Liquid spraying device

Abstract

A liquid ejection device capable of achieving miniaturization and improved liquid ejection accuracy. In the liquid ejection device, a substrate unit connected to a print head having a first connector and a piezoelectric element comprises: a second connector mating with the first connector, a reference voltage signal output circuit for outputting a reference voltage signal supplied to the piezoelectric element, an electrolytic capacitor, and a wiring substrate, wherein the wiring substrate comprises a plurality of rigid components and a flexible component comprising a first surface, a second surface, a first region, and a second region; the reference voltage signal output circuit is disposed on the first rigid component comprising the first surface and stacked on the first surface of the first region; the electrolytic capacitor is disposed on the second rigid component comprising the second surface and stacked on the first surface of the second region; and the second connector is disposed on the third rigid component stacked on the second surface of the second region. The first rigid component and the second rigid component are positioned such that a normal direction of the first surface intersects a normal direction of the second surface.

Description

Technical Field

[0001] The present invention relates to a liquid ejection device. Background Art

[0002] Over half a century has passed since the invention of liquid ejection technology using piezoelectric elements. Liquid ejection devices using this technology have been flexibly applied in a wide range of fields, including inkjet printers and color filter manufacturing equipment. In recent years, with the establishment of the fundamental technology for this liquid ejection technology, market demand for liquid ejection devices has centered on improving the productivity of products produced using these devices. To meet these market demands, technological development in liquid ejection technology has focused on multi-nozzle systems and increasing the amount of ink ejected per unit time.

[0003] Patent document 1 discloses a printing device (liquid ejection device) that uses multiple heads with multiple nozzles to realize the concept of increasing the ejection volume per unit time in order to improve the productivity of the product. The liquid ejection device has multiple head units (liquid ejection heads) in a housing, multiple drive circuits that supply drive signals to the head units, and a cooling mechanism that cools the drive circuits.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-099835

[0005] However, although the liquid ejection device described in Patent Document 1 can improve productivity, it is still insufficient from the perspectives of miniaturization of the liquid ejection device and improvement of liquid ejection accuracy, and there is room for improvement. Summary of the Invention

[0006] The liquid ejection device has:

[0007] a print head, which ejects liquid; and

[0008] a substrate unit, electrically connected to the print head,

[0009] The print head has:

[0010] a first ejection portion including a first piezoelectric element that is displaced based on a first drive signal whose voltage value varies and is supplied to a first electrode and a reference voltage signal whose voltage value is fixed and is supplied to a second electrode, and ejects liquid by displacement of the first piezoelectric element; and

[0011] a first connector electrically connected to the substrate unit,

[0012] The substrate unit comprises:

[0013] a second connector, engaged with the first connector, thereby being electrically connected to the print head;

[0014] A reference voltage signal output circuit, outputting the reference voltage signal;

[0015] an electrolytic capacitor for reducing a variation in a voltage value of the reference voltage signal; and

[0016] a wiring substrate provided with the second connector, the reference voltage signal output circuit, and the electrolytic capacitor;

[0017] The wiring substrate is a rigid-flexible substrate including a plurality of rigid components on which the reference voltage signal output circuit and the electrolytic capacitor are provided, and a flexible component that is softer than the plurality of rigid components.

[0018] The flexible component includes a first surface, a second surface opposite to the first surface, a first region, a second region, and a third region.

[0019] The third area is located between the first area and the second area.

[0020] The plurality of rigid components include a first rigid component, a second rigid component, and a third rigid component,

[0021] The first rigid component includes a first surface, and the first surface is laminated on the first surface of the first region in a manner extending along the first surface.

[0022] The second rigid component includes a second surface, and the second surface is laminated on the first surface of the second region in a manner extending along the first surface.

[0023] The third rigid component includes a third surface, and the third surface is laminated on the second surface of the second region in a manner extending along the second surface.

[0024] The reference voltage signal output circuit is provided on the first rigid component,

[0025] The electrolytic capacitor is arranged on the second rigid component,

[0026] The second connector is provided on the third rigid component,

[0027] The first rigid component and the second rigid component are located at positions where a normal direction of the first surface intersects a normal direction of the second surface due to the bending of the flexible component in the third region. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1It is a diagram showing a schematic structure of a liquid ejecting device.

[0029] Figure 2 This is a diagram showing an example of the functional configuration of the head unit.

[0030] Figure 3 1 is a diagram showing the structure of a drive signal output circuit.

[0031] Figure 4 : is a diagram showing an example of the signal waveforms of the drive signals COMA and COMB.

[0032] Figure 5 3 is a diagram showing an example of the signal waveform of the drive signal VOUT.

[0033] Figure 6 3 is a diagram showing the functional structure of a drive signal selection circuit.

[0034] Figure 7 This is a diagram showing an example of the decoded content in the decoder.

[0035] Figure 8 is a diagram showing the structure of a selection circuit.

[0036] Figure 9 This is a diagram for explaining the operation of the drive signal selection circuit.

[0037] Figure 10 This is a side view showing the structure of a carriage on which the head unit is mounted.

[0038] Figure 11 It is a perspective view showing the peripheral structure of a carriage on which the head unit is mounted.

[0039] Figure 12 This is an exploded perspective view showing an example of the structure of the liquid ejection module.

[0040] Figure 13 This is a perspective view showing an example of the internal structure of the print head.

[0041] Figure 14 This is an exploded perspective view of the print head.

[0042] Figure 15 This is a diagram showing an example of the structure of the discharge portion of the discharge module.

[0043] Figure 16 It is a diagram showing a planar structure of a driving circuit substrate.

[0044] Figure 17 The drive circuit substrate is placed along Figure 16 A cross-sectional view taken along line Aa is shown.

[0045] Figure 18 The drive circuit substrate is placed along Figure 16 The cross-sectional view is taken along line Bb.

[0046] Figure 19 This is a diagram showing an example of the structure of a driver circuit board having a substantially box shape.

[0047] Figure 20 This is a diagram showing an example of component arrangement in a driver circuit board in an expanded state.

[0048] Figure 21 This is a diagram showing an example of a wiring pattern for transmitting voltage signals VHV, VMV, and VDD.

[0049] Figure 22 1 is a diagram showing an example of a wiring pattern for transmitting the driving signal COM and the reference voltage signal VBS.

[0050] Figure 23 This is a diagram showing an example of component arrangement in a driver circuit board in an assembled state.

[0051] Figure 24 This is a diagram showing an example of component arrangement in a driver circuit board in an assembled state.

[0052] Figure 25 It is a plan view showing an example of the structure of the relay substrate.

[0053] Figure 26 This is a side view showing an example of the structure of the relay substrate.

[0054] Figure 27 This is a diagram of the drive circuit module viewed from the -x2 side along the x2 axis.

[0055] Figure 28 This is a diagram of the drive circuit module viewed from the +x2 side along the x2 axis.

[0056] Figure 29 This is a diagram of the driving circuit module viewed from the -y2 side along the y2 axis.

[0057] Figure 30 This is a diagram of the driving circuit module viewed from the +z2 side along the z2 axis.

[0058] Figure 31 It is a diagram showing a schematic structure of a liquid ejection device according to a modified example.

[0059] Figure 32 It is an exploded perspective view showing an example of the structure of a liquid ejection module according to a modified example.

[0060] Figure 33This is a diagram showing an example of component arrangement in a driver circuit board in a developed state according to a modification.

[0061] Description of Reference Numerals

[0062] 1…Liquid ejection device; 2…Control unit; 3…Head unit; 4…Conveyor motor; 5…Conveyor roller; 6…Slide motor; 7…Slide guide shaft; 8…Slide; 9…Liquid container; 10…Ejection control module; 12…Head control circuit; 14…Cooling fan drive circuit; 16…Main control circuit; 18…Power supply voltage output circuit; 20…Liquid ejection module; 21, 22…FFC cable; 30…Print head; 31…Recovery circuit; 32…Ejection module; 50…Drive circuit module; 51…Ejection control circuit; 52…Drive signal output circuit; 53…Capacitor; 54…Abnormality detection circuit; 55…Abnormality notification circuit; 56…Temperature detection circuit; 58…Voltage conversion circuit; 59…Cooling fan; 60… Piezoelectric element; 72…guide rail; 81…slide body; 82…slide cover; 83…housing case; 85…loading portion; 86…fixing portion; 87…slide support portion; 100…control circuit board; 110…integrated circuit; 150…relay board; 151, 152…surface; 153-156…edge; 158, 159…through hole; 160…opening plate; 161-164…opening; 170…heat sink; 172…opening; 175…heat conducting member; 180…heat sink; 185…heat conducting member; 200…drive signal selection circuit; 210…selection control circuit; 212…register; 214…latch circuit; 216…decoder; 230…selection circuit; 232a, 232b…inverter 234a, 234b…transmission gate; 310…head holder; 315, 316…flange; 318…accommodation portion; 320…reinforcement plate; 325…opening; 330…fixing plate; 335…opening; 340…flow path component; 350…head cover; 360…head substrate; 370…head relay substrate; 372, 374, 376…FPC; 380…head relay substrate; 382, ​​384, 386…FPC; 500…integrated circuit; 510…modulation circuit; 512, 513…adder; 514…comparator; 515…inverter; 516…integrating attenuator; 517…attenuator; 520…gate drive circuit; 521, 522…gate driver; 530…reference voltage signal Output circuit; 550…amplifier circuit; 560…demodulator circuit; 570, 572…feedback circuit; 590…reference power supply circuit; 600…ejector; 601…piezoelectric element; 611, 612…electrodes; 621…vibration plate; 631…cavity; 632…nozzle plate; 641…reservoir; 651…nozzle; 661…supply port; 700…drive circuit substrate; 701-707…areas; 710…rigid wiring component; 711-714…edge; 721, 722…rigid component; 723, 724…surface; 730…rigid wiring component; 731-734…edge; 741, 742…rigid component; 743, 744…surface; 750…rigid wiring component; 751-754…edge;761, 762…rigid components; 763, 764…surfaces; 770…rigid wiring components; 771-774…edges; 781, 782…rigid components; 783, 784…surfaces; 790…flexible wiring components; 791, 792…surfaces; AR…compressed air; C1-C5, C7, C53…capacitors; CN1, CN1a, CN1b, CN2, CN2a, CN2b, CN3, CN3a, CN3b…connectors; CP…compressor; D1…diode; L1…inductor; M1, M2…transistors; P…dielectric; R1-R6…resistors; TB…tubes; wb1-wb8, wca1-wca4, wcb1-wcb4, wd1-wd3, wg, wh1-wh7, wm1-wm3…wiring. DETAILED DESCRIPTION

[0063] Below, preferred embodiments of the present invention are described in detail using the accompanying drawings. The accompanying drawings are for ease of explanation. It should be noted that the embodiments described below are not intended to improperly limit the content of the present invention as described in the claims. Furthermore, all of the structures described below are not necessarily essential components of the present invention.

[0064] 1. Functional structure of liquid ejection device

[0065] 1.1 Functional structure of liquid ejection device

[0066] Figure 1 This figure schematically illustrates the structure of a liquid ejection device 1. The liquid ejection device 1 of this embodiment is a so-called inkjet printer that ejects ink, an example of liquid, onto a conveyed medium P at a desired timing, thereby forming a desired image on the surface of the medium P. In the following description, the direction in which the medium P is conveyed may be referred to as the conveyance direction.

[0067] like Figure 1 As shown, the liquid ejection device 1 includes a control unit 2 , a head unit 3 , a transport motor 4 , a transport roller 5 , a carriage motor 6 , a carriage guide shaft 7 , a carriage 8 , and a liquid container 9 .

[0068] The control unit 2 generates control signals for controlling various components of the liquid ejection device 1 based on image data DATA supplied from an external device (not shown), such as a host computer, located outside the liquid ejection device 1, and outputs these signals to the corresponding components. Furthermore, the control unit 2 generates a voltage signal VDC, such as a power supply voltage, for each component of the liquid ejection device 1 based on the commercial AC voltage VAC supplied to the liquid ejection device 1, and supplies the voltage signal VDC to each component of the liquid ejection device 1.

[0069] Specifically, the control unit 2 generates a conveyance control signal Ctrl-T as a control signal for controlling various components of the liquid ejection device 1 and outputs it to the conveyance motor 4. The conveyance motor 4 is driven based on the input conveyance control signal Ctrl-T. The conveyance roller 5 rotates in response to the drive of the conveyance motor 4. The driving force generated by the rotation of the conveyance roller 5 conveys the medium P in the conveyance direction. In other words, the conveyance motor 4 and the conveyance roller 5 convey the medium P based on the conveyance control signal Ctrl-T output by the control unit 2.

[0070] In addition, the control unit 2 generates a carriage control signal Ctrl-C as a control signal for controlling each element of the liquid ejection device 1, and outputs it to the carriage motor 6. The carriage motor 6 is driven based on the input carriage control signal Ctrl-C. The driving force generated by the driving of the carriage motor 6 is transmitted to the carriage 8 supported on the carriage guide shaft 7 via a timing belt not shown in the figure. The carriage guide shaft 7 extends in a direction intersecting with the conveying direction and supports the carriage 8. And, based on the driving force generated by the driving of the carriage motor 6, the carriage 8 supported on the carriage guide shaft 7 moves along the carriage guide shaft 7. That is, the carriage motor 6 and the carriage guide shaft 7 move the carriage 8 along the carriage guide shaft 7 according to the carriage control signal Ctrl-C output by the control unit 2.

[0071] The control unit 2 also generates a print data signal pDATA as a control signal for controlling various components of the liquid ejection device 1, and outputs it to the head unit 3. The head unit 3 includes a discharge control module 10 and multiple liquid ejection modules 20. Furthermore, each of the multiple liquid ejection modules 20 includes a drive circuit module 50 and a print head 30. In other words, the head unit 3 includes multiple sets of drive circuit modules 50 and print heads 30. The head unit 3 is mounted on the carriage 8 and moves as the carriage 8 moves along the carriage guide shaft 7.

[0072] The print data signal pDATA output by the control unit 2 is input to the ejection control module 10. Based on the input print data signal pDATA, the ejection control module 10 generates a control signal for controlling the operation of each of the plurality of liquid ejection modules 20, and outputs the control signal to the corresponding liquid ejection module 20. The control signal output by the ejection control module 10 is input to the corresponding drive circuit module 50. The drive circuit module 50 is electrically connected to the corresponding print head 30, and drives the print head 30 at the timing specified by the input control signal so that the print head 30 ejects the amount of ink specified by the control signal. As a result, the print head 30 ejects a predetermined amount of ink at a predetermined timing. That is, the head unit 3 ejects a predetermined amount of ink from the print head 30 at a predetermined timing according to the print data signal pDATA output by the control unit 2.

[0073] The liquid container 9 stores ink ejected from the print head 30. The ink stored in the liquid container 9 is supplied to the print head 30 via a tube (not shown). Examples of the liquid container 9 include an ink cartridge, a bag-shaped ink pack formed of a flexible film, and an ink tank capable of refilling ink.

[0074] As described above, in the liquid ejection device 1, the control unit 2 controls the transport of the medium P, the movement of the carriage 8, and the timing of ejecting ink from the print head 30 mounted on the carriage 8. This allows the ink to land at a desired position on the medium P, resulting in a desired image being formed on the medium P.

[0075] 1.2 Functional structure of the head unit

[0076] Next, the functional configuration of the head unit 3 included in the liquid ejecting device 1 will be described in detail. Figure 2 : is a diagram showing an example of the functional structure of the head unit 3. Figure 2 As shown, the head unit 3 includes a discharge control module 10 and a plurality of liquid discharge modules 20. Here, the plurality of liquid discharge modules 20 included in the head unit 3 are all of the same structure, but when the plurality of liquid discharge modules 20 are described separately, they are sometimes referred to as liquid discharge modules 20-1 to 20-n. Figure 2 The illustrated head unit 3 is described as including n liquid ejection modules 20 , ie, liquid ejection modules 20 - 1 to 20 - n .

[0077] in addition, Figure 2 The figure shows a portion of the structure of the control unit 2, namely, a main control circuit 16 and a power supply voltage output circuit 18, based on the structure of the head unit 3. The main control circuit 16 of 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. Furthermore, the main control circuit 16 performs predetermined signal processing on image data DATA supplied from an external device (not shown), such as a host computer, located outside the liquid ejection device 1, to generate a print data signal pDATA, which is then output to the ejection control module 10.

[0078] The power supply voltage output circuit 18 includes an AC / DC converter such as a flyback circuit, and a DC / DC converter such as a step-down circuit or a step-up circuit. Based on the commercial voltage VAC input from the outside of the liquid ejection device 1, the power supply voltage output circuit 18 generates the following signals as voltage signals VDC and outputs them to the ejection control module 10: a DC voltage signal with a voltage value of 42V, namely, a voltage signal VHV, and a DC voltage signal with a voltage value of 24V, namely, a voltage signal VMV. It should be noted that the voltage values ​​of the voltage signal VHV and the voltage signal VMV are not limited to 42V and 24V. Alternatively, the power supply voltage output circuit 18 may output a DC voltage signal with a different voltage value as the voltage signal VDC, instead of or in addition to the voltage signals VHV and VMV.

[0079] The ejection control module 10 operates using the voltage signals VHV and VMV output by the power supply voltage output circuit 18, or a DC voltage signal generated based on the voltage signals VHV and VMV, as a power supply voltage. Furthermore, based on the print data signal pDATA output by the control unit 2, the ejection control module 10 generates control signals for controlling the operation of the n liquid ejection modules 20 and outputs these signals to the corresponding liquid ejection modules 20.

[0080] The ejection control module 10 includes a head control circuit 12 and a cooling fan drive circuit 14. A print data signal pDATA is input to the head control circuit 12 included in the ejection control module 10. Based on the input print data signal pDATA, the head control circuit 12 generates and outputs the following signals: a clock signal SCK commonly input to n liquid ejection modules 20; differential print data signals Dp1 to Dpn corresponding to each of the n liquid ejection modules 20; and differential drive data signals Dd1 to Ddn corresponding to each of the n liquid ejection modules 20.

[0081] Specifically, the print data signal pDATA is a differential signal generated based on the image data DATA. It serially includes a clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn. The head control circuit 12 deserializes and restores the input print data signal pDATA to generate a clock signal SCK commonly input to the n liquid ejection modules 20. The head control circuit 12 also deserializes the input print data signal pDATA to generate differential print data signals Dp1-Dpn and differential drive data signals Dd1-Ddn corresponding to each of the n liquid ejection modules 20. The head control circuit 12 then outputs the generated clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn to the corresponding liquid ejection modules 20.

[0082] In the following description, it is assumed that the differential print data signal Dp1 and the differential drive data signal Dd1 are signals corresponding to the liquid ejection module 20-1, and the differential print data signal Dpn and the differential drive data signal Ddn are signals corresponding to the liquid ejection module 20-n. Specifically, the clock signal SCK, the differential print data signal Dp1, and the differential drive data signal Dd1 are input to the liquid ejection module 20-1, and the clock signal SCK, the differential print data signal Dpn, and the differential drive data signal Ddn are input to the liquid ejection module 20-n. Furthermore, the clock signal SCK, the differential print data signal Dp, and the differential drive data signal Dd are input to the liquid ejection module 20.

[0083] The head control circuit 12 also generates a fan control signal Fc for controlling the operation of the cooling fan drive circuit 14 and outputs it to the cooling fan drive circuit 14. In addition to the fan control signal Fc, the cooling fan drive circuit 14 also receives a voltage signal VMV. Based on the input fan control signal Fc, the cooling fan drive circuit 14 switches whether to output the voltage signal VMV as the fan drive signals Fp1 to Fpn. Specifically, the cooling fan drive circuit 14 includes n switching circuits that switch whether to output the voltage signal VMV as the fan drive signals Fp1 to Fpn. The conductive state of each of the n switching circuits is switched based on the input fan control signal Fc. In other words, the cooling fan drive circuit 14 switches whether to output the voltage signal VMV as the fan drive signals Fp1 to Fpn.

[0084] The fan drive signals Fp1 to Fpn output by the cooling fan drive circuit 14 are output to the corresponding liquid ejection modules 20. In the following description, it is assumed that fan drive signal Fp1 corresponds to liquid ejection module 20-1, and fan drive signal Fpn corresponds to liquid ejection module 20-n. That is, fan drive signal Fp1 is input to liquid ejection module 20-1, and fan drive signal Fpn is input to liquid ejection module 20-n. Furthermore, the description assumes that fan drive signal Fp is input to liquid ejection module 20.

[0085] Note that the cooling fan driving circuit 14 may convert the voltage signal VMV into a predetermined voltage value based on the input fan control signal Fc, and output the converted signal as the fan driving signals Fp1 to Fpn.

[0086] Furthermore, the discharge control module 10 transmits the voltage signals VHV and VMV supplied from the power supply voltage output circuit 18 and supplies them to each of the liquid discharge modules 20 - 1 to 20 - n .

[0087] The clock signal SCK, differential print data signal Dp1, differential drive data signal Dd1, fan drive signal Fp1, and voltage signals VHV and VMV output by the ejection control module 10 are input to the liquid ejection module 20-1. The liquid ejection module 20-1 then operates using the voltage signals VHV and VMV, or a DC voltage generated from the voltage signals VHV and VMV, as a power supply voltage. It ejects the amount of ink specified by the differential print data signal Dp1 and the differential drive data signal Dd1 onto the medium P at the timing specified by the differential print data signal Dp1 and the differential drive data signal Dd1.

[0088] The liquid ejection module 20-1 includes a drive circuit module 50 and a print head 30. The drive circuit module 50 includes an ejection control circuit 51, drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m, a capacitor 53, an abnormality detection circuit 54, an abnormality notification circuit 55, a temperature detection circuit 56, a voltage conversion circuit 58, and a cooling fan 59.

[0089] The clock signal SCK, the differential print data signal Dp1, and the differential drive data signal Dd1 are input to the ejection control circuit 51. The ejection control circuit 51 then analyzes the input differential print data signal Dp1 and the differential drive data signal Dd1 to generate and output the following signals: a differential print data signal Dpt for controlling the operation of the print head 30; base drive signals dA1 to dAm, which serve as the basis for drive signals COMA1 to COMAm, described later; and base drive signals dB1 to dBm, which serve as the basis for drive signals COMB1 to COMBm, described later. The ejection control circuit 51 is configured as an FPGA having circuitry for analyzing the input differential print data signal Dp1 and the differential drive data signal Dd1.

[0090] That is, the driving circuit module 50 has an FPGA on which the ejection control circuit 51 is implemented, wherein the ejection control circuit 51 is input with the differential printing data signal Dp1 and the differential driving data signal Dd1, and based on the input differential printing data signal Dp1 and the differential driving data signal Dd1, the ejection control circuit 51 outputs the differential printing data signal Dpt for controlling the operation of the print head 30, and the base driving signals dA1~dAm, dB1~dBm which serve as the basis for the driving signals COMA1~COMAm, COMB1~COMBm.

[0091] Specifically, the ejection control circuit 51 analyzes the input differential printing data signal Dp1 based on the input clock signal SCK. Then, the ejection control circuit 51 generates a differential printing data signal Dpt, which is a differential signal corresponding to the analysis result of the differential printing data signal Dp1, and outputs it to the print head 30. At this time, the ejection control circuit 51 can output the differential printing data signal Dp1 as the differential printing data signal Dpt based on the analysis result of the differential printing data signal Dp1, or can output a signal obtained by applying predetermined signal processing to the differential printing data signal Dp1 as the differential printing data signal Dpt. Furthermore, the ejection control circuit 51 can also output a signal including predetermined information read from a storage circuit (not shown) as the differential printing data signal Dpt based on the analysis result of the differential printing data signal Dp1.

[0092] Furthermore, the discharge control circuit 51 converts the input differential drive data signal Dd1 into a single-ended signal based on the input clock signal SCK and analyzes it. The discharge control circuit 51 then generates base drive signals dA1 to dAm and dB1 to dBm corresponding to the analysis results and outputs them to the corresponding drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m. Alternatively, the discharge control circuit 51 may read information stored in a memory circuit (not shown) based on the analysis results of the single-ended signal obtained by converting the differential drive data signal Dd1 into a single-ended signal, generate base drive signals dA1 to dAm and dB1 to dBm including the read information, and output them to the corresponding drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m. Alternatively, the ejection control circuit 51 may generate a single-ended signal by restoring the differential drive data signal Dd1, and deserialize the single-ended signal to generate base drive signals dA1 to dAm, dB1 to dBm, and output them to the corresponding drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m.

[0093] Here, the explanation is provided assuming that the base drive signal dA1 output by the discharge control circuit 51 corresponds to the drive signal output circuit 52a-1, and the base drive signal dAm output by the discharge control circuit 51 corresponds to the drive signal output circuit 52a-m. Similarly, the explanation is provided assuming that the base drive signal dB1 output by the discharge control circuit 51 corresponds to the drive signal output circuit 52b-1, and the base drive signal dBm output by the discharge control circuit 51 corresponds to the drive signal output circuit 52b-m. That is, the base drive signal dA1 is input to the drive signal output circuit 52a-1, the base drive signal dAm is input to the drive signal output circuit 52a-m, the base drive signal dB1 is input to the drive signal output circuit 52b-1, and the base drive signal dBm is input to the drive signal output circuit 52b-m.

[0094] The drive signal output circuit 52a-1 generates a drive signal COMA1 by performing digital-to-analog conversion on the input base drive signal dA1 and performing class-D amplification, and outputs the drive signal to the print head 30. The drive signal output circuit 52b-1 generates a drive signal COMB1 by performing digital-to-analog conversion on the input base drive signal dB1 and performing class-D amplification, and outputs the drive signal to the print head 30. Similarly, the drive signal output circuit 52a-m generates a drive signal COMAm by performing digital-to-analog conversion on the input base drive signal dAm and performing class-D amplification, and outputs the drive signal to the print head 30. The drive signal output circuit 52b-m generates a drive signal COMBm by performing digital-to-analog conversion on the input base drive signal dBm and performing class-D amplification, and outputs the drive signal to the print head 30.

[0095] That is, each of the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m generates drive signals COMA1 to COMAm and COMB1 to COMBm by performing digital-to-analog conversion and class D amplification on the input basic drive signals dA1 to dAm and dB1 to dBm, and outputs the drive signals to the print head 30. In other words, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m each include a class D amplifier circuit, and the drive signal output circuits 52a-1 to 52a-m output the drive signals COMA1 to COMAm, while the drive signal output circuits 52b-1 to 52b-m output the drive signals COMB1 to COMBm. At this time, each of the base drive signals dA1~dAm, dB1~dBm output by the ejection control circuit 51 is a signal that becomes the basis of the drive signals COMA1~COMAm, COMB1~COMBm output by each of the drive signal output circuits 52a-1~52a-m, 52b-1~52b-m, and is a signal that specifies the signal waveform of the drive signals COMA1~COMAm, COMB1~COMBm.

[0096] While the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m are described herein as generating drive signals COMA1 to COMAm and COMB1 to COMBm by performing class D amplification of the signal waveforms specified by the base drive signals dA1 to dAm and dB1 to dBm, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m may alternatively generate drive signals COMA1 to COMAm and COMB1 to COMBm by performing class A amplification, class B amplification, or class AB amplification of the signal waveforms specified by the base drive signals dA1 to dAm and dB1 to dBm. However, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m consume a large amount of power and therefore generate a large amount of heat. From the viewpoint of reducing power consumption and suppressing heat generation, it is necessary for the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m to efficiently generate the drive signals COMA1 to COMAm and COMB1 to COMBm.

[0097] In view of this, it is preferable that the drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m include class D amplification capable of efficiently amplifying the signal waveforms defined by the base drive signals dA1 to dAm, dB1 to dBm. The details of the structure of the drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m including class D amplification will be described later.

[0098] Furthermore, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m each generate and output a reference voltage signal VBS. At this point, the drive circuit module 50 stabilizes the voltage value of the reference voltage signal VBS output by the drive signal output circuit 52a-1 using a capacitor 53. Specifically, the drive circuit module 50 includes a capacitor 53 to reduce fluctuations in the voltage value of the reference voltage signal VBS. After the voltage value of the reference voltage signal VBS is stabilized by the capacitor 53, it is branched and output to the printhead 30. The wiring for transmitting the reference voltage signal VBS output by each of the drive signal output circuits 52a-2 to 52a-m and 52b-1 to 52b-m is opened. Specifically, the drive circuit module 50 outputs the reference voltage signal VBS output by the drive signal output circuit 52a-1 to the printhead 30, while not outputting the reference voltage signal VBS output by each of the drive signal output circuits 52a-2 to 52a-m and 52b-1 to 52b-m to the printhead 30.

[0099] The reference voltage signal VBS functions as a reference potential for driving the piezoelectric element 60, described later, included in the print head 30. If the voltage value of the reference voltage signal VBS, functioning as such a reference potential, fluctuates, the driving characteristics of the piezoelectric element 60 change. Therefore, by using only the reference voltage signal VBS output by the drive signal output circuit 52a-1 as the reference voltage signal VBS supplied to the piezoelectric element 60, the risk of fluctuations in the voltage value of the reference voltage signal VBS supplied to the piezoelectric element 60 is reduced, even if circuit variations cause variations in the voltage value of the reference voltage signal VBS output by each of the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m. This improves the driving accuracy of the piezoelectric element 60.

[0100] It should be noted that the reference voltage signal VBS output from the driving circuit module 50, that is, the reference voltage signal VBS input to the print head 30, can be the reference voltage signal VBS output by any one of the driving signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m, and is not limited to the reference voltage signal VBS output by the driving signal output circuit 52a-1.

[0101] Here, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m all have the same structure, differing only in the input signals and the output signals. Therefore, in the following description, when it is not necessary to distinguish between the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m, they may be referred to simply as the drive signal output circuit 52. In this case, the description assumes that the drive signal dO is input to the drive signal output circuit 52 and that the drive signal output circuit 52 outputs the drive signal COM.

