signal LATj are input to the ejection module 23-j. These signals are then fed into the drive signal selection circuit 200 of the ejection module 23-j. Based on the input clock signal SCKj, printing data signal SIj, and latch signal LATj, the drive signal selection circuit 200 selects or deselects the drive signals COMAj, COMBj, and COMCj to generate a drive signal VOUT, which is then supplied to one end of the piezoelectric element 60 of the corresponding ejection section 600. Simultaneously, the reference voltage signal VBSj is supplied to the other end of the piezoelectric element 60. The piezoelectric element 60 is then 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. As a result, ink is ejected from the corresponding ejection section 600.

[0085] As described above, in the liquid ejection device 1 of the first embodiment, the control unit 2 controls the transport of the medium P via the transport unit 4 based on image data supplied by a host or other device (not shown), and controls the ejection of ink from the liquid ejection module 20 of the ejection unit 5. Thus, the liquid ejection device 1 can cause a desired amount of ink to land at a desired position on the medium P, thereby forming a desired image on the medium P.

[0086] Here, the ejection modules 23-1 to 23-m of the liquid ejection module 20 are identical in configuration, differing only in the input signals. Therefore, in the following description, unless it is necessary to distinguish between ejection modules 23-1 to 23-m, they will sometimes be simply referred to as ejection module 23. Furthermore, in this case, the drive signals COMA1 to COMAm input to the ejection module 23 will sometimes be referred to as drive signals COMA, drive signals COMB1 to COMBm as drive signals COMB, drive signals COMC1 to COMCm as drive signals COMC, reference voltage signals VBS1 to VBSm as reference voltage signals VBS, clock signals SCK1 to SCKm as clock signals SCK, printing data signals SI1 to SIm as printing data signals SI, and latch signals LAT1 to LATm as latch signals LAT.

[0087] 1.2 Functional Composition of the Drive Signal Selection Circuit

[0088] Next, the configuration and operation of the drive signal selection circuit 200 of the ejection module 23 will be explained. When explaining the configuration and operation of the drive signal selection circuit 200 of the ejection module 23, an example of the signal waveforms included in the drive signals COMA, COMB, and COMC input to the drive signal selection circuit 200 will first be explained.

[0089] Figure 3 This is a diagram illustrating an example of the signal waveforms for the drive signals COMA, COMB, and COMC. (See diagram for example.) Figure 3 As shown, the drive signal COMA includes a trapezoidal waveform Adp configured according to a period T from the rise of the latch signal LAT to the rise of the next latch signal LAT. The trapezoidal waveform Adp is a signal waveform that causes a predetermined amount of ink to be ejected from the ejection section 600 corresponding to the piezoelectric element 60 by means of being supplied to one end of the piezoelectric element 60.

[0090] The drive signal COMB includes a trapezoidal waveform Bdp configured in period T. This trapezoidal waveform Bdp is a signal waveform with a voltage amplitude smaller than that of the trapezoidal waveform Adp. It is a signal waveform that causes a smaller than specified amount of ink to be ejected from the ejection section 600 corresponding to the piezoelectric element 60 by means of ink supplied to one end of the piezoelectric element 60.

[0091] That is, the driving amount of piezoelectric element 60 when a driving signal COMA is supplied is greater than the driving amount of piezoelectric element 60 when a driving signal COMB is supplied. Furthermore, the amount of ink ejected from the corresponding ejection section 600 when a driving signal COMA is supplied is greater than the amount of ink ejected from the corresponding ejection section 600 when a driving signal COMB is supplied. In other words, the amount of ink ejected from the ejection section 600 corresponding to piezoelectric element 60 when a driving signal COMA is supplied is greater than the amount of ink ejected from the ejection section 600 corresponding to piezoelectric element 60 when a driving signal COMB is supplied. Therefore, the current generated with the transmission of the driving signal COMA is greater than the current generated with the transmission of the driving signal COMB.

[0092] Furthermore, the drive signal COMC includes a trapezoidal waveform Cdp configured according to a period T. This trapezoidal waveform Cdp is a signal waveform with a voltage amplitude smaller than that of trapezoidal waveforms Adp and Bdp. It is a signal waveform that, when supplied to one end of the piezoelectric element 60, causes the ink near the nozzle orifice to vibrate to a degree that prevents ink from being ejected from the ejection portion 600 corresponding to the piezoelectric element 60. This trapezoidal waveform Cdp, when supplied to the piezoelectric element 60, causes the ink near the nozzle orifice of the ejection portion 600, which includes the piezoelectric element 60, to vibrate. As a result, the possibility of increased viscosity of the ink near the nozzle orifice is reduced.

[0093] That is, drive signals COMA and COMB drive the corresponding piezoelectric element 60 to eject ink from the ejection section 600, and drive signal COMC drives the corresponding piezoelectric element 60 to prevent ink from being ejected from the ejection section 600. Therefore, the drive amount of the piezoelectric element 60 when drive signals COMA and COMB are supplied is greater than the drive amount of the piezoelectric element 60 when drive signal COMC is supplied. Consequently, the current generated with the transmission of drive signals COMA and COMB is greater than the current generated with the transmission of drive signal COMC.

[0094] Furthermore, at the start and end timings of each of the trapezoidal waveforms Adp, Bdp, and Cdp, the voltage values ​​of the trapezoidal waveforms Adp, Bdp, and Cdp are all the same voltage Vc. In other words, the trapezoidal waveforms Adp, Bdp, and Cdp are signal waveforms that begin and end with voltage Vc, respectively.

[0095] In the following description, the amount of ink ejected from the ejection section 600 corresponding to the piezoelectric element 60 when a trapezoidal waveform Adp is supplied to one end of the piezoelectric element 60 is sometimes referred to as a "large amount," and the amount of ink ejected from the ejection section 600 corresponding to the piezoelectric element 60 when a trapezoidal waveform Bdp is supplied to one end of the piezoelectric element 60 is sometimes referred to as a "small amount," which differs from the large amount. Furthermore, when a trapezoidal waveform Cdp is supplied to one end of the piezoelectric element 60, the ink near the nozzle opening vibrates to a degree that prevents it from being ejected from the ejection section 600 corresponding to the piezoelectric element 60, this is sometimes referred to as "micro-vibration."

[0096] As described above, in the liquid ejection device 1 of the first embodiment, the drive circuit 52a outputs a drive signal COMA to drive the piezoelectric element 60 to eject a large amount of ink of a predetermined quantity from the ejection section 600 of the ejection module 23, the drive circuit 52b outputs a drive signal COMB to drive the piezoelectric element 60 to eject a small amount of ink of less than the predetermined quantity from the ejection section 600 of the ejection module 23, and the drive circuit 52c outputs a drive signal COMC to drive the piezoelectric element 60 to prevent the ejection section 600 of the ejection module 23 from ejecting ink.

[0097] It should be noted that the signal waveforms included in the drive signals COMA, COMB, and COMC are not limited to... Figure 3 The illustrated signal waveforms can be varied depending on the type of ink ejected from the ejection section 600, the number of piezoelectric elements 60 driven by the drive signals COMA, COMB, and COMC, and the wiring length for transmitting the drive signals COMA, COMB, and COMC. That is, the drive signals COMA1 to COMAm can include different signal waveforms, and the amount of ink ejected from the ejection section 600 including the piezoelectric element 60 supplied with drive signal COMA1 can differ from the amount of ink ejected from the ejection section 600 including the piezoelectric element 60 supplied with drive signal COMAj. Similarly, the drive signals COMB1 to COMBm can include different signal waveforms, and the amount of ink ejected from the ejection section 600 including the piezoelectric element 60 supplied with drive signal COMB1 can differ from the amount of ink ejected from the ejection section 600 including the piezoelectric element 60 supplied with drive signal COMBj. Similarly, the drive signals COMC1 to COMCm may include different signal waveforms. The displacement generated by the piezoelectric element 60 when the drive signal COMC1 is supplied may be different from the displacement generated by the piezoelectric element 60 when the drive signal COMCj is supplied.

[0098] Next, the configuration and operation of the drive signal selection circuit 200, which outputs the drive signal VOUT by making the drive signals COMA, COMB, and COMC select or not select respectively, will be explained. Figure 4 This is a diagram illustrating the functional configuration of the drive signal selection circuit 200. (See diagram for example.) Figure 4 As shown, the drive signal selection circuit 200 includes a selection control circuit 210 and multiple selection circuits 230.

[0099] The selection control circuit 210 receives the printing data signal SI, the latch signal LAT, and the clock signal SCK. Furthermore, the selection control circuit 210 has n groups of shift registers (S / R) 212, latch circuits 214, and decoders 216 corresponding to each of the n ejector sections 600. That is, the drive signal selection circuit 200 includes the same number of n shift registers 212, n latch circuits 214, and n decoders 216 as the number of ejector sections 600.

[0100] The printing data signal SI is a signal synchronized with the clock signal SCK, comprising 2 bits of printing data [SIH, SIL]. This 2-bit printing data [SIH, SIL] is used to specify the dot size formed by the ink ejected from each of the n ejector sections 600, using any one of "Large Dot LD", "Small Dot SD", "No Ejection ND", and "Micro Vibration BSD". The printing data signal SI is maintained in shift register 212 corresponding to the ejector section 600 in 2-bit increments of printing data [SIH, SIL].

[0101] Specifically, n shift registers 212 corresponding to the ejector section 600 are cascaded together. The serially input printing data signal SI is sequentially transmitted to the subsequent stage of the cascaded shift registers 212 according to the clock signal SCK. Then, by stopping the supply of the clock signal SCK, two bits of printing data [SIH, SIL] corresponding to the ejector section 600 of that shift register 212 are held in the n shift registers 212. It should be noted that... Figure 4 In order to distinguish the cascaded n shift registers 212, they are recorded as level 1, level 2, ..., level n from the upstream side to the downstream side of the input printed data signal SI.

[0102] Each of the n latching circuits 214 latches together the 2 bits of printed data [SIH, SIL] held by the corresponding shift register 212 at the rising edge of the latch signal LAT.

[0103] Each of the n decoders 216 decodes the 2-bit printed data [SIH, SIL] latched by the corresponding latch circuit 214, and outputs selection signals S1, S2, and S3 corresponding to the logic level of the decoded content in each cycle T. Figure 5This is a diagram illustrating an example of the decoded content in decoder 216. Decoder 216 outputs latched 2-bit printed data [SIH, SIL] and Figure 5 The selection signals S1, S2, and S3 are specified by the logic level of the decoded content. For example, when the 2-bit printed data [SIH, SIL] latched by the corresponding latch circuit 214 is [1, 0] when input to the decoder 216 in the first embodiment, the decoder 216 sets the logic level of each of the selection signals S1, S2, and S3 to L, H, and L levels respectively during the period T.

[0104] Each of the n ejector sections 600 is provided with a corresponding selection circuit 230. That is, the drive signal selection circuit 200 has n selection circuits 230. The selection signals S1, S2, S3 and drive signals COMA, COMB, COMC, output by the decoder 216 corresponding to the same ejector section 600 are input to the selection circuit 230. Based on the selection signals S1, S2, S3 and drive signals COMA, COMB, COMC, the selection circuit 230 selects or deselects the drive signals COMA, COMB, COMC, generating a drive signal VOUT and outputting it to the corresponding ejector section 600.

[0105] Figure 6 This diagram shows an example of the configuration of a selection circuit 230 corresponding to an ejector section 600. (See diagram for example.) Figure 6 As shown, the selection circuit 230 has inverters 232a, 232b, 232c and transmission gates 234a, 234b, 234c.

[0106] The selection signal S1 is input to the positive control terminal of transmission gate 234a (not marked with a circle), while it is logically inverted by inverter 232a and input to the negative control terminal of transmission gate 234a (marked with a circle). Additionally, a drive signal COMA is supplied to the input terminal of transmission gate 234a. When the input selection signal S1 is at a high level (H), transmission gate 234a conducts between its input and output terminals; when the input selection signal S1 is at a low level (L), it de-conducts between the input and output terminals. That is, transmission gate 234a outputs the drive signal COMA to the output terminal when the selection signal S1 is at a high level (H), and does not output the drive signal COMA to the output terminal when the selection signal S1 is at a low level (L).

[0107] The selection signal S2 is input to the positive control terminal of transmission gate 234b (not marked with a circle), while it is logically inverted by inverter 232b and input to the negative control terminal of transmission gate 234b (marked with a circle). Additionally, a drive signal COMB is supplied to the input terminal of transmission gate 234b. When the input selection signal S2 is at a high level (H), transmission gate 234b conducts between its input and output terminals; when the input selection signal S2 is at a low level (L), it de-conducts between the input and output terminals. That is, transmission gate 234b outputs the drive signal COMB to its output terminal when the selection signal S2 is at a high level (H), and does not output the drive signal COMB to its output terminal when the selection signal S2 is at a low level (L).

[0108] The selection signal S3 is input to the positive control terminal of transmission gate 234c (not marked with a circle), and is logically inverted by inverter 232c before being input to the negative control terminal of transmission gate 234c (marked with a circle). Additionally, a drive signal COMC is supplied to the input terminal of transmission gate 234c. When the input selection signal S3 is at a high level (H), transmission gate 234c conducts between its input and output terminals; when the input selection signal S3 is at a low level (L), it de-conducts between the input and output terminals. That is, transmission gate 234c outputs the drive signal COMC to its output terminal when the selection signal S3 is at a high level (H), and does not output the drive signal COMC to its output terminal when the selection signal S3 is at a low level (L).

[0109] The outputs of transmission gates 234a, 234b, and 234c are connected together. That is, drive signals COMA, COMB, and COMC, which are selected or not selected by selection signals S1, S2, and S3, are supplied to the outputs of the commonly connected transmission gates 234a, 234b, and 234c. The selection circuit 230 outputs the signal supplied to this commonly connected output as a drive signal VOUT to the corresponding ejection section 600.

[0110] The operation of the drive signal selection circuit 200 is explained. Figure 7 This diagram illustrates the operation of the drive signal selection circuit 200. The printing data signal SI is input serially in sync with the clock signal SCK, and is sequentially transmitted in the shift register 212 corresponding to the ejector unit 600. Then, by stopping the input of the clock signal SCK, the two bits of printing data [SIH, SIL] corresponding to each ejector unit 600 are held in the corresponding shift register 212.

[0111] Then, when the latch signal LAT rises, the 2 bits of printed data [SIH, SIL] held by shift register 212 are latched together by latch circuit 214. It should be noted that in... Figure 7In the diagram, the 2-bit printed data [SIH, SIL] corresponding to the shift registers 212 of levels 1, 2, ..., n, which are latched by the latching circuit 214, are illustrated as LT1, LT2, ..., LTn.

[0112] The decoder 216 outputs logic level selection signals S1, S2, and S3 based on the dot size specified by the latched 2-bit printed data [SIH, SIL].

[0113] Specifically, when the printed data [SIH, SIL] is [1, 1], decoder 216 sets the logic levels of selection signals S1, S2, and S3 to H, L, and L levels during period T and outputs them to selection circuit 230. As a result, selection circuit 230 selects the trapezoidal waveform Adp during period T and outputs the drive signal VOUT corresponding to "large dot LD". Alternatively, when the printed data [SIH, SIL] is [1, 0], decoder 216 sets the logic levels of selection signals S1, S2, and S3 to L, H, and L levels during period T and outputs them to selection circuit 230. As a result, selection circuit 230 selects the trapezoidal waveform Bdp during period T and outputs the drive signal VOUT corresponding to "small dot SD". Alternatively, when the printed data [SIH, SIL] is [0, 1], decoder 216 sets the logic levels of selection signals S1, S2, and S3 to L, L, and L levels during period T and outputs them to selection circuit 230. As a result, selection circuit 230 does not select any of the trapezoidal waveforms Adp, Bdp, or Cdp during period T, and outputs a constant voltage Vc driving signal VOUT corresponding to "No ejection ND". Additionally, when the printed data [SIH, SIL] is [0, 0], decoder 216 sets the logic levels of selection signals S1, S2, and S3 to L, L, and H levels during period T and outputs them to selection circuit 230. As a result, selection circuit 230 selects trapezoidal waveform Cdp during period T and outputs the driving signal VOUT corresponding to "Micro-vibration BSD".

[0114] Here, when the selection circuit 230 does not select any of the trapezoidal waveforms Adp, Bdp, and Cdp, the voltage Vc supplied to the piezoelectric element 60 just now is maintained at one end of the corresponding piezoelectric element 60 through the capacitive component of the piezoelectric element 60. That is, the drive signal VOUT output by the selection circuit 230 at a constant voltage Vc includes the case where the voltage Vc just now, maintained by the capacitive component of the piezoelectric element 60, is supplied to the piezoelectric element 60 as the drive signal VOUT when none of the trapezoidal waveforms Adp, Bdp, and Cdp are selected as the drive signal VOUT.

[0115] As described above, the drive signal selection circuit 200 selects or deselects drive signals COMA, COMB, and COMC based on the printing data signal SI, latch signal LAT, and clock signal SCK, thereby generating a drive signal VOUT corresponding to each of the multiple ejector sections 600 and outputting it to the corresponding ejector section 600. This allows for individual control of the amount of ink ejected from each of the multiple ejector sections 600.

[0116] 1.3 Composition of the drive signal output circuit

[0117] Next, the structure and operation of the drive circuit 52 for the output drive signal COM will be explained. Figure 8 This diagram shows the configuration of the drive circuit 52. The drive circuit 52 includes an integrated circuit 500, an amplifier circuit 550, a demodulation circuit 560, feedback circuits 570 and 572, and other electronic components.

[0118] Integrated circuit 500 has multiple terminals including terminal In, terminal Bst, terminal Hdr, terminal Sw, terminal Gvd, terminal Ldr, and terminal Gnd. Integrated circuit 500 is electrically connected to an external substrate (not shown) via these terminals. Integrated circuit 500 includes a DAC (Digital to Analog Converter) 511, a modulation circuit 510, a gate drive circuit 520, and a power supply circuit 590.

[0119] The power supply circuit 590 generates voltage signals DAC_HV and DAC_LV and supplies them to DAC 511. DAC 511 converts the digital fundamental drive signal do of the input specified drive signal COM into an analog signal representing the voltage value between voltage signals DAC_HV and DAC_LV, i.e., the fundamental drive signal ao, and outputs it to the modulation circuit 510. Here, the maximum value of the voltage amplitude of the fundamental drive signal ao is defined by the voltage signal DAC_HV, and the minimum value is defined by the voltage signal DAC_LV. That is, the voltage signal DAC_HV is the reference voltage on the high-voltage side of DAC 511, and the voltage signal DAC_LV is the reference voltage on the low-voltage side of DAC 511. Then, the analog fundamental drive signal ao output by DAC 511 is amplified and becomes the drive signal COM. In other words, the fundamental drive signal ao is equivalent to the target signal before amplification of the drive signal COM.

[0120] The modulation circuit 510 generates a modulated signal Ms after modulating the basic drive signal ao, and outputs it to the gate drive circuit 520. The modulation circuit 510 includes adders 512 and 513, comparator 514, inverter 515, integrator attenuator 516, and attenuator 517.

[0121] The integrator attenuator 516 attenuates and integrates the drive signal COM input via terminal Vfb and supplies it to the - input terminal of adder 512. Additionally, the base drive signal ao is input to the + input terminal of adder 512. Then, adder 512 supplies the voltage obtained by subtracting the voltage of the - input terminal from the voltage of the + input terminal and integrating the result to the + input terminal of adder 513.

[0122] Attenuator 517 supplies a voltage, after attenuating the high-frequency component of the drive signal COM input via terminal Ifb, to the input terminal on the - side of adder 513. Additionally, the voltage output from adder 512 is input to the input terminal on the + side of adder 513. Then, adder 513 outputs a voltage signal Os, obtained by subtracting the voltage from the input terminal on the - side from the voltage at the input terminal on the + side, to comparator 514.

[0123] Comparator 514 outputs a modulated signal Ms, which is a pulse modulated signal of the voltage signal Os output from adder 513. Specifically, the modulated signal Ms output by comparator 514 becomes a high level (H level) when the voltage value of the voltage signal Os output from adder 513 rises and reaches a predetermined threshold Vth1 or higher, and becomes a low level (L level) when the voltage value of the voltage signal Os falls and falls below a predetermined threshold Vth2. The thresholds Vth1 and Vth2 are set to a relationship where threshold Vth1 => threshold Vth2.

[0124] The modulation signal Ms output from comparator 514 is supplied to gate driver 521 included in gate driver circuit 520, and after its logic level is inverted by inverter 515, it is supplied to gate driver 522 included in gate driver circuit 520. That is, signals with exclusive logic levels are input to gate driver 521 and gate driver 522. Here, exclusive logic levels strictly mean that the logic levels of the signals supplied to gate driver 521 and gate driver 522 will not simultaneously be H level, and more specifically, that transistors M1 and M2 included in amplifier circuit 550 described later will not be turned on simultaneously. Therefore, modulation circuit 510 may also include a timing control circuit for controlling the timing of the modulation signal Ms supplied to gate driver 521 and the signal after the logic level of the modulation signal Ms supplied to gate driver 522 is inverted.

[0125] The gate drive circuit 520 includes a gate driver 521 and a gate driver 522. The gate driver 521 performs a level shift on the modulation signal Ms output from the comparator 514 and outputs it as an amplification control signal Hgd from the terminal Hdr.

[0126] Specifically, a voltage is supplied to the high-side of the power supply voltage to the gate driver 521 via terminal Bst, and a voltage is supplied to the low-side via terminal Sw. Terminal Bst is connected to one end of capacitor C5 and the cathode of diode D1, which is used to prevent backflow. Terminal Sw is connected to the other end of capacitor C5. Furthermore, the anode of diode D1 is connected to terminal Gvd, which is supplied with a DC voltage Vm, for example, 7.5V, via a power supply circuit not shown. That is, a DC voltage Vm is supplied to the anode of diode D1. Therefore, the potential difference between terminals Bst and Sw is approximately equal to the voltage Vm. As a result, the gate driver 521 outputs an amplified control signal Hgd from terminal Hdr according to the input modulation signal Ms, which is a voltage value greater than the voltage Vm at terminal Sw.

[0127] Gate driver 522 operates at a lower potential than gate driver 521. Gate driver 522 levels the logic level of the modulation signal Ms output from comparator 514, which is inverted by inverter 515, and outputs it as an amplification control signal Lgd from terminal Ldr.

[0128] Specifically, the high-order side of the power supply voltage of the gate driver 522 is supplied with a voltage Vm, and the low-order side is supplied with a ground potential, such as 0V, via the terminal Gnd. Then, the gate driver 522 outputs an amplified control signal Lgd from the terminal Ldr, based on the signal after inverting the logic level of the input modulation signal Ms, which is a voltage value relative to the high voltage Vm of the terminal Gnd.

[0129] The amplifier circuit 550 includes transistor M1 and transistor M2.

[0130] Transistor M1 is a surface-mount FET (Field Effect Transistor). A DC voltage VHV, for example 42V, is supplied to the drain of transistor M1 as the amplification voltage. Furthermore, the gate of transistor M1 is electrically connected to one end of resistor R1, and the other end of resistor R1 is electrically connected to the terminal Hdr of integrated circuit 500. That is, an amplification control signal Hgd is supplied to the gate of transistor M1. Additionally, the source of transistor M1 is electrically connected to the terminal Sw of integrated circuit 500.

[0131] Transistor M2 is a surface-mount FET. The drain of transistor M2 is electrically connected to terminal Sw of integrated circuit 500. That is, the drain of transistor M2 is electrically connected to the source of transistor M1. The gate of transistor M2 is electrically connected to one end of resistor R2, and the other end of resistor R2 is electrically connected to terminal Ldr of integrated circuit 500. In other words, an amplification control signal Lgd is supplied to the gate of transistor M2. Additionally, a ground potential is supplied to the source of transistor M2.

[0132] That is, the driving circuit 52 includes surface-mount transistors M1 and M2. Furthermore, in the amplifier circuit 550 configured as described above, when transistor M1 is controlled to be off and transistor M2 is controlled to be on, the potential of the node connected to terminal Sw becomes ground potential. Therefore, a voltage Vm is supplied to terminal Bst. On the other hand, when transistor M1 is controlled to be on and transistor M2 is controlled to be off, the potential of the node connected to terminal Sw becomes voltage VHV. Therefore, a voltage signal of voltage VHV + Vm is supplied to terminal Bst. In other words, the gate driver 521 driving transistor M1 uses capacitor C5 as a floating power supply. Depending on the operation of transistors M1 and M2, the potential of terminal Sw changes to 0V or voltage VHV, thereby supplying an amplified control signal Hgd, with an L level of voltage VHV and an H level of voltage VHV + Vm, to the gate of transistor M1.

[0133] On the other hand, the gate driver 522 that drives transistor M2 is independent of the operation of transistors M1 and M2, and supplies an amplified control signal Lgd, with the L level being ground potential and the H level being voltage Vm, to the gate of transistor M2.

[0134] The amplifier circuit 550, configured as described above, generates an amplified modulation signal AMs at the connection point between the source of transistor M1 and the drain of transistor M2, which amplifies the modulation signal Ms based on voltage VHV. Then, the amplifier circuit 550 outputs the generated amplified modulation signal AMs to the demodulation circuit 560.

[0135] Demodulation circuit 560 demodulates the amplified modulation signal AMs output from amplifier circuit 550 to generate a drive signal COM, which is then output from drive circuit 52. Demodulation circuit 560 includes an inductor L1 and a capacitor C1. One end of inductor L1 is connected to one end of capacitor C1. The amplified modulation signal AMs is input to the other end of inductor L1. Additionally, a ground potential is supplied to the other end of capacitor C1. That is, in demodulation circuit 560, inductor L1 and capacitor C1 constitute a low-pass filter. Therefore, demodulation circuit 560 smooths the amplified modulation signal AMs output from amplifier circuit 550 through this low-pass filter and outputs the demodulated signal as drive signal COM. In other words, drive signal COM is output from one end of inductor L1 included in demodulation circuit 560.

[0136] Feedback circuit 570 includes resistors R3 and R4. A drive signal COM is supplied to one end of resistor R3, and the other end is connected to terminal Vfb and one end of resistor R4. A voltage VHV is supplied to the other end of resistor R4. Thus, the drive signal COM, after passing through feedback circuit 570, is fed back to terminal Vfb in a state where it is pulled up by voltage VHV.

[0137] Feedback circuit 572 includes capacitors C2, C3, and C4, and resistors R5 and R6. A drive signal COM is supplied to one end of capacitor C2, and the other end is connected to one end of resistor R5 and one end of resistor R6. A ground potential is supplied to the other end of resistor R5. Thus, capacitor C2 and resistor R5 function as a high-pass filter. The cutoff frequency of this high-pass filter is set, for example, to approximately 9 MHz. Additionally, the other end of resistor R6 is connected to one end of capacitor C4 and one end of capacitor C3. A ground potential is supplied to the other end of capacitor C3. Thus, resistor R6 and capacitor C3 function as a low-pass filter. The cutoff frequency of this low-pass filter is set, for example, to approximately 160 MHz. In other words, feedback circuit 572 includes a high-pass filter and a low-pass filter, functioning as a band-pass filter that allows signals containing a specified frequency band in the drive signal COM to pass through.

[0138] Furthermore, the other end of capacitor C4 is connected to terminal Ifb of integrated circuit 500. Thus, the DC component of the high-frequency component of the drive signal COM, which is then filtered out by the feedback circuit 572 (which functions as a bandpass filter), is fed back to terminal Ifb.

[0139] The drive signal COM is the smoothed signal obtained by demodulation circuit 560 after amplifying and modulating the signal AMs based on the fundamental drive signal do. Furthermore, the drive signal COM is integrated and subtracted via terminal Vfb and then fed back to adder 512. Thus, the drive signal 52 oscillates self-excitedly at a frequency determined by the feedback delay and the feedback transfer function. However, due to the large delay in the feedback path via terminal Vfb, feedback solely via this terminal may not be sufficient to raise the self-excited oscillation frequency to adequately ensure the accuracy of the drive signal COM. Therefore, as... Figure 8 The path shown is different from the path via terminal Vfb; instead, a path is provided via terminal Ifb to feed back the high-frequency component of the drive signal COM, thereby reducing the delay in the overall circuit. Therefore, compared to the case where there is no path via terminal Ifb, the frequency of the voltage signal Os can be increased to sufficiently ensure the accuracy of the drive signal COM.

[0140] As described above, after performing digital-to-analog conversion on the input basic drive signal do, the drive circuit 52 amplifies the analog signal in Class D to generate the drive signal COM, and then outputs the generated drive signal COM.

[0141] 1.4 Composition of the liquid ejection module

[0142] Next, use Figures 9-11 The structure of the liquid ejection module 20 is described. Figure 9 This is a diagram showing the structure of the liquid ejection module 20. Here, the structure of the liquid ejection module 20 will be described. Figures 9 to 11 The middle diagram shows arrows indicating the mutually orthogonal X1, Y1, and Z1 directions. Additionally, in Figures 9 to 11 In the description, the starting side of the arrow indicating the X1 direction is sometimes referred to as the -X1 side, and the front end side as the +X1 side; the starting side of the arrow indicating the Y1 direction is referred to as the -Y1 side, and the front end side as the +Y1 side; the starting side of the arrow indicating the Z1 direction is referred to as the -Z1 side, and the front end side as the +Z1 side. Here, in the following description, we will use the liquid ejection module 20 of the liquid ejection device 1 in the first embodiment, which has six ejection modules 23. Therefore, when distinguishing between the individual ejection modules of the six ejection modules 23, each of the six ejection modules 23 is sometimes referred to as ejection modules 23-1 to 23-6.

[0143] like Figure 9 As shown, the liquid ejection module 20 includes a frame 31, a collection substrate 33, a flow path structure 34, a head substrate 35, a distribution flow path 37, a fixing plate 39, and ejection modules 23-1 to 23-6. In the liquid ejection module 20, the flow path structure 34, the head substrate 35, the distribution flow path 37, and the fixing plate 39 are stacked along the Z1 direction from the -Z1 side to the +Z1 side in the order of fixing plate 39, distribution flow path 37, head substrate 35, and flow path structure 34. The frame 31 is located around the flow path structure 34, the head substrate 35, the distribution flow path 37, and the fixing plate 39 to support the flow path structure 34, the head substrate 35, the distribution flow path 37, and the fixing plate 39. Furthermore, the assembly substrate 33 is erected on the +Z1 side of the frame 31 and held in place by the frame 31, and the six ejection modules 23 are located between the distribution flow path 37 and the fixing plate 39 with a portion of them exposed outside the liquid ejection module 20.

[0144] When describing the structure of the liquid ejection module 20, the structure of the ejection module 23 included in the liquid ejection module 20 will be described first. Figure 10 This is a diagram showing an example of the structure of the ejection module 23. Figure 11 This is a diagram showing an example of a cross-section of the ejection module 23. Here, Figure 11It is along Figure 10 The cross-sectional view shown is taken when the ejector module 23 is cut along line Aa. Figure 10 The Aa line shown is a virtual line segment that passes through the inlet channel 661 of the ejection module 23 and through nozzles N1 and N2.

[0145] like Figure 10 and Figure 11 As shown, the ejection module 23 has a plurality of nozzles N1 arranged side by side and a plurality of nozzles N2 arranged side by side. The total number of nozzles N1 and nozzles N2 in the ejection module 23 is n, the same number as the ejection section 600 in the ejection module 23. It should be noted that in the first embodiment, the ejection module 23 is described with the same number of nozzles N1 and nozzles N2. That is, the ejection module 23 is described with n / 2 nozzles N1 and n / 2 nozzles N2. Here, in the following description, when it is not necessary to distinguish between nozzles N1 and nozzles N2, they will sometimes be simply referred to as nozzle N.

[0146] The ejection module 23 includes a wiring component 388, a housing 660, a protective substrate 641, a flow path forming substrate 642, a connecting plate 630, a plastic substrate 620, and a nozzle plate 623.

[0147] On the flow path forming substrate 642, a pressure chamber CB1, divided by multiple partition walls through anisotropic etching from one side, is arranged side-by-side corresponding to nozzle N1, and a pressure chamber CB2, divided by multiple partition walls through anisotropic etching from one side, is arranged side-by-side corresponding to nozzle N2. In the following description, without needing to distinguish between pressure chamber CB1 and pressure chamber CB2, they will sometimes be simply referred to as pressure chamber CB.

[0148] The nozzle plate 623 is located on the -Z1 side of the flow path forming substrate 642. A nozzle array Ln1 formed by n / 2 nozzles N1 and a nozzle array Ln2 formed by n / 2 nozzles N2 are provided on the nozzle plate 623. Here, in the following description, the surface of the nozzle plate 623 on the -Z1 side where the nozzles N open will sometimes be referred to as the liquid jetting surface 623a.

[0149] The connecting plate 630 is located on the -Z1 side of the flow path forming substrate 642 and the +Z1 side of the nozzle plate 623. A nozzle connecting channel RR1 connecting pressure chamber CB1 to nozzle N1 and a nozzle connecting channel RR2 connecting pressure chamber CB2 to nozzle N2 are provided on the connecting plate 630. Additionally, a pressure chamber connecting channel RK1 connecting the end of pressure chamber CB1 to manifold MN1 and a pressure chamber connecting the end of pressure chamber CB2 to manifold MN2 are independently provided on the connecting plate 630, corresponding to both pressure chambers CB1 and CB2.

[0150] Manifold MN1 includes a supply connection channel RA1 and a connecting connection channel RX1. The supply connection channel RA1 is configured to penetrate the connecting plate 630 along the Z1 direction, while the connecting connection channel RX1 does not penetrate the connecting plate 630 in the Z1 direction, but instead opens on the nozzle plate 623 side of the connecting plate 630 and is positioned midway along the Z1 direction. Similarly, manifold MN2 includes a supply connection channel RA2 and a connecting connection channel RX2. The supply connection channel RA2 is configured to penetrate the connecting plate 630 along the Z1 direction, while the connecting connection channel RX2 does not penetrate the connecting plate 630 in the Z1 direction, but instead opens on the nozzle plate 623 side of the connecting plate 630 and is positioned midway along the Z1 direction. Thus, the connecting connection channel RX1 of manifold MN1 is connected to the corresponding pressure chamber CB1 via the pressure chamber connection channel RK1, and the connecting connection channel RX2 of manifold MN2 is connected to the corresponding pressure chamber CB2 via the pressure chamber connection channel RK2.

[0151] In the following description, when it is not necessary to distinguish between nozzle connection channel RR1 and nozzle connection channel RR2, they will sometimes be referred to simply as nozzle connection channel RR; when it is not necessary to distinguish between manifold MN1 and manifold MN2, they will sometimes be referred to simply as manifold MN; when it is not necessary to distinguish between supply connection channel RA1 and supply connection channel RA2, they will sometimes be referred to simply as supply connection channel RA; and when it is not necessary to distinguish between connection connection channel RX1 and connection connection channel RX2, they will sometimes be referred to simply as connection connection channel RX.

[0152] The vibrating plate 610 is located on the +Z1 side of the flow path forming substrate 642. Furthermore, on the +Z1 side of the vibrating plate 610, two rows of piezoelectric elements 60 are formed corresponding to nozzles N1 and N2. One electrode and piezoelectric layer of each piezoelectric element 60 are formed for each pressure chamber CB, and the other electrode of each piezoelectric element 60 is configured as a common electrode shared by the pressure chambers CB. Therefore, a drive signal VOUT is supplied from the drive signal selection circuit 200 to one electrode of the piezoelectric element 60, and a reference voltage signal VBS is supplied to the other electrode of the piezoelectric element 60, i.e., the common electrode.

[0153] The protective substrate 641 is bonded to the +Z1 side surface of the flow path forming substrate 642. The protective substrate 641 forms a protective space 644 for protecting the piezoelectric element 60. Furthermore, a through hole 643 extending along the Z1 direction is provided on the protective substrate 641. The end of the lead electrode 611 leading from the electrode of the piezoelectric element 60 extends outwards, exposed inside the through hole 643. Thus, the wiring member 388 is electrically connected to the end of the lead electrode 611 exposed inside the through hole 643.

[0154] Additionally, a housing 660 is fixed to the protective substrate 641 and the connecting plate 630, which divides a portion of the manifold MN that communicates with multiple pressure chambers CB. The housing 660 is engaged with the protective substrate 641 and also with the connecting plate 630. Specifically, the housing 660 has a recess 665 on the -Z1 side surface that accommodates the flow path forming substrate 642 and the protective substrate 641. The recess 665 has an opening area larger than the surface of the protective substrate 641 that is engaged with the flow path forming substrate 642. Thus, when the flow path forming substrate 642, etc., are accommodated in the recess 665, the opening surface on the -Z1 side of the recess 665 is sealed by the connecting plate 630. As a result, the housing 660, the flow path forming substrate 642, and the protective substrate 641 divide the outer periphery of the flow path forming substrate 642 into a supply communication channel RB1 and a supply communication channel RB2. Here, when it is not necessary to distinguish between the supply communication channel RB1 and the supply communication channel RB2, they are sometimes simply referred to as the supply communication channel RB.

[0155] Furthermore, a malleable substrate 620 is provided on the surface of the connecting plate 630 where the connecting channel RA and the opening of the connecting channel RX are supplied. This malleable substrate 620 seals the openings of the connecting channel RA and the connecting channel RX. This malleable substrate 620 has a sealing film 621 and a fixing substrate 622. The sealing film 621 is formed of a flexible thin film or the like, and the fixing substrate 622 is formed of a hard material such as stainless steel.

[0156] An inlet channel 661 for supplying ink to the manifold MN is provided on the housing 660. In addition, a connection port 662 is provided on the housing 660. The connection port 662 is an opening that communicates with the through hole 643 of the protective substrate 641 and extends through it in the Z1 direction. The wiring component 388 is inserted through the connection port 662.

[0157] The wiring component 388 is a flexible substrate for electrically connecting the ejection module 23 to the head substrate 35, such as an FPC. Additionally, an integrated circuit 201 is mounted on the wiring component 388 using a COF (Chip On Film) mount. At least a portion of the aforementioned drive signal selection circuit 200 is mounted in this integrated circuit 201.

[0158] In the ejection module 23 configured as described above, the drive signal VOUT and the reference voltage signal VBS output by the drive signal selection circuit 200 are supplied to the piezoelectric element 60 via the wiring component 388. Then, the piezoelectric element 60 is driven by the change in the potential difference between the drive signal VOUT and the reference voltage signal VBS. As the piezoelectric element 60 is driven, the vibrating plate 610 is displaced in the vertical direction, causing a change in the internal pressure of the pressure chamber CB. Then, the change in the internal pressure of the pressure chamber CB causes the ink stored inside the pressure chamber CB to be ejected from the corresponding nozzle N. Here, the configuration of the ejection module 23, including the nozzle N, the nozzle communication channel RR, the pressure chamber CB, the piezoelectric element 60, and the vibrating plate 610, corresponds to the ejection section 600 described above. That is, the ejection module 23 has multiple ejection sections 600, each ejection section 600 including the piezoelectric element 60 and ejecting ink in response to the drive of the piezoelectric element 60.

[0159] Return to Figure 9 The fixing plate 39 is located on the -Z1 side of the ejection module 23. The fixing plate 39 fixes six ejection modules 23. Specifically, the fixing plate 39 has six openings 391 extending through the fixing plate 39 along the Z2 direction. The liquid injection surface 623a of the ejection module 23 protrudes from each of these six openings 391. That is, the six ejection modules 23 are fixed to the fixing plate 39 in such a way that the liquid injection surface 623a protrudes from the corresponding opening 391.

[0160] The distribution flow path 37 is located on the +Z1 side of the ejection module 23. Four inlet portions 373 are provided on the +Z1 side surface of the distribution flow path 37. These four inlet portions 373 are flow path tubes protruding from the +Z1 side surface of the distribution flow path 37 along the Z1 direction towards the +Z1 side, communicating with flow path holes (not shown) formed on the -Z1 side surface of the flow path structure 34. Additionally, the (not shown) flow path tubes communicating with the four inlet portions 373 are located on the -Z1 side surface of the distribution flow path 37. These (not shown) flow path tubes on the -Z1 side surface of the distribution flow path 37 communicate with the inlet channels 661 of each of the six ejection modules 23. Furthermore, the distribution flow path 37 has six openings 371 extending along the Z1 direction. Wiring components 388 of each of the six ejection modules 23 are inserted through these six openings 371.

[0161] The head substrate 35 is located on the +Z1 side of the distribution flow path 37. A wiring component FC, electrically connected to the assembly substrate 33 (described later), is mounted on the head substrate 35. Four openings 351 and cutouts 352 and 353 are formed on the head substrate 35. Wiring components 388 of the ejection modules 23-2 to 23-5 are inserted through the four openings 351. The wiring components 388 of each of the ejection modules 23-2 to 23-5, inserted through the four openings 351, are then electrically connected to the head substrate 35 via solder or the like. The wiring component 388 of the ejection module 23-1 passes through the cutout 352, and the wiring component 388 of the ejection module 23-6 passes through the cutout 353. The wiring components 388 of each of the ejection modules 23-1 and 23-6, passing through the cutouts 352 and 353 respectively, are then electrically connected to the head substrate 35 via solder or the like.

[0162] In addition, four cutouts 355 are formed at the four corners of the head substrate 35. The inlet portion 373 passes through the four cutouts 355. Then, the four inlet portions 373 of the cutouts 355 are connected to the flow path structure 34 located on the +Z1 side of the head substrate 35.

[0163] The flow path structure 34 includes a flow path plate Su1 and a flow path plate Su2. The flow path plates Su1 and Su2 are stacked along the Z1 direction with Su1 on the +Z1 side and Su2 on the -Z1 side, and are bonded to each other by an adhesive or the like. Furthermore, the flow path structure 34 has four inlet portions 341 protruding towards the +Z1 side on its +Z1 side surface. These four inlet portions 341 communicate with flow path holes (not shown) formed on the -Z1 side surface of the flow path structure 34 via ink flow paths formed inside the flow path structure 34. Additionally, the flow path holes (not shown) formed on the -Z1 side surface of the flow path structure 34 communicate with the four inlet portions 373. Furthermore, a through hole 343 extending along the Z1 direction is formed in the flow path structure 34. A wiring component FC, electrically connected to the head substrate 35, is inserted through the through hole 343. In addition, inside the flow path structure 34, besides the ink flow path that connects the inlet portion 341 with the flow path hole (not shown) formed on the surface on the -Z1 side, a filter or the like for capturing foreign matter contained in the ink flowing in the ink flow path may also be provided.

[0164] The frame 31 is positioned to cover the flow path structure 34, the head substrate 35, the distribution flow path 37, and the fixing plate 39, and supports the flow path structure 34, the head substrate 35, the distribution flow path 37, and the fixing plate 39. The frame 31 has four openings 311, a substrate insertion portion 313, and a holding member 315.

[0165] The flow path structure 34 has four inlet portions 341 that are inserted through four openings 311. Ink is then supplied from the liquid container 3 to the four inlet portions 341 inserted through the four openings 311 via a tube (not shown).

[0166] The retaining member 315 holds the assembly substrate 33 in a state where a portion of the assembly substrate 33 is inserted through the assembly substrate insertion portion 313. A connection portion 330 is provided on the assembly substrate 33. Various signals, such as data signals DATA, drive signals COMA, COMB, COMC, reference voltage signal VBS, and other power supply voltages, output from the head drive module 10 are input to the connection portion 330 via the wiring member 30. In addition, the wiring member FC of the head substrate 35 is electrically connected to the assembly substrate 33. Thus, the assembly substrate 33 and the head substrate 35 are electrically connected. A semiconductor device including the above-mentioned recovery circuit 220 may also be provided on the assembly substrate 33. It should be noted that in Figure 9 The figure shows the case where the assembly substrate 33 has a connection portion 330. However, when the liquid ejection device 1 has multiple wiring components 30, and various signals such as data signal DATA, drive signal COMA, COMB, COMC, reference voltage signal VBS and other power supply voltages output by the head drive module 10 are input to the assembly substrate 33 via the multiple wiring components 30, the assembly substrate 33 may also have multiple connection portions 330 corresponding to each of the multiple wiring components 30.