[0102] The temperature detection circuit 56 acquires the ambient temperature of the drive circuit module 50. Here, the ambient temperature of the drive circuit module 50 does not refer to the temperature of the components of the drive circuit module 50 itself, but rather to the temperature of the space surrounding the drive circuit module 50, which changes as the temperature of these components rises. The temperature detection circuit 56 then generates a temperature information signal Tt containing temperature information corresponding to the acquired ambient temperature and outputs it to the head control circuit 12.

[0103] The head control circuit 12 estimates the temperature of the drive circuit module 50 based on the input temperature information signal Tt. The head control circuit 12 then corrects the clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn based on the estimated temperature of the drive circuit module 50, and outputs the corrected clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn. Specifically, the head control circuit 12 controls the operation of the drive signal output circuits 52a-1-52a-m, 52b-1-52b-m, and the print head 30 based on the temperature information signal Tt corresponding to the ambient temperature acquired by the temperature detection circuit 56.

[0104] Furthermore, when the estimated temperature of the drive circuit module 50 is above a predetermined threshold, the head control circuit 12 determines that a temperature abnormality has occurred in the drive circuit module 50, or that there is a risk of a temperature abnormality occurring. In this case, the head control circuit 12 may generate a clock signal SCK, differential print data signals Dp1 to Dpn, and differential drive data signals Dd1 to Ddn for halting the operation of the drive circuit module 50, and output these signals to the drive circuit module 50. Specifically, the head control circuit 12 may halt the operation of the drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m, and the print head 30 based on the temperature information signal Tt corresponding to the ambient temperature acquired by the temperature detection circuit 56.

[0105] Furthermore, the head control circuit 12 may notify the user via a notification unit (not shown), such as a display, of information corresponding to the estimated temperature of the drive circuit module 50, i.e., information about the temperature acquired by the temperature detection circuit 56. Specifically, the head control circuit 12 may notify the user of information based on the temperature information signal Tt corresponding to the ambient temperature acquired by the temperature detection circuit 56.

[0106] As the temperature detection circuit 56 for detecting the internal space temperature of the drive circuit module 50, i.e., the ambient temperature, a thermistor element or an IC temperature sensor element can be used, for example. Specifically, the temperature information signal Tt output by the temperature detection circuit 56 may include temperature information indicating the temperature of the drive circuit module 50 itself, or may include a voltage or current value that varies according to the temperature of the drive circuit module 50 as temperature information.

[0107] Furthermore, the voltage signals VHV and VMV transmitted within the ejection control module 10 are input to the drive circuit module 50. The voltage signal VHV is transmitted within the drive circuit module 50 and supplied to various components within the drive circuit module 50, as well as to the print head 30. The voltage signal VMV is transmitted within the drive circuit module 50 and supplied to various components within the drive circuit module 50, as well as to the voltage conversion circuit 58. The voltage conversion circuit 58 generates and outputs a voltage signal VDD by stepping down the input voltage signal VMV. The voltage signal VDD output by the voltage conversion circuit 58 is used as a power supply voltage for various circuits within the drive circuit module 50, and is also supplied to the print head 30. For example, the voltage signal VDD is a DC voltage such as 5V or 3.3V.

[0108] The voltage conversion circuit 58 may output not only one voltage signal VDD, but may also output multiple voltage signals VDD with different voltage values. Furthermore, the voltage signal VMV may be supplied to the print head 30 together with the voltage signals VHV and VDD.

[0109] The abnormality detection circuit 54 detects an abnormality occurring in the drive circuit module 50 and generates an abnormality information signal Te and an abnormality notification signal De according to the detection result. Such an abnormality detection circuit 54 is configured to include a comparison device that compares whether the detection target is above a predetermined threshold value. For example, the abnormality detection circuit 54 is configured to include a comparator.

[0110] The abnormality information signal Te output by the abnormality detection circuit 54 is input to the head control circuit 12. When the input abnormality information signal Te includes information indicating an abnormality in the drive circuit module 50, the head control circuit 12 generates a clock signal SCK, differential print data signals Dp1 to Dpn, and differential drive data signals Dd1 to Ddn for stopping the operation of the drive circuit module 50, and outputs them to the drive circuit module 50. This stops the operation of the drive circuit module 50.

[0111] Furthermore, the abnormality notification signal De output by the abnormality detection circuit 54 is input to the abnormality notification circuit 55. For example, the abnormality notification circuit 55 includes a light-emitting element such as a light-emitting diode. The abnormality notification circuit 55 then notifies the user of whether an abnormality has occurred in the drive circuit module 50 by having the light-emitting element light up, turn off, or flash based on the input abnormality notification signal De.

[0112] Here, an example of the operation of the abnormality detection circuit 54 and the abnormality notification circuit 55 will be described.

[0113] For example, when the abnormality detection circuit 54 detects that the voltage value of the voltage signal VHV is lower than the normal value, the abnormality detection circuit 54 determines that the voltage value of the voltage signal VHV is abnormal, generates an abnormality notification signal De for drawing the user's attention, and outputs the abnormality notification circuit 55. Based on the input abnormality notification signal De, the abnormality notification circuit 55 flashes the light emitting element to notify the user that the voltage value of the voltage signal VHV has decreased.

[0114] Thereafter, if the voltage value of voltage signal VHV further decreases and abnormality detection circuit 54 detects that the voltage value of voltage signal VHV is lower than a predetermined threshold, abnormality detection circuit 54 determines that the voltage value of voltage signal VHV is abnormal, generates abnormality notification signal De for notifying the user of the abnormality, and outputs the abnormality notification signal to abnormality notification circuit 55. Based on the input abnormality notification signal De, abnormality notification circuit 55 illuminates the light-emitting element to notify the user that the voltage value of voltage signal VHV is abnormal. At this time, abnormality detection circuit 54 generates abnormality information signal Te including abnormality information indicating an abnormality in drive circuit module 50, namely, an abnormality in the voltage value of voltage signal VHV, and outputs the abnormality information signal Te to head control circuit 12.

[0115] Furthermore, for example, if the abnormality detection circuit 54 detects that the voltage value of the voltage signal VDD, such as the power supply voltage of the FPGA constituting the ejection control circuit 51, is lower than a normal value, the abnormality detection circuit 54 determines that the voltage value of the voltage signal VDD is abnormal, generates an abnormality notification signal De for drawing the user's attention, and outputs the signal to the abnormality notification circuit 55. Based on the input abnormality notification signal De, the abnormality notification circuit 55 blinks the light emitting element to notify the user of the decrease in the voltage value of the voltage signal VDD.

[0116] Thereafter, if the voltage value of voltage signal VDD further decreases and abnormality detection circuit 54 detects that the voltage value of voltage signal VDD is lower than a predetermined threshold, abnormality detection circuit 54 determines that the voltage value of voltage signal VDD is abnormal, generates an abnormality notification signal De for notifying the user of the abnormality, and outputs the signal to abnormality notification circuit 55. Based on the input abnormality notification signal De, abnormality notification circuit 55 illuminates the light-emitting element to notify the user of the abnormality in the voltage value of voltage signal VDD. At this point, abnormality detection circuit 54 generates abnormality information signal Te, which includes information indicating an abnormality in the drive circuit module 50, namely, an abnormality in the voltage value of voltage signal VDD, and outputs the signal to head control circuit 12.

[0117] Here, the number of light-emitting elements included in the abnormality notification circuit 55 is not limited to one. For example, the abnormality notification circuit 55 may include a light-emitting element for notifying the user of the presence of an abnormality in the voltage signal VHV and a light-emitting element for notifying the user of the presence of an abnormality in the voltage signal VDD. Furthermore, if the abnormality notification circuit 55 includes multiple light-emitting elements, the presence of an abnormality in the drive circuit module 50 may be notified to the user by a combination of lighting, extinguishing, and flashing the multiple light-emitting elements. In the above description, the abnormality detection circuit 54 detects the presence of an abnormality in the drive circuit module 50 by, for example, detecting the presence of an abnormality in the voltage value of the voltage signal VHV and the voltage value of the voltage signal VDD. However, the abnormality detection circuit 54 may also detect the presence of an abnormality in the voltage signal VMV, instead of, or in addition to, detecting the presence of an abnormality in the voltage value of the voltage signal VHV and the voltage signal VDD, based on the temperature information signal Tt output by the temperature detection circuit 56.

[0118] The fan drive signal Fp1 output by the cooling fan drive circuit 14 is input to the cooling fan 59. The cooling fan 59 is then driven based on the input fan drive signal Fp1, generating an airflow around the drive circuit module 50. The drive circuit module 50 is cooled by the airflow generated by the cooling fan 59. Alternatively, the head control circuit 12 may output the fan control signal Fc based on the temperature information signal Tt output by the temperature detection circuit 56. Thus, the drive state of the cooling fan 59 is controlled based on the temperature detection result of the temperature detection circuit 56, i.e., the temperature condition of the drive circuit module 50 to be cooled. As a result, the risk of increased power consumption due to excessive driving of the cooling fan 59 is reduced, thereby reducing the power consumption of the liquid ejection device 1 and the risk of temperature abnormalities in the drive circuit module 50.

[0119] The print head 30 includes a restoration circuit 31 and ejection modules 32-1 to 32-m. The restoration circuit 31 operates using voltage signals VHV and VDD, or a DC voltage generated based on the voltage signals VHV and VDD, as a power supply voltage. The restoration circuit 31 restores the differential print data signal Dpt, a differential signal output by the ejection control circuit 51, into a single-ended signal. Specifically, the clock signal SCK and the differential print data signal Dpt are input to the restoration circuit 31. The restoration circuit 31 then restores the input differential print data signal Dpt into a single-ended signal based on the clock signal SCK and deserializes the restored signals to generate a latch signal LAT, a change signal CH, and print data signals SI1 to SIm. The restoration circuit 31 then outputs the clock signal SCK, the generated latch signal LAT, the change signal CH, and the print data signals SI1 to SIm to the corresponding ejection modules 32-1 to 32-m.

[0120] The ejection module 32 - 1 includes a driving signal selection circuit 200 and a plurality of ejection units 600 .

[0121] The latch signal LAT, change signal CH, print data signal SI1, clock signal SCK, and drive signals COMA1 and COMB1 output by the reset circuit 31 are input to the drive signal selection circuit 200. The drive signal selection circuit 200 operates using the voltage signals VHV and VDD, or a DC voltage generated from the voltage signals VHV and VDD, as a power supply voltage. During each period specified by the latch signal LAT and change signal CH, the drive signal selection circuit 200 selects or deselects the signal waveform included in the drive signal COMA1 and the signal waveform included in the drive signal COMB1 based on the print data signal SI1. This circuit generates and outputs a drive signal VOUT corresponding to each of the plurality of ejection units 600. Specifically, if the ejection module 32-1 includes p ejection units 600, the drive signal selection circuit 200 generates p drive signals VOUT corresponding to each of the p ejection units 600 and outputs them to the corresponding ejection units 600.

[0122] Each of the multiple ejection units 600 includes a piezoelectric element 60. The corresponding drive signal VOUT output by the drive signal selection circuit 200 is supplied to one end of the piezoelectric element 60. Furthermore, a reference voltage signal VBS is commonly supplied to the other end of each of the multiple piezoelectric elements 60 included in the multiple ejection units 600. The multiple piezoelectric elements 60 included in each of the multiple ejection units 600 then displace based on the potential difference between the drive signal VOUT and the reference voltage signal VBS. An amount of ink corresponding to the displacement of the piezoelectric element 60 is ejected from the corresponding ejection unit 600. The ink ejected from the ejection unit 600 then lands on the medium P, forming an image on the medium P. It should be noted that the operation of the drive signal selection circuit 200 that outputs the drive signal VOUT will be described in detail later.

[0123] Here, the ejection modules 32-2 to 32-m of the print head 30 have the same structure as the ejection module 32-1, except that the signals input thereto are different. Therefore, a detailed description of the ejection modules 32-2 to 32-m is omitted. That is, the ejection modules 32-2 to 32-m respectively include a drive signal selection circuit 200 and a plurality of ejection units 600. Then, the drive signal selection circuit 200 of each of the ejection modules 32-2 to 32-m selects or deselects the signal waveform included in the corresponding drive signals COMA2 to COMAm and selects or deselects the signal waveform included in the corresponding drive signals COMB2 to COMBm based on the corresponding print data signals SI2 to SIm within each period specified by the input latch signal LAT and the change signal CH, thereby outputting the drive signal VOUT corresponding to each of the plurality of ejection units 600. As a result, ink in an amount corresponding to the potential difference between the input drive signal VOUT and the reference voltage signal VBS is discharged from each of the plurality of discharge units 600 included in each of the discharge modules 32 - 2 to 32 - m .

[0124] In other words, the print head 30 includes ejection modules 32-1 to 32-m. Furthermore, the ejection module 32-1 includes an ejection unit 600 and a drive signal selection circuit 200. The ejection unit 600 includes a piezoelectric element 60. The piezoelectric element 60 receives a drive signal VOUT based on drive signals COMA1 and COMB1 and is displaced. The ejection unit 600 ejects ink based on the displacement of the piezoelectric element 60. The drive signal selection circuit 200 switches whether the drive signals COMA1 and COMB1 are supplied to the piezoelectric element 60. The ejection module 32-m includes an ejection unit 600 and a drive signal selection circuit 200. The ejection unit 600 includes a piezoelectric element 60. The piezoelectric element 60 receives a drive signal VOUT based on drive signals COMAm and COMBm and is displaced. The ejection unit 600 ejects ink based on the displacement of the piezoelectric element 60. The drive signal selection circuit 200 switches whether the drive signals COMAm and COMBm are supplied to the piezoelectric element 60.

[0125] Here, in the following description, when it is not necessary to distinguish between the ejection modules 32-1 to 32-m, they may be simply referred to as the ejection module 32. Furthermore, the description may be given assuming that the print data signal SI is input as the print data signal SI1 to SIm, the drive signal COMA is input as the drive signals COMA1 to COMAm, and the drive signal COMB is input as the drive signals COMB1 to COMBm. Specifically, the drive signal selection circuit 200 included in the ejection module 32 selects or deselects the signal waveform included in the drive signal COMA and the signal waveform included in the drive signal COMB based on the print data signal SI during each period specified by the latch signal LAT and the change signal CH, thereby outputting the drive signal VOUT corresponding to each of the plurality of ejection units 600.

[0126] As described above, the liquid ejection module 20-1 has a driving circuit module 50 and a print head 30, and operates based on the clock signal SCK, differential printing data signal Dp1, differential drive data signal Dd1, fan drive signal Fp1, and voltage signals VHV and VMV output by the ejection control module 10, thereby ejecting the amount of ink specified by the differential printing data signal Dp1 and the differential drive data signal Dd1 to the medium P at the timing specified by the differential printing data signal Dp1 and the differential drive data signal Dd1.

[0127] Here, the liquid ejection modules 20-2 to 20-n have the same structure and perform the same operations as the liquid ejection module 20-1, except that the input signals differ. Therefore, a detailed description of the liquid ejection modules 20-2 to 20-n is omitted. Specifically, each of the liquid ejection modules 20-2 to 20-n includes a drive circuit module 50 and a print head 30. Each of the liquid ejection modules 20-2 to 20-n operates based on the clock signal SCK output by the ejection control module 10, the corresponding differential print data signals Dp2 to Dpn, the corresponding differential drive data signals Dd2 to Ddn, the corresponding fan drive signals Fp2 to Fpn, and the voltage signals VHV and VMV. At the timing specified by the corresponding differential print data signals Dp2 to Dpn and the corresponding differential drive data signals Dd2 to Ddn, the modules eject the amount of ink specified by the corresponding differential print data signals Dp2 to Dpn and the corresponding differential drive data signals Dd2 to Ddn onto the medium P.

[0128] As described above, the liquid ejection device 1 includes a print head 30 for ejecting ink, a drive circuit module 50 electrically connected to the print head 30, a control unit 2 for controlling the operation of the print head 30 and the drive circuit module 50, and a head control circuit 12. Furthermore, the head unit 3 of the liquid ejection device 1, which includes the ejection control module 10, the print head 30, and the drive circuit module 50, is driven using the voltage signals VHV and VMV input from the control unit 2 as power supply voltages, ejecting ink at a timing based on the print data signal pDATA, thereby forming an image corresponding to the print data signal pDATA, that is, an image corresponding to the image data DATA, on the medium P.

[0129] 1.3 Functional structure of drive signal output circuit

[0130] Next, the configuration and operation of the drive signal output circuit 52 that outputs the drive signal COM will be described. Figure 3 : is a diagram showing the structure of the drive signal output circuit 52. The drive signal output circuit 52 includes an integrated circuit 500, an amplifier circuit 550, a demodulation circuit 560, feedback circuits 570 and 572, and other electronic components.

[0131] Integrated circuit 500 includes a plurality of terminals, including terminal In, terminal Bst, terminal Hdr, terminal Sw, terminal Gvd, terminal Ldr, terminal Gnd, terminal Vbs, terminal Vfb, and terminal Ifb. Integrated circuit 500 is electrically connected to an external substrate (not shown) via these terminals. Integrated circuit 500 also includes a DAC (Digital to Analog Converter) 511, a modulation circuit 510, a gate drive circuit 520, and a reference power supply circuit 590.

[0132] The reference power supply circuit 590 generates a voltage signal DAC_HV and a voltage signal DAC_LV, and supplies them to the DAC 511. Furthermore, a digital base drive signal dO, which defines the signal waveform of the drive signal COM, is input to the DAC 511. The DAC 511 converts the input base drive signal dO into an analog signal, namely a base drive signal aO, having a voltage value between the voltage values ​​of the voltage signals DAC_HV and DAC_LV, and outputs the signal to the modulation circuit 510. Specifically, the maximum value of the voltage amplitude of the base drive signal aO is defined by the voltage signal DAC_HV, and the minimum value is defined by the voltage signal DAC_LV. Furthermore, the signal obtained by amplifying the base drive signal aO output by the DAC 511 corresponds to the drive signal COM. In other words, the base drive signal aO corresponds to the target signal of the drive signal COM before amplification, and the base drive signals dO and aO define the signal waveform of the drive signal COM.

[0133] The modulation circuit 510 generates a modulation signal Ms obtained by modulating the base drive signal a0, and outputs the modulation signal Ms to the gate drive circuit 520. The modulation circuit 510 includes adders 512 and 513, a comparator 514, an inverter 515, an integral attenuator 516, and an attenuator 517.

[0134] The integrating attenuator 516 attenuates and integrates the drive signal COM input via the terminal Vfb, and outputs the attenuated signal to the negative input terminal of the adder 512. The base drive signal aO is input to the positive input terminal of the adder 512. The adder 512 then subtracts the voltage input to the negative input terminal from the voltage input to the positive input terminal, and outputs the resulting integrated voltage to the positive input terminal of the adder 513.

[0135] The attenuator 517 attenuates the high-frequency component of the drive signal COM input via the terminal Ifb, outputting a voltage obtained by attenuating the high-frequency component to the negative input terminal of the adder 513. The voltage output from the adder 512 is input to the positive input terminal of the adder 513. The adder 513 then generates a voltage signal Os, obtained by subtracting the voltage input to the negative input terminal from the voltage input to the positive input terminal, and outputs the voltage signal to the comparator 514.

[0136] The comparator 514 outputs a modulation signal Ms obtained by pulse-modulating the voltage signal Os input from the adder 513. Specifically, the comparator 514 generates and outputs a modulation signal Ms that becomes H-level when the voltage value of the voltage signal Os input from the adder 513 increases and becomes equal to or higher than a predetermined threshold value Vth1. When the voltage value of the voltage signal Os decreases, the modulation signal Ms becomes L-level when the voltage value falls below a predetermined threshold value Vth2. Here, the threshold values ​​Vth1 and Vth2 are set to satisfy the relationship Vth1 ≥ Vth2.

[0137] The modulation signal Ms output by the comparator 514 is input to the gate driver 521 included in the gate driver circuit 520 and, via the inverter 515, is also input to the gate driver 522 included in the gate driver circuit 520. That is, signals having exclusive logic levels are input to the gate drivers 521 and 522. Here, the exclusive logic level relationship means that the logic levels of the signals input to the gate drivers 521 and 522 do not reach the H level at the same time. Therefore, the modulation circuit 510 may include, in place of the inverter 515 or in addition to the inverter 515, a timing control circuit for controlling the timing between the modulation signal Ms input to the gate driver 521 and the signal obtained by inverting the logic level of the modulation signal Ms input to the gate driver 522.

[0138] The gate driving circuit 520 includes a gate driver 521 and a gate driver 522. The gate driver 521 generates an amplification control signal Hgd by level-shifting the modulation signal Ms output from the comparator 514, and outputs the amplification control signal Hgd from a terminal Hdr.

[0139] Specifically, of the power supply voltage of the gate driver 521, a voltage is supplied to the high side 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 for backflow prevention. Terminal Sw is connected to the other end of capacitor C5. In addition, the anode of diode D1 is connected to terminal Gvd. Furthermore, a DC voltage of, for example, 7.5V, output by a power supply circuit (not shown), i.e., voltage signal Vm, is supplied to terminal Gvd. That is, voltage signal Vm is supplied to the anode of diode D1. As a result, the potential difference between terminal Bst and terminal Sw becomes approximately equal to the voltage value of voltage signal Vm. As a result, the gate driver 521 generates an amplified control signal Hgd having a voltage value exactly equal to the voltage value of voltage signal Vm to terminal Sw based on the input modulation signal Ms, and outputs it from terminal Hdr.

[0140] The gate driver 522 operates at a lower potential than the gate driver 521. The gate driver 522 generates an amplification control signal Lgd by level-shifting the modulation signal Ms output from the comparator 514 by inverting the logic level of the modulation signal Ms by the inverter 515, and outputs the amplification control signal Lgd from the terminal Ldr.

[0141] Specifically, the gate driver 522 receives a voltage signal Vm on the high side of its power supply voltage, while the low side receives ground potential GND via terminal Gnd. Consequently, the gate driver 522 outputs an amplified control signal Lgd, whose voltage value is precisely equal to that of the voltage signal Vm, from terminal Ldr to terminal Gnd based on a signal obtained by inverting the logic level of the input modulation signal Ms. Here, ground potential GND refers to the reference potential of the drive signal output circuit 52, for example, 0V.

[0142] The amplifier circuit 550 includes a transistor M1 and a transistor M2 .

[0143] Transistor M1 is a surface-mount FET (Field Effect Transistor). A voltage signal VHV is supplied to the drain of transistor M1 as the amplification power supply voltage for amplifier circuit 550. 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 terminal Hdr of integrated circuit 500. In other words, amplification control signal Hgd is input to the gate of transistor M1. Furthermore, the source of transistor M1 is electrically connected to terminal Sw of integrated circuit 500.

[0144] 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, the amplification control signal Lgd is input to the gate of transistor M2. Furthermore, the source of transistor M2 is supplied with ground potential GND.

[0145] Furthermore, when the drain and source of transistor M1 are controlled to be non-conductive and the drain and source of transistor M2 are controlled to be conductive, the potential of the node connected to terminal Sw becomes ground potential GND. Consequently, voltage signal Vm is supplied to terminal Bst. On the other hand, when the drain and source of transistor M1 are controlled to be conductive and the drain and source of transistor M2 are controlled to be non-conductive, the potential of the node connected to terminal Sw becomes the voltage value of voltage signal VHV. Consequently, a voltage equal to the sum of the voltage values ​​of voltage signal VHV and voltage signal Vm is supplied to terminal Bst. That is, the gate driver 521 that drives the transistor M1 uses the capacitor C5 as a floating power supply. According to the operations of the transistors M1 and M2, the potential of the terminal Sw changes to the ground potential GND or the voltage value of the voltage signal VHV, thereby generating an amplified control signal Hgd whose L level is the voltage value of the voltage signal VHV and whose H level is the sum of the voltage value of the voltage signal VHV and the voltage value of the voltage signal Vm, and outputs the amplified control signal Hgd to the gate of the transistor M1.

[0146] On the other hand, the gate driver 522 driving the transistor M2 generates an amplified control signal Lgd whose L level is the ground potential GND and whose H level is the voltage value of the voltage signal Vm, independently of the operations of the transistors M1 and M2, and outputs the amplified control signal Lgd to the gate of the transistor M2.

[0147] The amplifier circuit 550 configured as described above generates an amplified modulated signal AMs at the connection point between the source of the transistor M1 and the drain of the transistor M2 by amplifying the modulated signal Ms based on the voltage signal VHV. The amplifier circuit 550 then outputs the generated amplified modulated signal AMs to the demodulation circuit 560.

[0148] Here, a capacitor C7 is provided in the transmission path for the voltage signal VHV input to the amplifier circuit 550. Specifically, one end of the capacitor C7 is the transmission path for the voltage signal VHV, and is electrically connected to the drain of the transistor M1, and the other end of the capacitor C7 is supplied with the ground potential GND. As a result, the risk of voltage value fluctuations of the voltage signal VHV input to the amplifier circuit 550 is reduced, and the risk of noise overlap in the voltage signal VHV is reduced. As a result, the waveform accuracy of the amplified modulated signal AMs output by the amplifier circuit 550 is improved. Therefore, a high-voltage and large-capacity electrolytic capacitor is used. It should be noted that the capacitor C7 can be set to correspond to one drive signal output circuit 52, or it can be set to correspond to multiple drive signal output circuits 52.

[0149] The demodulation circuit 560 generates a drive signal COM by demodulating the amplified modulation signal AMs output by the amplifier circuit 550, and outputs the drive signal COM from the drive signal output circuit 52. The demodulation circuit 560 includes an inductor L1 and a capacitor C1. One end of the inductor L1 is connected to one end of the capacitor C1. The amplified modulation signal AMs is input to the other end of the inductor L1. In addition, the other end of the capacitor C1 is supplied with a ground potential GND. That is, in the demodulation circuit 560, the inductor L1 and the capacitor C1 form a low-pass filter. Then, the demodulation circuit 560 demodulates the amplified modulation signal AMs by smoothing it with the low-pass filter, and outputs the demodulated signal as the drive signal COM. That is, the drive signal output circuit 52 outputs the drive signal COM from one end of the inductor L1 and one end of the capacitor C1 included in the demodulation circuit 560.

[0150] Feedback circuit 570 includes resistors R3 and R4. One end of resistor R3 is supplied with drive signal COM, and the other end is connected to terminal Vfb and one end of resistor R4. The other end of resistor R4 is supplied with voltage signal VHV. As a result, drive signal COM, which has passed through feedback circuit 570, is fed back to terminal Vfb in a state where it is pulled up to the voltage value of voltage signal VHV.

[0151] The feedback circuit 572 includes capacitors C2, C3, and C4, and resistors R5 and R6. The drive signal COM is input to one end of capacitor C2, and the other end of capacitor C2 is connected to one end of resistor R5 and one end of resistor R6. The other end of resistor R5 is supplied with a ground potential GND. Thus, capacitor C2 and resistor R5 function as a high-pass filter. In addition, the other end of resistor R6 is connected to one end of capacitor C4 and one end of capacitor C3. The other end of capacitor C3 is supplied with a ground potential GND. Thus, resistor R6 and capacitor C3 function as a low-pass filter. In other words, the feedback circuit 572 includes a high-pass filter and a low-pass filter, and functions as a band-pass filter that allows signals in a predetermined frequency domain included in the drive signal COM to pass.

[0152] The other end of the capacitor C4 is connected to the terminal Ifb of the integrated circuit 500. Thus, among the high-frequency components of the drive signal COM that have passed through the feedback circuit 572 functioning as a bandpass filter, a signal with a DC component cut off is fed back to the terminal Ifb.

[0153] The drive signal COM is obtained by smoothing the amplified modulated signal AMs based on the base drive signal dO by the demodulation circuit 560. Furthermore, the drive signal COM is integrated and subtracted via the terminal Vfb and then fed back to the adder 512. As a result, the drive signal output circuit 52 self-oscillates at a frequency determined by the feedback delay and the feedback transfer function. However, the feedback path via the terminal Vfb has a significant delay, so feedback via this terminal alone may not be able to raise the frequency of the self-oscillation to a level sufficient to ensure the accuracy of the drive signal COM. Therefore, in addition to the path via the terminal Vfb, a path is provided via the terminal Ifb to feed back the high-frequency components of the drive signal COM, thereby reducing the delay when viewed from the perspective of the entire circuit. This allows the frequency of the voltage signal Os to be raised to a level sufficient to ensure the accuracy of the drive signal COM, compared to a case where the path via the terminal Ifb does not exist.

[0154] Integrated circuit 500 also includes a reference voltage signal output circuit 530. Reference voltage signal output circuit 530 outputs a reference voltage signal VBS. Reference voltage signal output circuit 530 uses a bandgap reference voltage generated in integrated circuit 500 as a reference potential, and generates the reference voltage signal Vm by, for example, stepping down or stepping up the voltage based on this reference potential. Reference voltage signal output circuit 530 then outputs the generated reference voltage signal VBS from drive signal output circuit 52 via terminal Vbs.

[0155] As described above, the drive signal output circuit 52 performs a class D amplification on the analog signal after digital-to-analog conversion of the input base drive signal d0 to generate the drive signal COM, outputs the generated drive signal COM, and generates and outputs the reference voltage signal VBS. It should be noted that the reference voltage signal output circuit 530 that generates the reference voltage signal VBS can have a different structure from the drive signal output circuit 52 or the same structure as the drive signal output circuit 52. By being integrated into a single integrated circuit 500, the circuit scale of the drive circuit module 50, including the drive signal output circuit 52 and the drive signal output circuit 52, can be reduced.