[0167] In the liquid ejection module 20 configured as described above, ink stored in the liquid container 3 is supplied via a pipe (not shown) that connects the liquid container 3 and the inlet 341. The ink supplied to the liquid ejection module 20 is then guided through an ink flow path formed inside the flow path structure 34 to a flow path hole (not shown) formed on the -Z1 side of the flow path structure 34, and then supplied to four inlet 373s in the distribution flow path 37. The ink supplied to the distribution flow path 37 via the four inlet 373 is distributed to each of the six ejection modules 23 in the ink flow path (not shown) formed inside the distribution flow path 37, and then supplied to the inlet channel 661 of the corresponding ejection module 23. The ink supplied to the ejection module 23 via the inlet channel 661 is then stored in the pressure chamber CB included in the ejection section 600.

[0168] Furthermore, the head drive module 10 and the liquid ejection module 20 are electrically connected via one or more wiring components 30. Thus, various signals, including the drive signals COMA, COMB, COMC, reference voltage signal VBS, and data signal DATA output from the head drive module 10, are supplied to the liquid ejection module 20. These various signals, including the drive signals COMA, COMB, COMC, reference voltage signal VBS, and data signal DATA, are transmitted in the assembly substrate 33 and the head substrate 35. At this time, the recovery circuit 220 generates clock signals SCK1 to SCK6, printing data signals SI1 to SI6, and latch signals LAT1 to LAT6 corresponding to the ejection modules 23-1 to 23-6, based on the data signal DATA. Additionally, the integrated circuit 201, which includes a drive signal selection circuit 200, provided in the wiring component 388 generates a drive signal VOUT corresponding to each of the n ejection sections 600 and supplies it to the piezoelectric element 60 included in the corresponding ejection section 600. As a result, the piezoelectric element 60 is driven to eject the ink stored in the pressure chamber CB.

[0169] That is, the liquid ejection module 20 includes: ejection module 23-1, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60; ejection module 23-2, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60; ejection module 23-3, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60; ejection module 23-4, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60; ejection module 23-5, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60; and ejection module 23-6, comprising n ejection portions 600 including piezoelectric elements 60 and ejecting liquid in response to the driving of piezoelectric elements 60. In other words, the liquid ejection module 20 ejects liquid in response to the driving of the piezoelectric element 60 of the ejection module 23-1, the driving of the piezoelectric element 60 of the ejection module 23-2, the driving of the piezoelectric element 60 of the ejection module 23-3, the driving of the piezoelectric element 60 of the ejection module 23-4, the driving of the piezoelectric element 60 of the ejection module 23-5, and the driving of the piezoelectric element 60 of the ejection module 23-6.

[0170] 1.5 Head Driver Module Structure

[0171] Next, use Figure 12 The structure of the head drive module 10 will be described here. Figure 12 The diagram shows arrows indicating mutually orthogonal X2, Y2, and Z2 directions, which are independent of the aforementioned X1, Y1, and Z1 directions. Furthermore, in the following description, the starting side of the arrow indicating the X2 direction will sometimes be referred to as the -X2 side, and the leading side as the +X2 side; the starting side of the arrow indicating the Y2 direction will be referred to as the -Y2 side, and the leading side as the +Y2 side; the starting side of the arrow indicating the Z2 direction will be referred to as the -Z2 side, and the leading side as the +Z2 side.

[0172] Figure 12 This is a diagram illustrating an example of the structure of the head drive module 10. (As shown...) Figure 12 As shown, the head drive module 10 includes a drive circuit board 800, a heat-conducting component group 720, multiple screws 780, and a cooling fan 770.

[0173] The drive circuit board 800 includes a wiring board 810 for mounting the plurality of drive circuits 52 and outputs a drive signal COM to the liquid ejection module 20. A heat sink 710 is located on the +Z2 side of the drive circuit board 800 and is mounted to the wiring board 810 using multiple screws 780. A heat-conducting component assembly 720 is located between the drive circuit board 800 and the heat sink 710. By mounting the heat sink 710 to the wiring board 810, it comes into contact with both the plurality of drive circuits 52 mounted on the wiring board 810 and the heat sink 710. Thus, the heat-conducting component assembly 720 conducts heat generated by the plurality of drive circuits 52 mounted on the wiring board 810 to the heat sink 710.

[0174] The structure of the head drive module 10 configured as described above will be explained in detail using the accompanying drawings.

[0175] First, a specific example of the structure of the drive circuit board 800 of the head drive module 10 will be described. Figure 13 This is a diagram showing an example of the cross-sectional structure of a wiring substrate 810 for arranging multiple drive circuits 52. (See diagram for example.) Figure 13 As shown, the wiring substrate 810 has a first layer 831, a second layer 832, a third layer 833, a fourth layer 834, a fifth layer 835, and a plurality of insulating layers 840. Furthermore, the first layer 831, the second layer 832, the third layer 833, the fourth layer 834, and the fifth layer 835 are positioned along the Z2 direction from the +Z2 side to the -Z2 side in the order of first layer 831, second layer 832, third layer 833, fourth layer 834, and fifth layer 835. The plurality of insulating layers 840 are located along the Z2 direction between the first layer 831 and the second layer 832, between the second layer 832 and the third layer 833, between the third layer 833 and the fourth layer 834, and between the fourth layer 834 and the fifth layer 835.

[0176] Multiple electronic components constituting various circuits including multiple drive circuits 52 are disposed on the first layer 831 and the fifth layer 835. Furthermore, multiple wiring patterns are formed on the first layer 831, second layer 832, third layer 833, fourth layer 834, and fifth layer 835 to electrically connect and transmit various signals between the electronic components disposed on the first layer 831 and the fifth layer 835. The multiple wiring patterns formed on the first layer 831, second layer 832, third layer 833, fourth layer 834, and fifth layer 835 are made of materials with excellent conductivity, such as those formed by etching copper foil. Additionally, the insulating layer 840 functions as an insulating layer that insulates the multiple wiring patterns formed on the first layer 831, second layer 832, third layer 833, fourth layer 834, and fifth layer 835 from each other. For example, epoxy glass formed by impregnating glass fiber cloth with epoxy resin can be used as such an insulating layer 840.

[0177] That is, the wiring substrate 810 in the first embodiment is a multilayer substrate including a first layer 831, a second layer 832, a third layer 833, a fourth layer 834, and a fifth layer 835. The first layer 831 and the fifth layer 835 constitute the surface layer of the wiring substrate 810, and the second layer 832, the third layer 833, and the fourth layer 834 constitute the inner layer of the wiring substrate 810. It should be noted that the wiring substrate 810 may also have through holes (not shown) that penetrate the insulating layer 840 along the Z2 direction and electrically connect the first layer 831, the second layer 832, the third layer 833, the fourth layer 834, and the fifth layer 835 to each other. In addition, in the following description, electronic components constituting various circuits including the plurality of drive circuits 52 included in the drive circuit substrate 800 are provided on the first layer 831, but a part of the electronic components constituting various circuits including the plurality of drive circuits 52 included in the drive circuit substrate 800 may also be provided on the fifth layer 835.

[0178] use Figures 14-17 The detailed composition of the first layer 831, the second layer 832, the third layer 833, and the fourth layer 834 is explained. Figure 14 This is a diagram showing an example of the configuration of the first layer 831 when viewed from the Z2 side along the Z2 direction on the wiring substrate 810.

[0179] like Figure 14As shown, the wiring substrate 810 is a generally rectangular multilayer substrate including sides 811 and 812 that are opposite to each other along the X2 direction and sides 813 and 814 that are opposite to each other along the Y2 direction. Specifically, side 811 is located on the +X2 side of the wiring substrate 810, side 812 is located on the -X2 side of the wiring substrate 810, side 813 intersects with both sides 811 and 812 and is located on the +Y2 side of the wiring substrate 810, and side 814 intersects with both sides 811 and 812 and is located on the -Y2 side of the wiring substrate 810.

[0180] Connection portions CN1, CN2, integrated circuit 101, and multiple driving circuits 52 are provided on the first layer 831 of the wiring substrate 810.

[0181] The connecting part CN1 is positioned along edge 811 and is electrically connected to the control unit 2. Specifically, a cable (not shown) electrically connected to the control unit 2 is installed on the connecting part CN1. Thus, the signal output by the control unit 2, including the image information signal IP, is supplied to the head drive module 10. It should be noted that the connecting part CN1 can also be a BtoB (Board to Board) connector capable of electrically connecting the control unit 2 and the head drive module 10 without a cable.

[0182] The connecting portion CN2 is positioned along the edge 812 of the wiring substrate 810 and is electrically connected to the liquid ejection module 20. Specifically, one end of the wiring component 30 is mounted on the connecting portion CN2. The other end of the wiring component 30 is connected to the connecting portion 330 of the liquid ejection module 20. Thus, signals including the drive signals COMA1-COMA6, COMB1-COMB6, COMC1-COMC6 and the data signal DATA output from the head drive module 10 are supplied to the liquid ejection module 20 via the connecting portion CN2 and the wiring component 30 from the connecting portion 330. That is, the connecting portion CN2 is provided on the wiring substrate 810, and the drive signals COMA1-COMA6, COMB1-COMB6, and COMC1-COMC6 are transmitted to the liquid ejection module 20 by electrically connecting the wiring substrate 810 to the liquid ejection module 20. Here, the connecting portions CN2 and 330 can also be BtoB connectors capable of electrical connection without cables, etc. In this case, the connecting portions CN2 and 330 constitute the wiring component 30.

[0183] Integrated circuit 101 is located on the -X2 side of the connection portion CN1. Integrated circuit 101 constitutes part or all of the control circuit 100 described above. That is, an image information signal IP is input to integrated circuit 101 via the connection portion CN1. Then, integrated circuit 101 generates and outputs various signals based on the input image information signal IP. Here, integrated circuit 101 may also include part or all of the conversion circuit 120 in addition to the control circuit 100. It should be noted that in the liquid ejection device 1 of the first embodiment, the integrated circuit 101 is described as including all of the control circuit 100 and all of the conversion circuit 120, but part of the control circuit 100 or part of the conversion circuit 120 may also be configured outside integrated circuit 101.

[0184] Here, in Figure 14 The example shown illustrates an integrated circuit 101 disposed together with multiple driving circuits 52 on the first layer 831 of a wiring substrate 810. However, the integrated circuit 101 may also be disposed on a substrate (not shown) different from the wiring substrate 810. Figure 14 As shown, when the integrated circuit 101 and the multiple drive circuits 52 are mounted on a common substrate, the wiring pattern for transmitting signals between the multiple drive circuits 52 and the integrated circuit 101 can be shortened. This reduces the possibility of noise or other superimposed noise on the signals transmitted between the multiple drive circuits 52 and the integrated circuit 101. On the other hand, the multiple drive circuits 52 generate more heat than the integrated circuit 101; therefore, if the heat generated by the multiple drive circuits 52 affects the integrated circuit 101, the stability of the integrated circuit 101's operation may decrease. To address this problem, by mounting the integrated circuit 101 on a different substrate than the multiple drive circuits 52, the possibility of the heat generated by the multiple drive circuits 52 affecting the integrated circuit 101 can be reduced.

[0185] Multiple driving circuits 52 are located between the integrated circuit 101 and the connection part CN2, and are arranged along the X2 direction. Specifically, driving circuits 52a1 to 52a6, 52b1 to 52b6, and 52c1 to 52c6, which are multiple driving circuits 52, are provided on the first layer 831 of the wiring substrate 810, and are arranged and positioned along the X2 direction from the -X2 side to the +X2 side in the order of driving circuits 52a1, 52b1, 52a2, 52b2, 52a3, 52b3, 52a4, 52b4, 52a5, 52b5, 52a6, 52b6, 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6.

[0186] In this configuration, the transistors M1 and M2 of each of the multiple drive circuits 52 are arranged along the X2 direction with transistor M1 on the +X2 side and transistor M2 on the -X2 side. The inductor L1 is located on the -Y2 side of the transistors M1 and M2 arranged along the X2 direction, and the integrated circuit 500 is located on the +Y2 side of the transistors M1 and M2 arranged along the X2 direction. That is, the integrated circuit 500, transistors M1 and M2, and inductor L1 of the drive circuit 52 are arranged on the first layer 831 of the wiring substrate 810 along the direction from edge 813 to edge 814 in the order of integrated circuit 500, side-by-side transistors M1 and M2, and inductor L1.

[0187] Furthermore, the integrated circuits 500 of each of the multiple driving circuits 52 are arranged and positioned along the X2 direction, the transistors M1 and M2 arranged side by side are alternately arranged and positioned along the X2 direction, and the inductors L1 are arranged and positioned along the X2 direction. That is, on the first layer 831 of the wiring substrate 810, there are columns of integrated circuits 500 arranged side by side from edge 812 to edge 811, columns of transistors M1 and M2 arranged side by side from edge 812 to edge 811, and columns of inductors L1 arranged side by side from edge 812 to edge 811.

[0188] Therefore, in the first layer 831 of the wiring substrate 810 of the liquid ejection device 1 in the first embodiment, the driving circuits 52a1, 52a2, 52b1, 52b2, 52c1, and 52c2 are positioned such that the driving circuit 52a2 is located between the driving circuit 52a1 and the driving circuit 52c1 along the X2 direction, and the shortest distance between the driving circuit 52c2 and the driving circuit 52c1 is shorter than the shortest distance between the driving circuit 52c2 and the driving circuit 52a2. The driving circuits 52b1 and 52b2 are located between the driving circuit 52a1 and the driving circuit 52c1 along the X2 direction, and are also located between the driving circuit 52a1 and the driving circuit 52c2.

[0189] Similarly, in the first layer 831 of the wiring substrate 810 of the liquid ejection device 1 in the first embodiment, the driving circuits 52a3, 52a4, 52b3, 52b4, 52c3, and 52c4 are positioned such that the driving circuit 52a4 is located between the driving circuit 52a3 and the driving circuit 52c3 along the X2 direction, and the shortest distance between the driving circuit 52c4 and the driving circuit 52c3 is shorter than the shortest distance between the driving circuit 52c4 and the driving circuit 52a4. The driving circuits 52b3 and 52b4 are located between the driving circuit 52a3 and the driving circuit 52c3 along the X2 direction and between the driving circuit 52a3 and the driving circuit 52c4.

[0190] Similarly, in the first layer 831 of the wiring substrate 810 of the liquid ejection device 1 in the first embodiment, the driving circuits 52a5, 52a6, 52b5, 52b6, 52c5, and 52c6 are positioned such that the driving circuit 52a6 is located between the driving circuit 52a5 and the driving circuit 52c5 along the X2 direction, and the shortest distance between the driving circuit 52c6 and the driving circuit 52c5 is shorter than the shortest distance between the driving circuit 52c6 and the driving circuit 52a6. The driving circuits 52b5 and 52b6 are located between the driving circuit 52a5 and the driving circuit 52c5 along the X2 direction and between the driving circuit 52a5 and the driving circuit 52c6.

[0191] In this configuration, the drive circuit 52a1 that outputs drive signal COMA1 to the piezoelectric element 60 of the ejection module 23-1 and the drive circuit 52b1 that outputs drive signal COMB1 are located adjacent to each other along the X2 direction; the drive circuit 52a2 that outputs drive signal COMA2 to the piezoelectric element 60 of the ejection module 23-2 and the drive circuit 52b2 that outputs drive signal COMB2 are located adjacent to each other along the X2 direction; and the drive circuit 52a3 that outputs drive signal COMA3 to the piezoelectric element 60 of the ejection module 23-3 and the drive circuit 52b3 that outputs drive signal COMB3 are located adjacent to each other along the X2 direction. The driving circuits 52a4 and 52b4 that output driving signals COMA4 and COMB4 to the piezoelectric element 60 of the ejection module 23-4 are located adjacent to each other along the X2 direction. The driving circuits 52a5 and 52b5 that output driving signals COMA5 and COMB5 to the piezoelectric element 60 of the ejection module 23-5 are located adjacent to each other along the X2 direction. The driving circuits 52a6 and 52b6 that output driving signals COMA6 and COMB6 to the piezoelectric element 60 of the ejection module 23-6 are located adjacent to each other along the X2 direction.

[0192] In detail, the drive circuit 52a1 that outputs a drive signal COMA1 for driving the piezoelectric element 60 of the ejection module 23-1 to eject ink from the ejection section 600 of the ejection module 23-1 and the drive circuit 52b1 that outputs a drive signal COMB1 for driving the piezoelectric element 60 of the ejection module 23-1 to eject ink from the ejection section 600 of the ejection module 23-1 are located adjacent to each other in the X2 direction on the first layer 831 of the wiring substrate 810, with the drive circuit 52a1 on the -X2 side and the drive circuit 52b1 on the +X2 side.

[0193] The drive circuit 52a2 that outputs a drive signal COMA2 for driving the piezoelectric element 60 of the ejection module 23-2 to eject ink from the ejection section 600 of the ejection module 23-2 and the drive circuit 52b2 that outputs a drive signal COMB2 for driving the piezoelectric element 60 of the ejection module 23-2 to eject ink from the ejection section 600 of the ejection module 23-2 are located adjacent to each other on the +X2 side of the first layer 831 of the wiring substrate 810 along the X2 direction, with the drive circuit 52a2 on the -X2 side and the drive circuit 52b2 on the +X2 side.

[0194] The drive circuit 52a3, which outputs a drive signal COMA3 to drive the piezoelectric element 60 of the ejection module 23-3 to eject ink from the ejection section 600 of the ejection module 23-3, and the drive circuit 52b3, which outputs a drive signal COMB3 to drive the piezoelectric element 60 of the ejection module 23-3 to eject ink from the ejection section 600 of the ejection module 23-3, are located adjacent to each other on the +X2 side of the first layer 831 of the wiring substrate 810 along the X2 direction, with the drive circuit 52a3 on the -X2 side and the drive circuit 52b3 on the +X2 side.

[0195] The drive circuit 52a4, which outputs a drive signal COMA4 to drive the piezoelectric element 60 of the ejection module 23-4 to eject ink from the ejection section 600 of the ejection module 23-4, and the drive circuit 52b4, which outputs a drive signal COMB4 to drive the piezoelectric element 60 of the ejection module 23-4 to eject ink from the ejection section 600 of the ejection module 23-4, are located adjacent to each other on the +X2 side of the drive circuit 52b3 along the X2 direction on the first layer 831 of the wiring substrate 810, with the drive circuit 52a4 on the -X2 side and the drive circuit 52b4 on the +X2 side.

[0196] The drive circuit 52a5, which outputs a drive signal COMA5 to drive the piezoelectric element 60 of the ejection module 23-5 to eject ink from the ejection section 600 of the ejection module 23-5, and the drive circuit 52b5, which outputs a drive signal COMB5 to drive the piezoelectric element 60 of the ejection module 23-5 to eject ink from the ejection section 600 of the ejection module 23-5, are located adjacent to each other on the +X2 side of the drive circuit 52b4 along the X2 direction on the first layer 831 of the wiring substrate 810, with the drive circuit 52a5 on the -X2 side and the drive circuit 52b5 on the +X2 side.

[0197] The drive circuit 52a6, which outputs a drive signal COMA6 to drive the piezoelectric element 60 of the ejection module 23-6 to eject ink from the ejection section 600 of the ejection module 23-6, and the drive circuit 52b6, which outputs a drive signal COMB6 to drive the piezoelectric element 60 of the ejection module 23-6 to eject ink from the ejection section 600 of the ejection module 23-6, are located adjacent to each other on the +X2 side of the drive circuit 52b5 along the X2 direction on the first layer 831 of the wiring substrate 810, with the drive circuit 52a6 on the -X2 side and the drive circuit 52b6 on the +X2 side.

[0198] Additionally, a drive circuit 52c1 that outputs a drive signal COMC1 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-1 is located on the +X2 side of the drive circuit 52b6 along the X2 direction on the first layer 831 of the wiring substrate 810. A drive circuit 52c2 that outputs a drive signal COMC2 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-2 is located on the +X2 side of the drive circuit 52c1 along the X2 direction on the first layer 831 of the wiring substrate 810. A drive circuit 52c3 that outputs a drive signal COMC3 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-3 is located on the +X2 side of drive circuit 52c2 along the X2 direction on the first layer 831 of wiring substrate 810. A drive circuit 52c4 that outputs a drive signal COMC4 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-4 is located on the +X2 side of drive circuit 52c3 along the X2 direction on the first layer 831 of wiring substrate 810. A drive circuit 52c5 that outputs a drive signal COMC5 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-5 is located on the +X2 side of drive circuit 52c4 along the X2 direction on the first layer 831 of wiring substrate 810. The drive circuit 52c6 that outputs the drive signal COMC6 to drive the piezoelectric element 60 of the ejection module 23-6 to prevent ink from being ejected from the ejection section 600 of the ejection module 23-6 is located on the +X2 side of the drive circuit 52c5 along the X2 direction on the first layer 831 of the wiring substrate 810.

[0199] That is, in the head drive module 10, the output drive piezoelectric element 60 is driven by the ink ejection drive signals COMA1~COMA6, COMB1~COMB6, and the drive circuits 52a1~52a6, 52b1~52b6 are located in adjacent positions along the X2 direction on the first layer 831 of the wiring substrate 810, corresponding to each ejection module 23. The output drive piezoelectric element 60 is driven by the non-ink ejection drive signals COMC1~COMC6, and the drive circuits 52c1~52c6 are located in the X2 direction on the first layer 831 of the wiring substrate 810, in the order of drive circuits 52c1, 52c2, 52c3, 52c4, 52c5, 52c6.

[0200] In the drive circuit board 800 configured as described above, the image information signal IP input via the connection section CN1 is supplied to the integrated circuit 101. Then, the integrated circuit 101 generates and outputs basic drive signals dA1-dA6, dB1-dB6, dC1-dC6, and a data signal DATA based on the input image information signal IP. The basic drive signals dA1-dA6, dB1-dB6, and dC1-dC6 output by the integrated circuit 101 are transmitted in a wiring pattern (not shown) on the wiring board 810 and input to the corresponding drive circuit 52. Multiple drive circuits 52 generate and output drive signals COMA1-COMA6, COMB1-COMB6, and COMC1-COMC6 based on the input basic drive signals dA1-dA6, dB1-dB6, and dC1-dC6. Then, multiple signals, including the drive signals COMA1~COMA6, COMB1~COMB6, COMC1~COMC6 output by each of the multiple drive circuits 52, and the data signal DATA output by the integrated circuit 101, are supplied to the liquid ejection module 20 via the connection part CN2.

[0201] In the signals supplied from the head drive module 10 to the liquid ejection module 20 as described above, the drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 output by the multiple drive circuits 52 are analog signals supplied to the corresponding piezoelectric elements 60 to drive the piezoelectric elements 60. When the drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 exhibit waveform distortion, it directly affects the ejection of ink from the corresponding ejection section 600. That is, from the viewpoint of improving the ejection accuracy of the ink ejected from the liquid ejection module 20, reducing the possibility of waveform distortion in the drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 is an important factor in improving the ejection accuracy of the ink ejected from the liquid ejection module 20.

[0202] Therefore, using Figures 15-17 An example of the wiring pattern configuration of the drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 output by the transmission drive circuits 52a1~52a6, 52b1~52b6, and 52c1~52c6 in the head drive module 10 will be described.

[0203] Figure 15 This is a diagram showing an example of a wiring pattern disposed on the second layer 832 of the wiring substrate 810. Figure 16 This is a diagram showing an example of a wiring pattern disposed on the third layer 833 of the wiring substrate 810. Figure 17 This diagram shows an example of a wiring pattern disposed on the fourth layer 834 of the wiring substrate 810. Here, the description will focus on the first embodiment's head drive module 10, where multiple wiring patterns transmitting drive signals COMA1 to COMA6 are disposed on the second layer 832 of the wiring substrate 810, multiple wiring patterns transmitting drive signals COMB1 to COMB6 are disposed on the third layer 833 of the wiring substrate 810, and multiple wiring patterns transmitting drive signals COMC1 to COMC6 are disposed on the fourth layer 834 of the wiring substrate 810. It should be noted that... Figures 15-17 This is a perspective view of the wiring substrate 810 viewed along the Z2 direction from the +Z2 side to the -Z2 side. Figures 15-17 In the diagram, dashed lines represent multiple driving circuits 52, connection portions CN1, CN2, and integrated circuit 101 disposed on the first layer 831 of the wiring substrate 810.

[0204] like Figure 14 As shown, the drive circuit 52a1 for outputting the drive signal COMA1 is located on the +X2 side of the connection part CN2 in the first layer 831. Additionally, as... Figure 15As shown, one end of the inductor L1 that outputs the drive signal COMA1 from the drive circuit 52a1 is electrically connected to one end of the wiring WA1 disposed on the second layer 832 via a through-hole (not shown). The wiring WA1 extends along the X2 direction on the second layer 832. Furthermore, the other end of the wiring WA1 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA1 that electrically connects the drive circuit 52a1 and the connection portion CN2 and transmits the drive signal COMA1. Thus, the drive signal COMA1 output by the drive circuit 52a1 is transmitted to the connection portion CN2.

[0205] In addition, such as Figure 14 As shown, the drive circuit 52b1 that outputs the drive signal COMB1 is located on the +X2 side of the drive circuit 52a1 in the first layer 831. Additionally, as... Figure 16 As shown, one end of the inductor L1 that outputs the drive signal COMB1 from the drive circuit 52b1 is electrically connected to one end of the wiring WB1 disposed on the third layer 833 via a through-hole (not shown). The wiring WB1 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB1 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB1 that electrically connects the drive circuit 52b1 to the connection portion CN2 and transmits the drive signal COMB1. Thus, the drive signal COMB1 output by the drive circuit 52b1 is transmitted to the connection portion CN2.

[0206] In addition, such as Figure 14 As shown, the driving circuit 52a2 that outputs the driving signal COMA2 is located on the +X2 side of the driving circuit 52b1 in the first layer 831. Additionally, as... Figure 15 As shown, one end of the inductor L1, from which the drive circuit 52a2 outputs the drive signal COMA2, is electrically connected to one end of the wiring WA2 disposed on the second layer 832 via a through-hole (not shown). The wiring WA2 extends along the X2 direction on the second layer 832. Furthermore, the other end of the wiring WA2 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA2 that electrically connects the drive circuit 52a2 and the connection portion CN2 and transmits the drive signal COMA2. Thus, the drive signal COMA2 output by the drive circuit 52a2 is transmitted to the connection portion CN2.

[0207] In addition, such as Figure 14 As shown, the drive circuit 52b2 for outputting the drive signal COMB2 is located on the +X2 side of the drive circuit 52a2 in the first layer 831. Additionally, as... Figure 16As shown, one end of the inductor L1 that outputs the drive signal COMB2 from the drive circuit 52b2 is electrically connected to one end of the wiring WB2 disposed on the third layer 833 via a through-hole (not shown). The wiring WB2 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB2 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB2 that electrically connects the drive circuit 52b2 and the connection portion CN2 and transmits the drive signal COMB2. Thus, the drive signal COMB2 output by the drive circuit 52b2 is transmitted to the connection portion CN2.

[0208] In addition, such as Figure 14 As shown, the driving circuit 52a3 that outputs the driving signal COMA3 is located on the +X2 side of the driving circuit 52b2 in the first layer 831. Additionally, as... Figure 15 As shown, one end of the inductor L1, which outputs the drive signal COMA3 from the drive circuit 52a3, is electrically connected to one end of the wiring WA3 disposed on the second layer 832 via a through-hole (not shown). The wiring WA3 extends along the X2 direction on the second layer 832. Furthermore, the other end of the wiring WA3 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA3 that electrically connects the drive circuit 52a3 to the connection portion CN2 and transmits the drive signal COMA3. Thus, the drive signal COMA3 output by the drive circuit 52a3 is transmitted to the connection portion CN2.

[0209] In addition, such as Figure 14 As shown, the drive circuit 52b3 for outputting the drive signal COMB3 is located on the +X2 side of the drive circuit 52a3 in the first layer 831. Additionally, as... Figure 16 As shown, one end of the inductor L1 that outputs the drive signal COMB3 from the drive circuit 52b3 is electrically connected to one end of the wiring WB3 disposed on the third layer 833 via a through-hole (not shown). The wiring WB3 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB3 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB3 that electrically connects the drive circuit 52b3 to the connection portion CN2 and transmits the drive signal COMB3. Thus, the drive signal COMB3 output by the drive circuit 52b3 is transmitted to the connection portion CN2.

[0210] In addition, such as Figure 14 As shown, the driving circuit 52a4 that outputs the driving signal COMA4 is located on the +X2 side of the driving circuit 52b3 in the first layer 831. Additionally, as... Figure 15As shown, one end of the inductor L1 that outputs the drive signal COMA4 from the drive circuit 52a4 is electrically connected to one end of the wiring WA4 disposed on the second layer 832 via a through-hole (not shown). The wiring WA4 extends along the X2 direction on the second layer 832. Furthermore, the other end of the wiring WA4 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA4 that electrically connects the drive circuit 52a4 and the connection portion CN2 and transmits the drive signal COMA4. Thus, the drive signal COMA4 output by the drive circuit 52a4 is transmitted to the connection portion CN2.

[0211] In addition, such as Figure 14 As shown, the drive circuit 52b4 that outputs the drive signal COMB4 is located on the +X2 side of the drive circuit 52a4 in the first layer 831. Additionally, as... Figure 16 As shown, one end of the inductor L1 that outputs the drive signal COMB4 from the drive circuit 52b4 is electrically connected to one end of the wiring WB4 disposed on the third layer 833 via a through-hole (not shown). The wiring WB4 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB4 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB4 that electrically connects the drive circuit 52b4 to the connection portion CN2 and transmits the drive signal COMB4. Thus, the drive signal COMB4 output by the drive circuit 52b4 is transmitted to the connection portion CN2.

[0212] In addition, such as Figure 14 As shown, the driving circuit 52a5 that outputs the driving signal COMA5 is located on the +X2 side of the driving circuit 52b4 in the first layer 831. Additionally, as... Figure 15 As shown, one end of the inductor L1 that outputs the drive signal COMA5 from the drive circuit 52a5 is electrically connected to one end of the wiring WA5 disposed on the second layer 832 via a through-hole (not shown). The wiring WA5 extends along the X2 direction on the second layer 832. Furthermore, the other end of the wiring WA5 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA5 that electrically connects the drive circuit 52a5 to the connection portion CN2 and transmits the drive signal COMA5. Thus, the drive signal COMA5 output by the drive circuit 52a5 is transmitted to the connection portion CN2.

[0213] In addition, such as Figure 14 As shown, the drive circuit 52b5 for outputting the drive signal COMB5 is located on the +X2 side of the drive circuit 52a5 in the first layer 831. Additionally, as... Figure 16As shown, one end of the inductor L1 that outputs the drive signal COMB5 from the drive circuit 52b5 is electrically connected to one end of the wiring WB5 disposed on the third layer 833 via a through-hole (not shown). The wiring WB5 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB5 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB5 that electrically connects the drive circuit 52b5 to the connection portion CN2 and transmits the drive signal COMB5. Thus, the drive signal COMB5 output by the drive circuit 52b5 is transmitted to the connection portion CN2.

[0214] In addition, such as Figure 14 As shown, the driving circuit 52a6 that outputs the driving signal COMA6 is located on the +X2 side of the driving circuit 52b5 in the first layer 831. Additionally, as... Figure 15 As shown, one end of the inductor L1 that outputs the drive signal COMA6 from the drive circuit 52a6 is electrically connected to one end of the wiring WA6 disposed on the second layer 832 via a through-hole (not shown). The wiring WA6 extends along the X2 direction on the second layer 832.

[0215] Furthermore, the other end of the wiring WA6 is electrically connected to the connection portion CN2 provided on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WA6 that electrically connects the driving circuit 52a6 to the connection portion CN2 and transmits the driving signal COMA6. Thus, the driving signal COMA6 output by the driving circuit 52a6 is transmitted to the connection portion CN2.

[0216] In addition, such as Figure 14 As shown, the drive circuit 52b6 for outputting the drive signal COMB6 is located on the +X2 side of the drive circuit 52a6 in the first layer 831. Additionally, as... Figure 16 As shown, one end of the inductor L1 that outputs the drive signal COMB6 from the drive circuit 52b6 is electrically connected to one end of the wiring WB6 disposed on the third layer 833 via a through-hole (not shown). The wiring WB6 extends along the X2 direction in the third layer 833. Furthermore, the other end of the wiring WB6 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WB6 that electrically connects the drive circuit 52b6 to the connection portion CN2 and transmits the drive signal COMB6. Thus, the drive signal COMB6 output by the drive circuit 52b6 is transmitted to the connection portion CN2.

[0217] In addition, such as Figure 14 As shown, the drive circuit 52c1 that outputs the drive signal COMC1 is located on the +X2 side of the drive circuit 52b6 in the first layer 831. Additionally, as... Figure 17As shown, one end of the inductor L1 that outputs the drive signal COMC1 from the drive circuit 52c1 is electrically connected to one end of the wiring WC1 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC1 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC1 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC1 that electrically connects the drive circuit 52c1 to the connection portion CN2 and transmits the drive signal COMC1. Thus, the drive signal COMC1 output by the drive circuit 52c1 is transmitted to the connection portion CN2.

[0218] In addition, such as Figure 14 As shown, the drive circuit 52c2 that outputs the drive signal COMC2 is located on the +X2 side of the drive circuit 52c1 in the first layer 831. Additionally, as... Figure 17 As shown, one end of the inductor L1 that outputs the drive signal COMC2 from the drive circuit 52c2 is electrically connected to one end of the wiring WC2 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC2 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC2 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC2 that electrically connects the drive circuit 52c2 and the connection portion CN2 and transmits the drive signal COMC2. Thus, the drive signal COMC2 output by the drive circuit 52c2 is transmitted to the connection portion CN2.

[0219] In addition, such as Figure 14 As shown, the drive circuit 52c3 that outputs the drive signal COMC3 is located on the +X2 side of the drive circuit 52c2 in the first layer 831. Additionally, as... Figure 17 As shown, one end of the inductor L1 that outputs the drive signal COMC3 from the drive circuit 52c3 is electrically connected to one end of the wiring WC3 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC3 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC3 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC3 that electrically connects the drive circuit 52c3 to the connection portion CN2 and transmits the drive signal COMC3. Thus, the drive signal COMC3 output by the drive circuit 52c3 is transmitted to the connection portion CN2.

[0220] In addition, such as Figure 14 As shown, the drive circuit 52c4 that outputs the drive signal COMC4 is located on the +X2 side of the drive circuit 52c3 in the first layer 831. Additionally, as... Figure 17As shown, one end of the inductor L1 that outputs the drive signal COMC4 from the drive circuit 52c4 is electrically connected to one end of the wiring WC4 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC4 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC4 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC4 that electrically connects the drive circuit 52c4 to the connection portion CN2 and transmits the drive signal COMC4. Thus, the drive signal COMC4 output by the drive circuit 52c4 is transmitted to the connection portion CN2.

[0221] In addition, such as Figure 14 As shown, the drive circuit 52c5 that outputs the drive signal COMC5 is located on the +X2 side of the drive circuit 52c4 in the first layer 831. Additionally, as... Figure 17 As shown, one end of the inductor L1 that outputs the drive signal COMC5 from the drive circuit 52c5 is electrically connected to one end of the wiring WC5 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC5 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC5 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC5 that electrically connects the drive circuit 52c5 to the connection portion CN2 and transmits the drive signal COMC5. Thus, the drive signal COMC5 output by the drive circuit 52c5 is transmitted to the connection portion CN2.

[0222] In addition, such as Figure 14 As shown, the drive circuit 52c6 that outputs the drive signal COMC6 is located on the +X2 side of the drive circuit 52c5 in the first layer 831. Additionally, as... Figure 17 As shown, one end of the inductor L1 that outputs the drive signal COMC6 from the drive circuit 52c6 is electrically connected to one end of the wiring WC6 disposed on the fourth layer 834 via a through-hole (not shown). The wiring WC6 extends along the X2 direction in the fourth layer 834. Furthermore, the other end of the wiring WC6 is electrically connected to the connection portion CN2 disposed on the first layer 831 via a through-hole (not shown). That is, the wiring substrate 810 includes the wiring WC6 that electrically connects the drive circuit 52c6 to the connection portion CN2 and transmits the drive signal COMC6. Thus, the drive signal COMC6 output by the drive circuit 52c6 is transmitted to the connection portion CN2.

[0223] As described above, in the liquid ejection device 1 of the first embodiment, the drive circuit board 800 of the head drive module 10 includes drive circuits 52a1 to 52a6, 52b1 to 52b6, and 52c1 to 52c6, which are multiple drive circuits 52. The wiring board 810 of the drive circuit board 800 includes wiring patterns WA1 to WA6, WB1 to WB6, and WC1 to WC6, which electrically connect each of the multiple drive circuits 52 to the connection part CN2. In addition, the driving circuits 52a1~52a6, 52b1~52b6, and 52c1~52c6 are arranged on the wiring substrate 810 along the X2 direction from the -X2 side to the +X2 side in the order of driving circuits 52a1, 52b1, 52a2, 52b2, 52a3, 52b3, 52a4, 52b4, 52a5, 52b5, 52a6, 52b6, 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6.

[0224] That is, the driving circuits 52a1, 52b1, and 52c1 that output driving signals COMA1, COMB1, and COMC1 to the piezoelectric element 60 of the ejection module 23-1 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located toward the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a1, driving circuit 52b1, and driving circuit 52c1. Therefore, the length of the wiring WA1 that electrically connects the driving circuit 52a1 to the connection part CN2 is shorter than the lengths of the wiring WB1 that electrically connects the driving circuit 52b1 to the connection part CN2 and the wiring WC1 that electrically connects the driving circuit 52c1 to the connection part CN2, and the length of the wiring WB1 that electrically connects the driving circuit 52b1 to the connection part CN2 is shorter than the length of the wiring WC1 that electrically connects the driving circuit 52c1 to the connection part CN2. In other words, wiring WB1 is longer than wiring WA1 and shorter than wiring WC1.

[0225] Furthermore, the driving circuits 52a2, 52b2, and 52c2 that output driving signals COMA2, COMB2, and COMC2 to the piezoelectric element 60 of the ejection module 23-2 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located toward the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a2, driving circuit 52b2, and driving circuit 52c2. Therefore, the length of the wiring WA2 that electrically connects the driving circuit 52a2 to the connection part CN2 is shorter than the lengths of the wiring WB2 that electrically connects the driving circuit 52b2 to the connection part CN2 and the wiring WC2 that electrically connects the driving circuit 52c2 to the connection part CN2, and the length of the wiring WB2 that electrically connects the driving circuit 52b2 to the connection part CN2 is shorter than the length of the wiring WC2 that electrically connects the driving circuit 52c2 to the connection part CN2. That is, wiring WB2 is longer than wiring WA2 and shorter than wiring WC2.

[0226] Furthermore, the driving circuits 52a3, 52b3, and 52c3 that output driving signals COMA3, COMB3, and COMC3 to the piezoelectric element 60 of the ejection module 23-3 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located toward the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a3, driving circuit 52b3, and driving circuit 52c3. Therefore, the length of the wiring WA3 that electrically connects the driving circuit 52a3 to the connection part CN2 is shorter than the lengths of the wiring WB3 that electrically connects the driving circuit 52b3 to the connection part CN2 and the wiring WC3 that electrically connects the driving circuit 52c3 to the connection part CN2, and the length of the wiring WB3 that electrically connects the driving circuit 52b3 to the connection part CN2 is shorter than the length of the wiring WC3 that electrically connects the driving circuit 52c3 to the connection part CN2. That is, wiring WB3 is longer than wiring WA3 and shorter than wiring WC3.

[0227] Furthermore, the driving circuits 52a4, 52b4, and 52c4 that output driving signals COMA4, COMB4, and COMC4 to the piezoelectric element 60 of the ejection module 23-4 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located toward the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a4, driving circuit 52b4, and driving circuit 52c4. Therefore, the length of the wiring WA4 that electrically connects the driving circuit 52a4 to the connection part CN2 is shorter than the lengths of the wiring WB4 that electrically connects the driving circuit 52b4 to the connection part CN2 and the wiring WC4 that electrically connects the driving circuit 52c4 to the connection part CN2, and the length of the wiring WB4 that electrically connects the driving circuit 52b4 to the connection part CN2 is shorter than the length of the wiring WC4 that electrically connects the driving circuit 52c4 to the connection part CN2. That is, wiring WB4 is longer than wiring WA4 and shorter than wiring WC4.

[0228] Furthermore, the driving circuits 52a5, 52b5, and 52c5 that output driving signals COMA5, COMB5, and COMC5 to the piezoelectric element 60 of the ejection module 23-5 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located towards the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a5, driving circuit 52b5, and driving circuit 52c5. Therefore, the length of the wiring WA5 that electrically connects the driving circuit 52a5 to the connection part CN2 is shorter than the lengths of the wiring WB5 that electrically connects the driving circuit 52b5 to the connection part CN2 and the wiring WC5 that electrically connects the driving circuit 52c5 to the connection part CN2, and the length of the wiring WB5 that electrically connects the driving circuit 52b5 to the connection part CN2 is shorter than the length of the wiring WC5 that electrically connects the driving circuit 52c5 to the connection part CN2. That is, wiring WB5 is longer than wiring WA5 and shorter than wiring WC5.

[0229] Furthermore, the driving circuits 52a6, 52b6, and 52c6 that output driving signals COMA6, COMB6, and COMC6 to the piezoelectric element 60 of the ejection module 23-6 are positioned on the first layer 831 of the wiring substrate 810 from the edge 812 where the connection part CN2 is located toward the edge 811 where the connection part CN1 is located along the X2 direction in the order of driving circuit 52a6, driving circuit 52b6, and driving circuit 52c6. Therefore, the length of the wiring WA6 that electrically connects the driving circuit 52a6 to the connection part CN2 is shorter than the lengths of the wiring WB6 that electrically connects the driving circuit 52b6 to the connection part CN2 and the wiring WC6 that electrically connects the driving circuit 52c6 to the connection part CN2, and the length of the wiring WB6 that electrically connects the driving circuit 52b6 to the connection part CN2 is shorter than the length of the wiring WC6 that electrically connects the driving circuit 52c6 to the connection part CN2. That is, wiring WB6 is longer than wiring WA6 and shorter than wiring WC6.

[0230] In addition, such as Figure 14As shown, in the liquid ejection device 1 of the first embodiment, on the first layer 831 of the wiring substrate 810, from the edge 812 where the connecting part CN2 is located toward the edge 811 where the connecting part CN1 is located, according to the piezoelectric element 60 corresponding to the output drive to eject ink from the ejection part 600 of the ejection module 23-1, the drive circuits 52a1 and 52b1 of the piezoelectric element 60 corresponding to the output drive to eject ink from the ejection part 600 of the ejection module 23-2, the drive circuits 52a2 and 52b2 of the piezoelectric element 60 corresponding to the output drive to eject ink from the ejection part 600 of the ejection module 23-2, the drive circuits 52a3 and 52b3 of the piezoelectric element 60 corresponding to the output drive to eject ink from the ejection part 600 of the ejection module 23-3, and the drive circuits 52a3 and 52b3 of the piezoelectric element 60 corresponding to the output drive to eject ink from the ejection part 600 of the ejection module 23-4, ...2, the piezoelectric element 60 corresponding The drive circuits 52a4 and 52b4 of MB4, and the piezoelectric element 60 corresponding to the output drive, are positioned in sequence according to the drive signals COMA5 and COMB5 for ink ejection from the ejection section 600 of the ejection module 23-5, and the piezoelectric element 60 corresponding to the output drive, are positioned in sequence according to the drive signals COMA6 and COMB6 for ink ejection from the ejection section 600 of the ejection module 23-6. The corresponding piezoelectric element 60 is driven by drive circuits 52c1 to 52c6 with drive signals COMC1 to COMC6 that do not eject ink. On the first layer 831 of the wiring substrate 810, the drive circuits 52a1 to 52a6 and 52b1 to 52b6 are positioned from the side 812 where the connection part CN2 is located toward the side 811 where the connection part CN1 is located in the order of drive circuits 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6.

[0231] That is, the piezoelectric element 60 corresponding to the output drive is located closest to the connection part CN2 among the multiple drive circuits 52 arranged along the X2 direction of the drive circuit 52 for the drive signal COMA1 that ejects ink from the ejection part 600 of the ejection module 23-1, and the piezoelectric element 60 corresponding to the output drive is located furthest from the connection part CN2 among the multiple drive circuits 52 arranged along the X2 direction of the drive signal COMC6 that does not eject ink from the ejection part 600 of the ejection module 23-6.