[0156] Specifically, the drive signal output circuit 52 of the liquid ejection device 1 of this embodiment, namely, the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4, each includes an integrated circuit 500, transistors M1 and M2, and an inductor L1. Furthermore, the drive signal output circuits 52a-m and 52b-m output drive signals COMAm and COMBm to the print head 30 to displace the piezoelectric element 60 in order to eject ink from the ejection module 32-m of the print head 30.

[0157] Furthermore, the reference voltage signal VBS supplied to the other end of the piezoelectric element 60 included in each of the ejection modules 32-1 to 32-m is output from the integrated circuit 500 included in the drive signal output circuit 52a-1. Specifically, the drive signal output circuit 52a-1 includes a reference voltage signal output circuit 530 that outputs the reference voltage signal VBS to the print head 30, and at least a portion of the reference voltage signal output circuit 530 is included in the integrated circuit 500 included in the drive signal output circuit 52a-1.

[0158] 1.4 Functional structure of the drive signal selection circuit

[0159] Next, the structure and operation of the drive signal selection circuit 200 will be described. The structure and operation of the drive signal selection circuit 200 will be described with reference to an example of the signal waveforms of the drive signals COMA and COMB input to the drive signal selection circuit 200 and an example of the signal waveform of the drive signal VOUT output from the drive signal selection circuit 200.

[0160] Figure 4 FIG is a diagram showing an example of the signal waveforms of the drive signals COMA and COMB. Figure 4 As shown, the drive signal COMA is a signal waveform that combines a trapezoidal waveform Adp1, which is arranged in a period t1 from the rise of the latch signal LAT to the rise of the change signal CH, and a trapezoidal waveform Adp2, which is arranged in a period t2 from the rise of the change signal CH to the rise of the latch signal LAT. Furthermore, the trapezoidal waveform Adp1 is a signal waveform that, when supplied to the piezoelectric element 60 included in the discharge unit 600, causes a predetermined amount of ink to be discharged from the discharge unit 600. The trapezoidal waveform Adp2 is a signal waveform that, when supplied to the piezoelectric element 60 included in the discharge unit 600, causes an amount of ink greater than the predetermined amount to be discharged from the discharge unit 600. Here, in the following description, there is a case where the amount of ink ejected from the ejection section 600 when the trapezoidal waveform Adp1 is supplied to the piezoelectric element 60 included in the ejection section 600 is referred to as a small amount, and the amount of ink ejected from the ejection section 600 when the trapezoidal waveform Adp2 is supplied to the piezoelectric element 60 included in the ejection section 600 is referred to as a medium amount.

[0161] In addition, if Figure 4As shown, the drive signal COMB is a signal waveform that connects the trapezoidal waveform Bdp1 configured during period t1 and the trapezoidal waveform Bdp2 configured during period t2. Furthermore, the trapezoidal waveform Bdp1 is a signal waveform that, when supplied to the piezoelectric element 60 included in the ejection section 600, prevents ink from being ejected from the ejection section 600. The trapezoidal waveform Bdp2 is a signal waveform that, when supplied to the piezoelectric element 60 included in the ejection section 600, causes a small amount of ink to be ejected from the ejection section 600. Here, the trapezoidal waveform Bdp1 is a signal waveform used to vibrate the ink near the nozzle opening of the ejection section 600 to such an extent that ink is not ejected, thereby preventing an increase in ink viscosity. In the following description, the action of vibrating the ink near the nozzle opening when the trapezoidal waveform Bdp1 is supplied to the piezoelectric element 60 included in the ejection section 600 is sometimes referred to as microvibration.

[0162] Here, if Figure 4 As shown, the voltage values ​​of each of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 at the start and end timings are the same as voltage Vc. That is, each of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 starts and ends at voltage Vc. Furthermore, the period tp consisting of period t1 and period t2 corresponds to the printing cycle in which a new dot is formed on the medium P.

[0163] It should be noted that in Figure 4 In the figure, the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 are the same signal waveform, but the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 may be different signal waveforms. In addition, the case where the trapezoidal waveform Adp1 is supplied to the piezoelectric element 60 included in the ejection unit 600 and the case where the trapezoidal waveform Bdp2 is supplied to the piezoelectric element 60 included in the ejection unit 600 are both described to eject a small amount of ink from the ejection unit 600, but the present invention is not limited to this. That is, the signal waveforms of the drive signals COMA and COMB are not limited to Figure 4 The signal waveforms shown may be a combination of various signal waveforms depending on the properties of the ink ejected from the ejection unit 600 , the material of the medium P onto which the ejected ink lands, and the like.

[0164] in addition, Figure 4In the figure, an example is given in which one change signal CH specifies the timing of switching between the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 included in the drive signal COMA, and the timing of switching between the trapezoidal waveform Bdp1 and the trapezoidal waveform Bdp2 included in the drive signal COMB. However, the change signal CH that specifies the timing of switching between the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 included in the drive signal COMA and the change signal CH that specifies the timing of switching between the trapezoidal waveform Bdp1 and the trapezoidal waveform Bdp2 included in the drive signal COMB may be different signals.

[0165] Figure 5 1 is a diagram showing an example of a signal waveform of the driving signal VOUT when the sizes of dots formed on the medium P are respectively a large dot LD, a medium dot MD, a small dot SD, and a non-recording ND.

[0166] like Figure 5 As shown, the drive signal VOUT for forming a large dot LD on the medium P is a signal waveform consisting of a continuous trapezoidal waveform Adp1 during period t1 within cycle tp and a trapezoidal waveform Adp2 during period t2 within cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection unit 600, a small amount of ink and a medium amount of ink are ejected from the corresponding ejection unit 600. Each ink then lands on the medium P and forms a large dot LD on the medium P within cycle tp.

[0167] When the midpoint MD is formed on the medium P, the drive signal VOUT has a waveform that is a combination of a trapezoidal waveform Adp1 during period t1 within the cycle tp and a trapezoidal waveform Bdp2 during period t2 within the cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection unit 600, two small amounts of ink are ejected from the corresponding ejection unit 600. Each ink droplet then lands on the medium P and forms the combined body, forming the midpoint MD on the medium P within the cycle tp.

[0168] When forming a small dot SD on the medium P, the drive signal VOUT has a waveform that combines a trapezoidal waveform Adp1 during period t1 within cycle tp with a signal waveform constant at voltage Vc during period t2 within cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection unit 600, a small amount of ink is ejected from the corresponding ejection unit 600. This ink then lands on the medium P, forming a small dot SD on the medium P within period tp.

[0169] The drive signal VOUT corresponding to the non-recording ND, which does not form dots on the medium P, has a waveform that combines a trapezoidal waveform Bdp1 during period t1 within cycle tp with a signal waveform constant at voltage Vc during period t2 within cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection unit 600, the ink near the nozzle opening of the corresponding ejection unit 600 only vibrates slightly, and no ink is ejected from the ejection unit 600. Consequently, no dots are formed on the medium P during period tp.

[0170] Here, the signal waveform of the drive signal VOUT that is fixed to the voltage Vc refers to the voltage Vc immediately preceding the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2, which corresponds to the voltage value maintained by the capacitance component of the piezoelectric element 60 included in the discharge unit 600, when none of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 is selected as the drive signal VOUT. In other words, when none of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 is selected as the drive signal VOUT, the previously supplied voltage Vc is supplied to the piezoelectric element 60 included in the discharge unit 600 as the drive signal VOUT.

[0171] Here, if Figure 5 As shown, the drive signal selection circuit 200 generates a drive signal VOUT corresponding to each of the multiple ejection parts 600 by setting the trapezoidal waveforms Adp1 and Adp2 included in the drive signal COMA and the trapezoidal waveforms Bdp1 and Bdp2 included in the drive signal COMB to selection or non-selection, and outputs it to the piezoelectric element 60 included in the corresponding ejection part 600.

[0172] Figure 6 2 is a diagram showing the functional structure of the drive signal selection circuit 200. Figure 6 As shown, the drive signal selection circuit 200 includes a selection control circuit 210 and a plurality of selection circuits 230. Figure 6 , the diagram also shows a plurality of ejection units 600 to which the drive signal VOUT output from the drive signal selection circuit 200 is supplied. It should be noted that in the following description, the ejection module 32 including the drive signal selection circuit 200 and the plurality of ejection units 600 is assumed to include p ejection units 600 as the plurality of ejection units 600.

[0173] The print data signal SI, the clock signal SCK, the latch signal LAT, and the change signal CH are input to the selection control circuit 210. In the selection control circuit 210, a set of registers 212, latch circuits 214, and decoders 216 is provided to correspond to each of the p ejection units 600. In other words, the selection control circuit 210 includes at least the same number of sets of registers 212, latch circuits 214, and decoders 216 as the number of p ejection units 600.

[0174] The print data signal SI is synchronized with the clock signal SCK and includes, in serial form, 2p bits of 2-bit print data [SIH, SIL] for selecting one of large dots LD, medium dots MD, small dots SD, and non-recording dots ND for each of the p ejecting units 600. The print data signal SI corresponds to the p ejecting units 600, and the print data [SIH, SIL] included in each print data signal SI is stored in the register 212.

[0175] Specifically, in the selection control circuit 210, registers 212 are connected in cascade to form p-stage shift registers. Print data [SIH, SIL], which is serially input as the print data signal SI, is sequentially transmitted to the subsequent registers 212 according to the clock signal SCK. The supply of the clock signal SCK then stops, and the print data [SIH, SIL] corresponding to each of the p ejection units 600 is retained in the registers 212 corresponding to each of the p ejection units 600. It should be noted that in the following description, to distinguish the p registers 212 that constitute the shift register, they may be referred to as stage 1, stage 2, ..., stage p, from the upstream side of the print data signal SI transmission toward the downstream side.

[0176] Each of the p latch circuits 214 is provided corresponding to the p registers 212 . Each latch circuit 214 latches the print data [SIH, SIL] held in each of the p registers 212 at once when the latch signal LAT rises, and outputs the data to the corresponding decoder 216 .

[0177] Figure 7 is a diagram showing an example of the decoding content in the decoder 216. The decoder 216 uses Figure 7 The decoder 216 decodes the print data [SIH, SIL] latched by the latch circuit 214 to generate and output selection signals S1 and S2. For example, when the input print data [SIH, SIL] is [1, 0], the decoder 216 sets the logic level of the selection signal S1 to the H and L levels during periods t1 and t2 and outputs it to the selection circuit 230. The decoder 216 also sets the logic level of the selection signal S2 to the L and H levels during periods t1 and t2 and outputs it to the selection circuit 230.

[0178] The selection circuit 230 is provided corresponding to each of the p ejecting units 600. That is, the drive signal selection circuit 200 includes at least p selection circuits 230, which is equal in number to the p ejecting units 600. Figure 8 1 is a diagram showing the configuration of the selection circuit 230 corresponding to one of the ejection units 600. Figure 8 As shown, the selection circuit 230 includes inverters 232a and 232b as NOT circuits and transmission gates 234a and 234b.

[0179] Select signal S1 is input to the positive control terminal (not marked with a circle) of transmission gate 234a. Select signal S1 is logically inverted by inverter 232a and input to the negative control terminal (marked with a circle) of transmission gate 234a. Drive signal COMA is also supplied to the input of transmission gate 234a. Select signal S2 is input to the positive control terminal (not marked with a circle) of transmission gate 234b. Select signal S2 is logically inverted by inverter 232b and input to the negative control terminal (marked with a circle) of transmission gate 234b. Drive signal COMB is also supplied to the input of transmission gate 234b. The output of transmission gate 234a is commonly connected to the output of transmission gate 234b. The signal at this common connection terminal of the output of transmission gate 234a and the output of transmission gate 234b is output as drive signal VOUT.

[0180] Specifically, when selection signal S1 is at an H level, conduction occurs between the input and output terminals of transmission gate 234a, while when selection signal S1 is at an L level, conduction occurs between the input and output terminals of transmission gate 234a. Furthermore, when selection signal S2 is at an H level, conduction occurs between the input and output terminals of transmission gate 234b, while when selection signal S2 is at an L level, conduction occurs between the input and output terminals of transmission gate 234b. In other words, selection circuit 230 switches the conduction state between the input and output terminals of transmission gates 234a and 234b based on selection signals S1 and S2, thereby selecting or deselecting the signal waveforms of drive signals COMA and COMB supplied to the input terminals of transmission gates 234a and 234b, and outputting drive signal VOUT to the connection terminal commonly connected to the output terminals of transmission gates 234a and 234b.

[0181] use Figure 9 , the operation of the drive signal selection circuit 200 will be described. Figure 9This diagram illustrates the operation of the drive signal selection circuit 200. The print data [SIH, SIL] included in the print data signal SI is serially input in synchronization with the clock signal SCK. The print data [SIH, SIL] is then sequentially transmitted through the register 212 constituting the shift register, corresponding to the p ejection units 600, in synchronization with the clock signal SCK. The supply of the clock signal SCK is then stopped, so that each register 212 retains the print data [SIH, SIL] corresponding to each of the p ejection units 600. It should be noted that the print data [SIH, SIL] included in the print data signal SI is input in the order corresponding to the ejection units 600 of the register 212 constituting the shift register, namely, the p-stage, ..., 2-stage, and 1-stage segments.

[0182] Then, when the latch signal LAT rises, each latch circuit 214 latches the printing data [SIH, SIL] held in the register 212 at the same time. Figure 9 In FIG. 1 , LS1 , LS2 , . . . , LSp indicate the print data [SIH, SIL] latched by the latch circuits 214 corresponding to the registers 212 of the 1st, 2nd, . . . , pth stages.

[0183] The decoder 216 changes the logic level of the selection signals S1 and S2 to the value of the dot size specified by the latched print data [SIH, SIL] during each of the periods t1 and t2. Figure 7 The content shown is output.

[0184] Specifically, when the input print data [SIH, SIL] is [1, 1], the decoder 216 sets the logic level of the selection signal S1 to the H, H level during periods t1 and t2, and sets the logic level of the selection signal S2 to the L, L level during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1 and the trapezoidal waveform Adp2 during period t2. As a result, the output terminal of the selection circuit 230 generates Figure 5 The driving signal VOUT corresponding to the large dot LD is shown.

[0185] Furthermore, when the input print data [SIH, SIL] is [1, 0], the decoder 216 sets the logic level of the selection signal S1 to the H and L levels during periods t1 and t2, and sets the logic level of the selection signal S2 to the L and H levels during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1 and the trapezoidal waveform Bdp2 during period t2. As a result, the output terminal of the selection circuit 230 generates Figure 5 The driving signal VOUT shown corresponds to the midpoint MD.

[0186] Furthermore, when the input print data [SIH, SIL] is [0, 1], the decoder 216 sets the logic level of the selection signal S1 to the H and L levels during periods t1 and t2, and sets the logic level of the selection signal S2 to the L and L levels during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1, and does not select either the trapezoidal waveform Adp2 or Bdp2 during period t2. As a result, the output terminal of the selection circuit 230 generates Figure 5 The driving signal VOUT corresponding to the small dot SD is shown.

[0187] Furthermore, when the input print data [SIH, SIL] is [0, 0], the decoder 216 sets the logic level of the selection signal S1 to the L, L level during periods t1 and t2, and sets the logic level of the selection signal S2 to the H, L level during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Bdp1 during period t1, and does not select either the trapezoidal waveform Adp2 or Bdp2 during period t2. As a result, the output terminal of the selection circuit 230 generates Figure 5 The driving signal VOUT corresponding to the non-recording ND is shown.

[0188] As described above, the driving signal selection circuit 200 selects the signal waveforms of the driving signals COMA and COMB based on the printing data signal SI, the clock signal SCK, the latch signal LAT, and the change signal CH, thereby generating and outputting the driving signal VOUT.

[0189] 2. Structure of the head unit

[0190] 2.1 Structure of the head unit

[0191] Next, the structure of the head unit 3 included in the liquid ejecting device 1 will be described. Figure 10 It is a side view showing the structure of the carriage 8 on which the head unit 3 is mounted. Figure 11 : is a stereoscopic diagram showing the peripheral structure of the carriage 8 equipped with the head unit 3. Here, in the following description, the X-axis, Y-axis, and Z-axis that are orthogonal to each other are illustrated and described. In addition, in the following description, there is a case where the starting point side of the arrow in the diagram along the X-axis is referred to as the -X side, and the front end side is referred to as the +X side, the starting point side of the arrow in the diagram along the Y-axis is referred to as the -Y side, and the front end side is referred to as the +Y side, the starting point side of the arrow in the diagram along the Z-axis is referred to as the -Z side, and the front end side is referred to as the +Z side. Furthermore, in the following description, there is a case where the plane formed by the X-axis and the Y-axis is referred to as the XY plane, the plane formed by the X-axis and the Z-axis is referred to as the XZ plane, and the plane formed by the Y-axis and the Z-axis is referred to as the YZ plane.

[0192] like Figure 10 as well as Figure 11 As shown, the carriage 8 includes a carriage body 81, a carriage cover 82, and a housing 83. The carriage body 81 includes a loading portion 85 and a fixing portion 86. The loading portion 85 is a plate-shaped component extending along the XY plane, and the fixing portion 86 is a plate-shaped component extending along the YZ plane from the -Y side end of the loading portion 85 toward the -Z side. That is, the carriage body 81 has an L-shaped cross-section when viewed along the X-axis. The carriage cover 82 is located on the -Z side of the carriage body 81 and is assembled to be freely removable relative to the carriage body 81. At this time, the carriage body 81 and the carriage cover 82 form a closed space. The housing 83 is a roughly rectangular parallelepiped shape that includes a storage space capable of accommodating various structures. On the -Y side of the carriage body 81, the +Y side end of the housing 83 is fixed to the -Z side end of the fixing portion 86.

[0193] Furthermore, a carriage support portion 87 is formed on the -Y side surface of the fixing portion 86 included in the carriage body 81. The guide rail 72 formed on the +Y side of the carriage guide shaft 7 is fitted into the carriage support portion 87, and the carriage support portion 87 is movably supported by the carriage guide shaft 7. Thus, the carriage 8 can move along the carriage guide shaft 7.

[0194] The internal space of the carriage 8 constructed in the above manner, namely, the closed space formed by the carriage body 81 and the carriage cover 82, and the storage space formed within the storage housing 83, houses the discharge control module 10, multiple liquid discharge modules 20, and multiple FFC cables 21 and FFC cables 22 corresponding to the multiple liquid discharge modules 20. Here, the liquid discharge device 1 of this embodiment is described as having five liquid discharge modules 20. That is, the internal space of the carriage 8 of this embodiment houses five liquid discharge modules 20, five FFC cables 21, and five FFC cables 22. It should be noted that the number of liquid discharge modules 20 provided in the liquid discharge device 1 is not limited to five.

[0195] The discharge control module 10 is housed in a housing space formed inside the housing case 83. The discharge control module 10 includes a control circuit board 100 and an integrated circuit 110 mounted on the control circuit board 100. The integrated circuit 110 constitutes part or all of the head control circuit 12 described above.

[0196] Five FFC cables 21 and five FFC cables 22 are provided to correspond to the five liquid ejection modules 20. Specifically, one end of each of the five FFC cables 21 and one end of each of the five FFC cables 22 are electrically connected to the control circuit substrate 100. In addition, the other end of each of the five FFC cables 21 and the other end of each of the five FFC cables 22 are electrically connected to the corresponding liquid ejection module 20. In other words, the other end of the FFC cable 21 and the other end of the FFC cable 22 are electrically connected to each of the five liquid ejection modules 20. For example, a flexible flat cable (FFC) can be used as such FFC cables 21 and 22.

[0197] The five liquid ejection modules 20 include a drive circuit module 50 and a print head 30 and are housed in a closed space formed by the carriage body 81 and the carriage cover 82. The five liquid ejection modules 20 are mounted on the mounting portion 85 at equal intervals along the X axis.

[0198] The other ends of the FFC cables 21 and 22 are electrically connected to the drive circuit module 50 on the -Z side of the corresponding liquid ejection module 20. Furthermore, the printhead 30 is located on the +Z side of the drive circuit module 50. The printheads 30 are mounted on the mounting portion 85 at equal intervals along the X-axis. At this point, the multiple ejection units 600 of the printhead 30 are exposed from the -Z side of the mounting portion 85. This allows ink ejected from the multiple ejection units 600 of the printhead 30 to be ejected onto the medium P without being obstructed by the carriage 8.

[0199] In the liquid ejection module 20, the print head 30 and the drive circuit module 50 are electrically connected via a connector CN1. As such a connector CN1, a board-to-board (BtoB) connector is preferably used.

[0200] A BtoB connector can electrically connect a structure equipped with one of the two connectors to a structure equipped with the other connector without using a cable by directly mating the two connectors. Therefore, without adding any new structure, the structure equipped with one of the two connectors can be electrically connected to the structure equipped with the other connector, and the relative arrangement relationship between the structures can be determined.

[0201] Specifically, when a BtoB connector is used as the connector CN1 that electrically connects the print head 30 and the drive circuit module 50, the relative configuration relationship between the print head 30 and the drive circuit module 50 is fixed. Therefore, it is sufficient to ensure an area in the carriage 8 for fixing at least one of the print head 30 and the drive circuit module 50. In other words, the mounting area of ​​the print head 30 and the drive circuit module 50 in the carriage 8 can be reduced. As a result, the print head 30 and the drive circuit module 50 can be arranged at a high density, and the carriage 8 can be miniaturized. Furthermore, the print head 30 and the drive circuit module 50 are electrically connected using the BtoB connector as the connector CN1, so that there is no longer any influence from the impedance generated by the cable. As a result, the accuracy of the signal transmitted between the print head 30 and the drive circuit module 50 is improved. As a result, the ejection accuracy of the ink ejected from the print head 30 is improved.

[0202] In the head unit 3 configured as described above, the print data signal pDATA and the voltage signals VHV and VMV output by the control unit 2 are transmitted via a cable (not shown) and input to the ejection control module 10. Based on the input print data signal pDATA and the voltage signals VHV and VMV, the ejection control module 10 generates a clock signal SCK, a differential print data signal Dp, and a differential drive data signal Dd corresponding to each of the five liquid ejection modules 20, and also generates a fan drive signal Fp corresponding to each liquid ejection module 20. The ejection control module 10 then outputs the generated clock signal SCK, differential print data signal Dp, differential drive data signal Dd, fan drive signal Fp, and voltage signals VHV and VMV to the FFC cables 21 and 22.

[0203] The clock signal SCK, differential print data signal Dp, differential drive data signal Dd, fan drive signal Fp, and voltage signals VHV and VMV output by the ejection control module 10 are transmitted through the FFC cables 21 and 22 and input to the drive circuit module 50 included in the liquid ejection module 20. The drive circuit module 50 operates based on the input clock signal SCK, differential print data signal Dp, differential drive data signal Dd, and voltage signals VHV and VMV to generate the clock signal SCK, differential print data signal Dpt, and multiple drive signals COM for controlling the operation of the print head 30. These signals are then supplied to the print head 30 via the connector CN1. This causes ink to be ejected from the ejection unit 600 included in the print head 30.

[0204] 2.2 Structure of liquid ejection module

[0205] 2.2.1 Schematic structure of liquid ejection module

[0206] Next, a specific example of the structure of the liquid ejection module 20 included in the head unit 3 will be described. Figure 12 1 is an exploded perspective view showing an example of the structure of the liquid ejection module 20. Figure 12 As shown, the liquid ejection module 20 includes a print head 30 for ejecting liquid, and a drive circuit module 50 electrically connected to the print head 30. Here, the print head 30 of this embodiment is assumed to have ejection modules 32-1 to 32-4 as four ejection modules 32 for description, but the number of ejection modules 32 included in the print head 30 is not limited to 4. It should be noted that the positional relationship between the ejection modules 32-1 to 32-4 is not limited to 4. Figure 12 The positional relationship shown.

[0207] like Figure 12 As shown, the driving circuit module 50 includes a relay substrate 150 , a driving circuit substrate 700 , an opening plate 160 , heat sinks 170 , 180 , and heat conducting members 175 , 185 .

[0208] The relay substrate 150 is a plate-shaped component extending along the XY plane. The -Z side surface of the relay substrate 150 is electrically connected to the other ends of the FFC cables 21 and 22. A connector CN2a is provided on the +Z side surface of the relay substrate 150. Furthermore, the relay substrate 150 has a through-hole 158 extending through the relay substrate 150 along the Z axis. A cooling fan 59 is mounted in this through-hole 158. Specifically, the cooling fan 59 is fixed to the relay substrate 150 to generate airflow along the Z axis.

[0209] The driver circuit substrate 700 is located on the +Z side of the relay substrate 150 and includes rigid wiring components 710, 730, 750, and 770. The rigid wiring components 710, 730, 750, and 770 included in the driver circuit substrate 700 are electrically connected to one another. Furthermore, various circuits including the aforementioned ejection control circuit 51, drive signal output circuit 52, capacitor 53, abnormality detection circuit 54, abnormality notification circuit 55, temperature detection circuit 56, and voltage conversion circuit 58, as well as connectors CN1a and CN2b, are mounted on the rigid wiring components 710, 730, 750, and 770 included in the driver circuit substrate 700.

[0210] The rigid wiring member 710 is a plate-shaped member extending along the YZ plane, with its -Z-side end positioned along the +X-side end of the relay substrate 150. The rigid wiring member 730 is a plate-shaped member extending along the YZ plane, with its -Z-side end positioned along the -X-side end of the relay substrate 150. Specifically, the rigid wiring member 710 is positioned on the +X side of the rigid wiring member 730, and the rigid wiring member 710 and the rigid wiring member 730 are positioned opposite each other along the X-axis.

[0211] Furthermore, rigid wiring member 750 is a plate-shaped member extending along the XZ plane, with its -Z end positioned along the +Y end of relay substrate 150, its +X end positioned along the +Y end of rigid wiring member 710, and its -X end positioned along the +Y end of rigid wiring member 730. In other words, rigid wiring member 750 is positioned so as to intersect both rigid wiring member 710 and rigid wiring member 730.

[0212] Furthermore, rigid wiring member 770 is a plate-shaped member extending along the XY plane. Its +X end is located along the +Z end of rigid wiring member 710, its -X end is located along the +Z end of rigid wiring member 730, and its +Y end is located along the +Z end of rigid wiring member 750. In other words, rigid wiring member 770 is located at a position intersecting rigid wiring member 710, rigid wiring member 730, and rigid wiring member 750.

[0213] As described above, in the driving circuit substrate 700 , the rigid wiring member 710 and the rigid wiring member 730 are located opposite each other in the direction along the X-axis, and the rigid wiring members 750 and 770 are located so as to cover at least a portion of the space generated between the rigid wiring member 710 and the rigid wiring member 730 .

[0214] Connector CN2b is provided on the -X side surface of the rigid wiring component 710 and is positioned along the -Z side end of the rigid wiring component 710. That is, connector CN2b is provided near the relay substrate 150. Connector CN2b mates with connector CN2a provided on the +Z side surface of the relay substrate 150 to electrically connect the drive circuit substrate 700 including the rigid wiring component 710 and the relay substrate 150. That is, connector CN2a and connector CN2b directly mate to form a BtoB connector that electrically connects the drive circuit substrate 700 and the relay substrate 150. In the following description, the BtoB connector formed by connector CN2a and connector CN2b may be referred to as connector CN2.

[0215] Connector CN1a is provided on the +Z side surface of rigid wiring member 770. Furthermore, drive circuit board 700 is electrically connected to print head 30 via connector CN1a. In other words, connector CN1a corresponds to one side of connector CN1, a BtoB connector that electrically connects drive circuit board 700 and print head 30.

[0216] Heat sink 170 is located on the -X side of rigid wiring component 730 and is attached to rigid wiring component 730 via heat-conducting member 175. Heat sink 170 and heat-conducting member 175 absorb heat generated in rigid wiring component 730 and discharge it into the atmosphere. Thus, heat sink 170 cools the various circuits installed in rigid wiring component 730. For reasons of thermal conductivity, workability, and availability, heat sink 170 is typically made of a metal such as copper, copper alloys, aluminum, or aluminum alloys. Furthermore, heat-conducting member 175 improves the heat absorption efficiency of heat sink 170 by enhancing the close contact between heat sink 170 and rigid wiring component 730. To ensure insulation between the metal heat sink 170 and rigid wiring component 730, a flame-retardant and electrically insulating material, such as a thermally conductive gel sheet or rubber sheet such as silicone or acrylic resin, is used.

[0217] Heat sink 180 is located on the +X side of rigid wiring component 710 and is attached to rigid wiring component 710 via heat-conductive component 185. Heat sink 180 and heat-conductive component 185 absorb heat generated in rigid wiring component 710 and discharge it into the atmosphere. Thus, heat sink 180 cools the various circuits installed in rigid wiring component 710. For reasons of thermal conductivity, workability, and availability, heat sink 180 is typically made of a metal such as copper, copper alloys, aluminum, or aluminum alloys. Furthermore, heat-conductive component 185 improves the heat absorption efficiency of heat sink 180 by enhancing the close contact between heat sink 180 and rigid wiring component 710. To ensure insulation between the metal heat sink 180 and rigid wiring component 710, a flame-retardant and electrically insulating material, such as a thermally conductive gel sheet or rubber sheet made of silicone or acrylic resin, is used.

[0218] Opening plate 160 is a plate-shaped member extending along the XZ plane. Its +X end is located along the -Y end of rigid wiring member 710, its -X end is located along the -Y end of rigid wiring member 730, its +Z end is located along the -Y end of rigid wiring member 770, and its -Z end is located along the -Y end of relay substrate 150. Specifically, opening plate 160 is positioned so as to cover at least a portion of the space formed between rigid wiring member 710 and rigid wiring member 730, which are located at opposing positions along the X-axis.