[0232] Therefore, the length of the wiring WA1 that electrically connects the drive circuit 52a1 to the connection part CN2 is shorter than the wiring WA2-WA6, WB1-WB6, and WC1-WC6 that electrically connect the drive circuits 52a2-52a6, 52b1-52b6, and 52c1-52c6 to the connection part CN2, respectively. Conversely, the length of the wiring WC6 that electrically connects the drive circuit 52c6 to the connection part CN2 is longer than the wiring WA1-WA6, WB1-WB6, and WC1-WC5 that electrically connect the drive circuits 52a1-52a6, 52b1-52b6, and 52c1-52c5 to the connection part CN2, respectively. That is, the wiring substrate 810 includes multiple wiring patterns that electrically connect multiple drive circuits 52 to the connection part CN2. Among these multiple wiring patterns, the wiring WA1 that electrically connects the drive circuit 52a1 to the connection part CN2 is the shortest, and the wiring WC6 that electrically connects the drive circuit 52c6 to the connection part CN2 is the longest.

[0233] In the head drive module 10 configured as described above, as mentioned above, the voltage amplitudes of the drive signals COMA1 and COMB1 are larger than the voltage amplitude of the drive signal COMC1, which drives the piezoelectric element 60 to eject ink from the nozzle N of the ejection module 23-1, because the piezoelectric element 60 ejects ink from the nozzle N of the ejection module 23-1. That is, the current generated with the transmission of drive signals COMA1 and COMB1 is larger than the current generated with the transmission of drive signal COMC1. Therefore, drive signals COMA1 and COMB1 are more susceptible to the impedance generated in the wiring pattern compared to drive signal COMC1. By making the wiring lengths WA1 and WB1, which transmit drive signals COMA1 and COMB1 that are susceptible to the impedance generated in the wiring pattern, shorter than the wiring length of wiring WC1, which transmits drive signal COMC1, the waveform accuracy of drive signals COMA1 and COMB1, which directly promote ink ejection, can be improved. As a result, the ink ejection accuracy in the liquid ejection device 1 is improved.

[0234] Furthermore, the amount of ink ejected from the corresponding nozzle N by supplying a drive signal COMA1 to the piezoelectric element 60 is greater than the amount of ink ejected from the corresponding nozzle N by supplying a drive signal COMB1 to the piezoelectric element 60. Therefore, the voltage amplitude of the drive signal COMA1 is larger than that of the drive signal COMB1, and the current generated during the transmission of the drive signal COMA1 is greater than that generated during the transmission of the drive signal COMB1. Therefore, by making the wiring length of the wiring WA1 that transmits the drive signal COMA1 shorter than the wiring length of the wiring WB1 that transmits the drive signal COMB1, the possibility of a decrease in the waveform accuracy of the drive signal COMA1 due to the impedance generated in the wiring pattern is reduced.

[0235] Similarly, the current generated by the transmission of drive signals COMA2 and COMB2 supplied to the piezoelectric element 60 of the ejection module 23-2 is greater than the current generated by the transmission of drive signal COMC2, and the current generated by the transmission of drive signal COMA2 is greater than the current generated by the transmission of drive signal COMB2. Therefore, by making the wiring lengths of the wirings WA2 and WB2 that transmit drive signals COMA2 and COMB2 shorter than the wiring length of the wiring WC2 that transmits drive signal COMC2, the waveform accuracy of the drive signals COMA2 and COMB2 output from the drive module 10 can be improved. Furthermore, by making the wiring length of the wiring WA2 that transmits drive signal COMA2 shorter than the wiring length of the wiring WB2 that transmits drive signal COMB2, the possibility of a decrease in the waveform accuracy of drive signal COMA2 is reduced, and the ejection accuracy of ink in the liquid ejection device 1 is improved.

[0236] Similarly, the current generated by the transmission of drive signals COMA3 and COMB3 supplied to the piezoelectric element 60 of the ejection module 23-3 is greater than the current generated by the transmission of drive signal COMC3, and the current generated by the transmission of drive signal COMA3 is greater than the current generated by the transmission of drive signal COMB3. Therefore, by making the wiring lengths of the wirings WA3 and WB3 that transmit drive signals COMA3 and COMB3 shorter than the wiring length of the wiring WC3 that transmits drive signal COMC3, the waveform accuracy of the drive signals COMA3 and COMB3 output from the drive module 10 can be improved. Furthermore, by making the wiring length of the wiring WA3 that transmits drive signal COMA3 shorter than the wiring length of the wiring WB3 that transmits drive signal COMB3, the possibility of a decrease in the waveform accuracy of drive signal COMA3 is reduced, and the ejection accuracy of ink in the liquid ejection device 1 is improved.

[0237] Similarly, the current generated by the transmission of drive signals COMA4 and COMB4 supplied to the piezoelectric element 60 of the ejection module 23-4 is greater than the current generated by the transmission of drive signal COMC4, and the current generated by the transmission of drive signal COMA4 is greater than the current generated by the transmission of drive signal COMB4. Therefore, by making the wiring lengths of the wirings WA4 and WB4 that transmit drive signals COMA4 and COMB4 shorter than the wiring length of the wiring WC4 that transmits drive signal COMC4, the waveform accuracy of the drive signals COMA4 and COMB4 output from the drive module 10 can be improved. Furthermore, by making the wiring length of the wiring WA4 that transmits drive signal COMA4 shorter than the wiring length of the wiring WB4 that transmits drive signal COMB4, the possibility of a decrease in the waveform accuracy of drive signal COMA4 is reduced, and the ejection accuracy of ink in the liquid ejection device 1 is improved.

[0238] Similarly, the current generated by the transmission of drive signals COMA5 and COMB5 supplied to the piezoelectric element 60 of the ejection module 23-5 is greater than the current generated by the transmission of drive signal COMC5, and the current generated by the transmission of drive signal COMA5 is greater than the current generated by the transmission of drive signal COMB5. Therefore, by making the wiring lengths of the wirings WA5 and WB5 that transmit drive signals COMA5 and COMB5 shorter than the wiring length of the wiring WC5 that transmits drive signal COMC5, the waveform accuracy of the drive signals COMA5 and COMB5 output from the drive module 10 can be improved. Furthermore, by making the wiring length of the wiring WA5 that transmits drive signal COMA5 shorter than the wiring length of the wiring WB5 that transmits drive signal COMB5, the possibility of a decrease in the waveform accuracy of drive signal COMA5 is reduced, and the ejection accuracy of ink in the liquid ejection device 1 is improved.

[0239] Similarly, the current generated by the transmission of drive signals COMA6 and COMB6 supplied to the piezoelectric element 60 of the ejection module 23-6 is greater than the current generated by the transmission of drive signal COMC6, and the current generated by the transmission of drive signal COMA6 is greater than the current generated by the transmission of drive signal COMB6. Therefore, by making the wiring lengths of the wirings WA6 and WB6 that transmit drive signals COMA6 and COMB6 shorter than the wiring length of the wiring WC6 that transmits drive signal COMC6, the waveform accuracy of the drive signals COMA6 and COMB6 output from the drive module 10 can be improved. Furthermore, by making the wiring length of the wiring WA6 that transmits drive signal COMA6 shorter than the wiring length of the wiring WB6 that transmits drive signal COMB6, the possibility of a decrease in the waveform accuracy of drive signal COMA6 is reduced, and the ejection accuracy of ink in the liquid ejection device 1 is improved.

[0240] Furthermore, in the liquid ejection device 1 of the first embodiment, the drive circuits 52a1-52a6 and 52b1-52b6 of the piezoelectric elements 60 of the output drive ejection modules 23-1 to 23-6 that drive the ink ejection signals COMA1-COMA6, COMB1-COMB6 from the corresponding nozzle N are located closer to the connection part CN2 than the drive circuits 52c1-52c6 of the piezoelectric elements 60 of the output drive ejection modules 23-1 to 23-6 that drive the ink ejection signals COMC1-COMC6 not from the corresponding nozzle N. Therefore, as Figures 15-17 As shown, the wiring lengths of the wiring WA1-WA6 and WB1-WB6 that electrically connect the drive circuits 52a1, 52b1, 52a2, 52b2, 52a3, 52b3, 52a4, 52b4, 52a5, 52b5, 52a6, and 52b6 to the connection part CN2 and transmit drive signals COMA1-COMA6 and COMB1-COMB6 are shorter than the wiring lengths of the wiring WC1-WC6 that electrically connect the drive circuits 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6 to the connection part CN2 and transmit drive signals COMC1-COMC6.

[0241] That is, the wiring lengths of the drive signals COMA1-COMA6 and COMB1-COMB6, which transmit large currents during transmission, WA1-WA6 and WB1-WB6, are made shorter than the wiring lengths of the drive signals COMC1-COMC6, which transmit small currents during transmission, WC1-WC6. As a result, the waveform accuracy of the drive signals COMA1-COMA6 and COMB1-COMB6, which directly promote ink ejection, can be further improved. The ink ejection accuracy in the liquid ejection device 1 is further improved.

[0242] Here, in the drive circuit board 800 of the first embodiment, drive circuits 52a1-52a6, 52b1-52b6, and 52c1-52c6 are provided on the first layer 831 of the wiring board 810, wirings WA1-WA6 for transmitting drive signals COMA1-COMA6 are provided on the second layer 832 of the wiring board 810, wirings WB1-WB6 for transmitting drive signals COMB1-COMB6 are provided on the third layer 833, and wirings WC1-WC6 for transmitting drive signals COMC1-COMC6 are provided on the fourth layer 834. However, this is not a limitation. For example, a portion of the drive circuits 52a1-52a6, 52b1-52b6, and 52c1-52c6 may also be provided on the second layer 832, the third layer 833, the fourth layer 834, and the fifth layer 835. Furthermore, at least a portion of the wiring WA1-WA6 for transmitting drive signals COMA1-COMA6, the wiring WB1-WB6 for transmitting drive signals COMB1-COMB6, and the wiring WC1-WC6 for transmitting drive signals COMC1-COMC6 can also be provided on the same wiring layer. Furthermore, in the drive circuit board 800 of the first embodiment, the second layer 832, the third layer 833, and the fourth layer 834 are illustrated stacked along the Z2 direction from the +Z2 side to the -Z2 side in the order of the second layer 832, the third layer 833, and the fourth layer 834, but the stacking order in the wiring board 810 is not limited to this. Furthermore, in the first embodiment, the wiring board 810 is described with the second layer 832, the third layer 833, and the fourth layer 834 as inner layers, but the wiring board 810 may also include multiple inner layers such as a layer for transmitting reference voltage signals VBS1-VBS6, a layer for transmitting various control signals including data signals DATA, and a layer maintained at ground potential.

[0243] In addition, such as Figure 14As shown, the wiring substrate 810 has a plurality of through holes 820 through which a plurality of screws 780 are inserted. Several of the plurality of through holes 820 are arranged side by side along the edge 813 of the wiring substrate 810, and different several of the plurality of through holes 820 are arranged side by side along the edge 814 of the wiring substrate 810. That is, the wiring substrate 810 has a plurality of through holes 820 arranged in two columns along the X2 direction. Here, "arranged side-by-side along the edge 813 of the wiring substrate 810" means that, in the state where the shortest distance between each of the multiple through holes 820 arranged side-by-side and the edge 813 of the wiring substrate 810 is shorter than the shortest distance between each of the multiple through holes 820 and the edge 814 of the wiring substrate 810, the multiple through holes 820 are arranged side-by-side along the X2 direction. "Arranged side-by-side along the edge 814 of the wiring substrate 810" means that, in the state where the shortest distance between each of the multiple through holes 820 arranged side-by-side and the edge 814 of the wiring substrate 810 is shorter than the shortest distance between each of the multiple through holes 820 and the edge 813 of the wiring substrate 810, the multiple through holes 820 are arranged side-by-side along the X2 direction.

[0244] Furthermore, at least one of the plurality of through holes 820 arranged side-by-side along the edge 813 of the wiring substrate 810 and at least one of the plurality of through holes 820 arranged side-by-side along the edge 814 of the wiring substrate 810 are located between the connection portion CN2 and the drive circuit 52a1. That is, at least one of the plurality of through holes 820 is located between the connection portion CN2 and the drive circuit 52a1 in the direction along the X2 direction.

[0245] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a1 and drive circuit 52b1. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a1 and drive circuit 52b1 in the direction along the X2 direction.

[0246] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b1 and drive circuit 52a2. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b1 and drive circuit 52a2 in the direction along the X2 direction.

[0247] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a2 and drive circuit 52b2. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a2 and drive circuit 52b2 in the direction along the X2 direction.

[0248] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b2 and drive circuit 52a3. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b2 and drive circuit 52a3 in the direction along the X2 direction.

[0249] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a3 and drive circuit 52b3. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a3 and drive circuit 52b3 in the direction along the X2 direction.

[0250] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b3 and drive circuit 52a4. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b3 and drive circuit 52a4 in the direction along the X2 direction.

[0251] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a4 and drive circuit 52b4. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a4 and drive circuit 52b4 in the direction along the X2 direction.

[0252] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b4 and drive circuit 52a5. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b4 and drive circuit 52a5 in the direction along the X2 direction.

[0253] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a5 and drive circuit 52b5. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a5 and drive circuit 52b5 in the direction along the X2 direction.

[0254] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b5 and drive circuit 52a6. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b5 and drive circuit 52a6 in the direction along the X2 direction.

[0255] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52a6 and drive circuit 52b6. That is, at least one of the plurality of through holes 820 is located between drive circuit 52a6 and drive circuit 52b6 in the direction along the X2 direction.

[0256] At least one of a plurality of through holes 820 arranged side-by-side along edge 813 of the wiring substrate 810 and at least one of a plurality of through holes 820 arranged side-by-side along edge 814 of the wiring substrate 810 are located between drive circuit 52b6 and drive circuit 52c1. That is, at least one of the plurality of through holes 820 is located between drive circuit 52b6 and drive circuit 52c1 in the direction along the X2 direction.

[0257] At least one of a plurality of through holes 820 arranged side by side along edge 813 of wiring substrate 810 and at least one of a plurality of through holes 820 arranged side by side along edge 814 of wiring substrate 810 are located between drive circuit 52c3 and drive circuit 52c4. At least one of a plurality of through holes 820 arranged side by side along edge 813 of wiring substrate 810 and at least one of a plurality of through holes 820 arranged side by side along edge 814 of wiring substrate 810 are located between drive circuit 52c6 and integrated circuit 101. At least one of a plurality of through holes 820 arranged side by side along edge 813 of wiring substrate 810 and at least one of a plurality of through holes 820 arranged side by side along edge 814 of wiring substrate 810 are located between integrated circuit 101 and connection portion CN1.

[0258] That is, on the wiring substrate 810, through holes 820 are respectively located between the drive circuits 52a1 and 52b1 of the output drive piezoelectric element 60 for ejecting ink from the ejection module 23-1 with drive signals COMA1 and COMB1, between the drive circuits 52a2 and 52b2 of the output drive piezoelectric element 60 for ejecting ink from the ejection module 23-2 with drive signals COMA2 and COMB2, and between the drive circuits 52a2 and 52b2 of the output drive piezoelectric element 60 for ejecting ink from the ejection module 23-3 with drive signals COMA3 and COMB3. Between a3 and 52b3, between the drive circuits 52a4 and 52b4 that drive the piezoelectric element 60 to eject ink from the ejection module 23-4 with drive signals COMA4 and COMB4, between the drive circuits 52a5 and 52b5 that drive the piezoelectric element 60 to eject ink from the ejection module 23-5 with drive signals COMA5 and COMB5, and between the drive circuits 52a6 and 52b6 that drive the piezoelectric element 60 to eject ink from the ejection module 23-6 with drive signals COMA6 and COMB6.

[0259] In addition, in such Figure 14When the driving circuits 52a1 and 52b1 for output driving signals COMA1 and COMB1 and the driving circuits 52a2 and 52b2 for output driving signals COMA2 and COMB2 are located adjacent to each other along the X2 direction, it is preferable that the through hole 820 is also located between the driving circuits 52a1 and 52b1 and the driving circuits 52a2 and 52b2. Similarly, when the driving circuits 52a2 and 52b2 for output driving signals COMA2 and COMB2 and the driving circuits 52a3 and 52b3 for output driving signals COMA3 and COMB3 are located adjacent to each other along the X2 direction, it is preferable that the through-hole 820 is also located between the driving circuits 52a2 and 52b2 and the driving circuits 52a3 and 52b3. Similarly, when the driving circuits 52a3 and 52b3 for output driving signals COMA3 and COMB3 and the driving circuits 52a4 and 52b4 for output driving signals COMA4 and COMB4 are located adjacent to each other along the X2 direction, it is preferable that the through-hole 820 is also located between the driving circuits 52a3 and 52b3 and the driving circuits 52a4 and 52b4. When the driving circuits 52a4 and 52b4 for output driving signals COMA4 and COMB4 and the driving circuits 52a5 and 52b5 for output driving signals COMA5 and COMB5 are located adjacent to each other along the X2 direction, it is preferable that the through hole 820 is also located between the driving circuits 52a4 and 52b4 and the driving circuits 52a5 and 52b5. When the driving circuits 52a5 and 52b5 for output driving signals COMA5 and COMB5 and the driving circuits 52a6 and 52b6 for output driving signals COMA6 and COMB6 are located adjacent to each other along the X2 direction, it is preferable that the through hole 820 is also located between the driving circuits 52a5 and 52b5 and the driving circuits 52a6 and 52b6.

[0260] Return to Figure 12 The following describes a specific example of the structure of the heat sink 710 in the head drive module 10. The heat sink 710 is located on the +Z2 side of the drive circuit board 800. The heat sink 710 includes a bottom 711, sides 712 and 713, protrusions 715, 716 and 717, and a plurality of fin portions 718.

[0261] The bottom portion 711 is located opposite the wiring substrate 810 and is approximately rectangular, extending in a plane formed by the X2 and Y2 directions. A side portion 712 protrudes from the -Y2 side end of the bottom portion 711 toward the -Z2 side and extends along the X2 direction. At least a portion of the -Z2 side end of the side portion 712 contacts the -Y2 side end of the wiring substrate 810. A side portion 713 protrudes from the +Y2 side end of the bottom portion 711 toward the -Z2 side and extends along the X2 direction. At least a portion of the -Z2 side end of the side portion 713 contacts the +Y2 side end of the wiring substrate 810. In other words, the heat sink 710, through the bottom portion 711 and the side portions 712 and 713, forms a receiving space with an opening on the -Z2 side. Thus, the receiving space formed by the heat sink 710 accommodates a plurality of drive circuits 52 of the drive circuit substrate 800. In other words, the heat sink 710 is mounted on the wiring board 810 and configured to cover multiple drive circuits 52.

[0262] Protrusions 715, 716, and 717 are respectively disposed within the receiving space formed by the bottom 711 and the sides 712 and 713, corresponding to the inductor L1, transistors M1 and M2, and integrated circuit 500 disposed on the wiring substrate 810. Protrusion 715 is positioned corresponding to the inductor L1 disposed on the wiring substrate 810, protruding from the bottom 711 toward the -Z2 side and extending along the X2 direction. Protrusion 716 is positioned corresponding to the transistors M1 and M2 disposed on the wiring substrate 810, protruding from the bottom 711 toward the -Z2 side and extending along the X2 direction. Protrusion 717 is positioned corresponding to the integrated circuit 500 disposed on the wiring substrate 810, protruding from the bottom 711 toward the -Z2 side and extending along the X2 direction.

[0263] Multiple finned portions 718 protrude from the bottom 711 toward the -Z2 side and extend along the X2 direction, located at positions separated from each other in the Y2 direction. By having multiple finned portions 718, the surface area of ​​the heat sink 710 is increased, resulting in improved heat dissipation performance. The number of finned portions 718 in such a heat sink 710 is set based on an optimal spacing determined by factors such as the amount of heat released by the heat sink 710 from the drive circuit board 800, the length of the finned portions 718 along the Z2 direction, and the airflow applied to the finned portions 718.

[0264] The heat sink 710 configured as described above releases heat generated by the plurality of drive circuits 52 disposed on the wiring substrate 810 of the drive circuit substrate 800. That is, the head drive module 10 includes a heat sink 710 mounted on the wiring substrate 810 and releasing heat from at least one of the plurality of drive circuits 52. Such a heat sink 710 is constructed from a material, such as aluminum, iron, or copper, which, in addition to high thermal conductivity, provides sufficient rigidity to protect the drive circuits 52.

[0265] Furthermore, in the head drive module 10 of the first embodiment, the heat sink 710 is constructed of metals such as aluminum, iron, and copper, and is arranged to cover the multiple drive circuits 52. As a result, the heat sink 710 releases the heat generated by the multiple drive circuits 52, and also functions as a shielding component to reduce the possibility of interference noise affecting the multiple drive circuits 52. Consequently, the waveform accuracy of the drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 output by the multiple drive circuits 52 is further improved.

[0266] A heat-conducting component assembly 720 is located between the drive circuit board 800 and the heat sink 710 in the Z2 direction. This heat-conducting component assembly 720 improves the heat transfer efficiency from the drive circuit board 800 to the heat sink 710 by contacting both the heat-generating electronic components on the drive circuit board 800 and the heat sink 710. Preferably, the heat-conducting component assembly 720 is made of a material that, in addition to thermal conductivity, also possesses elasticity, flame retardancy, and electrical insulation properties; for example, a gel sheet or rubber sheet with high thermal conductivity containing silicone or acrylic resin can be used. Thus, the heat-conducting component assembly 720 functions as a heat-conducting component that conducts heat generated by the drive circuit board 800 to the heat sink 710, as an insulating component that ensures electrical insulation between the drive circuit board 800 and the heat sink 710, and further as a buffer component that alleviates the stress generated when the heat sink 710 is mounted on the drive circuit board 800.