[0219] The printhead 30 is located on the +Z side of the drive circuit module 50 and includes ejection modules 32-1 to 32-4 and a connector CN1b. The ejection modules 32-1 to 32-4 are located on the +Z side of the printhead 30 and are at least partially exposed from the surface of the printhead 30 on the +Z side. Of the four ejection modules 32, ejection modules 32-1 and 32-2 are positioned along the Y axis, with ejection module 32-1 on the -Y side and ejection module 32-2 on the +Y side. Of the four ejection modules 32, ejection modules 32-3 and 32-4 are positioned on the +X side of ejection modules 32-1 and 32-2, and are positioned along the Y axis, with ejection module 32-3 on the -Y side and ejection module 32-4 on the +Y side. That is, the ejection modules 32 - 1 and 32 - 2 of the four ejection modules 32 are arranged along the −X side end of the print head 30 , and the ejection modules 32 - 3 and 32 - 4 of the four ejection modules 32 are arranged along the +X side end of the print head 30 .

[0220] Connector CN1b is located on the -Z side of the print head 30, with at least a portion exposed from the -Z side surface of the print head 30. This connector CN1b engages with connector CN1a of the drive circuit module 50. This electrically connects the drive circuit substrate 700 and the print head 30. Specifically, connector CN1b serves as the other side of connector CN1, a BtoB connector that electrically connects the drive circuit substrate 700 and the print head 30. Connector CN1a and connector CN1b together constitute connector CN1, a BtoB connector.

[0221] 2.2.2 Print head structure

[0222] The following describes a more specific structure of the liquid ejection module 20 configured as described above. First, the following describes a specific structure of the print head 30 included in the liquid ejection module 20. Figure 13 3 is a perspective view showing an example of the internal structure of the print head 30. Figure 13 In FIG. 3 , the head cover 350 of the print head 30 is shown by a dotted line diagram, and the internal structure of the head cover 350 is shown by a solid line diagram. Figure 13 The middle figure shows a state where the head cover 350 of the print head 30 is removed.

[0223] like Figure 13As shown, the print head 30 includes a head holder 310 and a head cover 350. A flange 315 is provided at the end of the head holder 310 on the -Y side, and a flange 316 is provided at the end of the head holder 310 on the +Y side. The head holder 310 is exposed from the +Z side of the mounting portion 85 of the carriage body 81. Since the flanges 315 and 316 are supported by the mounting portion 85, the print head 30 is supported by the carriage body 81 with the plurality of ejection portions 600 exposed from the -Z side of the mounting portion 85. Alternatively, the flanges 315 and 316 may be fixed to the mounting portion 85 using screws (not shown).

[0224] The head cap 350 is located on the -Z side of the head holder 310 and has a storage space therein. The head cap 350 stores various components of the print head 30 in the storage space, thereby functioning as a protective member to protect the various components of the print head 30 from ink mist and impact.

[0225] The flow path member 340 , the head substrate 360 ​​, the head relay substrates 370 and 380 , and the FPCs 372 , 374 , 376 , 382 , 384 , and 386 are accommodated in the accommodation space of the head cover 350 .

[0226] The flow path member 340 includes an ink flow path (not shown) for supplying ink from the liquid container 9 to the plurality of ejection units 600. The head substrate 360 ​​is located on the -Z side of the flow path member 340 and extends along the XY plane. A connector CN1b is provided on the -Z side of the head substrate 360. At least a portion of this connector CN1b is exposed to the outside of the print head 30 by being inserted through a through hole (not shown) formed in the head cover 350.

[0227] The head relay substrate 370 is located on the -X side of the flow path member 340 and extends along the YZ plane. The head relay substrate 370 is electrically connected to the head substrate 360 ​​via an FPC 372. Furthermore, the head relay substrate 370 is connected to one end of an FPC 374 and one end of an FPC 376. The other end of the FPC 374 is electrically connected to the ejection module 32-1, and the other end of the FPC 376 is electrically connected to the ejection module 32-2.

[0228] The head relay substrate 380 is located on the +X side of the flow path member 340 and extends along the YZ plane. The head relay substrate 380 is electrically connected to the head substrate 360 ​​via an FPC 382. Furthermore, the head relay substrate 380 is connected to one end of an FPC 384 and one end of an FPC 386. The other end of the FPC 384 is electrically connected to the ejection module 32-3, and the other end of the FPC 386 is electrically connected to the ejection module 32-4.

[0229] The various signals output by the drive circuit module 50 are input to the printhead 30 configured as described above via connector CN1b. The signals input via connector CN1b are branched by the head substrate 360 ​​and the head relay substrates 370 and 380 before being supplied to each of the ejection modules 32-1 to 32-4. For example, the reset circuit 31 included in the printhead 30 is provided on the head substrate 360.

[0230] Figure 14 3 is an exploded perspective view of the print head 30 when viewed from the +Z side along the Z axis. Figure 14 As shown, the head holder 310 of the print head 30 is provided with a reinforcing plate 320, a fixing plate 330, and ejection modules 32-1 to 32-4.

[0231] For example, the head holder 310 is made of a conductive material such as metal having greater strength than the reinforcing plate 320. Four housings 318 for housing each of the ejection modules 32-1 to 32-4 are provided on the +Z side surface of the head holder 310.

[0232] The four accommodating sections 318 have a concave shape that opens on the +Z side and individually accommodate the ejection modules 32-1 to 32-4 secured by the fixing plate 330. The openings of the accommodating sections 318 are sealed by the fixing plate 330. That is, the ejection modules 32-1 to 32-4 are individually accommodated within the space formed by the accommodating sections 318 and the fixing plate 330. It should be noted that the accommodating sections 318 may be individually configured to correspond to each of the ejection modules 32-1 to 32-4, or may be configured to accommodate all of the ejection modules 32-1 to 32-4.

[0233] On the surface of the head holder 310 where the accommodation portion 318 is provided, the reinforcing plate 320 and the fixing plate 330 are stacked in this order from the −Z side toward the +Z side along the Z axis.

[0234] The fixing plate 330 is composed of a plate-shaped member formed of a conductive material such as metal. Furthermore, openings 335 are provided along the Z-axis through the fixing plate 330 to expose the nozzles 651 included in the multiple ejection units 600 of each ejection module 32-1 to 32-4. These openings 335 are individually provided for each ejection module 32-1 to 32-4.

[0235] The reinforcing plate 320 is preferably made of a material stronger than the fixing plate 330. An opening 325 having an inner diameter larger than the outer circumference of each of the ejection modules 32-1 to 32-4 is provided in the reinforcing plate 320, extending along the Z-axis, corresponding to each of the ejection modules 32-1 to 32-4 joined to the fixing plate 330. Each of the ejection modules 32-1 to 32-4, through which the opening 325 of the reinforcing plate 320 is inserted, is joined to the fixing plate 330.

[0236] The ejection modules 32-1 to 32-4 of the print head 30 are arranged in a staggered pattern on the +Z side surface of the head holder 310. In each of the ejection modules 32-1 to 32-4, the ejection unit 600 for ejecting ink includes nozzles 651 arranged in two rows along the X axis, aligned along the Y axis.

[0237] Here, the structure of the ejection portion 600 including the nozzle 651 will be described. Figure 15 : is a diagram showing an example of the structure of the discharge unit 600 included in the discharge module 32. Figure 15 6 , the nozzle plate 632 , the reservoir 641 , and the supply port 661 are shown in addition to the ejection unit 600 .

[0238] like Figure 15 As shown, the ejection portion 600 includes a piezoelectric element 60, a vibration plate 621, a cavity 631, and a nozzle 651. The piezoelectric element 60 includes a piezoelectric body 601 and electrodes 611 and 612. Furthermore, the electrodes 611 and 612 are located so as to sandwich the piezoelectric body 601 therebetween, thereby constituting the piezoelectric element 60. Such a piezoelectric element 60 is driven in such a manner that the central portion is displaced in the vertical direction according to the potential difference between the voltage supplied to the electrode 611 and the voltage supplied to the electrode 612. Specifically, a drive signal VOUT based on the drive signal COM is supplied to the electrode 611, and a reference voltage signal VBS is supplied to the electrode 612. Furthermore, if the voltage value of the drive signal VOUT supplied to the electrode 611 changes, the potential difference between the drive signal VOUT supplied to the electrode 611 and the reference voltage signal VBS supplied to the electrode 612 changes, and the piezoelectric element 60 is driven in such a manner that the central portion is displaced in the vertical direction.

[0239] The vibration plate 621 is located at Figure 15 In other words, the piezoelectric element 60 is formed below the vibration plate 621. Figure 15 Such a vibration plate 621 is displaced in the vertical direction as the piezoelectric element 60 is driven in the vertical direction.

[0240] Cavity 631 is located on the vibrating plate 621 Figure 15. Ink is supplied from reservoir 641 to cavity 631. Furthermore, ink stored in liquid container 9 is introduced into reservoir 641 via supply port 661. In other words, the interior of cavity 631 is filled with ink stored in liquid container 9. The internal volume of cavity 631 expands or contracts with the vertical displacement of vibrating plate 621. In other words, vibrating plate 621 functions as a diaphragm that changes the internal volume of cavity 631, and cavity 631 functions as a pressure chamber whose internal pressure changes with the vertical displacement of vibrating plate 621.

[0241] The nozzle 651 is an opening provided in the nozzle plate 632 and communicates with the cavity 631. When the internal volume of the cavity 631 changes, the ink filled in the cavity 631 is ejected from the nozzle 651 in accordance with the change in the internal volume.

[0242] In the ejection unit 600 constructed as described above, when the piezoelectric element 60 is driven to flex upward, the vibration plate 621 displaces upward. This increases the internal volume of the cavity 631, causing ink stored in the reservoir 641 to be drawn into the cavity 631. On the other hand, when the piezoelectric element 60 is driven to flex downward, the vibration plate 621 displaces downward. This decreases the internal volume of the cavity 631, causing an amount of ink to be ejected from the nozzle 651 in accordance with the degree of decrease in the internal volume of the cavity 631. In other words, each of the multiple ejection units 600 included in the ejection module 32 of the print head 30 ejects an amount of ink in accordance with the voltage value of the drive signal VOUT.

[0243] It should be noted that the piezoelectric element 60 is not limited to any structure as long as it can be driven by the driving signal VOUT corresponding to the driving signal COM and ejects ink from the nozzle 651 by the driving. Figure 15 The structure shown.

[0244] As described above, the print head 30 has a connector CN1b electrically connected to the ejection modules 32-1 to 32-4 and the drive circuit module 50. In addition, the ejection module 32-1 has an ejection portion 600, which includes a piezoelectric element 60 and ejects liquid based on the displacement of the piezoelectric element 60. The piezoelectric element 60 is displaced by receiving a drive signal VOUT supplied to an electrode 611 that varies based on the voltage value of the drive signals COMA1 and COMB1, and a reference voltage signal VBS supplied to an electrode 612 that is fixed in voltage. The ejection module 32-2 has an ejection portion 600, which includes a piezoelectric element 60 and ejects liquid based on the displacement of the piezoelectric element 60. The piezoelectric element 60 is displaced by receiving a drive signal VOUT supplied to an electrode 611 that varies based on the voltage value of the drive signals COMA2 and COMB2, and a reference voltage signal VBS supplied to an electrode 612 that is fixed in voltage. The ejection module 32-3 has an ejection portion 600, which includes a piezoelectric element 60 and ejects liquid based on the displacement of the piezoelectric element 60. The piezoelectric element 60 receives a drive signal VOUT supplied to the electrode 611 and the voltage value of the drive signals COMA3 and COMB3 changes, and a reference voltage signal VBS supplied to the electrode 612 and the voltage value of the drive signals is fixed, and is displaced; The ejection module 32-4 has an ejection portion 600, which includes a piezoelectric element 60 and ejects liquid based on the displacement of the piezoelectric element 60. The piezoelectric element 60 receives a drive signal VOUT supplied to the electrode 611 and the voltage value of the drive signals COMA4 and COMB4 changes, and a reference voltage signal VBS supplied to the electrode 612 and the voltage value of the drive signals is fixed, and is displaced.

[0245] 2.2.3 Structure of the Driving Circuit Module of the Liquid Ejection Module

[0246] Next, the structure of the driving circuit module 50 included in the liquid ejection module 20 will be described. Figure 12 As shown, the driving circuit module 50 includes a relay substrate 150 , a driving circuit substrate 700 , an opening plate 160 , heat sinks 170 , 180 , and heat conducting members 175 , 185 .

[0247] 2.2.3.1 Structure of the drive circuit substrate

[0248] First, the structure of the driving circuit substrate 700 will be described. Figure 16is a diagram showing a top view of the drive circuit substrate 700. In the following description, the X-axis, Y-axis, and Z-axis are independent axes, and the diagram illustrates the mutually orthogonal x1-axis, y1-axis, and z1-axis for explanation. In the following description, the starting point side of the illustrated arrow along the x1-axis is referred to as the -x1-side, and the front end side is referred to as the +x1-side. The starting point side of the illustrated arrow along the y1-axis is referred to as the -y1-side, and the front end side is referred to as the +y1-side. The starting point side of the illustrated arrow along the z1-axis is referred to as the -z1-side, and the front end side is referred to as the +z1-side. Furthermore, the plane formed by the x1-axis and y1-axis is referred to as the x1y1-plane, the plane formed by the x1-axis and z1-axis is referred to as the x1z1-plane, and the plane formed by the y1-axis and z1-axis is referred to as the y1z1-plane.

[0249] As described above, the driver circuit substrate 700 includes rigid wiring members 710, 730, 750, and 770. Rigid wiring members 710, 730, and 750 are arranged in this order, from the -y1 side toward the +y1 side, along the y1 axis. Furthermore, rigid wiring member 770 is located on the -x1 side of the arranged rigid wiring members 710, 750, and 730, specifically, on the -x1 side of rigid wiring member 730.

[0250] Rigid wiring component 710 includes a surface 723 on the +z1 side, a surface 724 on the -z1 side, edges 711 and 712, and edges 713 and 714 that are longer than edges 711 and 712. Edges 711 and 712 extend along the y1 axis and face each other in the direction along the x1 axis, with edge 711 located on the +x1 side and edge 712 located on the -x1 side. Furthermore, edges 713 and 714 intersect both edges 711 and 712 and extend along the x1 axis and face each other in the direction along the y1 axis, with edge 713 located on the -y1 side and edge 714 located on the +y1 side. In other words, rigid wiring component 710 includes edges 711 and 712 that face each other, edges 713 and 714 that intersect and face each other, and surface 723. In other words, the rigid wiring member 710 includes a surface 723 , a surface 724 opposite to the surface 723 , and a side 711 , and is a substantially rectangular plate-shaped member extending along the x1y1 plane.

[0251] The rigid wiring component 730 includes a surface 743 on the +z1 side, a surface 744 on the -z1 side, edges 731 and 732, and edges 733 and 734 that are longer than edges 731 and 732. The rigid wiring component 730 is located on the +y1 side of the rigid wiring component 710. Edges 731 and 732 extend along the y1 axis and face each other along the x1 axis, with edge 731 located on the +x1 side and edge 732 located on the -x1 side. Furthermore, edges 733 and 734 intersect both edges 731 and 732 and extend along the x1 axis and face each other along the y1 axis, with edge 733 located on the -y1 side and edge 734 located on the +y1 side. Specifically, rigid wiring member 730 includes sides 731 and 732 that face each other, sides 733 and 734 that intersect and face each other, and surface 743. In other words, rigid wiring member 730 includes surface 743, surface 744 opposite to surface 743, and side 731, and is a generally rectangular plate-shaped member extending along the x1y1 plane.

[0252] The rigid wiring component 750 includes a surface 763 on the +z1 side, a surface 764 on the -z1 side, edges 751 and 752, and edges 753 and 754 that are longer than edges 751 and 752. The rigid wiring component 750 is located between the rigid wiring component 710 and the rigid wiring component 730 along the y1 axis. Edges 751 and 752 extend along the y1 axis and face each other along the x1 axis, with edge 751 located on the +x1 side and edge 752 located on the -x1 side. Furthermore, edges 753 and 754 intersect both edges 751 and 752 and extend along the x1 axis and face each other along the y1 axis, with edge 753 located on the -y1 side and edge 754 located on the +y1 side. Specifically, rigid wiring member 750 includes sides 751 and 752 that face each other, sides 753 and 754 that intersect and face each other, and surface 763. In other words, rigid wiring member 750 includes surface 763, surface 764 opposite to surface 763, and side 751, and is a substantially rectangular plate-shaped member extending along the x1y1 plane.

[0253] The rigid wiring component 770 includes a surface 783 on the +z1 side, a surface 784 on the -z1 side, edges 771 and 772, and edges 773 and 774 that are shorter than edges 771 and 772. These edges are located on the -x1 side of the rigid wiring component 770 along the x1 axis. Edges 771 and 772 extend along the y1 axis and face each other along the x1 axis, with edge 771 located on the +x1 side and edge 772 located on the -x1 side. Furthermore, edges 773 and 774 intersect both edges 771 and 772 and extend along the x1 axis and face each other along the y1 axis, with edge 773 located on the -y1 side and edge 774 located on the +y1 side. Specifically, rigid wiring member 770 includes sides 771 and 772 that face each other, sides 773 and 774 that intersect and face each other, and surface 783. In other words, rigid wiring member 770 includes surface 783, surface 784 opposite to surface 783, and side 771, and is a substantially rectangular plate-shaped member extending along the x1y1 plane.

[0254] Each of such rigid wiring components 710, 730, 750, 770 constitutes a so-called multi-layer rigid substrate including a base material and multiple wiring layers, wherein the base material is obtained by stacking multiple layers of hard composite materials such as epoxy glass in the direction along the z1 axis, and the multiple wiring layers are located between the layers of the base material and form wiring patterns for transmitting various signals.

[0255] Here, if Figure 16As shown, in driver circuit substrate 700, sides 711, 731, and 751 are located in a substantially linear position along the y1 axis, while sides 712, 732, and 752 are located in a substantially linear position along the y1 axis. Specifically, the lengths of sides 713 and 714 included in rigid wiring component 710 along the x1 axis, the lengths of sides 733 and 734 included in rigid wiring component 730 along the x1 axis, and the lengths of sides 753 and 754 included in rigid wiring component 750 along the x1 axis are substantially equal. Furthermore, the lengths of sides 711 and 712 along the y1 axis are substantially equal to the lengths of sides 731 and 732 along the y1 axis, while the lengths of sides 751 and 752 along the y1 axis are shorter than the lengths of sides 711 and 712 along the y1 axis and the lengths of sides 731 and 732 included in rigid wiring component 730 along the y1 axis. That is, the size of the rigid wiring component 710 when the driving circuit substrate 700 is observed along the z1 axis is approximately equal to the size of the rigid wiring component 730 when the driving circuit substrate 700 is observed along the z1 axis, and the size of the rigid wiring component 750 when the driving circuit substrate 700 is observed along the z1 axis is smaller than the size of the rigid wiring component 710 when the driving circuit substrate 700 is observed along the z1 axis and the size of the rigid wiring component 730 when the driving circuit substrate 700 is observed along the z1 axis.

[0256] Furthermore, in the driver circuit substrate 700, sides 733 and 773 are located in a substantially linear position along the x1 axis, and sides 734 and 774 are located in a substantially linear position along the x1 axis. That is, the length of sides 731 and 732 included in the rigid wiring component 730 along the y1 axis is substantially equal to the length of sides 771 and 772 included in the rigid wiring component 770 along the y1 axis. Furthermore, the length of sides 773 and 774 along the x1 axis is shorter than the length of sides 733 and 734 along the x1 axis and is substantially equal to the length of sides 751 and 752 along the y1 axis. In other words, the size of the rigid wiring component 770 when viewing the driver circuit substrate 700 along the z1 axis is smaller than the sizes of the rigid wiring components 710, 730, and 750. That is, the size of the rigid wiring component 770 when the driving circuit substrate 700 is viewed along the z1 axis is smaller than the size of the rigid wiring component 710 when the driving circuit substrate 700 is viewed along the z1 axis, and is smaller than the size of the rigid wiring component 730 when the driving circuit substrate 700 is viewed along the z1 axis.

[0257] The rigid wiring members 710, 730, 750, and 770 configured as described above are electrically connected to one another via the flexible wiring member 790. Specifically, the rigid wiring members 710, 730, 750, and 770 are electrically connected to one another. Here, the arrangement of the rigid wiring members 710, 730, 750, and 770 and the flexible wiring member 790 that electrically connects the rigid wiring members 710, 730, 750, and 770 will be described.

[0258] Figure 17 The driving circuit substrate 700 is Figure 16 A cross-sectional view taken along line Aa is shown. Figure 18 The driving circuit substrate 700 is Figure 16 The cross-sectional view is taken along line Bb.

[0259] Here, in the following description, the flexible wiring component 790 is divided into the following Figure 17 as well as Figure 18 The seven regions 701 to 707 shown in FIG. Figure 17 as well as Figure 18 As shown, the flexible wiring member 790 includes a surface 791 on the +z1 side and a surface 792 on the -z1 side. That is, the flexible wiring member 790 is described as including the surface 791, the surface 792 opposite to the surface 791, and the regions 701 to 707.

[0260] like Figure 17 As shown, regions 701 to 705 of the flexible wiring member 790 are arranged in the order of region 701, region 702, region 703, region 704, and region 705 along the y1-axis from the -y1 side toward the +y1 side. Specifically, region 702 is located between regions 701 and 703, and region 704 is located between regions 703 and 705. Therefore, regions 702, 703, and 704 are located between region 701 and 705.

[0261] Rigid component 721, a portion of rigid wiring component 710, is laminated on surface 791 of region 701, while rigid component 722, a different portion of rigid wiring component 710, is laminated on surface 792 of region 701. Specifically, rigid wiring component 710 includes rigid component 721 and rigid component 722. Rigid component 721 includes surface 723, corresponding to the +z1 side surface of rigid wiring component 710. Furthermore, rigid component 721 is laminated on surface 791 of region 701 of flexible wiring component 790, such that surface 723 extends along surface 791 of flexible wiring component 790. Furthermore, rigid component 722 includes surface 724, corresponding to the -z1 side surface of rigid wiring component 710. Furthermore, rigid component 722 is laminated on surface 792 of region 701 of flexible wiring component 790, such that surface 724 extends along surface 792 of flexible wiring component 790.

[0262] Surface 791 of region 703 is laminated with rigid component 761, a portion of rigid wiring component 750, and surface 792 of region 703 is laminated with rigid component 762, a different portion of rigid wiring component 750. Specifically, rigid wiring component 750 includes rigid component 761 and rigid component 762. Rigid component 761 includes surface 763, corresponding to the +z1 side surface of rigid wiring component 750. Furthermore, rigid component 761 is laminated on surface 791 of region 703 of flexible wiring component 790, such that surface 763 extends along surface 791 of flexible wiring component 790. Rigid component 762 includes surface 764, corresponding to the -z1 side surface of rigid wiring component 750. Furthermore, rigid component 762 is laminated on surface 792 of region 703 of flexible wiring component 790, such that surface 764 extends along surface 792 of flexible wiring component 790.

[0263] Rigid component 741, a portion of rigid wiring component 730, is laminated on surface 791 of region 705, while rigid component 742, a different portion of rigid wiring component 730, is laminated on surface 792 of region 705. Specifically, rigid wiring component 730 includes rigid component 741 and rigid component 742. Rigid component 741 includes surface 743, corresponding to the +z1 side surface of rigid wiring component 730. Furthermore, rigid component 741 is laminated on surface 791 of region 705 of flexible wiring component 790, such that surface 743 extends along surface 791 of flexible wiring component 790. Rigid component 742 includes surface 744, corresponding to the -z1 side surface of rigid wiring component 730. Furthermore, rigid component 742 is laminated on surface 792 of region 705 of flexible wiring component 790, such that surface 744 extends along surface 792 of flexible wiring component 790.

[0264] No hard composite material such as epoxy glass is provided in regions 702 and 704. Specifically, region 702 is located between rigid wiring component 710 and rigid wiring component 750 and is used to separate rigid wiring component 710 from rigid wiring component 750. Region 704 is located between rigid wiring component 750 and rigid wiring component 730 and is used to separate rigid wiring component 750 from rigid wiring component 730.

[0265] In addition, if Figure 18 As shown, regions 705 to 707 of the flexible wiring member 790 are arranged along the x1 axis from the +x1 side toward the -x1 side in the order of region 705, region 706, and region 707. Specifically, region 706 is located between region 705 and region 707, i.e., between regions 701, 702, 703, 704, 705, and region 707.

[0266] On surface 791 of region 707, a rigid component 781, which is a portion of rigid wiring component 770, is laminated. On surface 792 of region 707, a rigid component 782, which is a different portion of rigid wiring component 770, is laminated. Specifically, rigid wiring component 770 includes rigid component 781 and rigid component 782. Rigid component 781 includes surface 783, which corresponds to the +z1 side surface of rigid wiring component 770. Furthermore, rigid component 781 is laminated on surface 791 of region 707 of flexible wiring component 790, such that surface 783 extends along surface 791 of flexible wiring component 790. Rigid component 782 includes surface 784, which corresponds to the -z1 side surface of rigid wiring component 770. Furthermore, rigid component 782 is laminated on surface 792 of region 707 of flexible wiring component 790, such that surface 784 extends along surface 792 of flexible wiring component 790.

[0267] Region 706 is not provided with a hard composite material such as epoxy glass, similar to regions 702 and 704. That is, region 706 is located between rigid wiring member 730 and rigid wiring member 770 and is used to separate rigid wiring member 730 and rigid wiring member 770.

[0268] In the driver circuit substrate 700 constructed as described above, the flexible wiring member 790 constitutes at least one layer in each of the wiring layers of the rigid wiring members 710, 730, 750, and 770. Thus, the flexible wiring member 790 electrically connects each of the rigid wiring members 710, 730, 750, and 770 and transmits signals generated by each of the rigid wiring members 710, 730, 750, and 770. Specifically, the flexible wiring member 790 constitutes at least one layer in the plurality of wiring layers included in the rigid wiring member 710, at least one layer in the plurality of wiring layers included in the rigid wiring member 730, at least one layer in the plurality of wiring layers included in the rigid wiring member 750, and at least one layer in the plurality of wiring layers included in the rigid wiring member 770, thereby electrically connecting each of the rigid wiring members 710, 730, 750, and 770. Such a flexible wiring member 790 is a so-called flexible substrate having flexibility, including one or more layers of a base material such as a plastic film or polyimide laminated thereon and one or more wiring layers on which wiring patterns for transmitting various signals are formed.

[0269] That is, the driving circuit substrate 700 includes rigid wiring components 710, 730, 750, 770, namely rigid components 721, 722, 741, 742, 761, 762, 781, 782 as multiple rigid substrates, and the driving circuit substrate 700 is a so-called rigid-flexible substrate that includes these multiple rigid substrates and a flexible wiring component 790 that is a flexible substrate that is softer than the rigid wiring components 710, 730, 750, 770.

[0270] Furthermore, in the liquid ejection device 1 of this embodiment, the aforementioned driving circuit substrate 700 is substantially box-shaped and electrically connected to the print head 30. This reduces the mounting area of ​​the driving circuit substrate 700 in the liquid ejection device 1, enabling dense arrangement of the driving circuit substrates 700, and consequently miniaturizing the liquid ejection device 1.

[0271] Figure 19 FIG is a diagram showing an example of the structure of a driver circuit substrate 700 that is substantially box-shaped. Figure 19 As shown, in the driving circuit substrate 700 , since the flexible wiring member 790 is bent, each of the rigid wiring members 710 , 730 , 750 , and 770 constitutes one surface of the driving circuit substrate 700 having a substantially box shape.

[0272] Specifically, region 702 of flexible wiring member 790 is bent at a substantially right angle so that surface 723 of rigid wiring member 710 and surface 763 of rigid wiring member 750 form the inner surface of the substantially box-shaped driver circuit substrate 700, and surface 724 of rigid wiring member 710 and surface 764 of rigid wiring member 750 form the outer surface of the substantially box-shaped driver circuit substrate 700. Furthermore, region 704 of flexible wiring member 790 is bent at a substantially right angle so that surface 763 of rigid wiring member 750 and surface 743 of rigid wiring member 730 form the inner surface of the substantially box-shaped driver circuit substrate 700, and surface 764 of rigid wiring member 750 and surface 744 of rigid wiring member 730 form the outer surface of the substantially box-shaped driver circuit substrate 700. Furthermore, region 706 of the flexible wiring component 790 is bent roughly at a right angle so that surface 743 of the rigid wiring component 730 and surface 783 of the rigid wiring component 770 constitute the inner surface of the roughly box-shaped driving circuit substrate 700, and surface 744 of the rigid wiring component 730 and surface 784 of the rigid wiring component 770 constitute the outer surface of the roughly box-shaped driving circuit substrate 700.

[0273] That is, in the liquid ejection device 1 of this embodiment, for the driving circuit substrate 700 which is roughly in the shape of a box, the surface 723 of the rigid wiring component 710, the surface 763 of the rigid wiring component 750, the surface 743 of the rigid wiring component 730, and the surface 783 of the rigid wiring component 770 constitute the inner surface of the roughly box shape, and the surface 724 of the rigid wiring component 710, the surface 764 of the rigid wiring component 750, the surface 744 of the rigid wiring component 730, and the surface 784 of the rigid wiring component 770 constitute the outer surface of the roughly box shape. At this time, since the flexible wiring component 790 is bent in areas 702 and 704, the rigid wiring component 710 and the rigid wiring component 730 are located at a position where the surface 723 of the rigid wiring component 710 is opposite to the surface 743 of the rigid wiring component 730. Since the flexible wiring component 790 is bent in areas 702 and 704, the rigid wiring component 750 is located at a position where the normal direction of the surface 763 of the rigid wiring component 750 intersects with the normal direction of the surface 723 of the rigid wiring component 710 and the normal direction of the surface 743 of the rigid wiring component 730. Since the flexible wiring component 790 is bent in area 706, the rigid wiring component 770 is located at a position where the normal direction of the surface 783 of the rigid wiring component 770 intersects with the normal direction of the surface 723 of the rigid wiring component 710 and the normal direction of the surface 743 of the rigid wiring component 730.

[0274] In other words, the rigid component 721 and the rigid component 741 are located at a position where the surface 723 of the rigid component 721 is opposite to the surface 743 of the rigid component 741 due to the bending of the flexible wiring component 790 in the regions 702 and 704. The rigid component 761 is located at a position where the normal direction of the surface 763 of the rigid component 761 intersects with the normal direction of the surface 723 of the rigid component 721 and the normal direction of the surface 743 of the rigid component 741 due to the bending of the flexible wiring component 790 in the regions 702 and 704. The rigid component 781 is located at a position where the normal direction of the surface 783 of the rigid component 781 intersects with the normal direction of the surface 723 of the rigid component 721 and the normal direction of the surface 743 of the rigid component 741 due to the bending of the flexible wiring component 790 in the region 706.

[0275] It should be noted that the so-called box-shaped driving circuit substrate 700 is not limited to the case where all surfaces of the box-shaped driving circuit substrate are made of a rigid substrate such as a rigid flexible substrate. In other words, as long as the shape of the driving circuit substrate 700 can be regarded as a box-shaped driving circuit substrate, it can also be Figure 19 As shown, one or more sides are open.

[0276] In the following description, the x1-axis, y1-axis, and z1-axis are described as independent axes using a driver circuit substrate 700 having a substantially box-like shape. The x2-axis, y2-axis, and z2-axis are illustrated as being orthogonal to each other. Furthermore, in the following description, the starting point side of an arrow shown along the x2-axis is referred to as the -x2-side, and the leading end side is referred to as the +x2-side. The starting point side of an arrow shown along the y2-axis is referred to as the -y2-side, and the leading end side is referred to as the +y2-side. The starting point side of an arrow shown along the z2-axis is referred to as the -z2-side, and the leading end side is referred to as the +z2-side. The plane formed by the x2-axis and y2-axis is referred to as the x2y2-plane, the plane formed by the x2-axis and z2-axis is referred to as the x2z2-plane, and the plane formed by the y2-axis and z2-axis is referred to as the y2z2-plane. Here, in the driving circuit substrate 700 which is roughly in the shape of a box, the surface 723 of the rigid component 721 and the surface 743 of the rigid component 741 are located at opposite positions along the x2 axis, the normal direction of the surface 723 of the rigid component 721 is the direction from the -x2 side toward the +x2 side along the x2 axis, the normal direction of the surface 743 of the rigid component 741 is the direction from the +x2 side toward the -x2 side along the x2 axis, the normal direction of the surface 763 of the rigid component 761 is the direction from the +y2 side toward the -y2 side along the y2 axis, and the normal direction of the surface 783 of the rigid component 781 is the direction from the -z2 side toward the +z2 side along the z2 axis.

[0277] In addition, in the following description, there are the following situations, Figure 16 、 Figure 17 、 Figure 18 The driving circuit substrate 700 in the unfolded state shown in FIG. 7 is referred to as the driving circuit substrate 700 in the unfolded state. Figure 19 The driving circuit substrate 700 assembled on the substantially housing as shown is referred to as the driving circuit substrate 700 in an assembled state.

[0278] 2.2.3.2 Component Configuration in the Driver Circuit Board

[0279] Next, the arrangement of electronic components constituting various circuits in the driver circuit board 700 will be described. Figure 20 1 is a diagram showing an example of component arrangement in the driver circuit board 700 in the expanded state.

[0280] like Figure 20 As shown, a plurality of circuit components are provided in the rigid wiring component 710, including drive signal output circuits 52a-1, 52b-1, 52a-2, 52b-2, a discharge control circuit 51 composed of an FPGA, a capacitor C7a, and connectors CN2b, CN3a.

[0281] The drive signal output circuit 52a-1 includes the integrated circuit 500, transistors M1 and M2, and an inductor L1, and is provided on the surface 723 of the rigid wiring member 710 of the drive circuit substrate 700. In this case, the transistors M1 and M2 included in the drive signal output circuit 52a-1 are arranged in this order along the direction from the edge 713 toward the edge 714. The integrated circuit 500 included in the drive signal output circuit 52a-1 is located on the side 711 of the arranged transistors M1 and M2, and the inductor L1 included in the drive signal output circuit 52a-1 is located on the side 712 of the arranged transistors M1 and M2.

[0282] Drive signal output circuit 52b-1 includes integrated circuit 500, transistors M1 and M2, and inductor L1, and is disposed on side 714 of drive signal output circuit 52a-1 on surface 723 of rigid wiring member 710 of drive circuit substrate 700. Transistors M1 and M2 included in drive signal output circuit 52b-1 are arranged in that order, along a direction from side 713 toward side 714. Integrated circuit 500 included in drive signal output circuit 52b-1 is located on side 711 of the arranged transistors M1 and M2, and inductor L1 included in drive signal output circuit 52b-1 is located on side 712 of the arranged transistors M1 and M2.

[0283] Drive signal output circuit 52a-2 includes integrated circuit 500, transistors M1 and M2, and inductor L1, and is disposed on side 714 of drive signal output circuit 52b-1 on surface 723 of rigid wiring member 710 of drive circuit substrate 700. Transistors M1 and M2 included in drive signal output circuit 52a-2 are arranged in that order, along a direction from side 713 toward side 714. Integrated circuit 500 included in drive signal output circuit 52a-2 is located on side 711 of the arranged transistors M1 and M2, and inductor L1 included in drive signal output circuit 52a-2 is located on side 712 of the arranged transistors M1 and M2.

[0284] Drive signal output circuit 52b-2 includes integrated circuit 500, transistors M1 and M2, and inductor L1, and is disposed on side 714 of drive signal output circuit 52a-2 on surface 723 of rigid wiring member 710 of drive circuit substrate 700. Transistors M1 and M2 included in drive signal output circuit 52b-2 are arranged in that order, along a direction from side 713 toward side 714. Integrated circuit 500 included in drive signal output circuit 52b-2 is located on side 711 of the arranged transistors M1 and M2, and inductor L1 included in drive signal output circuit 52b-2 is located on side 712 of the arranged transistors M1 and M2.

[0285] That is, the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-1 are arranged on the surface 723 in the direction from the side 711 to the side 712 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1. The integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-1 are arranged on the surface 723 in the direction from the side 711 to the side 712 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1. The integrated circuit 500, transistors M1, M2, and inductor L1 included in the driving signal output circuit 52a-2 are arranged on the surface 723 along the direction from the edge 711 toward the edge 712 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1. The integrated circuit 500, transistors M1, M2, and inductor L1 included in the driving signal output circuit 52b-2 are arranged on the surface 723 along the direction from the edge 711 toward the edge 712 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1.

[0286] Furthermore, the drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 are located on the surface 723 of the rigid wiring component 710 of the drive circuit substrate 700, and are arranged adjacent to each other in the order of drive signal output circuit 52a-1, drive signal output circuit 52b-1, drive signal output circuit 52a-2, and drive signal output circuit 52b-2 from edge 713 toward edge 714.

[0287] In this case, all electronic components constituting the drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 are provided on the surface 723 of the rigid wiring member 710. In other words, the electronic components constituting the drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 are not provided on the surface 724 of the rigid wiring member 710.

[0288] Furthermore, the drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2 are arranged in a staggered pattern from side 713 toward side 714. Specifically, in the direction from side 711 toward side 712, the drive signal output circuit 52a-1 and the drive signal output circuit 52a-2 are arranged at approximately the same position, the drive signal output circuit 52b-1 and the drive signal output circuit 52b-2 are arranged at approximately the same position, the drive signal output circuit 52a-1 and the drive signal output circuits 52b-1 and 52b-2 are arranged at different positions, and the drive signal output circuit 52a-2 and the drive signal output circuits 52b-1 and 52b-2 are arranged at different positions.

[0289] In detail, the drive signal output circuit 52a-1 is configured to overlap with at least a portion of the drive signal output circuit 52b-1, at least a portion of the drive signal output circuit 52a-2, and at least a portion of the drive signal output circuit 52b-2 when viewed in a direction from edge 713 toward edge 714, and the integrated circuit 500 included in the drive signal output circuit 52a-1 is configured to not overlap with the integrated circuit 500 included in the drive signal output circuit 52b-1 and the integrated circuit 500 included in the drive signal output circuit 52b-2 when viewed in a direction from edge 713 toward edge 714, and to overlap with at least a portion of the integrated circuit 500 included in the drive signal output circuit 52a-2.

[0290] In this case, transistors M1 and M2 included in drive signal output circuit 52a-1 may be arranged so as not to overlap with transistors M1 and M2 included in drive signal output circuit 52b-1 and transistors M1 and M2 included in drive signal output circuit 52b-2, and may overlap with at least a portion of transistors M1 and M2 included in drive signal output circuit 52a-2, when viewed along side 713 toward side 714. Furthermore, inductor L1 included in drive signal output circuit 52a-1 may be arranged so as not to overlap with inductor L1 included in drive signal output circuit 52b-1 and inductor L1 included in drive signal output circuit 52b-2, and may overlap with at least a portion of inductor L1 included in drive signal output circuit 52a-2, when viewed along side 713 toward side 714.

[0291] Similarly, the drive signal output circuit 52b-1 is configured to overlap with at least a portion of the drive signal output circuit 52a-1, at least a portion of the drive signal output circuit 52a-2, and at least a portion of the drive signal output circuit 52b-2 when viewed in a direction from edge 713 toward edge 714, and the integrated circuit 500 included in the drive signal output circuit 52b-1 is configured to not overlap with the integrated circuit 500 included in the drive signal output circuit 52a-1 and the integrated circuit 500 included in the drive signal output circuit 52a-2, and to overlap with at least a portion of the integrated circuit 500 included in the drive signal output circuit 52b-2 when viewed in a direction from edge 713 toward edge 714.

[0292] In this case, transistors M1 and M2 included in drive signal output circuit 52b-1 may be arranged so as not to overlap with transistors M1 and M2 included in drive signal output circuit 52a-1 and transistors M1 and M2 included in drive signal output circuit 52a-2, and to overlap with at least a portion of transistors M1 and M2 included in drive signal output circuit 52b-2, when viewed along side 713 toward side 714. Furthermore, inductor L1 included in drive signal output circuit 52b-1 may be arranged so as not to overlap with inductor L1 included in drive signal output circuit 52a-1 and inductor L1 included in drive signal output circuit 52a-2, and to overlap with at least a portion of inductor L1 included in drive signal output circuit 52b-2, when viewed along side 713 toward side 714.

[0293] Here, the term "being configured to overlap with the drive signal output circuit 52a-1, the drive signal output circuit 52b-1, the drive signal output circuit 52a-2, and at least a portion of the drive signal output circuit 52b-2 when viewed along the direction from the side 713 toward the side 714" means that when viewed along the direction from the side 713 toward the side 714, at least any one of the electronic components included in the drive signal output circuit 52a-1, at least any one of the electronic components included in the drive signal output circuit 52b-1, at least any one of the electronic components included in the drive signal output circuit 52a-2, and the electronic components included in the drive signal output circuit 52b-2 are overlapped. At least any one of the components overlaps, for example, including the following situations, including overlapping with at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-1, at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-1, at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-2, and at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-2 when viewed in the direction from edge 713 toward edge 714.

[0294] Capacitor C7a is located on surface 723 of rigid wiring member 710 on the side 711 of drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2, which are arranged from side 713 to side 714. Capacitor C7a corresponds to capacitor C7 described above for drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2, and reduces the risk of fluctuations in the voltage value of voltage signal VHV supplied to each of drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2, and also reduces the risk of noise being superimposed on voltage signal VHV.

[0295] The ejection control circuit 51 composed of FPGA is located on the side 711 of the driving signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2 arranged from the side 713 to the side 714 on the surface 723 of the rigid wiring component 710, that is, on the side 714 of the capacitor C7a.

[0296] Connector CN2b includes a plurality of terminals TM2b and is located closer to side 711 than capacitor C7a and discharge control circuit 51 provided on surface 723 of rigid wiring member 710. Connector CN2b is located so that the plurality of terminals TM2b are arranged along side 711 of rigid wiring member 710.

[0297] Connector CN3a includes a plurality of terminals TM3a and is located closer to side 712 than capacitor C7a and discharge control circuit 51 provided on surface 723 of rigid wiring member 710. Connector CN3a is located so that the plurality of terminals TM3a are arranged along side 712 of rigid wiring member 710.

[0298] The rigid wiring component 730 includes drive signal output circuits 52a-3, 52b-3, 52a-4, 52b-4, a capacitor C7b, abnormality detection circuits 54a and 54b as the abnormality detection circuit 54, and abnormality notification circuits 55a and 55b as the abnormality notification circuit 55.

[0299] The drive signal output circuit 52a-3 includes the integrated circuit 500, transistors M1 and M2, and an inductor L1, and is provided on the surface 743 of the rigid wiring member 730 of the drive circuit substrate 700. In this case, the transistors M1 and M2 included in the drive signal output circuit 52a-3 are arranged in this order along the direction from the edge 733 toward the edge 734. The integrated circuit 500 included in the drive signal output circuit 52a-3 is located on the side 731 of the arranged transistors M1 and M2, and the inductor L1 included in the drive signal output circuit 52a-3 is located on the side 732 of the arranged transistors M1 and M2.

[0300] The drive signal output circuit 52b-3 includes the integrated circuit 500, transistors M1 and M2, and an inductor L1, and is provided on the side 734 of the drive signal output circuit 52a-3 on the surface 743 of the rigid wiring member 730 of the drive circuit substrate 700. In this case, the transistors M1 and M2 included in the drive signal output circuit 52b-3 are arranged in this order along the direction from the side 733 toward the side 734. The integrated circuit 500 included in the drive signal output circuit 52b-3 is located on the side 731 of the arranged transistors M1 and M2, and the inductor L1 included in the drive signal output circuit 52b-3 is located on the side 732 of the arranged transistors M1 and M2.

[0301] The drive signal output circuit 52a-4 includes the integrated circuit 500, transistors M1 and M2, and an inductor L1, and is provided on the side 734 of the drive signal output circuit 52b-1 on the surface 743 of the rigid wiring member 730 of the drive circuit substrate 700. In this case, the transistors M1 and M2 included in the drive signal output circuit 52a-4 are arranged in this order along the direction from the side 733 to the side 734, the integrated circuit 500 included in the drive signal output circuit 52a-4 is located on the side 731 of the arranged transistors M1 and M2, and the inductor L1 included in the drive signal output circuit 52a-4 is located on the side 732 of the arranged transistors M1 and M2.

[0302] The drive signal output circuit 52b-4 includes the integrated circuit 500, transistors M1 and M2, and an inductor L1, and is provided on the side 734 of the drive signal output circuit 52a-4 on the surface 743 of the rigid wiring member 730 of the drive circuit substrate 700. In this case, the transistors M1 and M2 included in the drive signal output circuit 52b-4 are arranged in this order along the direction from the side 733 toward the side 734. The integrated circuit 500 included in the drive signal output circuit 52b-4 is located on the side 731 of the arranged transistors M1 and M2, and the inductor L1 included in the drive signal output circuit 52b-4 is located on the side 732 of the arranged transistors M1 and M2.

[0303] That is, the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-3 are arranged on the surface 743 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1 along the direction from the side 731 to the side 732, and the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-3 are arranged on the surface 743 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1 along the direction from the side 731 to the side 732. The integrated circuit 500, transistors M1, M2, and inductor L1 included in the driving signal output circuit 52a-4 are arranged on surface 743 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1 along the direction from edge 731 toward edge 732, and the integrated circuit 500, transistors M1, M2, and inductor L1 included in the driving signal output circuit 52b-4 are arranged on surface 743 in the order of the integrated circuit 500, transistors M1, M2, and inductor L1 along the direction from edge 731 toward edge 732.

[0304] Furthermore, the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are located on the surface 743 of the rigid wiring component 730 of the drive circuit substrate 700, and are arranged adjacent to each other in the order of drive signal output circuit 52a-3, drive signal output circuit 52b-3, drive signal output circuit 52a-4, and drive signal output circuit 52b-4 from edge 733 toward edge 734.

[0305] In this case, all electronic components constituting the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are provided on the surface 743 of the rigid wiring member 730. In other words, the electronic components constituting the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are not provided on the surface 744 of the rigid wiring member 730.

[0306] Furthermore, the drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4 are arranged in a staggered pattern from side 733 toward side 734. Specifically, in the direction from side 731 toward side 732, the drive signal output circuit 52a-3 and the drive signal output circuit 52a-4 are arranged at approximately the same position, the drive signal output circuit 52b-3 and the drive signal output circuit 52b-4 are arranged at approximately the same position, the drive signal output circuit 52a-3 and the drive signal output circuits 52b-3 and 52b-4 are arranged at different positions, and the drive signal output circuit 52a-4 and the drive signal output circuits 52b-3 and 52b-4 are arranged at different positions.

[0307] In detail, the drive signal output circuit 52a-3 is configured to overlap with at least a portion of the drive signal output circuit 52b-3, at least a portion of the drive signal output circuit 52a-4, and at least a portion of the drive signal output circuit 52b-4 when viewed in a direction from edge 733 toward edge 734, and the integrated circuit 500 included in the drive signal output circuit 52a-3 is configured to not overlap with the integrated circuit 500 included in the drive signal output circuit 52b-3 and the integrated circuit 500 included in the drive signal output circuit 52b-4 when viewed in a direction from edge 733 toward edge 734, and to overlap with at least a portion of the integrated circuit 500 included in the drive signal output circuit 52a-4.

[0308] In this case, transistors M1 and M2 included in drive signal output circuit 52a-3 may be arranged so as not to overlap with transistors M1 and M2 included in drive signal output circuit 52b-3 and transistors M1 and M2 included in drive signal output circuit 52b-4, and to overlap with at least a portion of transistors M1 and M2 included in drive signal output circuit 52a-4, when viewed along side 733 toward side 734. Furthermore, inductor L1 included in drive signal output circuit 52a-3 may be arranged so as not to overlap with inductor L1 included in drive signal output circuit 52b-3 and inductor L1 included in drive signal output circuit 52b-4, and to overlap with at least a portion of inductor L1 included in drive signal output circuit 52a-4, when viewed along side 733 toward side 734.

[0309] Similarly, the drive signal output circuit 52b-3 is configured to overlap with at least a portion of the drive signal output circuit 52a-3, at least a portion of the drive signal output circuit 52a-4, and at least a portion of the drive signal output circuit 52b-4 when viewed in a direction from edge 733 toward edge 734, and the integrated circuit 500 included in the drive signal output circuit 52b-3 is configured to not overlap with the integrated circuit 500 included in the drive signal output circuit 52a-3 and the integrated circuit 500 included in the drive signal output circuit 52a-4 when viewed in a direction from edge 733 toward edge 734, and to overlap with at least a portion of the integrated circuit 500 included in the drive signal output circuit 52b-4.

[0310] In this case, transistors M1 and M2 included in drive signal output circuit 52b-3 may be arranged so as not to overlap with transistors M1 and M2 included in drive signal output circuit 52a-3 and transistors M1 and M2 included in drive signal output circuit 52a-4, and to overlap with at least a portion of transistors M1 and M2 included in drive signal output circuit 52b-4, when viewed along side 733 toward side 734. Furthermore, inductor L1 included in drive signal output circuit 52b-3 may be arranged so as not to overlap with inductor L1 included in drive signal output circuit 52a-3 and inductor L1 included in drive signal output circuit 52a-4, and to overlap with at least a portion of inductor L1 included in drive signal output circuit 52b-2, when viewed along side 733 toward side 734.

[0311] Here, the term "being configured to overlap with the drive signal output circuit 52a-3, the drive signal output circuit 52b-3, the drive signal output circuit 52a-4, and at least a portion of the drive signal output circuit 52b-4 when viewed along the direction from the edge 733 toward the edge 734" means that when viewed along the direction from the edge 733 toward the edge 734, at least any one of the electronic components included in the drive signal output circuit 52a-3, at least any one of the electronic components included in the drive signal output circuit 52b-3, at least any one of the electronic components included in the drive signal output circuit 52a-4, and the electronic components included in the drive signal output circuit 52b-4 are overlapped. At least any one of the components overlaps, for example, including the following situations, including overlapping with the integrated circuit 500, transistors M1, M2, inductor L1 included in the drive signal output circuit 52a-3, at least any one of the integrated circuit 500, transistors M1, M2, inductor L1 included in the drive signal output circuit 52b-3, at least any one of the integrated circuit 500, transistors M1, M2, inductor L1 included in the drive signal output circuit 52a-4, and at least any one of the integrated circuit 500, transistors M1, M2, inductor L1 included in the drive signal output circuit 52b-4 when viewed in the direction along edge 733 toward edge 734.

[0312] Capacitor C7b is located on surface 743 of rigid wiring member 730 on the side 731 of drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, which are arranged from side 733 to side 734. Capacitor C7b corresponds to capacitor C7 described above, corresponding to drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, and reduces the risk of fluctuations in the voltage value of voltage signal VHV supplied to each of drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, and also reduces the risk of noise being superimposed on voltage signal VHV.

[0313] Abnormality detection circuits 54a and 54b are located on surface 743 of rigid wiring member 730, on the side of side 731 of drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, which are arranged from side 733 to side 734. That is, on the side of capacitor C7b with respect to side 734. Abnormality detection circuit 54a detects whether the voltage value of voltage signal VHV is normal, while abnormality detection circuit 54b detects whether the voltage value of voltage signal VDD generated based on voltage signal VMV is normal.

[0314] Abnormality notification circuits 55a and 55b are located on surface 744 of rigid wiring member 730, on the side of edge 731 of drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, which are arranged from edge 733 to edge 734. In other words, they are located near abnormality detection circuits 54a and 54b. Abnormality notification circuit 55a illuminates, extinguishes, or flashes based on the results of abnormality detection circuit 54a detecting an abnormality. Abnormality notification circuit 55b illuminates, extinguishes, or flashes based on the results of abnormality detection circuit 54b detecting an abnormality.

[0315] The rigid wiring member 750 is provided with a temperature detection circuit 56 and a voltage conversion circuit 58 .

[0316] The temperature detection circuit 56 is located approximately in the center of the rigid wiring member 750 on the surface 763 of the rigid wiring member 750. Specifically, the temperature detection circuit 56 is positioned so that at least a portion of it overlaps with the intersection of two virtual lines: a virtual line whose distance from edge 751 is equal to that from edge 752, and a virtual line whose distance from edge 753 is equal to that from edge 754. The temperature detection circuit 56 detects the ambient temperature of the drive circuit module 50, generates a temperature information signal Tt containing temperature information corresponding to the ambient temperature, and outputs it to the head control circuit 12. Such a temperature detection circuit 56 needs to comprehensively detect temperature information from multiple circuits provided on the drive circuit substrate 700.

[0317] In the liquid ejection device 1 of this embodiment, the temperature detection circuit 56 is provided in a rigid wiring member 750 that is separate from the rigid wiring members 710 and 730 on which the drive signal output circuit 52, which generates a relatively large amount of heat, is provided. Furthermore, the temperature detection circuit 56 is located approximately in the center of the rigid wiring member 750. This reduces the contribution of the drive signal output circuit 52, which generates a relatively large amount of heat, and as a result, improves the accuracy of obtaining the ambient temperature of the entire drive circuit module 50.

[0318] Voltage conversion circuit 58 is located on surface 763 of rigid wiring member 750, on the side 751 of temperature detection circuit 56. Voltage conversion circuit 58 converts the voltage value of voltage signal VMV to generate and output voltage signal VDD. Voltage signal VDD is used in various components provided on driver circuit board 700. Since its voltage value is smaller than voltage signals VHV and VMV, it is susceptible to noise. By setting the voltage conversion circuit 58 that outputs such a voltage signal VDD in a rigid wiring component 750 located between the rigid wiring component 710 on which a plurality of circuits including drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2 are provided, and the rigid wiring component 730 on which a plurality of circuits including drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4 are provided, the wiring length for transmitting the voltage signal VDD can be shortened. As a result, the risk of the voltage signal VDD causing a voltage value fluctuation is reduced, and the risk of noise being superimposed on the voltage signal VDD is also reduced.

[0319] The rigid wiring member 770 is provided with the capacitor 53 , the connector CN3 b , and the connector CN1 a .

[0320] The connector CN3 b includes a plurality of terminals TM3 b and is located on the surface 783 of the rigid wiring member 770 such that the plurality of terminals TM3 b are arranged side by side along the side 772 .

[0321] The capacitor 53 is located at the surface 783 of the rigid wiring member 770. The capacitor 53 stabilizes the voltage value of the reference voltage signal VBS outputted from the drive signal output circuit 52a-1.

[0322] The connector CN1a is located on the surface 784 of the rigid wiring member 770. The connector CN1a is mated with the connector CN1b of the print head 30, so that various signals generated in the driving circuit board 700 are supplied to the print head 30.

[0323] As described above, on the surface 723 of the rigid wiring component 710 of the driving circuit substrate 700, that is, on the surface 723 of the rigid component 721, there are provided the driving signal output circuits 52a-1, 52b-1, 52a-2, 52b-2, the ejection control circuit 51 composed of the FPGA, the capacitor C7a, and the connectors CN2b and CN3a. On the surface 743 of the rigid wiring component 730, that is, on the surface 743 of the rigid component 741, there are provided the driving signal output circuits 52a-3, 52b-3, 52a-4, 52b-4, the capacitor C7b, and the abnormality detection circuit 51. The detection circuits 54a and 54b are provided on the surface 744 of the rigid wiring component 730, that is, the surface 744 of the rigid component 742, and the abnormality notification circuits 55a and 55b are provided. The temperature detection circuit 56 and the voltage conversion circuit 58 are provided on the surface 763 of the rigid wiring component 750, that is, the surface 763 of the rigid component 761. The capacitor 53 and the connector CN3b are provided on the surface 783 of the rigid wiring component 770, that is, the surface 783 of the rigid component 781. The connector CN1a is provided on the surface 784 of the rigid wiring component 770, that is, the surface 784 of the rigid component 782.

[0324] Here, an example of a wiring pattern formed on the driving circuit substrate 700 constructed in the above manner is described, that is, an example of a wiring pattern for transmitting voltage signals VHV, VMV, and VDD that function as power supply voltages for various circuits provided on the driving circuit substrate 700, and an example of a wiring pattern for transmitting driving signals COMA1 to COMA4, COMB1 to COMB4, and a reference voltage signal VBS generated in the driving circuit substrate 700 is described.

[0325] Figure 21 This diagram shows an example of a wiring pattern for transmitting voltage signals VHV, VMV, and VDD. As previously described, the voltage signals VHV and VMV transmitted within the driver circuit board 700 are output by the power supply voltage output circuit 18 included in the control unit 2. Furthermore, the voltage signals VHV and VMV are input to the driver circuit board 700 via the connector CN2b.

[0326] The voltage signal VHV input via the connector CN2b is transmitted through the wirings wh1 to wh5 of the flexible wiring component 790 provided on the driving circuit substrate 700, the wiring wh6 provided on the rigid wiring component 710, and the wiring wh7 provided on the rigid wiring component 730, and is input to the various structures provided on the driving circuit substrate 700 and the driving signal selection circuit 200 possessed by the print head 30.

[0327] The wiring wh1 has one end electrically connected to the terminal TM2b of the connector CN2b and extends along the x1 axis toward the −x1 side, and the other end electrically connected to the wiring wh2.

[0328] Wiring wh2 is provided continuously across regions 701, 702, 703, 704, and 705. Specifically, the flexible wiring component 790 includes wiring wh2 for transmitting the voltage signal VHV supplied to the drive signal selection circuit 200 and the drive signal output circuit 52. Wiring wh2 is provided continuously across regions 701, 702, 703, 704, and 705. In this case, wiring wh2 is preferably provided in a straight line along the y1 axis across regions 701, 702, 703, 704, and 705. Furthermore, after transmitting through wiring wh2, the voltage signal VHV is branched in each of regions 701, 703, and 705 and supplied to various circuits provided in the rigid wiring components 710, 730, and 750 via through-holes (not shown).

[0329] For example, the wiring wh2 branches off into the wiring wh3 in the region 701. The wiring wh3 is supplied to the capacitor C7a provided in the rigid wiring member 710 via a through-hole (not shown). Furthermore, the voltage signal VHV supplied to the capacitor C7a is transmitted through the wiring wh6 provided in the rigid wiring member 710 and supplied to each of the drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2.

[0330] Furthermore, for example, the wiring wh2 branches off into the wiring wh4 in the region 705. The wiring wh4 is supplied to the capacitor C7b provided in the rigid wiring member 730 via a through-hole (not shown). The voltage signal VHV supplied to the capacitor C7b is transmitted through the wiring wh7 provided in the rigid wiring member 730 and supplied to each of the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4.

[0331] For example, wiring wh2 branches into wiring wh5 in region 705. Wiring wh5 travels through regions 706 and 707 and is supplied via a through-hole (not shown) to terminal TM1a of connector CN1a provided on rigid wiring member 770. This supplies voltage signal VHV to drive signal selection circuit 200 included in print head 30.

[0332] As described above, voltage signal VHV is input to driver circuit substrate 700 via wiring wh1 and propagated through wiring wh2, thereby being supplied to various circuit structures of driver circuit substrate 700 and print head 30. Therefore, a large amount of current is generated in wiring wh2 due to the transmission of voltage signal VHV, which is supplied to various circuit structures of driver circuit substrate 700 and print head 30. By providing such wiring wh2 in a continuous manner across regions 701, 702, 703, 704, and 705 in flexible wiring member 790, the need for through-hole wiring and the like is eliminated, thereby reducing the risk of impedance fluctuations in wiring wh2. As a result, the risk of voltage signal VHV transmitted through wiring wh2 is reduced, and the operational stability of various circuits that operate using voltage signal VHV as a power supply voltage is improved.