[0267] The heat-conducting component group 720 includes heat-conducting components 730, 740, 750, and 760. Heat-conducting component 730 is located between the inductors L1 of each of the plurality of drive circuits 52 and the protrusions 715 of the heat sink 710. With the heat sink 710 mounted on the drive circuit substrate 800, it is in contact with both the inductors L1 and the protrusions 715 of each of the plurality of drive circuits 52. Therefore, heat-conducting component 730 improves the efficiency of heat conduction from the inductors L1 to the heat sink 710. Heat-conducting component 740 is located between the transistors M1 of each of the plurality of drive circuits 52 and the protrusions 716 of the heat sink 710. With the heat sink 710 mounted on the drive circuit substrate 800, it is in contact with both the transistors M1 and the protrusions 716 of each of the plurality of drive circuits 52. Therefore, heat-conducting component 740 improves the efficiency of heat conduction from the transistors M1 to the heat sink 710. A heat-conducting component 750 is located between the transistor M2 of each of the plurality of drive circuits 52 and the protrusion 716 of the heat sink 710. With the heat sink 710 mounted on the drive circuit substrate 800, it is in contact with both the transistor M2 and the protrusion 716 of each of the plurality of drive circuits 52. Therefore, the heat-conducting component 750 improves the efficiency of heat conduction from the transistor M2 to the heat sink 710. A heat-conducting component 760 is located between the integrated circuit 500 of each of the plurality of drive circuits 52 and the protrusion 717 of the heat sink 710. With the heat sink 710 mounted on the drive circuit substrate 800, it is in contact with both the integrated circuit 500 and the protrusion 717 of each of the plurality of drive circuits 52. Therefore, the heat-conducting component 760 improves the efficiency of heat conduction from the integrated circuit 500 to the heat sink 710.

[0268] Multiple screws 780, each made of metal such as steel, iron, aluminum, or stainless steel, are inserted from the -Z2 side toward the +Z2 side through multiple through holes 820 in the wiring substrate 810 of the drive circuit board 800, and fastened to the heat sink 710 located on the +Z2 side of the drive circuit board 800, thereby mounting the heat sink 710 to the wiring substrate 810 of the drive circuit board 800.

[0269] Specifically, several of the multiple screws 780 are inserted through the through holes 820 formed on the wiring substrate 810, located between the connection portion CN2 and the drive circuit 52a1. Then, the heat sink 710 is mounted on the wiring substrate 810 by fastening the screws 780 to the sides 712, 713 of the heat sink 710.

[0270] Similarly, several of the multiple screws 780 are inserted through the through holes 820 arranged side-by-side along the edge 813 of the wiring substrate 810, including the through hole 820 between the drive circuit 52a1 and the drive circuit 52b1, the through hole 820 between the drive circuit 52b1 and the drive circuit 52a2, the through hole 820 between the drive circuit 52a2 and the drive circuit 52b2, the through hole 820 between the drive circuit 52b2 and the drive circuit 52a3, the through hole 820 between the drive circuit 52a3 and the drive circuit 52b3, the through hole 820 between the drive circuit 52b3 and the drive circuit 52a4, and the through hole 820 between the drive circuit 52a4 and the drive circuit 52b4. Through-holes 820 are located between drive circuits 52b4 and 52a5, 52a5 and 52b5, 52b5 and 52a6, 52a6 and 52b6, 52b6 and 52c1, 52c3 and 52c4, 52c6 and integrated circuit 101, and integrated circuit 101 and connection portion CN1. Then, the heat sink 710 is mounted on the wiring substrate 810 by fastening screws 780 to the sides 712 and 713 of the heat sink 710.

[0271] As described above, multiple screws 780 are inserted through multiple through holes 820 in the wiring substrate 810 and fastened to the sides 712 and 713, thereby mounting the heat sink 710, including the sides 712 and 713, onto the wiring substrate 810 of the drive circuit substrate 800. As a result, the heat-conducting component 730 is in close contact with both the inductor L1 and the protrusion 715, the heat-conducting component 740 is in close contact with both the transistor M1 and the protrusion 716, the heat-conducting component 750 is in close contact with both the transistor M2 and the protrusion 716, and the heat-conducting component 750 is in close contact with both the integrated circuit 500 and the protrusion 717. That is, the thermal connection efficiency between the high-heat-generating inductors L1, transistors M1 and M2, integrated circuit 500, and the heat sink 710 is improved. As a result, the heat from the high-heat-generating inductors L1, transistors M1 and M2, and integrated circuit 500 can be more efficiently conducted to the heat sink 710, reducing the temperature rise of the drive circuit 52 on the drive circuit board 800.

[0272] Here, drive circuit 52a1 outputs a drive signal COMA1 to drive the piezoelectric element 60 of the ejection module 23-1 to eject a large amount of ink from the liquid ejection module 20; drive circuit 52b1 outputs a drive signal COMB1 to drive the piezoelectric element 60 of the ejection module 23-1 to eject a small amount of ink from the liquid ejection module 20; and drive circuit 52c1 outputs a drive signal COMC1 to drive the piezoelectric element 60 of the ejection module 23-1 to not eject ink from the liquid ejection module 20. Therefore, the heat generated by drive circuits 52a1 and 52b1 is greater than that of drive circuit 52c1, and the heat generated by drive circuit 52a1 is greater than that of drive circuit 52b1.

[0273] Such driving circuits 52a1, 52b1, and 52c1 are arranged and positioned in the X2 direction in the order of driving circuits 52a1, 52b1, and 52c1 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between the driving circuit 52a1 and the driving circuit 52b1, which generate a large amount of heat. That is, the heat sink 710 is mounted on the wiring substrate 810 between the driving circuit 52a1 that outputs the driving signal COMA1 for ink ejection and the driving circuit 52b1 that outputs the driving signal COMB1 for ink ejection of the piezoelectric element 60, using a metal screw 780. Thus, the heat conducted to the wiring substrate 810 from the heat generated by the driving circuits 52a1 and 52b1 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a1 and 52b1 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a1 and 52b1, which generate a lot of heat, is improved.

[0274] Similarly, the heat generated by drive circuits 52a2 and 52b2 is greater than that generated by drive circuit 52c2. Furthermore, the heat generated by drive circuit 52a2 is greater than that generated by drive circuit 52b2. These drive circuits 52a2, 52b2, and 52c2 are arranged and positioned in the X2 direction in the order of drive circuits 52a2, 52b2, and 52c2 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between drive circuits 52a2 and 52b2. Thus, the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a2 and 52b2 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a2 and 52b2 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a2 and 52b2, which generate a lot of heat, is improved.

[0275] Similarly, the heat generated by drive circuits 52a3 and 52b3 is greater than that generated by drive circuit 52c3. Furthermore, the heat generated by drive circuit 52a3 is greater than that generated by drive circuit 52b3. These drive circuits 52a3, 52b3, and 52c3 are arranged and positioned in the X2 direction in the order of drive circuits 52a3, 52b3, and 52c3 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between drive circuits 52a3 and 52b3. Thus, the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a3 and 52b3 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a3 and 52b3 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a3 and 52b3, which generate a lot of heat, is improved.

[0276] Similarly, the heat generated by drive circuits 52a4 and 52b4 is greater than that generated by drive circuit 52c4. Furthermore, the heat generated by drive circuit 52a4 is greater than that generated by drive circuit 52b4. These drive circuits 52a4, 52b4, and 52c4 are arranged and positioned in the X2 direction in the order of drive circuits 52a4, 52b4, and 52c4 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between drive circuits 52a4 and 52b4. Thus, the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a4 and 52b4 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a4 and 52b4 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a4 and 52b4, which generate a lot of heat, is improved.

[0277] Similarly, the heat generated by drive circuits 52a5 and 52b5 is greater than that of drive circuit 52c5. Furthermore, the heat generated by drive circuit 52a5 is greater than that of drive circuit 52b5. These drive circuits 52a5, 52b5, and 52c5 are arranged and positioned in the X2 direction in the order of drive circuits 52a5, 52b5, and 52c5 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between drive circuits 52a5 and 52b5. Thus, the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a5 and 52b5 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a5 and 52b5 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a5 and 52b5, which generate a lot of heat, is improved.

[0278] Similarly, the heat generated by drive circuits 52a6 and 52b6 is greater than that generated by drive circuit 52c6. Furthermore, the heat generated by drive circuit 52a6 is greater than that generated by drive circuit 52b6. These drive circuits 52a6, 52b6, and 52c6 are arranged and positioned in the X2 direction in the order of drive circuits 52a6, 52b6, and 52c6 on the first layer 831 of the wiring substrate 810, and a through hole 820 through which a screw 780 is inserted is located between drive circuits 52a6 and 52b6. Thus, the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a6 and 52b6 is released to the heat sink 710 via the metal screw 780. That is, the heat generated by the drive circuits 52a6 and 52b6 is conducted to the heat sink 710 via the heat-conducting components 730, 740, 750, and 760, and also via the metal screws 780. As a result, the heat dissipation efficiency of the drive circuits 52a6 and 52b6, which generate a lot of heat, is improved.

[0279] Furthermore, in the liquid ejection device 1 of the first embodiment, the drive circuits 52a1-52a6 and 52b1-52b6 of the output drive piezoelectric element 60 with ink ejection drive signals COMA1-COMA6 and COMB1-COMB6 are located adjacent to each corresponding ejection module 23 along the X2 direction of the wiring substrate 810. The drive circuits 52c1-52c6 of the output drive piezoelectric element 60 with non-ink ejection drive signals COMC1-COMC6 are located adjacent to each other along the X2 direction of the wiring substrate 810 in the order of drive circuits 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6, located closer to the +X2 side than the drive circuits 52a1-52a6 and 52b1-52b6.

[0280] In this head-driving module 10, the wiring substrate 810 has through holes 820 between driving circuits 52b1 and 52a2, 52b2 and 52a3, 52b3 and 52a4, 52b4 and 52a5, and 52b5 and 52a6, respectively. Through holes 820 are inserted between driving circuits 52b1 and 52a2, and between driving circuits 52b2 and 52a3, respectively. The screws 780 in the through holes 820 between the drive circuits 52b3 and 52a4, between the drive circuits 52b4 and 52a5, and between the drive circuits 52b5 and 52a6 mount the heat sink 710 onto the wiring substrate 810. This further improves the heat release efficiency generated by the drive circuits 52a1-52a6 and 52b1-52b6, which generate a lot of heat, even when they are concentrated on the wiring substrate 810.

[0281] Here, the head drive module 10 can also use, for example, metal rivets instead of multiple metal screws 780 to mount the heat sink 710 to the drive circuit board 800. Alternatively, a portion of the heat sink 710 can be inserted through the through hole 820, and the portion of the heat sink 710 inserted through the through hole 820 can be soldered to the metal part of the drive circuit board 800, thereby mounting the heat sink 710 to the drive circuit board 800. However, in the case where the multiple drive circuits 52 of the drive circuit board 800, as shown in the first embodiment, are housed inside the heat sink 710, the maintainability of the drive circuit board 800 is reduced when using metal rivets, solder, etc. to mount the heat sink 710 to the drive circuit board 800. That is, from the viewpoint of improving the maintainability of the drive circuit board 800, it is preferable to use metal screws 780 that allow easy attachment and detachment of the drive circuit board 800 and the heat sink 710, and that have excellent thermal conductivity.

[0282] The cooling fan 770 is located on the -Z2 side of the heat sink 710. Thus, the cooling fan 770 introduces external air into the head drive module 10 through the opening 714 provided on the upper part of the +X2 side of the heat sink 710.

[0283] Specifically, the cooling fan 770 is mounted to cover the opening 714. The opening 714 is a through hole extending through the heat sink 710 in the Z2 direction, communicating with the interior of the head drive module 10 when the heat sink 710 has been mounted on the drive circuit board 800. Thus, when the cooling fan 770 operates, external air is introduced into the interior of the head drive module 10 through the opening 714. As a result, the circulation efficiency of the air floating inside the head drive module 10 is improved, and the heat sink 710's efficiency in releasing heat generated by the drive circuit board 800 is improved.

[0284] Here, the cooling fan 770 can be installed in a way that improves the circulation efficiency of the air floating inside the head drive module 10, or it can be installed on any side of the head drive module 10, either the +X2 side, -X2 side, +Y2 side, or -Y2 side. Furthermore, the cooling fan 770's operation of introducing external air into the head drive module 10 is not limited to the cooling fan 770 drawing external air into the head drive module 10; it also includes the cooling fan 770 operating to expel air floating inside the head drive module 10.

[0285] In the liquid ejection device 1 configured as described above, the piezoelectric element 60 included in the ejection module 23-1 is an example of a first piezoelectric element, the piezoelectric element 60 included in the ejection module 23-2 is an example of a second piezoelectric element, and the liquid ejection module 20, which ejects ink in response to the driving of the piezoelectric elements 60 included in the ejection module 23-1 and the piezoelectric elements 60 included in the ejection module 23-2, is an example of an ejection head. Furthermore, the head drive module 10 that drives the liquid ejection module 20 corresponds to a head drive circuit.

[0286] Furthermore, the drive signal COMA1 of the piezoelectric element 60 included in the drive ejection module 23-1 is an example of a first drive signal, the drive signal COMB1 is an example of a second drive signal, and the drive signal COMC1 is an example of a third drive signal. The drive circuit 52a1 that outputs the drive signal COMA1 is an example of a first drive circuit, the drive circuit 52b1 that outputs the drive signal COMB1 is an example of a second drive circuit, and the drive circuit 52c1 that outputs the drive signal COMC1 is an example of a third drive circuit. Additionally, the amount of ink ejected when the drive signal COMA1 is supplied to the piezoelectric element 60 is an example of a first ejection amount, and the amount of ink ejected when the drive signal COMB1 is supplied to the piezoelectric element 60 is an example of a second ejection amount.

[0287] Furthermore, the drive signal COMA2 of the piezoelectric element 60 included in the drive ejection module 23-2 is an example of a fourth drive signal, the drive signal COMB2 is an example of a fifth drive signal, and the drive signal COMC2 is an example of a sixth drive signal. The drive circuit 52a2 that outputs the drive signal COMA2 is an example of a fourth drive circuit, the drive circuit 52b2 that outputs the drive signal COMB2 is an example of a fifth drive circuit, and the drive circuit 52c2 that outputs the drive signal COMC2 is an example of a sixth drive circuit. Additionally, when the drive signal COMA2 is supplied to the piezoelectric element 60, the amount of ink ejected is an example of a third ejection amount, and when the drive signal COMB2 is supplied to the piezoelectric element 60, the amount of ink ejected is an example of a fourth ejection amount.

[0288] In addition, the wiring substrate 810, which is provided with driving circuits 52a1, 52b1, 52c1, 52a2, 52b2, and 52c2, is an example of a substrate. On the wiring substrate 810, the X2 direction in which the driving circuits 52a1, 52b1, 52c1, 52a2, 52b2, and 52c2 are arranged is an example of a single direction. Furthermore, the through-hole 820 located between the driving circuit 52a1 and the driving circuit 52b1 among the plurality of through-holes 820 provided in the wiring substrate 810 is an example of a first through-hole, and the screw 780 inserted through the through-hole 820 corresponding to the first through-hole is an example of a first screw. The through-hole 820 located between the driving circuit 52b1 and the driving circuit 52a2 among the plurality of through-holes 820 provided in the wiring substrate 810 is an example of a fourth through-hole, and the screw 780 inserted through the through-hole 820 corresponding to the fourth through-hole is an example of a fourth screw. The through-hole 820 located between the driving circuit 52a2 and the driving circuit 52b2 among the plurality of through-holes 820 provided in the wiring substrate 810 is an example of a fifth through-hole, and the screw 780 inserted through the through-hole 820 corresponding to the fifth through-hole is an example of a fifth screw.

[0289] In addition, the heat sink 710, which is mounted on the wiring board 810 by screws 780, is an example of a metal frame.

[0290] 1.6 Effects

[0291] In the liquid ejection device 1 of the first embodiment configured as described above, the head drive module 10 includes: a drive circuit 52a1 that outputs a drive signal COMA1 to drive the piezoelectric element 60 to eject a large amount of ink from the liquid ejection module 20; a drive circuit 52b1 that outputs a drive signal COMB1 to drive the piezoelectric element 60 to eject a small amount of ink from the liquid ejection module 20; a drive circuit 52c1 that outputs a drive signal COMC1 to drive the piezoelectric element 60 to prevent the liquid ejection module 20 from ejecting ink; a wiring substrate 810 on which the drive circuits 52a1, 52b1, and 52c1 are arranged and positioned sequentially along the X2 direction; and a heat sink 710 mounted on the wiring substrate 810.

[0292] In this head drive module 10, the heat generated by the drive circuits 52a1 and 52b1 that output drive piezoelectric elements 60 to drive signals COMA1 and COMB1 to eject ink from the liquid ejection module 20 is greater than the heat generated by the drive circuit 52c1 that output drive piezoelectric elements 60 to drive signal COMC1 to prevent the liquid ejection module 20 from ejecting ink. Because a through hole 820, through which the screw 780 for mounting the heat sink 710 to the wiring substrate 810 is inserted, is located between the heat-generating drive circuits 52a1 and 52b1, the heat conducted to the wiring substrate 810 from the drive circuits 52a1 and 52b1 is released to the heat sink 710 via the screw 780. This allows for more efficient heat dissipation in the head drive module 10.

[0293] In addition to the drive circuits 52a1, 52b1, and 52c1, the head drive module 10 also includes drive circuits 52a2 and 52b2 that output drive piezoelectric elements 60 to drive signals COMA2 and COMB2 to cause the liquid ejection module 20 to eject ink, and drive circuit 52c2 that output drive piezoelectric elements 60 to drive signal COMC2 to prevent the liquid ejection module 20 from ejecting ink. By using the through hole 820 through which the screw 780 for mounting the heat sink 710 to the wiring substrate 810 is inserted, it is located not only between drive circuits 52a1 and 52b1, but also between drive circuits 52a2 and 52b2, and between drive circuits 52b1 and 52a2. This allows the heat conducted to the wiring substrate 810 from the heat generated by drive circuits 52a1, 52b1, 52a2, and 52b2 to be released to the heat sink 710 via the screw 780. That is, even when the head drive module 10 has multiple sets of drive circuits 52 that supply drive signals COM to different piezoelectric elements 60, the heat generated in the head drive module 10 can be released more efficiently.

[0294] Furthermore, regarding the liquid ejection device 1 of this embodiment, in the head drive module 10, the heat generated by the multiple drive circuits 52 that is conducted to the wiring substrate 810 can also be efficiently conducted to the heat sink 710. Therefore, even if the transistors M1 and M2 included in the drive circuit 52 are surface-mount types that conduct most of the heat to the wiring substrate 810, the heat generated by the drive circuit 52 can be efficiently conducted to the heat sink 710.

[0295] Furthermore, in the liquid ejection device 1 of the first embodiment, the head drive module 10 includes: a drive circuit 52a1 that outputs a drive signal COMA1 to drive the piezoelectric element 60 of the ejection module 23-1 to eject ink from the corresponding ejection section 600; a drive circuit 52c1 that outputs a drive signal COMC1 to drive the piezoelectric element 60 of the ejection module 23-1 to not eject ink from the corresponding ejection section 600; a drive circuit 52a2 that outputs a drive signal COMA2 to drive the piezoelectric element 60 of the ejection module 23-2 to eject ink from the corresponding ejection section 600; and a drive circuit 52c2 that outputs a drive signal COMC2 to drive the piezoelectric element 60 of the ejection module 23-2 to not eject ink from the corresponding ejection section 600.

[0296] Here, the voltage amplitude of the drive signal COMA1 output by drive circuit 52a1 is greater than the voltage amplitude of the drive signal COMC1 when the piezoelectric element 60 of the ejection module 23-1 is not ejecting ink from the corresponding ejection section 600 because it drives the piezoelectric element 60 of the ejection module 23-1 to eject ink. Similarly, the voltage amplitude of the drive signal COMA2 output by drive circuit 52a2 is greater than the voltage amplitude of the drive signal COMC2 when the piezoelectric element 60 of the ejection module 23-2 is not ejecting ink from the corresponding ejection section 600 because it drives the piezoelectric element 60 of the ejection module 23-2 to eject ink. Therefore, the heat generated by drive circuit 52a1 is greater than the heat generated by drive circuit 52c1, and the heat generated by drive circuit 52a2 is greater than the heat generated by drive circuit 52c2. That is, the liquid ejection device 1 of the first embodiment has multiple drive circuits 52, namely 52a1, 52c1, 52a2, and 52c2 with different heat generation.

[0297] In this first embodiment of the liquid ejection device 1, drive circuits 52a1, 52c1, 52a2, and 52c2 are arranged along the X2 direction on the wiring substrate 810, with drive circuit 52a2 located between drive circuits 52a1 and 52c1 along the X2 direction. The shortest distance between drive circuits 52c2 and 52c1 is shorter than the shortest distance between drive circuits 52c2 and 52a2. That is, drive circuits 52a1, 52c1, 52a2, and 52c2 are arranged and positioned in the X2 direction along the wiring substrate 810 in the order of drive circuits 52a1, 52a2, 52c1, and 52c2. In other words, on the wiring substrate 810, drive circuits 52a1 and 52a2, which generate more heat, are arranged nearby, while drive circuits 52c1 and 52c2, which generate less heat, are arranged nearby. Therefore, in the head drive module 10, heat dissipation components such as heat sinks 710 for releasing heat from the drive circuits 52 can be easily concentrated on the drive circuits 52a1 and 52a2, which generate a lot of heat. Furthermore, it is easy to select whether to equip the drive circuits 52c1 and 52c2, which generate less heat, with these heat dissipation components based on the operating environment and conditions of the liquid ejection device 1. In other words, in the liquid ejection device 1 of the first embodiment, by concentrating the drive circuits 52 that generate a lot of heat on the wiring board 810 and concentrating the drive circuits 52 that generate less heat on the wiring board 810, it is possible to reduce the possibility of the structure of heat dissipation components such as heat sinks 710, which dissipate heat from a large number of drive circuits 52, becoming more complex, and to appropriately select whether to equip these heat dissipation components based on the heat generated by the large number of drive circuits 52. Therefore, even when the liquid ejection device 1 has a large number of drive circuits 52, an optimal heat dissipation structure corresponding to the heat generated by these large number of drive circuits 52 can be applied, enabling efficient release of the heat generated by the large number of drive circuits 52.

[0298] Furthermore, in the liquid ejection device 1 of the first embodiment, the head drive module 10 includes: a drive circuit 52b1 that outputs a drive signal COMB1 to drive the piezoelectric element 60 of the ejection module 23-1 to eject ink from the corresponding ejection section 600; and a drive circuit 52a2 that outputs a drive signal COMB2 to drive the piezoelectric element 60 of the ejection module 23-2 to eject ink from the corresponding ejection section 600. Thus, the amount of ink ejected from the ejection module 23-1 can be controlled by the drive signals COMB1 and COMB1, and similarly, the amount of ink ejected from the ejection module 23-2 can be controlled by the drive signals COMB2 and COMB2. That is, more detailed control of the amount of ink ejected from each of the ejection modules 23-1 and 23-2 is possible, resulting in improved image quality on the medium.