[0333] Furthermore, by providing a straight line across regions 701, 702, 703, 704, and 705, the risk of current density fluctuations occurring in the curved portions of wiring wh2 is reduced. As a result, the risk of voltage signal VHV transmitted through wiring wh2 fluctuating is further reduced, further improving the operational stability of various circuits operating using voltage signal VHV as a power supply voltage. It should be noted that wiring wh2 may also be electrically connected to multiple branch wirings in addition to wirings wh3, wh4, and wh5.

[0334] Furthermore, the voltage signal VMV inputted via the connector CN2 b is transmitted through the wirings wm1 to wm3 of the flexible wiring member 790 provided on the driving circuit substrate 700 , and is inputted to various components provided on the driving circuit substrate 700 .

[0335] The wiring wm1 has one end electrically connected to the terminal TM2b of the connector CN2b and extends along the x1 axis toward the −x1 side, and the other end electrically connected to the wiring wm2.

[0336] Wiring wm2 is provided continuously across regions 701, 702, 703, 704, and 705. Preferably, wiring wm2 is provided linearly along the y1 axis across regions 701, 702, 703, 704, and 705. Furthermore, after voltage signal VMV is transmitted through wiring wm2, it is branched in each of regions 701, 703, and 705 and supplied to various circuits provided in rigid wiring members 710, 730, and 750 via through-holes (not shown).

[0337] For example, the wiring wm2 branches to the wiring wm3 in the region 703. The wiring wm3 is provided to the voltage conversion circuit 58 via a via (not shown). The voltage conversion circuit 58 generates and outputs the voltage signal VDD based on the supplied voltage signal VMV.

[0338] As described above, voltage signal VMV is input to driver circuit substrate 700 via wiring wm1, propagates through wiring wm2, and is supplied to various circuit structures on driver circuit substrate 700. Therefore, a large amount of current is generated in wiring wm2 due to the propagation of voltage signal VMV supplied to various circuit structures on driver circuit substrate 700. By providing this wiring wm2 continuously across regions 701, 702, 703, 704, and 705 in flexible wiring member 790, the need for vias and other wiring is eliminated, thereby reducing the risk of impedance fluctuations in wiring wm2. As a result, the risk of voltage signal VMV fluctuations transmitted through wiring wm2 is reduced, and the operational stability of various circuits that operate using voltage signal VMV as a power supply voltage is improved.

[0339] Furthermore, by providing a straight line across regions 701, 702, 703, 704, and 705, the risk of current density fluctuations occurring at the curved portions of wiring wm2 is reduced. Consequently, the risk of voltage signal VMV transmitted through wiring wm2 fluctuating is further reduced, further improving the operational stability of various circuits operating using voltage signal VMV as a power supply voltage.

[0340] Furthermore, the voltage signal VDD outputted from the voltage conversion circuit 58 is transmitted through the wirings wd1 and wd2 of the flexible wiring member 790 provided on the driving circuit substrate 700 , and is inputted to various components provided on the driving circuit substrate 700 .

[0341] The wiring wd1 has one end electrically connected to the voltage conversion circuit 58 and extends along the x1 axis toward the +x1 side, and the other end electrically connected to the wiring wd2 .

[0342] Wiring wd2 is provided continuously across regions 701, 702, 703, 704, and 705. Preferably, wiring wd2 is provided linearly along the y1 axis across regions 701, 702, 703, 704, and 705. Furthermore, after voltage signal VDD is transmitted through wiring wd2, it is branched in each of regions 701, 703, and 705 and supplied to various circuits provided in rigid wiring members 710, 730, and 750 via through-holes (not shown).

[0343] For example, the wiring wd2 branches to the wiring wd3 in the region 701. The wiring wd3 is supplied to the FPGA including the discharge control circuit 51 via a through hole (not shown). The discharge control circuit 51 operates based on the supplied voltage signal VDD.

[0344] As described above, voltage signal VDD is input to driver circuit substrate 700 via wiring wd1, propagates through wiring wd2, and is supplied to various circuit structures on driver circuit substrate 700. Therefore, a large amount of current flows in wiring wd2 due to the propagation of voltage signal VDD, which is supplied to various circuit structures on driver circuit substrate 700. By providing this wiring wd2 continuously across regions 701, 702, 703, 704, and 705 in flexible wiring member 790, the need for vias and other wiring is eliminated, thereby reducing the risk of impedance fluctuations in wiring wd2. As a result, the risk of voltage signal VDD transmitted through wiring wd2 is reduced, and the operational stability of various circuits that operate using voltage signal VDD as a power supply voltage is improved.

[0345] Furthermore, by providing a straight line across regions 701, 702, 703, 704, and 705, the risk of current density fluctuations occurring at the curved portion of wiring wd2 is reduced. Consequently, the risk of voltage signal VDD transmitted through wiring wd2 fluctuating is further reduced, further improving the operational stability of various circuits operating using voltage signal VDD as a power supply voltage.

[0346] Next, an example of a wiring pattern for transmitting the driving signals COMA1 to COMA4 and COMB1 to COMB4 and the reference voltage signal VBS generated in the driving circuit substrate 700 will be described. Figure 22 1 is a diagram showing an example of a wiring pattern for transmitting the driving signal COM and the reference voltage signal VBS.

[0347] Drive signal COMA1 output by drive signal output circuit 52a-1 propagates through wiring wca1 and is input to terminal TM1a of connector CN1a. Drive signal COMB1 output by drive signal output circuit 52b-1 propagates through wiring wcb1 and is input to terminal TM1a of connector CN1a. Drive signal COMA1 and drive signal COMB1 are then input to drive signal selection circuit 200 included in discharge module 32-1 via corresponding terminals TM1a of connector CN1a.

[0348] Similarly, the drive signal COMA2 output by the drive signal output circuit 52a-2 is transmitted through the wiring wca2 and input to the drive signal selection circuit 200 of the ejection module 32-2 via the terminal TM1a of the connector CN1a. The drive signal COMB2 output by the drive signal output circuit 52b-2 is transmitted through the wiring wcb2 and input to the drive signal selection circuit 200 of the ejection module 32-2 via the terminal TM1a of the connector CN1a. Similarly, the drive signal COMA3 output by the drive signal output circuit 52a-3 is transmitted through the wiring wca3 and input to the drive signal selection circuit 200 of the ejection module 32-3 via the terminal TM1a of the connector CN1a. The drive signal COMB3 output by the drive signal output circuit 52b-3 is transmitted through the wiring wcb3 and input to the drive signal selection circuit 200 of the ejection module 32-3 via the terminal TM1a of the connector CN1a. Similarly, the drive signal COMA4 output by the drive signal output circuit 52a-4 is transmitted in the wiring wca4 and is input into the drive signal selection circuit 200 of the ejection module 32-4 via the terminal TM1a of the connector CN1a. The drive signal COMB4 output by the drive signal output circuit 52b-4 is transmitted in the wiring wcb4 and is input into the drive signal selection circuit 200 of the ejection module 32-4 via the terminal TM1a of the connector CN1a.

[0349] The reference voltage signal VBS output by the reference voltage signal output circuit 530 included in the integrated circuit 500 of the drive signal output circuit 52a-1 is transmitted through the wiring wb1 and input to the wiring wb2 electrically connected to the capacitor 53. After being input to the capacitor 53, the reference voltage signal VBS is transmitted through the wiring wb4 and the wiring wb6, and is supplied to the electrode 612 of the piezoelectric element 60 included in the discharge module 32-1 via the terminal TM1a of the connector CN1a. Furthermore, the reference voltage signal VBS input to the capacitor 53 is transmitted through the wiring wb4 and the wiring wb5, and is supplied to the electrode 612 of the piezoelectric element 60 included in the discharge module 32-2 via the terminal TM1a of the connector CN1a. Furthermore, the reference voltage signal VBS input to the capacitor 53 is transmitted through the wiring wb3 and the wiring wb7, and is supplied to the electrode 612 of the piezoelectric element 60 included in the discharge module 32-3 via the terminal TM1a of the connector CN1a. Furthermore, after being input to capacitor 53, reference voltage signal VBS is transmitted through wiring wb3 and wiring wb8, and supplied to electrode 612 of piezoelectric element 60 included in ejection module 32-4 via terminal TM1a of connector CN1a. Specifically, after being input to capacitor 53, reference voltage signal VBS is branched and supplied to electrode 612 of piezoelectric element 60 included in each of ejection modules 32-1 to 32-4.

[0350] At this time, the wiring wb6 for transmitting the reference voltage signal VBS supplied to the ejection module 32-1 is located between a portion of the wiring wca1 for transmitting the drive signal COMA1 supplied to the ejection module 32-1 and a portion of the wiring wcb1 for transmitting the drive signal COMB1 supplied to the ejection module 32-1; the wiring wg for transmitting the ground signal is located between a different portion of the wiring wca1 for transmitting the drive signal COMA1 supplied to the ejection module 32-1 and a different portion of the wiring wcb1 for transmitting the drive signal COMB1 supplied to the ejection module 32-1.

[0351] Similarly, the wiring wb5 for transmitting the reference voltage signal VBS supplied to the ejection module 32-2 is located between a portion of the wiring wca2 for transmitting the drive signal COMA2 supplied to the ejection module 32-2 and a portion of the wiring wcb2 for transmitting the drive signal COMB2 supplied to the ejection module 32-2; the wiring wg for transmitting the ground signal is located between a different portion of the wiring wca2 for transmitting the drive signal COMA2 supplied to the ejection module 32-2 and a different portion of the wiring wcb2 for transmitting the drive signal COMB2 supplied to the ejection module 32-2.

[0352] Similarly, the wiring wb7 for transmitting the reference voltage signal VBS supplied to the ejection module 32-3 is located between a portion of the wiring wca3 for transmitting the drive signal COMA3 supplied to the ejection module 32-3 and a portion of the wiring wcb3 for transmitting the drive signal COMB3 supplied to the ejection module 32-3; the wiring wg for transmitting the ground signal is located between a different portion of the wiring wca3 for transmitting the drive signal COMA3 supplied to the ejection module 32-3 and a different portion of the wiring wcb3 for transmitting the drive signal COMB3 supplied to the ejection module 32-3.

[0353] Similarly, the wiring wb8 for transmitting the reference voltage signal VBS supplied to the ejection module 32-4 is located between a portion of the wiring wca4 for transmitting the drive signal COMA4 supplied to the ejection module 32-4 and a portion of the wiring wcb4 for transmitting the drive signal COMB4 supplied to the ejection module 32-4; ​​the wiring wg for transmitting the ground signal is located between a different portion of the wiring wca4 for transmitting the drive signal COMA4 supplied to the ejection module 32-4 and a different portion of the wiring wcb4 for transmitting the drive signal COMB4 supplied to the ejection module 32-4.

[0354] That is, the drive circuit substrate 700 includes wiring wca1, wiring wcb1, wiring wca2, wiring wcb2, wiring wca3, wiring wcb3, wiring wca4, wiring wcb4, wiring wb1, wiring wb6, wiring wb5, wiring wb7, wiring wb8, and wiring wg. Among them, the wiring wca1 electrically connects the drive signal output circuit 52a-1 to the terminal TM1a of the connector CN1a; the wiring wcb1 electrically connects the drive signal output circuit 52b-1 to the terminal TM1a of the connector CN1a; the wiring wc Wiring a2 electrically connects the drive signal output circuit 52a-2 to the terminal TM1a of the connector CN1a; wiring wcb2 electrically connects the drive signal output circuit 52b-2 to the terminal TM1a of the connector CN1a; wiring wca3 electrically connects the drive signal output circuit 52a-3 to the terminal TM1a of the connector CN1a; wiring wcb3 electrically connects the drive signal output circuit 52b-3 to the terminal TM1a of the connector CN1a; wiring wca4 electrically connects the drive signal output circuit 52a-4 to the terminal TM1a of the connector CN1a Wiring wcb4 electrically connects the drive signal output circuit 52b-4 to the terminal TM1a of the connector CN1a; wiring wb1 electrically connects the reference voltage signal output circuit 530 to the capacitor 53; wiring wb6 electrically connects the capacitor 53 to the connector CN3a and branches off from wiring wb1 to transmit the reference voltage signal VBS supplied to the electrode 612 of the piezoelectric element 60 of the ejection module 32-1; wiring wb5 electrically connects the capacitor 53 to the connector CN3a and branches off from wiring wb1 to transmit the reference voltage signal VBS supplied to the ejection module 32-1. -2; wiring wb7 electrically connects the capacitor 53 with the connector CN3a, and branches from the wiring wb1 to transmit the reference voltage signal VBS supplied to the electrode 612 of the piezoelectric element 60 possessed by the ejection module 32-3; wiring wb8 electrically connects the capacitor 53 with the connector CN3a, and branches from the wiring wb1 to transmit the reference voltage signal VBS supplied to the electrode 612 of the piezoelectric element 60 possessed by the ejection module 32-4; ​​wiring wg transmits the ground signal.

[0355] Furthermore, for the wiring wca1, a portion is set to be adjacent to the wiring wb6, and a different portion is set to be adjacent to the wiring wg; for the wiring wcb1, a portion is set to be adjacent to the wiring wb6, and a different portion is set to be adjacent to the wiring wg; for the wiring wca2, a portion is set to be adjacent to the wiring wb5, and a different portion is set to be adjacent to the wiring wg; for the wiring wcb2, a portion is set to be adjacent to the wiring wb5, and a different portion is set to be adjacent to the wiring wg; for the wiring wca3, a portion is set to be adjacent to the wiring wb7, and a different portion is set to be adjacent to the wiring wg; for the wiring wcb3, a portion is set to be adjacent to the wiring wb7, and a different portion is set to be the same as the wiring wg; for the wiring wca4, a portion is set to be adjacent to the wiring wb8, and a different portion is set to be adjacent to the wiring wg; for the wiring wcb4, a portion is set to be adjacent to the wiring wb8, and a different portion is set to be adjacent to the wiring wg.

[0356] With the above configuration, the current generated by the drive signals COMA1 and COMB1 supplied to the discharge module 32-1 is fed back via the wiring wb6 that supplies the reference voltage signal VBS to the discharge module 32-1. Therefore, the magnetic field generated by the current generated by the drive signals COMA1 and COMB1 supplied to the discharge module 32-1 is offset by the magnetic field generated by the current fed back via the wiring wb6 that supplies the reference voltage signal VBS to the discharge module 32-1. As a result, the waveform accuracy of the drive signals COMA1 and COMB1 supplied to the discharge module 32-1 is improved. Furthermore, with respect to the wirings wca1 and wcb1 that transmit the drive signals COMA1 and COMB1 to the ejection module 32-1, the wiring wg that transmits the ground signal is set to be adjacent to the wirings wca1 and wcb1 that transmit the drive signals COMA1 and COMB1 to the ejection module 32-1, within a section that is not adjacent to the wiring wb6 that supplies the reference voltage signal VBS to the ejection module 32-1. This reduces the risk of noise overlap in the drive signals COMA1 and COMB1 supplied to the ejection module 32-1, and further improves the waveform accuracy of the drive signals COMA1 and COMB1.

[0357] Similarly, the magnetic field generated by the current generated when the drive signals COMA2 and COMB2 are supplied to the ejection module 32-2 is offset by the magnetic field generated by the current fed back through the wiring wb5 that supplies the reference voltage signal VBS to the ejection module 32-2. Therefore, the waveform accuracy of the drive signals COMA2 and COMB2 supplied to the ejection module 32-2 is improved, and for the wirings wca2 and wcb2 that transmit the drive signals COMA2 and COMB2, in the interval that is not adjacent to the wiring wb5, the wiring wg is set to be adjacent to the wirings wca2 and wcb2, thereby reducing the risk of noise overlap in the drive signals COMA2 and COMB2, and further improving the waveform accuracy of the drive signals COMA2 and COMB2.

[0358] Similarly, the magnetic field generated by the current generated when the drive signals COMA3 and COMB3 are supplied to the ejection module 32-3 is offset by the magnetic field generated by the current fed back through the wiring wb7 that supplies the reference voltage signal VBS to the ejection module 32-3. Therefore, the waveform accuracy of the drive signals COMA3 and COMB3 supplied to the ejection module 32-3 is improved, and for the wirings wca3 and wcb3 that transmit the drive signals COMA3 and COMB3, in the interval that is not adjacent to the wiring wb7, the wiring wg is set to be adjacent to the wirings wca3 and wcb3, thereby reducing the risk of noise overlap in the drive signals COMA3 and COMB3, and further improving the waveform accuracy of the drive signals COMA3 and COMB3.

[0359] Similarly, the magnetic field generated by the current generated when the drive signals COMA4 and COMB4 are supplied to the ejection module 32-4 is offset by the magnetic field generated by the current fed back through the wiring wb8 that supplies the reference voltage signal VBS to the ejection module 32-4. Therefore, the waveform accuracy of the drive signals COMA4 and COMB4 supplied to the ejection module 32-4 is improved, and for the wirings wca4 and wcb4 that transmit the drive signals COMA4 and COMB4, in the interval that is not adjacent to the wiring wb8, the wiring wg is set to be adjacent to the wirings wca4 and wcb4, thereby reducing the risk of noise overlap in the drive signals COMA4 and COMB4, and further improving the waveform accuracy of the drive signals COMA4 and COMB4.

[0360] Next, the arrangement of components of the driver circuit board 700 in an assembled state on which various circuits are provided will be described. Figure 23 1 is a diagram showing an example of component arrangement when the drive circuit substrate 700 in an assembled state is viewed from the +x2 side along the x2 axis. Figure 24 1 is a diagram showing an example of component arrangement when the drive circuit board 700 in an assembled state is viewed from the −y2 side along the y2 axis.

[0361] As described above, in the assembled driving circuit substrate 700, the surface 723 of the rigid wiring member 710 on which the driving signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 are provided and the surface 743 of the rigid wiring member 730 on which the driving signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are provided are located opposite each other in the direction along the x2 axis. Figure 23 As shown, they are configured so that, when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, the drive signal output circuit 52a-1 provided on the surface 723 of the rigid wiring component 710 and the drive signal output circuit 52b-4 provided on the surface 743 of the rigid wiring component 730 at least partially overlap, and the integrated circuit 500 included in the drive signal output circuit 52a-1 and the integrated circuit 500 included in the drive signal output circuit 52b-4 do not overlap.

[0362] In this case, the transistors M1 and M2 included in the drive signal output circuit 52a-1 may be arranged so as not to overlap with the transistors M1 and M2 included in the drive signal output circuit 52b-4 when viewed in the direction along the x2 axis. Furthermore, the inductor L1 included in the drive signal output circuit 52a-1 may be arranged so as not to overlap with the inductor L1 included in the drive signal output circuit 52b-4 when viewed in the direction along the x2 axis.

[0363] Here, the so-called drive signal output circuit 52a-1 and the drive signal output circuit 52b-4 are configured to overlap at least partially when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, which means that when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, at least any one of the electronic components included in the drive signal output circuit 52a-1 overlaps with at least any one of the electronic components included in the drive signal output circuit 52b-4, for example, including the following situations: at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-1 overlaps with at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-4.

[0364] Similarly, the drive signal output circuit 52b-1 provided on the surface 723 of the rigid wiring component 710 and the drive signal output circuit 52a-4 provided on the surface 743 of the rigid wiring component 730 are configured so as to at least partially overlap when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, and the integrated circuit 500 included in the drive signal output circuit 52b-1 and the integrated circuit 500 included in the drive signal output circuit 52a-4 are configured so as not to overlap.

[0365] In this case, the transistors M1 and M2 included in the drive signal output circuit 52b-1 may be arranged so as not to overlap with the transistors M1 and M2 included in the drive signal output circuit 52a-4 when viewed in the direction along the x2 axis. Furthermore, the inductor L1 included in the drive signal output circuit 52b-1 may be arranged so as not to overlap with the inductor L1 included in the drive signal output circuit 52a-4 when viewed in the direction along the x2 axis.

[0366] Here, the so-called drive signal output circuit 52b-1 and the drive signal output circuit 52a-4 are configured to overlap at least partially when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, which means that when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, at least any one of the electronic components included in the drive signal output circuit 52b-1 overlaps with at least any one of the electronic components included in the drive signal output circuit 52a-4, for example, including the following situations: at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-1 overlaps with at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-4.

[0367] Similarly, the drive signal output circuit 52a-2 provided on the surface 723 of the rigid wiring component 710 and the drive signal output circuit 52b-3 provided on the surface 743 of the rigid wiring component 730 are configured so as to at least partially overlap when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, and the integrated circuit 500 included in the drive signal output circuit 52a-2 and the integrated circuit 500 included in the drive signal output circuit 52b-3 are configured so as not to overlap.

[0368] In this case, the transistors M1 and M2 included in the drive signal output circuit 52a-2 may be arranged so as not to overlap with the transistors M1 and M2 included in the drive signal output circuit 52b-3 when viewed in the direction along the x2 axis. Furthermore, the inductor L1 included in the drive signal output circuit 52a-2 may be arranged so as not to overlap with the inductor L1 included in the drive signal output circuit 52b-3 when viewed in the direction along the x2 axis.

[0369] Here, the so-called drive signal output circuit 52a-2 and the drive signal output circuit 52b-3 are configured to overlap at least partially when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, which means that when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, at least any one of the electronic components included in the drive signal output circuit 52a-2 overlaps with at least any one of the electronic components included in the drive signal output circuit 52b-3, for example, including the following situations: at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-2 overlaps with at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-3.

[0370] Similarly, the drive signal output circuit 52b-2 provided on the surface 723 of the rigid wiring component 710 and the drive signal output circuit 52a-3 provided on the surface 743 of the rigid wiring component 730 are configured so as to at least partially overlap when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, and the integrated circuit 500 included in the drive signal output circuit 52b-2 and the integrated circuit 500 included in the drive signal output circuit 52a-3 are configured so as not to overlap.

[0371] In this case, the transistors M1 and M2 included in the drive signal output circuit 52b-2 may be arranged so as not to overlap with the transistors M1 and M2 included in the drive signal output circuit 52a-3 when viewed in the direction along the x2 axis. Furthermore, the inductor L1 included in the drive signal output circuit 52b-2 may be arranged so as not to overlap with the inductor L1 included in the drive signal output circuit 52a-3 when viewed in the direction along the x2 axis.

[0372] Here, the so-called drive signal output circuit 52b-2 and the drive signal output circuit 52a-3 are configured to overlap at least partially when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, which means that when the drive circuit substrate 700 in the assembled state is observed along the x2 axis, at least any one of the electronic components included in the drive signal output circuit 52b-2 overlaps with at least any one of the electronic components included in the drive signal output circuit 52a-3, for example, including the following situations: at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52b-2 overlaps with at least any one of the integrated circuit 500, transistors M1, M2, and inductor L1 included in the drive signal output circuit 52a-3.

[0373] In addition, if Figure 23 As shown, in the assembled drive circuit substrate 700, connector CN3a provided on the rigid wiring component 710 and connector CN3b provided on the rigid wiring component 770 engage, thereby securing the rigid wiring component 710 to the rigid wiring component 770. Thus, the assembled state of the roughly box-shaped drive circuit substrate 700 is maintained by connector CN3a and connector CN3b. Specifically, the drive circuit substrate 700 includes connector CN3a provided on the rigid wiring component 710 and connector CN3b provided on the rigid wiring component 770. Connectors CN3a and CN3b engage, securing the rigid wiring component 710 to the rigid wiring component 770, thereby maintaining the assembled state of the drive circuit substrate 700. In other words, connector CN3, including connector CN3a and connector CN3b, functions as a retaining member for maintaining the assembled state of the drive circuit substrate 700.

[0374] Therefore, for the driving circuit substrate 700, there is no need to set up a frame for maintaining the assembly state in a roughly box shape. Therefore, the mounting area of ​​the driving circuit substrate 700 in the liquid ejecting device 1 can be further reduced, and a further dense configuration of the driving circuit substrate 700 and further miniaturization of the liquid ejecting device 1 can be achieved.

[0375] Furthermore, connector CN3a and connector CN3b are mated together, forming connector CN3, a B2B connector that electrically connects rigid wiring component 710 and rigid wiring component 770. Specifically, rigid wiring component 710 and rigid wiring component 770 are electrically connected via connector CN3a and connector CN3b. This allows signals generated in the circuit provided in rigid wiring component 710 to be supplied to rigid wiring component 770 via connector CN3a and connector CN3b, without passing through rigid wiring components 730 and 750. This shortens the transmission path for signals generated in the circuit provided in rigid wiring component 710 to rigid wiring component 770, reducing the risk of noise superimposition on the signals, resulting in improved signal accuracy.

[0376] At this time, the signals transmitted via connectors CN3a and CN3b are preferably the clock signal SCK and the differential print data signal Dpt output by the ejection control circuit 51 formed by the FPGA, which are part of the signals generated in the rigid wiring member 710. In other words, the clock signal SCK and the differential print data signal Dpt are preferably transmitted to the print head 30 via connectors CN3a and CN3b.

[0377] The clock signal SCK and differential print data signal Dpt output by the ejection control circuit 51, which is implemented using an FPGA, are susceptible to low-voltage signals, namely noise. Furthermore, since these signals control the operation of the print head 30, any superposition of noise can directly affect the accuracy of ink ejection from the print head 30. Transmitting these signals via connectors CN3a and CN3b improves the accuracy of the clock signal SCK and differential print data signal Dpt input to the print head 30, thereby enhancing ink ejection accuracy.

[0378] 2.2.3.3 Structure of relay substrate

[0379] Next, the structure of the relay substrate 150 included in the driving circuit module 50 will be described. Figure 25 is a plan view showing an example of the structure of the relay substrate 150. Figure 26 1 is a side view showing an example of the structure of the relay substrate 150. Figure 25 as well as Figure 26 As shown, interconnect substrate 150 includes surface 151, surface 152 opposite to surface 151, and edges 153, 154, 155, and 156. Furthermore, in interconnect substrate 150, edge 153 and edge 154 are located opposite each other, edge 155 and edge 156 are located opposite each other, edge 153 is located at a position intersecting both edge 155 and edge 156, and edge 154 is located at a position intersecting both edge 155 and edge 156.

[0380] On surface 151 of relay substrate 150, the other end of FFC cable 21 is electrically connected to the other end of FFC cable 22. FFC cable 21 transmits voltage signal VHV and voltage signal VMV supplied to driver circuit substrate 700, while FFC cable 22 transmits clock signal SCK, differential print data signal Dp, and differential drive data signal Dd supplied to driver circuit substrate 700. Specifically, FFC cable 21 includes multiple signal traces, including traces for transmitting voltage signal VHV and voltage signal VMV; and FFC cable 22 includes multiple signal traces, including traces for transmitting clock signal SCK, differential print data signal Dp, and differential drive data signal Dd. FFC cables 21 and 22 may be electrically connected to relay substrate 150 via an FFC connector (not shown) or by solder or the like.

[0381] Connector CN2a is provided on surface 152 of relay substrate 150. Connector CN2a mates with connector CN2b provided on driver circuit substrate 700. This electrically connects relay substrate 150 and driver circuit substrate 700. Specifically, connector CN2a and connector CN2b constitute connector CN2, a B2B connector that directly electrically connects relay substrate 150 and driver circuit substrate 700 without intervening cables.

[0382] The voltage signal VHV and voltage signal VMV transmitted through the FFC cable 21, as well as the clock signal SCK, differential print data signal Dp, and differential drive data signal Dd transmitted through the FFC cable 22, are input to the relay board 150 configured as described above. The relay board 150 transmits the input voltage signal VHV, voltage signal VMV, clock signal SCK, differential print data signal Dp, and differential drive data signal Dd to the connector CN2a. Furthermore, the voltage signal VHV, voltage signal VMV, clock signal SCK, differential print data signal Dp, and differential drive data signal Dd transmitted to the connector CN2a are input to the drive circuit board 700 via the connector CN2b.

[0383] As described above, multiple signals are transmitted through the FFC cables 21 and 22 and then input to the relay board 150. The relay board 150 transmits the input signals and outputs them to the drive circuit board 700 via the B2B connector, namely, connector CN2. In other words, the relay board 150 transmits the signals input via multiple cables. Furthermore, the relay board 150 outputs the signals via a smaller number of connectors than the number of cables used for signal transmission, preferably a single connector.

[0384] Thus, even when the number of cables connected to the liquid ejection module 20 increases, the drive circuit substrate 700 included in the liquid ejection module 20 and the print head 30 electrically connected to the drive circuit substrate 700 can be easily removed from the liquid ejection device 1 by simply attaching and detaching the connector CN1a provided on the relay substrate 150 and the connector CN1b provided on the drive circuit substrate 700. As a result, the workability during replacement, maintenance, and assembly of the drive circuit substrate 700 and the print head 30 electrically connected to the drive circuit substrate 700 is improved. As a result, the convenience of the liquid ejection device 1 is improved.

[0385] Furthermore, the drive circuit substrate 700 and the print head 30 of the liquid ejection module 20 can be easily assembled and disassembled, thereby reducing the space required for such assembly and disassembly. This allows for a more dense arrangement of the liquid ejection modules 20 of the liquid ejection device 1, resulting in further miniaturization of the liquid ejection device 1.

[0386] In the liquid ejection device 1 constructed as described above, of the B2B connectors (i.e., connector CN2) that electrically connect the relay substrate 150 to the drive circuit substrate 700, preferably, connector CN2a provided on the relay substrate 150 is a straight connector, while connector CN2b provided on the drive circuit substrate 700 is a right-angle connector. Consequently, when removing connector CN2a of the relay substrate 150 from connector CN2b of the drive circuit substrate 700, the relay substrate 150 can be moved along the normal direction of surface 152, further reducing the space required for assembly and removal. Consequently, a more dense arrangement of the liquid ejection modules 20 in the liquid ejection device 1 can be achieved, further miniaturizing the liquid ejection device 1.

[0387] In such relay substrate 150 , connectors CN2a and CN2b are preferably attachable and detachable more frequently than FFC cable 21 and FFC cable 22 electrically connected to relay substrate 150 .

[0388] Here, the so-called number of detachable times means the number of detachable times that can meet the desired reliability of the electrical connection, for example, based on the wear state of the terminal plating of the contact portion that may be caused by detachment, the exposure state of the base of the terminal plating, etc. Specifically, the number of detachable times of connector CN2a and connector CN2b can also be the number of plugging and unplugging times specified by the styles of connector CN2a and connector CN2b. In addition, the number of detachable times of FFC cables 21 and 22 can also be the number of plugging and unplugging times of the FFC connector when the FFC cables 21 and 22 are electrically connected to the relay substrate 150 via the FFC connector. In the case where the FFC cables 21 and 22 are directly electrically connected to the relay substrate 150 using solder or the like, it can also be the number of soldering times based on the soldering conditions of the FFC cables 21 and 22.

[0389] The relay substrate 150 of this embodiment outputs signals transmitted via the FFC cables 21 and 22 through the connector CN2a, allowing the liquid ejection module 20 to be attached and detached simply by attaching and detaching the connector CN2a. By setting the connector CN2a to be attachable and detachable more frequently than the FFC cables 21 and 22, the risk of loss of reliability in the electrical connection between the relay substrate 150, the driver circuit substrate 700, and the print head 30 is reduced even when the relay substrate 150 is repeatedly attached and detached. Consequently, the operational stability of the liquid ejection module 20 and the reliability of the liquid ejection device 1 are improved.

[0390] Furthermore, the relay substrate 150 has a through-hole 158 extending through the surface 151 and the surface 152. A portion of the cooling fan 59 is inserted through the through-hole 158. Thus, the cooling fan 59 is fixed to the relay substrate 150 with at least a portion inserted through the through-hole 158. In other words, the relay substrate 150 and the cooling fan 59 form an integral structure. Therefore, when the relay substrate 150 is removed from the driver circuit substrate 700, the cooling fan 59 is also separated from the driver circuit substrate 700 along with the relay substrate 150. When the relay substrate 150 is attached to the driver circuit substrate 700, the cooling fan 59 is also attached to the driver circuit substrate 700 along with the relay substrate 150.

[0391] Thus, even when the cooling fan 59 is used to cool the driver circuit substrate 700, the risk of the cooling fan 59 obstructing the attachment and detachment of the relay substrate 150 from the driver circuit substrate 700 and the print head 30 is reduced. It should be noted that, while the present embodiment has been described as being fixed to the relay substrate 150 by being inserted through the through-hole 158 formed in the relay substrate 150, the cooling fan 59 may alternatively be fixed to the relay substrate 150 by, for example, a retaining member (not shown) that secures the cooling fan 59 to the relay substrate 150.

[0392] Furthermore, when the cooling fan 59 is fixed to the relay substrate 150, the fan drive signal Fp for driving the cooling fan 59 is preferably supplied to the cooling fan 59 instead of being supplied to the driver circuit substrate 700. Specifically, the fan drive signal Fp for driving the cooling fan 59 is transmitted along with the voltage signals VHV and VMV through the FFC cable 21 and supplied to the relay substrate 150. The fan drive signal Fp is then transmitted through the relay substrate 150 and supplied to the cooling fan 59. In other words, the FFC cable 21 includes signal wiring for transmitting the voltage signal VHV for driving the driver circuit substrate 700, signal wiring for transmitting the voltage signal VMV for driving the driver circuit substrate 700, and signal wiring for transmitting the fan drive signal Fp for driving the cooling fan 59. The signal wiring for transmitting the fan drive signal Fp for driving the cooling fan 59 is electrically connected to the relay substrate 150, and the fan drive signal Fp is transmitted through the relay substrate 150 and input to the cooling fan 59.

[0393] When the relay substrate 150 and the cooling fan 59 are integrally formed, the fan drive signal Fp for driving the cooling fan 59 is transmitted and supplied to the cooling fan 59 through the relay substrate 150. This eliminates the need for wiring on the driver circuit substrate 700 for transmitting the fan drive signal Fp. Consequently, the risk of the driver circuit substrate 700 becoming larger is reduced. In other words, the risk of the driver circuit substrate 700 becoming larger is reduced, and the detachability of the liquid ejecting device 1 can be maintained.

[0394] Although not shown in the figure, when the cooling fan 59 is fixed to the relay substrate 150, the fan drive signal Fp for driving the cooling fan 59 may be supplied to the cooling fan 59 without being transmitted through the relay substrate 150. Specifically, the fan drive signal Fp for driving the cooling fan 59 is transmitted along the FFC cable 21 along with the voltage signals VHV and VMV. In this case, the signal wiring that transmits the fan drive signal Fp is branched from the FFC cable 21, and the branched signal wiring is directly electrically connected to the cooling fan 59. Thus, the fan drive signal Fp is supplied to the cooling fan 59 without being transmitted through the relay substrate 150. In other words, the FFC cable 21 may include signal wiring for transmitting a voltage signal VHV for driving the driving circuit substrate 700, signal wiring for transmitting a voltage signal VMV for driving the driving circuit substrate 700, and signal wiring for transmitting a fan driving signal Fp for driving the cooling fan 59. The signal wiring for transmitting the fan driving signal Fp for driving the cooling fan 59 is electrically connected to the cooling fan 59, and the fan driving signal Fp is input into the cooling fan 59 without being transmitted in the relay substrate 150.

[0395] When the relay substrate 150 and the cooling fan 59 are integrally formed, even when the fan drive signal Fp for driving the cooling fan 59 is supplied directly to the cooling fan 59 without passing through the relay substrate 150, there is no need to provide wiring for transmitting the fan drive signal Fp on the driver circuit substrate 700. As a result, the risk of the driver circuit substrate 700 becoming larger is reduced. In other words, even when the cooling fan 59 is used to cool the driver circuit substrate 700, the risk of the driver circuit substrate 700 becoming larger is reduced, and the detachability of the liquid ejection device 1 can be maintained.

[0396] As described above, whether the relay substrate 150 and the cooling fan 59 are formed into one body, the fan drive signal Fp for driving the cooling fan 59 is transmitted in the relay substrate 150 and supplied to the cooling fan 59, or the relay substrate 150 and the cooling fan 59 are formed into one body, the fan drive signal Fp for driving the cooling fan 59 is not transmitted in the relay substrate 150 but is directly supplied to the cooling fan 59, the following effects are achieved: the risk of the driving circuit substrate 700 becoming larger is reduced, and the detachability of the liquid ejecting device 1 can be maintained.

[0397] Furthermore, when relay substrate 150 and cooling fan 59 are integrated, and fan drive signal Fp for driving cooling fan 59 is transmitted through relay substrate 150 and supplied to cooling fan 59, a predetermined circuit is provided in relay substrate 150 to adjust the voltage value of fan drive signal Fp and remove noise included in fan drive signal Fp. This improves the driving accuracy of cooling fan 59 and enhances the operational stability of various circuits included in driver circuit substrate 700. Consequently, the accuracy of ink ejection from printhead 30 is enhanced.

[0398] On the other hand, when the relay substrate 150 and the cooling fan 59 are integrally formed, and the fan drive signal Fp for driving the cooling fan 59 is supplied directly to the cooling fan 59 without being transmitted through the relay substrate 150, there is no need to provide wiring for transmitting the fan drive signal Fp on the relay substrate 150. This allows for a more compact layout of the relay substrate 150. As a result, the liquid ejection module 20 can be further densely arranged, allowing for a further reduction in the size of the liquid ejection device 1.

[0399] 2.2.3.4 Construction of the drive circuit module

[0400] The structure of the driving circuit module 50 including the driving circuit substrate 700 and the relay substrate 150 configured as described above will be described. Figure 27This is a diagram of the driving circuit module 50 viewed from the −x2 side along the x2 axis. Figure 28 This is a diagram of the driving circuit module 50 viewed from the +x2 side along the x2 axis. Figure 29 This is a diagram of the driving circuit module 50 viewed from the −y2 side along the y2 axis. Figure 30 2 is a diagram showing the driving circuit module 50 viewed from the +z2 side along the z2 axis. Figures 27 to 30 In FIG. 5 , a portion of the print head 30 connected to the drive circuit module 50 is shown by a dotted line on the basis of the drive circuit module 50 .

[0401] like Figure 27 as well as Figure 29 As shown, the heat sink 180 is located on the outer surface side of the -x2 side of the driving circuit substrate 700, that is, on the surface 724 side of the rigid wiring component 710 of the driving circuit substrate 700. The heat sink 180 is attached to the rigid wiring component 710. Figure 29 As shown, heat conductive member 185 is located between heat sink 180 and surface 724 of rigid wiring member 710. This improves the close contact between heat sink 180 and surface 724, efficiently dissipating heat generated in rigid wiring member 710, including surface 724, and enhancing the insulation performance between heat sink 180 and surface 724. Specifically, heat sink 180 is located closer to surface 724 than surface 723 of rigid wiring member 710, that is, closer to rigid member 722 than rigid members 721, 741, and 742 along the x2 axis, and is attached to rigid wiring member 710. Heat conductive member 185 is located between heat sink 180 and surface 724 of rigid wiring member 710, contacting both heat sink 180 and surface 724 of rigid wiring member 710. Consequently, heat sink 180 and heat conductive member 185 dissipate heat generated in the various circuits provided in rigid wiring member 710 to the atmosphere.

[0402] Here, heat sink 180 and heat conductive member 185 are located so as to at least partially overlap with drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2 provided in rigid wiring member 710, when viewing drive circuit module 50 from the -x2 side toward the +x2 side along the x2 axis. Drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2 generate the most heat among the circuits provided in rigid wiring member 710. Heat sink 180 and heat conductive member 185 are located so as to overlap with these drive signal output circuits 52a-1, 52b-1, 52a-2, and 52b-2, thereby efficiently dissipating heat generated in rigid wiring member 710 to the atmosphere.

[0403] In addition, if Figure 28 as well as Figure 29 As shown, the heat sink 170 is located on the outer surface side of the +x2 side of the driving circuit substrate 700, that is, on the side of the surface 744 of the rigid wiring component 730 of the driving circuit substrate 700. The heat sink 170 is attached to the rigid wiring component 730. Figure 29 As shown, heat conducting member 175 is located between heat sink 170 and surface 744 of rigid wiring member 730. This improves the close contact between heat sink 170 and surface 744, allowing efficient dissipation of heat generated in rigid wiring member 730 including surface 744, and improving the insulation performance between heat sink 170 and surface 744.

[0404] Specifically, heat sink 170 is located closer to surface 744 of rigid wiring member 730 than surface 743, that is, closer to rigid member 742 than rigid members 721, 722, and 741 in the direction along the x2 axis, and is attached to rigid wiring member 730. Heat conductive member 175 is located between heat sink 170 and surface 744 of rigid wiring member 730 and contacts both heat sink 170 and surface 744 of rigid wiring member 730. Thus, heat sink 170 and heat conductive member 175 dissipate heat generated in various circuits provided in rigid wiring member 730 to the atmosphere.

[0405] Here, the heat sink 170 and the heat conductive member 175 are located so as to at least partially overlap with the drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4 provided in the rigid wiring member 730 when viewing the drive circuit module 50 from the +x2 side toward the -x2 side along the x2 axis. The drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4 generate the most heat among the circuits provided in the rigid wiring member 730. The heat sink 170 and the heat conductive member 175 are located so as to overlap with these drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4, thereby efficiently dissipating the heat generated in the rigid wiring member 730 to the atmosphere.

[0406] Furthermore, the abnormality notification circuits 55a and 55b are located on the surface 744 of the rigid wiring member 730 where the heat sink 170 and the heat conductive member 175 are located. In other words, the abnormality notification circuits 55a and 55b are provided on the surface 744 of the rigid wiring member 730, that is, on the rigid member 742.

[0407] As described above, the abnormality notification circuit 55a illuminates, extinguishes, or flashes based on the results of abnormality detection by the abnormality detection circuit 54a. The abnormality detection circuit 54a detects whether the voltage value of the voltage signal VHV is normal. Furthermore, the abnormality notification circuit 55b illuminates, extinguishes, or flashes based on the results of abnormality detection by the abnormality detection circuit 54b. The abnormality detection circuit 54b detects whether the voltage value of the voltage signal VDD generated based on the voltage signal VMV is normal. Specifically, the abnormality notification circuit 55a detects whether there is an abnormality in the voltage value of the voltage signal VHV, which serves as the power supply voltage for the drive signal output circuits 52a-1 to 52a-4, 52b-1 to 52b-4, and the print head 30. The abnormality notification circuit 55b detects whether there is an abnormality in the power supply voltage supplied to the FPGA that constitutes the ejection control circuit 51. Therefore, the heat sink 170 and the heat conductive member 175 are attached to the rigid wiring member 730 so that the user can visually confirm the illuminated states of the abnormality notification circuits 55a and 55b. It should be noted that, in addition to the abnormalities of the voltage signals VHV and VDD mentioned above, the abnormality detection circuits 54a and 54b may also detect various abnormalities of the driving circuit module 50, and the abnormality notification circuits 55a and 55b may also notify various abnormalities of the driving circuit module 50 in addition to the abnormalities of the voltage signals VHV and VDD mentioned above.

[0408] Specifically, if Figure 28 as well as Figure 29 As shown, heat sink 170 has an opening 172. When heat sink 170 is attached to rigid wiring member 730, opening 172 is positioned so as to overlap with abnormality notification circuits 55a and 55b disposed on surface 744 of rigid wiring member 730. Specifically, when viewing the drive circuit substrate 700 from rigid member 742 toward rigid member 741, abnormality notification circuits 55a and 55b overlap at least a portion of opening 172. This reduces the risk of reduced heat dissipation efficiency from the rigid wiring member 730 due to heat sink 170 and heat conductive member 175, and allows the user to be visually informed of any abnormality occurring in the drive circuit module 50. It should be noted that opening 172 does not necessarily need to be positioned at the location where abnormality notification circuits 55a and 55b are disposed when viewing the drive circuit substrate 700 from rigid member 742 toward rigid member 741. For example, a cutout or the like may be provided.

[0409] As previously mentioned, heat sink 170 and heat conductive member 175 are located so as to at least partially overlap with drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4. Therefore, when viewed from rigid member 742 toward rigid member 741, abnormality notification circuits 55a and 55b are located so as not to overlap with drive signal output circuits 52a-3, 52b-3, 52a-4, and 52b-4. This reduces the risk of reduced heat dissipation efficiency from rigid wiring member 730 due to heat sink 170 and heat conductive member 175, and allows the user to be visually notified of any abnormality in drive circuit module 50.

[0410] In addition, if Figure 27 、 Figure 28 ,as well as Figure 30As shown, relay substrate 150 is located on the +z2 side of driver circuit substrate 700 and is electrically connected to driver circuit substrate 700 via connector CN2. Relay substrate 150 is positioned on the +z2 side of driver circuit substrate 700 so that edge 153 is positioned along edge 711 of rigid wiring component 710, edge 154 is positioned along edge 731 of rigid wiring component 730, and the normal direction of surface 152 of relay substrate 150 intersects both the normal direction of surface 723 of rigid wiring component 710 and the normal direction of surface 743 of rigid wiring component 730. In other words, relay substrate 150 is positioned to form one surface of the roughly box-shaped structure formed by driver circuit substrate 700. Surface 151 of relay substrate 150 forms the outer surface of this roughly box-shaped structure, while surface 152 of relay substrate 150 forms the inner surface of this roughly box-shaped structure. At this time, cooling fan 59 fixed to relay substrate 150 blows air from surface 151 of relay substrate 150 toward surface 152 of relay substrate 150, or blows air from surface 152 of relay substrate 150 toward surface 151 of relay substrate 150. Thus, cooling fan 59 generates airflow toward surface 783 of rigid wiring component 770 within the space formed between surface 723 of rigid wiring component 710 and surface 743 of rigid wiring component 730 of driver circuit substrate 700, which are substantially box-shaped. In other words, the roughly box-shaped driver circuit substrate 700 includes a gas flow path. This gas flow path is configured to include the surface 723 of the rigid wiring component 710, the surface 743 of the rigid wiring component 730, and the surface 783 of the rigid wiring component 770. The cooling fan 59 provided on the relay substrate 150 generates airflow within this gas flow path. The cooling fan 59 uses this airflow to cool the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4. In other words, the cooling fan 59 generates airflow to cool the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4. Thus, even when the driver circuit substrate 700 is assembled in a roughly box-shaped configuration, the air circulation within this roughly box-shaped configuration can further improve the cooling efficiency of the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4 disposed within this roughly box-shaped configuration.

[0411] In this case, capacitor C7a provided on rigid wiring component 710 and capacitor C7b provided on rigid wiring component 730 are preferably located near cooling fan 59. Compared to integrated circuit 500 and transistors M1 and M2, which are surface-mount components, capacitors C7a and C7b, constructed as electrolytic capacitors, are taller and have a smaller contact area with driver circuit substrate 700. Therefore, less heat generated in capacitors C7a and C7b is dissipated to driver circuit substrate 700. By placing capacitors C7a and C7b near cooling fan 59, the airflow generated by cooling fan 59 can effectively cool capacitors C7a and C7b. This improves the cooling efficiency of capacitors C7a and C7b and reduces the temperature rise of driver circuit module 50.

[0412] In other words, the shortest distance between capacitor C7a and cooling fan 59 is smaller than the shortest distance between transistors M1 and M2 and cooling fan 59, and the shortest distance between capacitor C7b and cooling fan 59 is smaller than the shortest distance between transistors M1 and M2 and cooling fan 59. As a result, the cooling efficiency of capacitors C7a and C7b is improved, resulting in a reduction in the temperature rise of drive circuit module 50.

[0413] In addition, if Figure 27 、 Figure 28 ,as well as Figure 29 As shown, the opening plate 160 is located at the -y2 side of the assembled driving circuit substrate 700. The opening plate 160 is a plate-shaped component extending on the x2z2 plane, and the opening plate 160 is formed with openings 161, 162, 163, and 164 that pass through the plate-shaped component. Figure 29 As shown, the opening plate 160 constitutes one surface of the substantially box-shaped assembly of the driver circuit substrate 700. Furthermore, the opening plate 160 is positioned such that, when viewed along the normal direction of the opening plate 160, which is a plate-shaped member, the opening 161 overlaps at least a portion of the inductor L1 of the drive signal output circuit 52a-1 and at least a portion of the inductor L1 of the drive signal output circuit 52a-2; the opening 162 overlaps at least a portion of the inductor L1 of the drive signal output circuit 52b-4 and at least a portion of the inductor L1 of the drive signal output circuit 52b-3; the opening 163 overlaps at least a portion of the capacitor C7a; and the opening 164 overlaps at least a portion of the capacitor C7b.

[0414] The airflow generated by cooling fan 59 inside the assembled driver circuit board 700 passes through openings 161, 162, 163, and 164. The airflow generated inside the driver circuit board 700 reaches its highest velocity near openings 161, 162, 163, and 164. The inductor L1 and capacitors C7a and C7b included in each of the relatively high-height drive signal output circuits 52a-1, 52a-2, 52b-4, and 52b-3 are located near these relatively high-velocity openings 161, 162, 163, and 164, allowing them to be efficiently cooled by the airflow generated by cooling fan 59.

[0415] Compared to surface-mount components such as the integrated circuit 500 and transistors M1 and M2, electronic components with relatively high heights, such as the inductor L1 and capacitors C7a and C7b, included in the drive signal output circuit 52, have a smaller contact area with the drive circuit substrate 700. Consequently, less heat is dissipated to the drive circuit substrate 700. Consequently, the heat sinks 170 and 180 attached to the drive circuit substrate 700 may not be able to sufficiently cool the inductor L1 and capacitors C7a and C7b included in the drive signal output circuit 52, which are relatively high in height.

[0416] By placing the inductor L1 and capacitors C7a and C7b, which are relatively tall components, near the openings 161, 162, 163, and 164 where the airflow velocity is relatively high, even the inductor L1 and capacitors C7a and C7b, which are relatively tall components, can be efficiently cooled by the airflow generated by the cooling fan 59. As a result, the temperature rise of the drive circuit module 50 is reduced.

[0417] In this case, the opening plate 160 is preferably configured so that the inductor L1 of the drive signal output circuit 52a-1 does not cover the entire opening 161, the inductor L1 of the drive signal output circuit 52b-4 does not cover the entire opening 162, the capacitor C7a does not cover the entire opening 163, and the capacitor C7b does not cover the entire opening 164.

[0418] That is, the opening plate 160 is preferably located at a position such that, when viewed along the normal direction of the opening plate 160 as a plate-shaped component, at least a portion of the opening 161 does not overlap with the inductor L1 of the drive signal output circuit 52a-1, at least a portion of the opening 162 does not overlap with the inductor L1 of the drive signal output circuit 52b-4, at least a portion of the opening 163 does not overlap with the capacitor C7a, and at least a portion of the opening 164 does not overlap with the capacitor C7b.

[0419] As a result, the risk of the airflow passing through openings 161, 162, 163, and 164 being blocked by the inductor L1 of the drive signal output circuit 52a-1, the inductor L1 of the drive signal output circuit 52b-4, the capacitor C7a, and the capacitor C7b is reduced, and the risk of a local temperature rise in the drive circuit module 50 is reduced.

[0420] As described above, the driver circuit module 50 includes the driver circuit substrate 700, the relay substrate 150, the aperture plate 160, and the heat sinks 170 and 180 attached to the driver circuit substrate 700. The driver circuit module 50 operates based on various signals input via the relay substrate 150, thereby generating various control signals for controlling the operation of the print head 30 and outputting them to the print head 30 via the connector CN1.

[0421] The size of the driving circuit module 50 when viewed along the z2 axis is smaller than the size of the print head 30 when viewed from the connector CN1b toward the ejection unit 600. Figure 30 As shown, when the connector CN1a is attached to the print head 30, the drive circuit module 50 is disposed inside the print head 30. Specifically, in the drive circuit substrate 700 included in the drive circuit module 50, the rigid wiring member 770, as viewed from the rigid member 781 toward the rigid member 782, is smaller in size than the print head 30, as viewed from the connector CN1b toward the ejection unit 600. When the drive circuit substrate 700 is electrically connected to the print head 30 via the connectors CN1a and CN1b, the drive circuit substrate 700 included in the drive circuit module 50 is located inside the print head 30.

[0422] Thus, when the liquid ejection module 20 including the drive circuit substrate 700 and the print head 30 electrically connected to the drive circuit substrate 700 is mounted on the liquid ejection device 1, the risk of restrictions on the arrangement of the liquid ejection module 20 due to the size of the drive circuit substrate 700, which is provided with multiple circuit components, is reduced. As a result, the liquid ejection module 20 can be arranged more densely in the liquid ejection device 1, reducing the risk of the liquid ejection device 1 becoming larger.

[0423] Furthermore, as described above, for the driving circuit substrate 700 of this embodiment, the size of the rigid wiring component 710 when the driving circuit substrate 700 is observed along the z1 axis is approximately equal to the size of the rigid wiring component 730 when the driving circuit substrate 700 is observed along the z1 axis, the size of the rigid wiring component 750 when the driving circuit substrate 700 is observed along the z1 axis is smaller than the size of the rigid wiring component 710 when the driving circuit substrate 700 is observed along the z1 axis and the size of the rigid wiring component 730 when the driving circuit substrate 700 is observed along the z1 axis, and the size of the rigid wiring component 770 when the driving circuit substrate 700 is observed along the z1 axis is smaller than the size of the rigid wiring component 710 when the driving circuit substrate 700 is observed along the z1 axis and the size of the rigid wiring component 730 when the driving circuit substrate 700 is observed along the z1 axis. In other words, the size of the rigid component 781 when the driving circuit substrate 700 is viewed along the direction from the rigid component 781 toward the rigid component 782 is smaller than the size of the rigid component 721 when viewed along the direction from the rigid component 721 toward the rigid component 722, and is smaller than the size of the rigid component 741 when viewed along the direction from the rigid component 741 toward the rigid component 742.

[0424] This increases the mounting area of ​​the electronic components on the drive circuit substrate 700 of the liquid ejection module 20. This increases the number of ejection units 600 included in the print head 30. Therefore, even when the number of components mounted on the drive circuit substrate 700 increases, the liquid ejection modules 20 in the liquid ejection device 1 can be densely arranged, thereby reducing the risk of the liquid ejection device 1 becoming larger.

[0425] Here, the drive circuit module 50 is an example of a substrate unit. Furthermore, the drive signal output circuit 52a-1 is an example of a first drive circuit. The integrated circuit 500 included in the drive signal output circuit 52a-1 is an example of an integrated circuit. The drive signal VOUT based on the drive signal COMA1 output by the drive signal output circuit 52a-1, i.e., the trapezoidal waveform Adp1 or the trapezoidal waveform Adp2 of the drive signal COMA1, is an example of a first drive signal. The piezoelectric element 60 included in the ejection module 32-1 to which the drive signal COMA1 is input is an example of a first piezoelectric element. The electrode 611 of the piezoelectric element 60 included in the ejection module 32-1 to which the drive signal COMA1 is input is an example of a first electrode. The electrode 612 of the piezoelectric element 60 included in the ejection module 32-1 to which the drive signal COMA1 is input is an example of a second electrode. The ejection unit 600 included in the ejection module 32-1 to which the drive signal COMA1 is input is an example of a first ejection unit. In addition, the drive signal output circuit 52a-3 is an example of a second drive circuit, the drive signal VOUT based on the drive signal COMA3 output by the drive signal output circuit 52a-3, that is, the trapezoidal waveform Adp1 or the trapezoidal waveform Adp2 of the drive signal COMA3 is an example of a second drive signal, the piezoelectric element 60 included in the ejection module 32-3 to which the drive signal COMA3 is input is an example of a second piezoelectric element, the electrode 611 of the piezoelectric element 60 included in the ejection module 32-3 to which the drive signal COMA3 is input is an example of a third electrode, the electrode 612 of the piezoelectric element 60 included in the ejection module 32-3 to which the drive signal COMA3 is input is an example of a fourth electrode, and the ejection part 600 included in the ejection module 32-3 to which the drive signal COMA3 is input is an example of a second ejection part. The driving circuit substrate 700 is an example of a wiring substrate. The rigid components 721, 722, 741, 742, 761, 762, 781, and 782 included in the driving circuit substrate 700 are examples of a plurality of rigid components. The flexible wiring component 790 is an example of a flexible component. The surface 791 of the flexible wiring component 790 is an example of a first surface. The surface 792 of the flexible wiring component 790 is an example of a second surface. The flexible wiring component 790 includes the region 701 and the regions 701 to 702 of the region 701. 5 is an example of the first area, area 707 of the flexible wiring component 790 is an example of the second area, area 706 of the flexible wiring component 790 is an example of the third area, the rigid component 721 is an example of the first rigid component, the rigid component 781 is an example of the second rigid component, the rigid component 782 is an example of the third rigid component, the surface 723 of the rigid component 721 is an example of the first surface, the surface 783 of the rigid component 781 is an example of the second surface, and the surface 784 of the rigid component 782 is an example of the third surface.Furthermore, wiring wb1 provided on the driver circuit substrate 700 is an example of a first reference voltage wiring, wiring wb4 and wb6 provided on the driver circuit substrate 700 are examples of a second reference voltage wiring, wiring wb3 and wb7 provided on the driver circuit substrate 700 are examples of a third reference voltage wiring, wiring wca1 provided on the driver circuit substrate 700 is an example of a first drive signal wiring, wiring wca3 provided on the driver circuit substrate 700 is an example of a second drive signal wiring, and wiring wg provided on the driver circuit substrate 700 is an example of a ground wiring. Furthermore, connector CN1b is an example of a first connector, connector CN1a is an example of a second connector, and capacitor 53 is an example of an electrolytic capacitor.

[0426] 3. Effects

[0427] As described above, the liquid ejection device 1 of this embodiment includes a print head 30 for ejecting ink and a drive circuit substrate 700 electrically connected to the print head 30. Furthermore, the drive circuit substrate 700 includes a rigid wiring member 710 including rigid components 721 and 722 on which a plurality of circuit elements are provided, a rigid wiring member 730 including rigid components 741 and 742, a rigid wiring member 750 including rigid components 761 and 762, a rigid wiring member 770 including rigid components 781 and 782, and a flexible wiring member 790 that is more flexible than the rigid wiring members 710, 730, 750, and 770. Furthermore, the rigid components 721, 722, 741, 742, 761, 762, 781, and 782 are stacked on the flexible wiring member 790, so that the rigid wiring members 710, 730, 750, and 770 are electrically connected to each other via the flexible wiring member 790.

[0428] At this time, the rigid wiring member 710 and the rigid wiring member 730, that is, the rigid member 721 included in the rigid wiring member 710 and the rigid member 741 included in the rigid wiring member 730, are arranged so that the surface 723 and the surface 743 face each other due to the bending of the flexible wiring member 790 in the regions 702 and 704. As a result, the area occupied by the driver circuit substrate 700 electrically connected to the print head 30 in the liquid ejection module 20 can be reduced, enabling dense arrangement of the liquid ejection modules 20 and miniaturization of the liquid ejection device 1 including a plurality of liquid ejection modules 20.