[0299] In the liquid ejection device 1 of this first embodiment, the voltage amplitude of the drive signal COMB1 output by the drive circuit 52b1 is greater than the voltage amplitude of the drive signal COMC1 when the piezoelectric element 60 of the ejection module 23-1 is not ejecting ink from the corresponding ejection section 600 because it drives the piezoelectric element 60 of the ejection module 23-1 to eject ink. Similarly, the voltage amplitude of the drive signal COMB2 output by the drive circuit 52b2 is greater than the voltage amplitude of the drive signal COMC2 when the piezoelectric element 60 of the ejection module 23-2 is not ejecting ink from the corresponding ejection section 600 because it drives the piezoelectric element 60 of the ejection module 23-2 to eject ink. Therefore, the heat generated by the drive circuit 52b1 is greater than the heat generated by the drive circuit 52c1, and the heat generated by the drive circuit 52b2 is greater than the heat generated by the drive circuit 52c2.

[0300] In the liquid ejection device 1 of the first embodiment, when the liquid ejection device 1 is equipped with a drive circuit 52b1 that outputs a drive signal COMB1 for ejecting ink from the corresponding ejection section 600 using the piezoelectric element 60 of the drive ejection module 23-1, and a drive circuit 52b2 that outputs a drive signal COMB2 for ejecting ink from the corresponding ejection section 600 using the piezoelectric element 60 of the drive ejection module 23-2, along the X2 direction, drive circuits 52b1 and 52b2 are located between drive circuits 52a1 and 52c1, and between drive circuits 52a1 and 52c2. That is, drive circuits 52b1 and 52b2, which generate a lot of heat, are not arranged between drive circuits 52c1 and 52c2, which generate less heat.

[0301] Therefore, even when the liquid ejection device 1 has a drive circuit 52b1 that outputs a drive signal COMB1 from the corresponding ejection section 600 to drive the piezoelectric element 60 of the drive ejection module 23-1 to eject ink from the corresponding ejection section 600, and a drive circuit 52b2 that outputs a drive signal COMB2 from the corresponding ejection section 600 to drive the piezoelectric element 60 of the drive ejection module 23-2, it is possible to centrally arrange the drive circuits 52 that generate a lot of heat on the wiring board 810, and it is also possible to centrally arrange the drive circuits 52 that generate less heat on the wiring board 810. This reduces the possibility of the structure of heat dissipation components such as the heat sink 710 for cooling the drive circuits 52 becoming more complex, and allows for appropriate selection of whether to configure them based on the heat generated by the large number of drive circuits 52. As a result, even when the liquid ejection device 1 has a large number of drive circuits 52, the heat generated by these large number of drive circuits 52 can be efficiently released.

[0302] Furthermore, in the liquid ejection device 1 of the first embodiment, the drive circuits 52a1 and 52b1 that output drive signals COMA1 and COMB1 to the ejection module 23-1 are located adjacent to each other on the wiring substrate 810, and the drive circuits 52a2 and 52b2 that output drive signals COMA2 and COMB2 to the ejection module 23-2 are also located adjacent to each other on the wiring substrate 810. This reduces the difference between the wiring length for transmitting drive signal COMA1 to the ejection module 23-1 and the wiring length for transmitting drive signal COMB1, and similarly reduces the difference between the wiring length for transmitting drive signal COMA2 to the ejection module 23-2 and the wiring length for transmitting drive signal COMB2. As a result, the likelihood of a time difference in signal transmission between the drive signals COMA1 and COMB1 used for ejecting ink from the ejection module 23-1 is reduced. Similarly, the likelihood of a time difference in signal transmission between the drive signals COMA2 and COMB2 used for ejecting ink from the ejection module 23-2 is reduced. Consequently, the ejection accuracy of the ink ejected from the ejection modules 23-1 and 23-2 is further improved.

[0303] Furthermore, in the liquid ejection device 1 of the first embodiment, the drive circuit board 800 of the head drive module 10 includes: a plurality of drive circuits 52, including a drive circuit 52a1 that outputs a drive signal COMA1 to cause the ejection section 600 of the ejection module 23-1 to eject a large amount of ink, a drive circuit 52c1 that outputs a drive signal COMC1 to cause the ejection section 600 of the ejection module 23-1 to not eject ink, a drive circuit 52a6 that outputs a drive signal COMA6 to cause the ejection section 600 of the ejection module 23-6 to eject a large amount of ink, and a drive signal COMC1 to cause the ejection section 600 of the ejection module 23-6 to not eject ink. The drive circuit 52a6 of COMC6; the connecting part CN2, which electrically connects the head drive module 10 and the liquid ejection module 20; and the wiring substrate 810, which is provided with a plurality of drive circuits 52 and connecting parts CN2. The wiring substrate 810 includes a plurality of wiring patterns, including: wiring WA1, which transmits drive signal COMA1 from drive circuit 52a1 to connecting part CN2; wiring WC1, which transmits drive signal COMC1 from drive circuit 52c1 to connecting part CN2; wiring WA6, which transmits drive signal COMA6 from drive circuit 52a6 to connecting part CN2; and wiring WC6, which transmits drive signal COMC6 from drive circuit 52a6 to connecting part CN2. The plurality of wiring patterns further electrically connect each of the plurality of drive circuits 52 to the connecting part CN2. In such a head drive module 10, drive circuits 52a1, 52c1, 52a6, and 52c6 are arranged on the wiring substrate 810 such that wiring WA1 is shorter than wirings WC1, WA6, and WC6, and wiring WC6 is longer than wirings WA1, WC1, and WA6.

[0304] Here, the drive signal COMA1 drives the piezoelectric element 60 to eject a large amount of ink from the ejection section 600 of the ejection module 23-1, while the drive signal COMC1 drives the piezoelectric element 60 to prevent the ejection section 600 of the ejection module 23-1 from ejecting ink. Therefore, the current generated when transmitting the drive signal COMA1 is greater than the current generated when transmitting the drive signal COMC1. Similarly, the drive signal COMA6 drives the piezoelectric element 60 to eject a large amount of ink from the ejection section 600 of the ejection module 23-6, while the drive signal COMC6 drives the piezoelectric element 60 to prevent the ejection section 600 of the ejection module 23-6 from ejecting ink. Therefore, the current generated when transmitting the drive signal COMA6 is greater than the current generated when transmitting the drive signal COMC6. In other words, in the liquid ejection device 1 of the first embodiment, the wiring length for transmitting signals with a large current generated when transmitting the drive signal COMA1 is shorter than the wiring length for transmitting signals with a small current generated during signal transmission. Therefore, the influence of the impedance components of the wiring WA1 and WA6 of the drive signals COMA1 and COMA6, which may generate large currents during transmission, is reduced. As a result, the possibility of voltage drops in the drive signals COMA1 and COMA6 caused by the impedance components of the wiring WA1 and WA6 is reduced. That is, the waveform accuracy of the drive signals COMA1 and COMA6 supplied to the liquid ejection module 20 is improved. As a result, the ink ejection accuracy in the ejection modules 23-1 and 23-6 of the liquid ejection module 20 is improved.

[0305] In addition, in the liquid ejection device 1 of the first embodiment, the head drive module 10, in addition to the drive circuits 52a1, 52c1, 52a6, and 52c6, also includes: a drive circuit 52b1 that outputs a drive signal COMB1 to drive the piezoelectric element 60 to eject a small amount of ink from the ejection section 600 of the ejection module 23-1; and a drive circuit 52b6 that outputs a drive signal COMB6 to drive the piezoelectric element 60 to eject a small amount of ink from the ejection section 600 of the ejection module 23-6. The wiring substrate 810 includes: wiring WB1 that transmits the drive signal COMB1 from the drive circuit 52b1 to the connection section CN2; and wiring WB6 that transmits the drive signal COMB6 from the drive circuit 52b6 to the connection section CN2. Therefore, in the head drive module 10, the drive circuit 52b1 is arranged on the wiring substrate 810 such that wiring WB1 is longer than wiring WA1 and shorter than wiring WC1, and the drive circuit 52b6 is arranged on the wiring substrate 810 such that wiring WB6 is longer than wiring WA6 and shorter than wiring WC6.

[0306] The current generated when transmitting the drive signal COMB1 is smaller than the current generated when transmitting the drive signal COMA1, but larger than the current generated when transmitting the drive signal COMC1, because the piezoelectric element 60 drives the ejector portion 600 of the ejector module 23-1 to eject a small amount of ink. Similarly, the current generated when transmitting the drive signal COMB6 is smaller than the current generated when transmitting the drive signal COMA6, but larger than the current generated when transmitting the drive signal COMC6, because the piezoelectric element 60 drives the ejector portion 600 of the ejector module 23-6 to eject a small amount of ink. In this head drive module 10, the drive circuit 52b1 is arranged on the wiring substrate 810 such that wiring WB1 is longer than wiring WA1 and shorter than wiring WC1, and the drive circuit 52b6 is arranged on the wiring substrate 810 such that wiring WB6 is longer than wiring WA6 and shorter than wiring WC6. Therefore, even when the head drive module 10 includes a drive circuit 52b1 for outputting drive signal COMB1 and a drive circuit 52b6 for outputting drive signal COMB6, the possibility of voltage drops in drive signals COMA1 and COMA6 caused by the impedance components of wiring WA1 and WA6 can be reduced, and the possibility of voltage drops in drive signals COMB1 and COMB6 caused by the impedance components of wiring WB1 and WB6 can also be reduced. As a result, the ink ejection accuracy in the ejection modules 23-1 and 23-6 of the liquid ejection module 20 is improved.

[0307] 2. Second Implementation Method

[0308] The liquid ejection device 1 according to the second embodiment will now be described. In describing the liquid ejection device 1 according to the second embodiment, the same reference numerals will be used for components that are the same as those in the liquid ejection device 1 according to the first embodiment, and their descriptions will be simplified or omitted. In the liquid ejection device 1 according to the second embodiment, the arrangement of the plurality of drive circuits 52 provided on the wiring board 810 differs from that in the liquid ejection device 1 according to the first embodiment.

[0309] Figure 18 This is a diagram illustrating an example of the configuration of the first layer 831 of the wiring substrate 810 in the liquid ejection device 1 of the second embodiment. (See diagram below.) Figure 18 As shown, in the liquid ejection device 1 of the second embodiment, a plurality of drive circuits 52 are located between the integrated circuit 101 and the connecting part CN2 and are arranged along the X2 direction.

[0310] Specifically, the drive circuit 52a1 that outputs a drive signal COMA1 to drive the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-1 and the drive circuit 52a2 that outputs a drive signal COMA2 to drive the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-2 are located adjacent to each other along the X2 direction. The drive circuit 52a2 and the drive circuit 52a3 that outputs a drive signal COMA3 to drive the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-3 are located adjacent to each other along the X2 direction. The drive circuit 52a4 that drives the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-4 is located adjacent to the drive circuit 52a4 along the X2 direction. The drive circuit 52a4 and the drive circuit 52a5 that outputs the drive signal COMA5 for driving the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-5 are located adjacent to each other along the X2 direction. The drive circuit 52a5 and the drive circuit 52a6 that outputs the drive signal COMA6 for driving the piezoelectric element 60 to eject a large amount of ink from the ejection module 23-6 are located adjacent to each other along the X2 direction.

[0311] Additionally, the drive circuit 52b1, which outputs the drive signal COMB1 to drive the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-1, is located further to the +X2 side than the drive circuit 52a6. The drive circuit 52b1 and the drive circuit 52b2, which outputs the drive signal COMB2 to drive the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-2, are located adjacent to each other along the X2 direction. The drive circuit 52b2 and the drive circuit 52b3, which outputs the drive signal COMB3 to drive the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-3, are located adjacent to each other along the X2 direction. The drive circuit 52b3 and the drive circuit 52b4 that outputs a drive signal COMB4 for driving the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-4 are located adjacent to each other along the X2 direction. The drive circuit 52b4 and the drive circuit 52b5 that outputs a drive signal COMB5 for driving the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-5 are located adjacent to each other along the X2 direction. The drive circuit 52b5 and the drive circuit 52b6 that outputs a drive signal COMB6 for driving the piezoelectric element 60 to eject a small amount of ink from the ejection module 23-6 are located adjacent to each other along the X2 direction.

[0312] That is, in the head drive module 10, the drive circuits 52a1 to 52a6 that output drive signals COMA1 to COMA6 to drive the piezoelectric element 60 to eject a large amount of ink are located in adjacent positions on the first layer 831 of the wiring substrate 810, and the drive circuits 52b1 to 52b6 that output drive signals COMB1 to COMB6 to drive the piezoelectric element 60 to eject a small amount of ink are located in adjacent positions on the first layer 831 of the wiring substrate 810.

[0313] In addition, the drive circuits 52c1 to 52c6, which output drive signals COMC1 to COMC6 without ejecting ink, are positioned on the side of the wiring substrate 810 closer to the edge 811 than the drive circuits 52b1 to 52b6, arranged in the order of drive circuits 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6 in the X2 direction from the edge 812 toward the edge 811.

[0314] That is, in the liquid ejection device 1 of the second embodiment, the drive circuits 52a1 to 52a6, which generate a lot of heat due to ejecting a large amount of ink, are concentrated in the first layer 831 of the wiring substrate 810; the drive circuits 52b1 to 52b6, which generate a lot of heat due to ejecting a small amount of ink, are concentrated in the first layer 831 of the wiring substrate 810; and the drive circuits 52c1 to 52c6, which generate less heat, are concentrated in the first layer 831 of the wiring substrate 810. Thus, similar to the liquid ejection device 1 of the first embodiment, it is possible to reduce the possibility of the structure of heat dissipation components such as the heat sink 710, which dissipates heat from a large number of drive circuits 52, becoming more complex, and to appropriately select whether to configure them based on the heat generated by the large number of drive circuits 52. As a result, even when the liquid ejection device 1 has a large number of drive circuits 52, the heat generated by these large number of drive circuits 52 can be released efficiently.

[0315] Next, use Figures 19-21 An example of the wiring pattern configuration for transmitting drive signals COMA1~COMA6, COMB1~COMB6, and COMC1~COMC6 in the liquid ejection device 1 of the second embodiment will be described. Figure 19 This is a diagram showing an example of a wiring pattern disposed on the second layer 832 of the wiring substrate 810 in the second embodiment. Figure 20 This is a diagram showing an example of a wiring pattern disposed on the third layer 833 of the wiring substrate 810 in the second embodiment. Figure 21 This is a diagram showing an example of a wiring pattern disposed on the fourth layer 834 of the wiring substrate 810 in the second embodiment.

[0316] like Figure 18As shown, in the liquid ejection device 1 of the second embodiment, the drive circuits 52a1 to 52a6, 52b1 to 52b6, and 52c1 to 52c6, which are multiple drive circuits 52, are arranged in the X2 direction from the -X2 side to the +X2 side on the first layer 831 of the wiring substrate 810 in the order of drive circuits 52a1, 52a2, 52a3, 52a4, 52a5, 52a6, 52b1, 52b2, 52b3, 52b4, 52b5, 52b6, 52c1, 52c2, 52c3, 52c4, 52c5, and 52c6. That is, in the liquid ejection device 1 of the second embodiment, the drive circuits 52a1 to 52a6 of the piezoelectric elements 60 of the output drive ejection modules 23-1 to 23-6 that drive signals COMA1 to COMA6 to eject a large amount of ink from the corresponding nozzle N are concentrated near the connection part CN2. The drive circuits 52b1 to 52b6 of the piezoelectric elements 60 of the output drive ejection modules 23-1 to 23-6 that drive signals COMB1 to COMB6 to eject a small amount of ink from the corresponding nozzle N are concentrated at a position further away from the connection part CN2 than the drive circuits 52a1 to 52a6. The drive circuits 52c1 to 52c6 of the piezoelectric elements 60 of the output drive ejection modules 23-1 to 23-6 that drive signals COMC1 to COMC6 to not eject ink from the corresponding nozzle N are concentrated at a position further away from the connection part CN2 than the drive circuits 52b1 to 52b6.

[0317] Therefore, in the liquid ejection device 1 of the second embodiment, such as Figures 19-21 As shown, the wiring lengths of WA1-WA6, which electrically connect drive circuits 52a1-52a6 to the connection part CN2 and transmit drive signals COMA1-COMA6, are shorter than the wiring lengths of WB1-WB6, which electrically connect drive circuits 52b1-52b6 to the connection part CN2 and transmit drive signals COMB1-COMB6. Furthermore, the wiring lengths of WA1-WA6 and WB1-WB6, which electrically connect drive circuits 52a1-52a6 and 52b1-52b6 to the connection part CN2 and transmit drive signals COMA1-COMA6 and COMB1-COMB6, are shorter than the wiring lengths of WC1-WC6, which electrically connect drive circuits 52c1-52c6 to the connection part CN2 and transmit drive signals COMC1-COMC6.

[0318] As described above, in the head drive module 10, the voltage amplitudes of the drive signals COMA1 to COMA6 are larger than the voltage amplitudes of the drive signals COMB1 to COMB6, which drive the piezoelectric element 60 to eject a large amount of ink from the nozzles N of the ejection modules 23-1 to 23-6, because the piezoelectric element 60 ejects a large amount of ink from the nozzles N of the ejection modules 23-1 to 23-6. The voltage amplitudes of the drive signals COMA1 to COMA6 and COMB1 to COMB6 are larger than the voltage amplitudes of the drive signals COMC1 to COMC6, which drive the piezoelectric element 60 to eject ink from the nozzles N of the ejection modules 23-1 to 23-6, because the piezoelectric element 60 ejects ink from the nozzles N of the ejection modules 23-1 to 23-6, because the piezoelectric element 60 does not eject ink from the nozzles N of the ejection modules 23-1 to 23-6.

[0319] That is, the current generated by the transmission of drive signals COMA1 to COMA6 is greater than the current generated by the transmission of drive signals COMB1 to COMB6 and COMC1 to COMC6, and the current generated by the transmission of drive signals COMB1 to COMB6 is greater than the current generated by the transmission of drive signals COMC1 to COMC6. Therefore, drive signals COMA1 to COMA6 are more susceptible to the influence of impedance generated in the wiring pattern than drive signals COMB1 to COMB6 and COMC1 to COMC6, and drive signals COMB1 to COMB6 are more susceptible to the influence of impedance generated in the wiring pattern than drive signals COMC1 to COMC6. By making the wiring lengths of the drive signals COMA1 to COMA6, which are more susceptible to impedance generated in the wiring pattern, shorter than the wiring lengths of the drive signals COMB1 to COMB6, COMC1 to COMC6, WB1 to WB6, and WC1 to WC6, and by making the wiring lengths of the drive signals COMB1 to COMB6, WB1 to WB6, shorter than the wiring lengths of the drive signals COMC1 to COMC6, WC1 to WC6, the waveform accuracy of the drive signals COMA1 to COMA6 can be further improved compared to the liquid ejection device 1 of the first embodiment.

[0320] In addition, such as Figure 18As shown, in the liquid ejection device 1 of the second embodiment, several drive circuits 52a1 and 52a2, drive circuits 52a2 and 52a3, drive circuits 52a4 and 52a5, and drive circuits 52a5 are located in adjacent positions among the multiple through holes 820 through which screws 780 for mounting the heat sink 710 to the wiring substrate 810 are inserted. Between circuit 52a5 and drive circuit 52a6, between drive circuit 52a6 and drive circuit 52b1 located in adjacent positions, between drive circuit 52b1 and drive circuit 52b2 located in adjacent positions, between drive circuit 52b2 and drive circuit 52b3 located in adjacent positions, between drive circuit 52b3 and drive circuit 52b4 located in adjacent positions, between drive circuit 52b4 and drive circuit 52b5 located in adjacent positions, and between drive circuit 52b5 and drive circuit 52b6 located in adjacent positions.

[0321] That is, with the heat sink 710 already mounted on the wiring board 810, the screws 780 are respectively located between the drive circuits 52a1-52a6 and drive circuits 52b1-52b6 arranged on the wiring board 810. Thus, similar to the liquid ejection device 1 of the first embodiment, the heat conducted to the wiring board 810 from the heat generated by the high-heat drive circuits 52a1-52a6 and drive circuits 52b1-52b6 can be released to the heat sink 710 via the screws 780, enabling efficient heat release from the head drive module 10.

[0322] 3. Third Implementation Method

[0323] The liquid ejection device 1 according to the third embodiment will now be described. In describing the liquid ejection device 1 according to the third embodiment, the same reference numerals will be used for components that are the same as those in the liquid ejection devices 1 of the first and second embodiments, and their descriptions will be simplified or omitted. In the liquid ejection device 1 of the third embodiment, the arrangement of the plurality of drive circuits 52 provided on the wiring board 810 differs from that in the liquid ejection devices 1 of the first and second embodiments. Figure 22 This is a diagram showing an example of the configuration of the first layer 831 when viewed from the Z2 side along the Z2 direction of the wiring substrate 810 of the third embodiment. Figure 23 This is a diagram showing an example of a wiring pattern disposed on the second layer 832 of the wiring substrate 810 in the third embodiment. Figure 24 This is a diagram showing an example of a wiring pattern disposed on the third layer 833 of the wiring substrate 810 in the third embodiment. Figure 25This is a diagram showing an example of a wiring pattern disposed on the fourth layer 834 of the wiring substrate 810 in the third embodiment.

[0324] like Figure 22 As shown, in the liquid ejection device 1 of the third embodiment, the drive circuits 52a1 to 52a6, 52b1 to 52b6, and 52c1 to 52c6, which are multiple drive circuits 52, are arranged in the X2 direction from the -X2 side to the +X2 side on the first layer 831 of the wiring substrate 810 in the order of drive circuits 52a1, 52b1, 52c1, 52a2, 52b2, 52c2, 52a3, 52b3, 52c3, 52a4, 52b4, 52c4, 52a5, 52b5, 52c5, 52a6, 52b6, and 52c6. That is, in the liquid ejection device 1 of the third embodiment, the drive circuits 52a1, 52b1, and 52c1 for outputting the drive signals COMA1, COMB1, and COMC1 of the piezoelectric element 60 of the drive ejection module 23-1 are located near the connection part CN2; the drive circuits 52a2, 52b2, and 52c2 for outputting the drive signals COMA2, COMB2, and COMC2 of the piezoelectric element 60 of the drive ejection module 23-2 are located on the +X2 side of the drive circuits 52a1, 52b1, and 52c1; and the drive circuits 52a3, 52b3, and 52c3 for outputting the drive signals COMA3, COMB3, and COMC3 of the piezoelectric element 60 of the drive ejection module 23-3 are located on the +X2 side of the drive circuits 52a2, 52b2, and 52c2. On both sides, the driving circuits 52a4, 52b4, and 52c4 for the driving signals COMA4, COMB4, and COMC4 of the piezoelectric element 60 in the output driving ejection module 23-4 are located on the +X2 side of the driving circuits 52a3, 52b3, and 52c3. The driving circuits 52a5, 52b5, and 52c5 for the driving signals COMA5, COMB5, and COMC5 of the piezoelectric element 60 in the output driving ejection module 23-5 are located on the +X2 side of the driving circuits 52a4, 52b4, and 52c4. The driving circuits 52a6, 52b6, and 52c6 for the driving signals COMA6, COMB6, and COMC6 of the piezoelectric element 60 in the output driving ejection module 23-6 are located on the +X2 side of the driving circuits 52a5, 52b5, and 52c5.

[0325] Therefore, as Figures 23-25As shown, the wiring length of WA1, which electrically connects the drive circuit 52a1 to the connection part CN2 and transmits the drive signal COMA1, can be shorter than the wiring length of WB1, which electrically connects the drive circuit 52b1 to the connection part CN2 and transmits the drive signal COMB1. In addition, the wiring lengths of WA1 and WB1 can be shorter than the wiring length of WC1, which electrically connects the drive circuit 52c1 to the connection part CN2 and transmits the drive signal COMC1.

[0326] Similarly, the wiring length of WA2, which electrically connects the drive circuit 52a2 to the connection part CN2 and transmits the drive signal COMA2, can be shorter than the wiring length of WB2, which electrically connects the drive circuit 52b2 to the connection part CN2 and transmits the drive signal COMB2, and the wiring lengths of WA2 and WB2 can be shorter than the wiring length of WC2, which electrically connects the drive circuit 52c2 to the connection part CN2 and transmits the drive signal COMC2.

[0327] Similarly, the wiring length of the wiring WA3 that electrically connects the drive circuit 52a3 to the connection part CN2 and transmits the drive signal COMA3 can be made shorter than the wiring length of the wiring WB3 that electrically connects the drive circuit 52b3 to the connection part CN2 and transmits the drive signal COMB3, and the wiring lengths of wiring WA3 and WB3 can be made shorter than the wiring length of the wiring WC3 that electrically connects the drive circuit 52c3 to the connection part CN2 and transmits the drive signal COMC3.

[0328] Similarly, the wiring length of the wiring WA4 that electrically connects the drive circuit 52a4 to the connection part CN2 and transmits the drive signal COMA4 can be shorter than the wiring length of the wiring WB4 that electrically connects the drive circuit 52b4 to the connection part CN2 and transmits the drive signal COMB4, and the wiring lengths of wiring WA4 and WB4 can be shorter than the wiring length of the wiring WC4 that electrically connects the drive circuit 52c4 to the connection part CN2 and transmits the drive signal COMC4.

[0329] Similarly, the wiring length of the wiring WA5 that electrically connects the drive circuit 52a5 to the connection part CN2 and transmits the drive signal COMA5 can be shorter than the wiring length of the wiring WB5 that electrically connects the drive circuit 52b5 to the connection part CN2 and transmits the drive signal COMB5, and the wiring lengths of wiring WA5 and WB5 can be shorter than the wiring length of the wiring WC5 that electrically connects the drive circuit 52c5 to the connection part CN2 and transmits the drive signal COMC5.

[0330] Similarly, the wiring length of the wiring WA6 that electrically connects the drive circuit 52a6 to the connection part CN2 and transmits the drive signal COMA6 can be shorter than the wiring length of the wiring WB6 that electrically connects the drive circuit 52b6 to the connection part CN2 and transmits the drive signal COMB6, and the wiring lengths of wiring WA6 and WB6 can be shorter than the wiring length of the wiring WC6 that electrically connects the drive circuit 52c6 to the connection part CN2 and transmits the drive signal COMC6.

[0331] Therefore, for each ejection module 23, the wiring length of the wiring WA1 to WA6, which is easily affected by the impedance generated in the wiring pattern, can be made shorter than the wiring length of the wiring WB1 to WB6, COMC1 to COMC6, and WC1 to WC6, respectively, and the wiring length of the wiring WB1 to WB6, which is easily affected by the impedance generated in the wiring pattern, can be made shorter than the wiring length of the wiring WC1 to WC6, respectively, thereby improving the ink ejection accuracy of each ejection module 23.

[0332] Furthermore, in the liquid ejection device 1 of the third embodiment, the difference in the length of the wiring WA1 supplying the drive signal COMA1 to the ejection module 23-1, the wiring WB1 supplying the drive signal COMB1, and the wiring WC1 supplying the drive signal COMC1 can be reduced, thereby reducing the supply error that may occur to the drive signals COMA1, COMB1, and COMC1 supplied to the ejection module 23-1 due to the difference in wiring length.

[0333] Similarly, the length differences between the wiring lengths of the wiring WA2 supplying the drive signal COMA2 to the ejection module 23-2, the wiring lengths of the wiring WB2 supplying the drive signal COMB2, and the wiring lengths of the wiring WC2 supplying the drive signal COMC2 can be reduced. The length differences between the wiring lengths of the wiring WA3 supplying the drive signal COMA3, the wiring lengths of the wiring WB3 supplying the drive signal COMB3, and the wiring lengths of the wiring WC3 supplying the drive signal COMC3 to the ejection module 23-3 can also be reduced. Furthermore, the length differences between the wiring lengths of the wiring WA4 supplying the drive signal COMA4 to the ejection module 23-4 can also be reduced. The difference in the length of the wiring WB4 of COMB4 and the wiring WC4 of the drive signal COMC4 can reduce the difference in the length of the wiring WA5 of the drive signal COMA5, the wiring WB5 of the drive signal COMB5, and the wiring WC5 of the drive signal COMC5 supplied to the ejection module 23-5. It can also reduce the difference in the length of the wiring WA6 of the drive signal COMA6, the wiring WB6 of the drive signal COMB6, and the wiring WC6 of the drive signal COMC6 supplied to the ejection module 23-6.

[0334] This reduces the likelihood of timing differences in the signal input to the ejection modules 23-1 to 23-6 due to wiring length, thereby improving the ink ejection accuracy of each ejection module 23.

[0335] In addition, such as Figure 22 As shown, in the liquid ejection device 1 of the third embodiment, several drive circuits 52a1 and 52b1, drive circuits 52a2 and 52b2, drive circuits 52a3 and 52b3, drive circuits 52a4 and 52b4, drive circuits 52a5 and 52b5, and drive circuits 52a6 and 52b6 are located in adjacent positions among the multiple through holes 820 through which screws 780 for mounting the heat sink 710 to the wiring substrate 810 are inserted.

[0336] That is, in the liquid ejection device 1 of the third embodiment, the drive circuits 52a1 to 52a6, drive circuits 52b1 to 52b6, and drive circuits 52c1 to 52c6 are mounted on the wiring substrate 810 in the order of drive circuits 52a1, 52b1, 52c1, 52a2, 52b2, 52c2, 52a3, 52b3, 52c3, 52a4, 52b4, 52c4, 52a5, 52b5, 52c5, 52a6, 52b6, 52c6 along X2. The through holes 820, through which screws 780 for mounting the heat sink 710 to the wiring substrate 810 are inserted, are positioned in the X2 direction between drive circuits 52a1 and 52b1, drive circuits 52a2 and 52b2, drive circuits 52a3 and 52b3, drive circuits 52a4 and 52b4, drive circuits 52a5 and 52b5, and drive circuits 52a6 and 52b6.

[0337] Even the liquid ejection device 1 in the third embodiment configured as described above, like the liquid ejection device 1 in the first and second embodiments, can release the heat generated by the high-heat-generating drive circuits 52a1-52a6 and 52b1-52b6 that is conducted to the wiring board 810 via the screw 780 to the heat sink 710, thus achieving efficient release of the heat generated in the head drive module 10.

[0338] Here, in the liquid ejection device 1 of the third embodiment, as... Figure 26 As shown, along the X2 direction, between drive circuit 52c1 and drive circuit 52a2, between drive circuit 52c2 and drive circuit 52a3, between drive circuit 52c3 and drive circuit 52a4, between drive circuit 52c4 and drive circuit 52a5, and between drive circuit 52c5 and drive circuit 52a6, a plurality of through holes 820 may be further provided for screws 780 for mounting heat sink 710 to wiring substrate 810 to insert through. Figure 26 This is a diagram showing an example of the configuration of the first layer 831 when viewed from the Z2 side along the Z2 direction of a modified example of the third embodiment of the wiring substrate 810.

[0339] In the liquid ejection device 1 of the modified third embodiment configured as described above, the heat generated by the drive circuits 52a1 to 52a6, which generate a particularly large amount of heat, and conducted to the wiring board 810 can be released to the heat sink 710 via two screws 780, which can further improve the heat release efficiency generated in the head drive module 10.

[0340] In the liquid ejection device 1 of the third embodiment configured as described above, Figure 22 and Figure 26 Of the plurality of through holes 820 shown on the wiring substrate 810, the through hole 820 located between drive circuit 52a1 and drive circuit 52b1 is an example of a first through hole, the through hole 820 located between drive circuit 52a2 and drive circuit 52b2 is an example of a second through hole, and the through hole 820 located between drive circuit 52c1 and drive circuit 52a2 is an example of a third through hole. Furthermore, a screw 780 inserted through the through hole 820 corresponding to the first through hole is an example of a first screw, a screw 780 inserted through the through hole 820 corresponding to the second through hole is an example of a second screw, and a screw 780 inserted through the through hole 820 corresponding to the third through hole is an example of a third screw.

[0341] The embodiments and variations have been described above, but the present invention is not limited to these embodiments and can be implemented in various ways without departing from its spirit. For example, the above embodiments can also be appropriately combined.

[0342] This invention includes configurations that are substantially the same as those described in the embodiments (e.g., configurations with the same function, method, and result, or configurations with the same purpose and effect). Additionally, this invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, this invention includes configurations capable of achieving the same effects or purposes as those described in the embodiments. Additionally, this invention includes configurations in which known techniques are added to the configurations described in the embodiments.

[0343] The following content is derived from the above implementation method.

[0344] One aspect of the liquid ejection device includes:

[0345] The nozzle ejects liquid in response to the actuation of the first piezoelectric element;

[0346] The substrate has a first through hole;

[0347] The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate;

[0348] A metal frame is mounted on the substrate; and

[0349] A first screw is inserted through the first through hole to mount the metal frame onto the substrate.

[0350] The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid.

[0351] The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid.

[0352] The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid.

[0353] The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit.

[0354] The first through hole is located between the first driving circuit and the second driving circuit in the one direction.

[0355] According to this liquid ejection device, a metal frame is mounted on a substrate via a first screw between a first drive circuit that generates a large amount of heat due to a first drive signal that drives the first piezoelectric element to eject a first amount of liquid from the nozzle, and a second drive circuit that generates a large amount of heat due to a second drive signal that drives the first piezoelectric element to eject a second amount of liquid from the nozzle. This allows a portion of the heat generated by the first and second drive circuits to be conducted to a heat sink via the first screw. Consequently, the heat conduction efficiency from the first and second drive circuits to the metal frame is improved, and the heat dissipation efficiency of the metal frame for the first and second drive circuits is enhanced.

[0356] In one aspect of the liquid ejection device, it may also be that...

[0357] The ejector head includes a second piezoelectric element.

[0358] The liquid ejection device includes a fourth driving circuit, a fifth driving circuit, and a sixth driving circuit disposed on the substrate.

[0359] The fourth drive circuit outputs a fourth drive signal to drive the second piezoelectric element so that the nozzle ejects a third amount of liquid.

[0360] The fifth drive circuit outputs a fifth drive signal to drive the second piezoelectric element so that the nozzle ejects a fourth amount of liquid.

[0361] The sixth driving circuit outputs a sixth driving signal to drive the second piezoelectric element so that the nozzle does not eject liquid.

[0362] According to this liquid ejection device, even when there is a fourth drive circuit that outputs a fourth drive signal to the second piezoelectric element, a fifth drive circuit that outputs a fifth drive signal, and a sixth drive circuit that outputs a sixth drive signal, efficient heat dissipation via the metal frame can be achieved due to the improved heat conduction efficiency to the metal frame.

[0363] In one aspect of the liquid ejection device,

[0364] The first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit can also be arranged and positioned on the substrate in the order of the first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit along the one direction.

[0365] In one aspect of the liquid ejection device, it may also be that...

[0366] The substrate has a second through hole.

[0367] The liquid ejection device includes a second screw, which is inserted through the second through hole and mounts the metal frame to the substrate.

[0368] The second through hole is located between the fourth driving circuit and the fifth driving circuit in the one direction.

[0369] According to this liquid ejection device, a metal frame is mounted on a substrate via a second screw between a fourth drive circuit that generates a large amount of heat due to a fourth drive signal that drives the second piezoelectric element to eject a third amount of liquid from the nozzle, and a fifth drive circuit that generates a large amount of heat due to a fifth drive signal that drives the second piezoelectric element to eject a fourth amount of liquid from the nozzle. This allows a portion of the heat generated by the fourth and fifth drive circuits to be conducted to a heat sink via the second screw. Consequently, the heat conduction efficiency from the fourth and fifth drive circuits to the metal frame is improved, and the heat dissipation efficiency of the metal frame for the fourth and fifth drive circuits is also improved.

[0370] In one aspect of the liquid ejection device, it may also be that...

[0371] The substrate has a third through hole.

[0372] The liquid ejection device includes a third screw, which is inserted through the third through hole and mounts the metal frame to the substrate.

[0373] The third through hole is located between the third driving circuit and the fourth driving circuit in one direction.

[0374] According to this liquid ejection device, a metal frame is mounted to the substrate on both sides of the fourth drive circuit using second and third screws, thereby enabling a portion of the heat generated by the fourth drive circuit to be conducted to the heat sink via the second and third screws. This further improves the heat conduction efficiency from the fourth drive circuit to the metal frame, and further enhances the heat dissipation efficiency of the metal frame for the fourth drive circuit.

[0375] In one aspect of the liquid ejection device, it may also be that...

[0376] The substrate has a fourth through hole and a fifth through hole.

[0377] The liquid ejection device includes:

[0378] A fourth screw is inserted through the fourth through hole to mount the metal frame to the substrate; and

[0379] A fifth screw is inserted through the fifth through hole to mount the metal frame onto the substrate.

[0380] The first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit are arranged and positioned on the substrate along the said direction in the order of the first driving circuit, the second driving circuit, the fourth driving circuit, the fifth driving circuit, the third driving circuit, and the sixth driving circuit.

[0381] The fourth through hole is located between the second driving circuit and the fourth driving circuit in one direction.

[0382] The fifth through hole is located between the fourth driving circuit and the fifth driving circuit in one direction.

[0383] According to the liquid ejection device, a first drive circuit that outputs a first drive signal to drive the first piezoelectric element to eject liquid from the ejector head, a second drive circuit that outputs a second drive signal to drive the first piezoelectric element to eject liquid from the ejector head, a fourth drive circuit that outputs a fourth drive signal to drive the second piezoelectric element to eject liquid from the ejector head, and a fifth drive circuit that outputs a fifth drive signal to drive the second piezoelectric element to eject liquid from the ejector head are centrally positioned on the substrate; a third drive circuit that outputs a third drive signal to drive the first piezoelectric element to prevent the ejector head from ejecting liquid, and a fifth drive circuit that outputs a third drive signal to drive the second piezoelectric element to prevent the ejector head from ejecting liquid are also centrally positioned on the substrate. The sixth driving circuit of the sixth driving signal is centrally positioned on the substrate. A metal frame is mounted to the substrate between the first and second driving circuits using a first screw, between the second and fourth driving circuits using a fourth screw, and between the fourth and fifth driving circuits using a fifth screw. This allows for more efficient heat transfer from the first, second, fourth, and fifth driving circuits (which generate significantly more heat than the third and sixth driving circuits) to the heat sink via the first, fourth, and fifth screws. Consequently, the heat dissipation efficiency of the first, second, fourth, and fifth driving circuits through the metal frame is further improved.

[0384] In one aspect of the liquid ejection device, it may also be that...

[0385] The first driving circuit includes surface-mount transistors.

[0386] According to the liquid ejection device, even if a portion of the heat generated by the first drive circuit is conducted to the substrate, the heat conducted to the substrate can be conducted to the metal frame via the first screw. Therefore, even if the first drive circuit includes a surface-mount transistor that conducts a large amount of heat to the substrate, the heat generated by the first drive circuit can be conducted to the heat sink more efficiently via the first screw.

[0387] In one aspect of the liquid ejection device, it may also be that...

[0388] The metal frame is a heat sink for releasing heat from at least one of the first drive circuit, the second drive circuit, and the third drive circuit.

[0389] According to the liquid ejection device, a heat sink is constructed with a metal frame for heat dissipation, thereby further improving the heat dissipation efficiency of the heat generated by the first drive circuit and the second drive circuit.

[0390] One aspect of the head drive circuit is a head drive circuit that drives a jet head to eject liquid in response to the drive of the first piezoelectric element, and it includes:

[0391] The substrate has a first through hole;

[0392] The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate;

[0393] A metal frame is mounted on the substrate; and

[0394] A first screw is inserted through the first through hole to mount the metal frame onto the substrate.

[0395] The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid.

[0396] The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid.

[0397] The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid.

[0398] The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit.

[0399] The first through hole is located between the first driving circuit and the second driving circuit in the one direction.

[0400] According to this head drive circuit, a metal frame is mounted on the substrate via a first screw between a first drive circuit that generates a large amount of heat due to a first drive signal that drives the first piezoelectric element to eject a first amount of liquid from the nozzle, and a second drive circuit that generates a large amount of heat due to a second drive signal that drives the first piezoelectric element to eject a second amount of liquid from the nozzle. This allows a portion of the heat generated by the first and second drive circuits to be conducted to the heat sink via the first screw. Consequently, the heat conduction efficiency from the first and second drive circuits to the metal frame is improved, and the heat dissipation efficiency of the metal frame for the first and second drive circuits is enhanced.

Claims

1. A liquid ejection device, characterized in that, have: The nozzle has a first ejection module that ejects liquid in response to a drive from a first piezoelectric element; The substrate has a first through hole; The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate; A metal frame is mounted on the substrate; as well as A first screw is inserted through the first through hole to mount the metal frame onto the substrate. The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid. The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid. The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid. The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit. The first through hole is located between the first driving circuit and the second driving circuit in the one direction.

2. The liquid ejection device according to claim 1, characterized in that, The nozzle includes a second ejection module that ejects liquid in response to the actuation of a second piezoelectric element. The liquid ejection device includes a fourth driving circuit, a fifth driving circuit, and a sixth driving circuit disposed on the substrate. The fourth drive circuit outputs a fourth drive signal to drive the second piezoelectric element so that the nozzle ejects a third amount of liquid. The fifth drive circuit outputs a fifth drive signal to drive the second piezoelectric element so that the nozzle ejects a fourth amount of liquid. The sixth driving circuit outputs a sixth driving signal to drive the second piezoelectric element so that the nozzle does not eject liquid.

3. The liquid ejection device according to claim 2, characterized in that, The first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit are arranged and positioned on the substrate in the order of the first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit along the first direction.

4. The liquid ejection device according to claim 3, characterized in that, The substrate has a second through hole. The liquid ejection device includes a second screw, which is inserted through the second through hole and mounts the metal frame to the substrate. The second through hole is located between the fourth driving circuit and the fifth driving circuit in the one direction.

5. The liquid ejection device according to claim 3 or 4, characterized in that, The substrate has a third through hole. The liquid ejection device includes a third screw, which is inserted through the third through hole and mounts the metal frame to the substrate. The third through hole is located between the third driving circuit and the fourth driving circuit in one direction.

6. The liquid ejection device according to claim 2, characterized in that, The substrate has a fourth through hole and a fifth through hole. The liquid ejection device includes: A fourth screw is inserted through the fourth through hole to mount the metal frame to the substrate; and A fifth screw is inserted through the fifth through hole to mount the metal frame onto the substrate. The first driving circuit, the second driving circuit, the third driving circuit, the fourth driving circuit, the fifth driving circuit, and the sixth driving circuit are arranged and positioned on the substrate along the said direction in the order of the first driving circuit, the second driving circuit, the fourth driving circuit, the fifth driving circuit, the third driving circuit, and the sixth driving circuit. The fourth through hole is located between the second driving circuit and the fourth driving circuit in one direction. The fifth through hole is located between the fourth driving circuit and the fifth driving circuit in one direction.

7. The liquid ejection device according to claim 1, characterized in that, The first driving circuit includes surface-mount transistors.

8. The liquid ejection device according to claim 1, characterized in that, The metal frame is a heat sink for releasing heat from at least one of the first drive circuit, the second drive circuit, and the third drive circuit.

9. A head driving circuit, characterized in that, A nozzle that ejects liquid in response to the actuation of a first piezoelectric element, the nozzle driving circuit comprising: The substrate has a first through hole; The first driving circuit, the second driving circuit, and the third driving circuit are disposed on the substrate; A metal frame is mounted on the substrate; as well as A first screw is inserted through the first through hole to mount the metal frame onto the substrate. The first drive circuit outputs a first drive signal to drive the first piezoelectric element so that the nozzle ejects a first amount of liquid. The second drive circuit outputs a second drive signal to drive the first piezoelectric element so that the nozzle ejects a second amount of liquid. The third driving circuit outputs a third driving signal to drive the first piezoelectric element so that the nozzle does not eject liquid. The first driving circuit, the second driving circuit, and the third driving circuit are arranged and positioned on the substrate in one direction in the order of the first driving circuit, the second driving circuit, and the third driving circuit. The first through hole is located between the first driving circuit and the second driving circuit in the one direction.

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