[0429] Furthermore, the rigid wiring member 770 of the driver circuit substrate 700 is positioned so that the normal direction of the surface 783 of the rigid component 781 included in the rigid wiring member 770 intersects both the normal direction of the surface 723 of the rigid component 721 included in the rigid wiring member 710 and the normal direction of the surface 743 of the rigid component 741 included in the rigid wiring member 730. In other words, the rigid wiring member 770 is positioned to cover at least a portion of the area between the rigid wiring members 710 and 730, which face each other. This reduces the risk of ink mist intruding into the area between the rigid wiring members 710 and 730. As a result, the risk of ink mist adhering to the various circuits provided on the driver circuit substrate 700 is reduced, improving the operational stability of the various circuits provided on the driver circuit substrate 700 and the operational stability of the print head 30, which operates based on the output signals of the various circuits provided on the driver circuit substrate 700. Consequently, the accuracy of ink ejection from the print head 30 is improved.

[0430] Furthermore, the rigid wiring component 770 is provided with a connector CN1a electrically connected to the print head 30. Connector CN1a engages with connector CN1b provided on the print head 30, thereby electrically connecting the drive circuit substrate 700 to the print head 30. Specifically, the drive circuit substrate 700 and the print head 30 are electrically connected via connector CN1, which functions as a B2B connector. This reduces the impedance of the transmission path for signals output from the drive circuit substrate 700 and input to the print head 30. As a result, the accuracy of the signals input to the print head 30 is improved, and the ink ejection accuracy of the print head 30 is also improved.

[0431] In the driver circuit substrate 700 constructed as described above, the circuitry formed by the various circuit components provided on the rigid members 721, 722, 741, 742, 761, 762, 781, and 782, as well as the wiring wh2 for transmitting the voltage signal VHV, which serves as the power supply voltage for the drive signal selection circuit 200 included in the print head 30, is continuously provided in the flexible wiring member 790. This extends across a region 701 where the rigid members 721 and 722 are stacked, a region 703 where the rigid members 761 and 762 are stacked, a region 705 where the rigid members 741 and 742 are stacked, a region 702 located between regions 701 and 703, and a region 704 located between regions 703 and 705. In other words, the voltage signal VHV is transmitted through the wiring wh2 without routing through vias, and is supplied to the rigid wiring member 710, the rigid wiring member 730, and the rigid wiring member 750. As a result, the risk of signals from different wiring layers overlapping as noise in the voltage signal VHV supplied to the rigid wiring member 710, the rigid wiring member 730, and the rigid wiring member 750 is reduced. Specifically, the accuracy of the voltage signal VHV supplied to the various circuits provided in the rigid wiring member 710, the various circuits provided in the rigid wiring member 730, and the various circuits provided in the rigid wiring member 750 is improved, and the operational stability of the various circuits provided in the rigid wiring member 710, the various circuits provided in the rigid wiring member 730, and the various circuits provided in the rigid wiring member 750 is improved. As a result, the accuracy of the output signals output by the various circuits provided in the rigid wiring member 710, the various circuits provided in the rigid wiring member 730, and the various circuits provided in the rigid wiring member 750 is improved, and the operation of the print head 30 based on these output signals is stabilized, thereby improving the accuracy of ink ejection from the print head 30.

[0432] Furthermore, in the liquid ejection device 1 of this embodiment, the wiring wh2 for transmitting the voltage signal VHV is provided continuously and linearly in the direction from region 701 toward region 705 of the flexible wiring member 790, spanning regions 701, 703, and 705. The voltage signal VHV functions as a power supply voltage for the circuit comprised of the various circuit components provided in the rigid members 721, 722, 741, 742, 761, 762, 781, and 782, as well as for the drive signal selection circuit 200 included in the print head 30. Therefore, a relatively large amount of current flows through the wiring wh2 for transmitting the voltage signal VHV. By linearizing the wiring wh2, the risk of variations in the current density of the voltage signal VHV transmitted through the wiring wh2 is reduced, thereby reducing the risk of fluctuations in the voltage value of the voltage signal VHV. As a result, the accuracy of the voltage signal VHV supplied to the various circuits provided in the rigid wiring members 710, 730, and 750 is improved, and the operational stability of the various circuits provided in the rigid wiring members 710, 730, and 750 is enhanced. As a result, the accuracy of the output signals output by the various circuits provided in the rigid wiring members 710, 730, and 750 is further improved, and the operation of the print head 30 based on these output signals is further stabilized, further improving the accuracy of ink ejection from the print head 30. Here, the term "straight line" includes the case where, in the extended state of the driver circuit substrate 700, the wiring wh2 is provided along a virtual straight line extending from the region 701 to the region 705.

[0433] Furthermore, drive signal output circuits 52a-1 to 52a-4, 52b-1 to 52b-4 are provided in the rigid component 721 of the rigid wiring component 710 and the rigid component 741 of the rigid wiring component 730. The drive signal output circuits 52a-1 to 52a-4, 52b-1 to 52b-4 perform class-D amplification based on the voltage signal VHV to generate drive signals COMA1 to COMA4, COMB1 to COMB4. The accuracy of the voltage signal VHV input to the rigid components 721 and 741 equipped with these drive signal output circuits 52a-1 to 52a-4, 52b-1 to 52b-4 is improved, thereby improving the accuracy of the drive signals COMA1 to COMA4, COMB1 to COMB4 output by the drive signal output circuits 52a-1 to 52a-4, 52b-1 to 52b-4. As a result, the ink ejection accuracy from the print head 30 is further improved.

[0434] Furthermore, the rigid wiring component 770 having the connector CN1a electrically connected to the connector CN1b of the print head 30 is set to a size when viewed in the direction from the rigid component 781 toward the rigid component 782 that is smaller than the size of the print head 30 when viewed in the direction from the connector CN1b toward the ejection portion 600, thereby enabling a dense arrangement of the liquid ejection module 20 including the driving circuit substrate 700 and the print head 30. As a result, further miniaturization can be achieved in the liquid ejection device 1 having a plurality of liquid ejection modules 20.

[0435] At this time, the drive circuit substrate 700 has connectors CN3a and CN3b. Connector CN3a is provided on the rigid wiring component 710, and connector CN3b is provided on the rigid wiring component 770. Moreover, in the assembled drive circuit substrate 700, connector CN3a and connector CN3b are engaged with each other to maintain a roughly box-shaped structure. Thus, a retaining member for maintaining the shape of the assembled drive circuit substrate 700 is no longer required, and further miniaturization of the drive circuit module 50 including the drive circuit substrate 700 can be achieved. As a result, a further dense arrangement of the liquid ejection module 20 including the drive circuit module 50 can be achieved, and as a result, further miniaturization can be achieved in the liquid ejection device 1 including multiple liquid ejection modules 20.

[0436] Furthermore, the connectors CN3a and CN3b of the drive circuit substrate 700 are engaged to electrically connect the rigid wiring component 710 and the rigid wiring component 770. This allows signals generated in the rigid wiring component 710 to be transmitted to the rigid wiring component 770 without passing through the rigid wiring components 730 and 750. Consequently, the number of wiring patterns provided on the drive circuit substrate 700 can be reduced, enabling further miniaturization of the drive circuit substrate 700. Consequently, the liquid ejection module 20 including the drive circuit module 50 can be arranged more densely, resulting in further miniaturization of the liquid ejection device 1 including multiple liquid ejection modules 20.

[0437] At this time, the clock signal SCK and the differential print data signal Dpt output by the ejection control circuit 51 included in the FPGA provided on the driver circuit substrate 700 are input to the print head 30 via the connectors CN1a and CN1b and the rigid wiring member 770. The clock signal SCK and the differential print data signal Dpt are signals with relatively low voltage values. By transmitting these clock signal SCK and the differential print data signal Dpt to the rigid wiring member 770 via the connectors CN3a and CN3b rather than via the rigid wiring members 730 and 750, the signal accuracy of the clock signal SCK and the differential print data signal Dpt input to the print head 30 is improved. As a result, the ink ejection accuracy from the print head 30 is further improved.

[0438] Furthermore, in the driver circuit module 50, the rigid wiring components 710 and 730 included in the driver circuit substrate 700 are positioned so that their surfaces 723 and 743 face each other. Heat sink 180 is located on surface 724 of the rigid wiring component 710, and heat sink 170 is located on surface 744 of the rigid wiring component 730. Cooling fan 59 generates airflow in the area between rigid wiring components 710 and 730, resulting from their opposing positions. Consequently, the driver circuit substrate 700 is cooled from both sides due to the heat dissipation effect of the airflow generated by cooling fan 59 and the heat dissipation effect of heat sinks 170 and 180. This improves the heat dissipation efficiency, or cooling efficiency, of the driver circuit substrate 700, further enhancing the operational stability of the various circuits provided on the driver circuit substrate 700. Consequently, the signal accuracy of the output signals output by the driver circuit substrate 700 is improved, and the ink ejection accuracy of the print head 30, which ejects ink based on the output signals from the various circuits provided on the driver circuit substrate 700, is also improved.

[0439] At this time, insulating thermally conductive member 185 is located between heat sink 180 and surface 724 of rigid wiring member 710, while insulating thermally conductive member 175 is located between heat sink 170 and surface 744 of rigid wiring member 730. Heat conductive member 185 contacts both surface 724 and heat sink 180, while heat conductive member 175 contacts both surface 744 and heat sink 170. This improves the adhesion and insulation between heat sink 170 and rigid wiring member 730, and between heat sink 180 and rigid wiring member 710. As a result, heat dissipation performance from heat sinks 170 and 180 is further enhanced, further improving heat dissipation efficiency, or cooling efficiency, from driver circuit board 700. Furthermore, insulation between heat sinks 170 and 180 and driver circuit board 700 is improved, further enhancing the operational stability of various circuits provided on driver circuit board 700.

[0440] Furthermore, in the driver circuit substrate 700 of this embodiment, the rigid wiring member 770 of the driver circuit substrate 700 is positioned such that the normal direction of the surface 783 of the rigid component 781 included in the rigid wiring member 770 intersects both the normal direction of the surface 723 of the rigid component 721 included in the rigid wiring member 710 and the normal direction of the surface 743 of the rigid component 741 included in the rigid wiring member 730. This position forms part of the gas flow path for the gas generated by the cooling fan 59. At this time, the cooling fan 59 generates an airflow directed toward the rigid wiring member 770. Thus, the cooling fan 59 can cool the electronic components that constitute the circuits provided on the rigid wiring member 770. This further improves the operational stability of the various circuits provided on the driver circuit substrate 700.

[0441] Furthermore, in the driver circuit module 50 constructed as described above, drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 for outputting drive signals COMA1, COMA2, COMB1, and COMB2 are provided on surface 723 of the rigid wiring member 710, and drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 for outputting drive signals COMA3, COMA4, COMB3, and COMB4 are provided on surface 743 of the rigid wiring member 730. Drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4 supply drive signals COMA1 to COMA4 and COMB1 to COMB4 based on voltage signal VHV to each of the plurality of ejection units 600, thereby generating a large amount of heat. Even in the case where the driving circuit substrate 700 is provided with such driving signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4 that generate a large amount of heat, the driving circuit substrate 700 of this embodiment is cooled by both the heat dissipation effect based on the airflow generated by the cooling fan 59 and the heat discharge effect based on the heat sinks 170 and 180, thereby further improving the stability of the operation of the driving signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4.

[0442] Furthermore, the driver circuit substrate 700 is provided with capacitors C7a and C7b, which are electrolytic capacitors. Capacitors C7a and C7b are arranged on the driver circuit substrate 700 so that the shortest distance between capacitors C7a and C7b and the cooling fan 59 is shorter than the shortest distance between transistors M1 and M2 included in the drive signal output circuit 52 and the cooling fan 59. Since capacitors C7a and C7b, which are electrolytic capacitors, are taller than surface-mount transistors M1 and M2, the cooling effect achieved by cooling the driver circuit substrate 700, i.e., by dissipating heat through heat sinks 170 and 180, is relatively small. By placing capacitors C7a and C7b close to the cooling fan 59, they can be cooled. As a result, the operational stability of the various circuits provided on the driver circuit substrate 700 is further improved.

[0443] The drive circuit module 50 also includes a plate-shaped opening plate 160 having openings 161 and 162 through which the airflow generated by the cooling fan 59 passes. Furthermore, the opening plate 160 is positioned so that, when viewed along the normal direction of the opening plate 160, opening 161 overlaps at least a portion of the inductor L1 of the drive signal output circuit 52a-1, and opening 162 overlaps at least a portion of the inductor L1 of the drive signal output circuit 52a-1. When the airflow generated by the cooling fan 59 passes through openings 161 and 162, the velocity of the airflow increases. By arranging the inductor L1, which is included in the drive signal output circuit 52 and has a relatively high component height, in this region where the velocity of the airflow generated by the cooling fan 59 increases, the cooling efficiency of the inductor L1 can be improved, thereby enhancing the operational stability of the various circuits provided on the drive circuit substrate 700. As a result, the signal accuracy of the output signal outputted from the driving circuit substrate 700 is improved, and the ink ejection accuracy from the print head 30 that ejects ink based on the output signals of various circuits provided in the driving circuit substrate 700 is also improved.

[0444] Furthermore, since the flow rate of the air flow generated in the cooling fan 59 when passing through the openings 161 and 162 can be increased, even a small cooling fan 59 can obtain sufficient cooling capacity. As a result, the risk of reduced ejection accuracy of the ink ejected from the print head 30 due to vibrations that may be generated by the driving of the cooling fan 59 is reduced.

[0445] Furthermore, the drive circuit module 50 is electrically connected to the FFC cable 21 and the FFC cable 22 on surface 151. The FFC cable 21 transmits voltage signals VHV and VMV, and the FFC cable 22 transmits the clock signal SCK, the differential print data signal Dp, and the differential drive data signal Dd. A relay substrate 150 is provided on surface 152 opposite to surface 151. The relay substrate 150 is provided with a connector CN2a electrically connected to the drive circuit substrate 700. Specifically, signals are transmitted through the FFC cables 21 and 22, input to the relay substrate 150, and output to the drive circuit substrate 700 via the connector CN2a. Consequently, the drive circuit substrate 700 can be attached to and detached from the liquid ejection device 1 simply by attaching and detaching the connectors CN2a and CN2b, thereby improving the efficiency of maintenance, replacement, and assembly of the drive circuit substrate 700.

[0446] Furthermore, the drive circuit substrate 700 can be attached and detached from the liquid ejection device 1 only by attaching and detaching the connectors CN2a and CN2b, thereby reducing the space required for such attachment and detachment. This allows for a more compact arrangement of the liquid ejection modules 20, resulting in a further reduction in size of the liquid ejection device 1.

[0447] Furthermore, the cooling fan 59 is fixed to the relay substrate 150. This allows the cooling fan 59 to be removed from the liquid ejection device 1 as the driver circuit substrate 700 is removed. Consequently, there is no need to provide wiring on the driver circuit substrate 700 for transmitting the fan drive signal Fp that drives the cooling fan 59, allowing the driver circuit substrate 700 to be miniaturized.

[0448] The drive circuit module 50 also includes a temperature detection circuit 56. This temperature detection circuit 56 detects the ambient temperature of the drive circuit module 50, i.e., the temperature within the drive circuit module 50. The control unit 2 and the head control circuit 12 control the operation of the drive circuit module 50 and the print head 30 based on the ambient temperature detected by the temperature detection circuit 56. In other words, the liquid ejection device 1 of this embodiment does not detect the temperatures of the various circuits within the drive circuit module 50 individually. Instead, the temperature detection circuit 56 detects the ambient temperature within the drive circuit module 50, which varies depending on the operating state of the drive circuit module 50. The control unit 2 and the head control circuit 12 then control the operation of the drive circuit module 50 and the print head 30 based on the ambient temperature detected by the temperature detection circuit 56. This eliminates the need for separate temperature detectors, such as sensor elements, for the electronic components within the drive circuit module 50, enabling a more compact design of the drive circuit module 50. Consequently, the liquid ejection module 20 can be further compacted, enabling a further reduction in the size of the liquid ejection device 1.

[0449] In the driver circuit board 700, such a temperature detection circuit 56 is provided in a rigid wiring member 750 located between the rigid wiring member 710 on which the drive signal output circuits 52a-1, 52a-2, 52b-1, and 52b-2 are provided and the rigid wiring member 730 on which the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are provided. This reduces the risk of the temperature detection circuit 56 excessively increasing the contribution of temperature changes, which could occur in the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4, which generate relatively high amounts of heat, to the ambient temperature detected by the temperature detection circuit 56. In other words, the accuracy of the ambient temperature detected by the temperature detection circuit 56 is improved. Consequently, the control unit 2 and the head control circuit 12 improve the accuracy of the control of the drive circuit module 50 and the print head 30 based on the ambient temperature detected by the temperature detection circuit 56, thereby improving the accuracy of ink ejection from the print head 30.

[0450] Furthermore, in the driver circuit substrate 700, the drive signal output circuits 52a-1 and 52b-1, each provided on the rigid wiring member 710, include an integrated circuit 500, transistors M1 and M2, and an inductor L1. Drive signal output circuits 52a-1 and 52b-1 are located at positions that at least partially overlap along a direction from side 713 toward side 714. In this case, the integrated circuit 500 included in the drive signal output circuit 52a-1 and the integrated circuit 500 included in the drive signal output circuit 52b-1 are arranged so as not to overlap along a direction from side 713 toward side 714. This reduces the risk of localized high-temperature areas in the driver circuit substrate 700 caused by the concentration of heat generated in the drive signal output circuits 52a-1 and 52b-1.

[0451] Furthermore, in the driver circuit substrate 700 of this embodiment, the drive signal output circuit 52b-4 provided on the rigid wiring member 730 includes an integrated circuit 500, transistors M1 and M2, and an inductor L1. Along the x2 axis, the drive signal output circuit 52a-1 and the drive signal output circuit 52b-4 are located at positions that at least partially overlap, while along the x2 axis, the integrated circuit 500 included in the drive signal output circuit 52a-1 and the integrated circuit 500 included in the drive signal output circuit 52b-4 are arranged so as not to overlap. Consequently, even in the assembled driver circuit substrate 700, the risk of heat generated in the drive signal output circuit 52a-1 and the drive signal output circuit 52b-4 concentrating, resulting in a localized high-temperature portion within the driver circuit substrate 700, is reduced.

[0452] Specifically, in the liquid ejection device 1 of this embodiment, the drive signal output circuits 52a-1 to 52a-4 and 52b-1 to 52b-4, which generate a large amount of heat, are arranged in a staggered pattern. This reduces the risk of localized heat concentration within the drive circuit substrate 700. Consequently, the waveform accuracy of the drive signals COMA1 to COMA4 and COMB1 to COMB4 output by the drive circuit substrate 700 to the print head 30 is improved, thereby improving the ejection accuracy of the ink ejected from the print head 30.

[0453] In this case, transistors M1 and M2 of drive signal output circuit 52a-1 and transistors M1 and M2 of drive signal output circuit 52b-1 are arranged so as not to overlap along the direction from side 713 toward side 714, and transistors M1 and M2 of drive signal output circuit 52a-1 and transistors M1 and M2 of drive signal output circuit 52b-4 are arranged so as not to overlap along the x2 axis, thereby further reducing heat concentration in drive circuit substrate 700. Furthermore, inductor L1 of drive signal output circuit 52a-1 and inductor L1 of drive signal output circuit 52b-1 are arranged so as not to overlap along the direction from side 713 toward side 714, and inductor L1 of drive signal output circuit 52a-1 and inductor L1 of drive signal output circuit 52b-4 are arranged so as not to overlap along the x2 axis, thereby further reducing heat concentration in drive circuit substrate 700.

[0454] Furthermore, capacitor C53, an electrolytic capacitor for stabilizing the voltage value of reference voltage signal VBS, is provided on surface 783 of rigid wiring member 770 of drive circuit substrate 700. Connector CN1a, electrically connected to print head 30, is provided on surface 784 of rigid wiring member 770 of drive circuit substrate 700. Specifically, the voltage value of reference voltage signal VBS is stabilized in rigid wiring member 770, where connector CN1a is provided, which is electrically connected to print head 30. This improves the stability of the voltage value of reference voltage signal VBS supplied to print head 30, improves the displacement accuracy of piezoelectric element 60 included in print head 30, and improves the ejection accuracy of ink ejected based on the displacement of piezoelectric element 60.

[0455] Furthermore, the reference voltage signal VBS supplied to the electrode 612 of the piezoelectric element 60 is commonly supplied to the piezoelectric element 60 supplied with the drive signal VOUT based on the drive signals COMA1 and COMB1, the piezoelectric element 60 supplied with the drive signal VOUT based on the drive signals COMA2 and COMB2, the piezoelectric element 60 supplied with the drive signal VOUT based on the drive signals COMA3 and COMB3, and the piezoelectric element 60 supplied with the drive signal VOUT based on the drive signals COMA4 and COMB4. This reference voltage signal VBS is supplied from a single reference voltage signal output circuit 530. Thus, even when the piezoelectric element 60 is supplied with the drive signal VOUT based on different drive signals COM, it can still be driven based on a common reference potential, thereby improving the displacement accuracy of the piezoelectric element 60 included in the print head 30 and improving the ejection accuracy of the ink ejected based on the displacement of the piezoelectric element 60.

[0456] Furthermore, the drive circuit module 50 includes abnormality notification circuits 55a and 55b, which are provided on the surface 744 of the rigid wiring member 730 of the drive circuit substrate 700, i.e., the surface 744 of the rigid member 742 included in the rigid wiring member 730. Specifically, the abnormality notification circuit 55 is provided on the outer surface of the assembled drive circuit substrate 700, which is generally configured in a box shape. This allows the user to visually confirm abnormalities in the liquid ejection module 20, thereby improving the reliability of the liquid ejection module 20 and the liquid ejection device 1.

[0457] At this time, as described above, heat sink 170 is located on surface 744 of rigid wiring member 730 of drive circuit substrate 700, i.e., surface 744 of rigid component 742 included in rigid wiring member 730. In this manner, along surface 744 of rigid wiring member 730 of drive circuit substrate 700, i.e., surface 744 of rigid component 742 included in rigid wiring member 730, abnormality notification circuits 55a and 55b are located at a position that does not overlap with drive signal output circuit 52 in the direction from rigid component 742 toward rigid component 741. Heat sink 170 is located at a position that does not overlap with drive signal output circuit 52, thereby dissipating heat generated in drive signal output circuit 52 without compromising visual visibility of abnormality notification circuits 55a and 55b. This improves the accuracy of the signal output by drive circuit substrate 700 and enhances the reliability of liquid ejection module 20 and liquid ejection device 1.

[0458] Furthermore, the heat sink 170 has an opening 172. The abnormality notification circuits 55a and 55b are located at a position overlapping with the opening 172 in the direction from the rigid member 742 toward the rigid member 741. This effectively dissipates heat generated in the drive signal output circuit 52 without compromising the visual visibility of the abnormality notification circuits 55a and 55b. This improves the accuracy of the signal output by the drive circuit substrate 700 and enhances the reliability of the liquid ejection module 20 and the liquid ejection device 1.

[0459] 4. Modifications

[0460] Next, a liquid ejection device 1 according to a modified example will be described. Figure 311 is a diagram showing a schematic structure of a modified example of a liquid ejection device 1. In the aforementioned liquid ejection device 1, it was assumed that the drive circuit module 50 included in the liquid ejection module 20 includes a cooling fan 59. The cooling fan 59 generates an airflow in the gas flow path formed by the rigid wiring components 710, 730, 750, and 770 of the drive circuit substrate 700, thereby cooling the drive circuit substrate 700. However, in the modified example of the liquid ejection device 1, a compressor CP is provided in place of or in addition to the cooling fan 59. The airflow generated by the compressor CP is supplied to the gas flow path formed by the rigid wiring components 710, 730, 750, and 770 of the drive circuit substrate 700, thereby cooling the drive circuit substrate 700.

[0461] That is, the liquid ejection device 1 of the modified example includes a print head 30 that ejects ink as an example of liquid, a drive circuit module 50 electrically connected to the print head 30, a compressor CP that sends compressed air AR, and a tube TB connecting the drive circuit module 50 and the compressor CP. The compressor CP supplies compressed air AR via the tube TB to an area where the surface 723 of the rigid wiring component 710 included in the drive circuit substrate 700, that is, the surface 723 of the rigid component 721, and the surface 743 of the rigid wiring component 730, that is, the surface 743 of the rigid component 741, are opposite.

[0462] like Figure 31 As shown, the compressor CP is provided separately from the head unit 3. In this case, the compressor CP is located outside the printing area where the head unit 3 ejects ink onto the medium P to form an image, preferably in a space separate from the printing area. The compressor CP is driven to draw and compress the air in this space, which is then output as compressed air AR. The compressed air AR output by the compressor CP is then supplied to the liquid ejection module 20 via the tube TB.

[0463] Figure 32 1 is an exploded perspective view showing an example of the structure of the liquid ejection module 20 of the modified example. Figure 32 As shown, the tube TB is connected to a through hole 159, which passes through the surface 151 and the surface 152 formed on the relay substrate 150. Thus, the compressed air AR is supplied to the liquid ejection module 20. Furthermore, the compressed air AR is supplied via the through hole 159 of the relay substrate 150 to the area where the surface 723 of the rigid wiring component 710 of the driving circuit substrate 700 of the driving circuit module 50, i.e., the surface 723 of the rigid component 721, and the surface 743 of the rigid wiring component 730, i.e., the surface 743 of the rigid component 741, face each other. The liquid ejection device 1 of the modified example constructed as described above can also achieve the same effects as the above-mentioned embodiment.

[0464] Furthermore, in the liquid ejection device 1 of the modified embodiment, as described above, the compressor CP is located in a space separate from the printing area. Consequently, the compressed air AR output by the compressor CP is protected from ink mist, a portion of the ink ejected by the print head 30 onto the medium P, and dust such as paper dust and feathers that may be generated during the transport of the medium P. Consequently, the risk of this ink mist and dust adhering to the various electronic components provided on the driver circuit board 700 and cooled by the compressed air AR is reduced. This further improves the operational stability of the driver circuit board 700 and the accuracy of ink ejection from the print head 30, which operates based on the output signal from the driver circuit board 700.

[0465] That is, in the liquid ejection device 1 of the modified example, in the case of a so-called printing and dyeing inkjet printer in which a cloth towel is used as the medium P, resulting in a high risk of dust floating in the printing area, the stability of the operation of the driving circuit substrate 700 is further improved, and the ink ejection accuracy from the print head 30 that operates based on the output signal output by the driving circuit substrate 700 is further improved. From this point of view, a particularly large effect is achieved.

[0466] In addition, in the above-mentioned embodiment, it is explained that the ambient temperature of the driving circuit module 50 is detected, a temperature information signal Tt including temperature information corresponding to the ambient temperature is generated, and the temperature detection circuit 56 that is output to the head control circuit 12 is set in the rigid wiring component 750, but it is also possible that the temperature detection circuit 56 is set in the rigid wiring component 730 in an area away from the driving signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4.

[0467] Figure 33 FIG. 7 is a diagram showing an example of component arrangement in a driver circuit substrate 700 in an expanded state according to a modified example. Figure 33As shown, in the modified example driving circuit substrate 700, the temperature detection circuit 56 is arranged in an area away from the driving signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4. Specifically, the temperature detection circuit 56 is arranged along the edge 731 of the rigid wiring component 730, and the driving signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are arranged in an area along the edge 732 located opposite to the edge 731 in the rigid wiring component 730. That is, in the rigid wiring component 730, the temperature detection circuit 56 and each of the drive signal output circuits 52a-3, 52a-4, 52b-3, 52b-4 are configured so that the shortest distance between the temperature detection circuit 56 and the edge 731 is smaller than the shortest distance between the temperature detection circuit 56 and the edge 732, and the shortest distance between the transistors M1, M2 of each of the drive signal output circuits 52a-3, 52a-4, 52b-3, 52b-4 and the edge 732 is smaller than the shortest distance between the transistors M1, M2 of each of the drive signal output circuits 52a-3, 52a-4, 52b-3, 52b-4 and the edge 731.

[0468] Even when the temperature detection circuit 56 is configured in such a configuration, since the temperature detection circuit 56 and the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 are located in separate positions, the contribution of the heat generated in the drive signal output circuits 52a-3, 52a-4, 52b-3, and 52b-4 to the temperature detection circuit 56 is reduced, and the same effect as the above-mentioned embodiment can be achieved.

[0469] Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments and can be implemented in various forms within the scope of the present invention. For example, the above embodiments can be appropriately combined.

[0470] The present invention includes structures that are substantially the same as the structures described in the embodiments (for example, structures having the same functions, methods, and results, or structures having the same purposes and effects). In addition, the present invention includes structures in which non-essential parts of the structures described in the embodiments are replaced. In addition, the present invention includes structures that achieve the same effects as the structures described in the embodiments or structures that can achieve the same purposes. In addition, the present invention includes structures in which known technologies are added to the structures described in the embodiments.

[0471] The following contents are derived from the above-mentioned embodiment.

[0472] One embodiment of a liquid ejection device comprises:

[0473] a print head, which ejects liquid; and

[0474] a substrate unit, electrically connected to the print head,

[0475] The print head has:

[0476] a first ejection portion including a first piezoelectric element that is displaced based on a first drive signal whose voltage value varies and is supplied to a first electrode and a reference voltage signal whose voltage value is fixed and is supplied to a second electrode, and ejects liquid by displacement of the first piezoelectric element; and

[0477] a first connector electrically connected to the substrate unit,

[0478] The substrate unit comprises:

[0479] a second connector, engaged with the first connector, thereby being electrically connected to the print head;

[0480] A reference voltage signal output circuit, outputting the reference voltage signal;

[0481] an electrolytic capacitor for reducing a variation in a voltage value of the reference voltage signal; and

[0482] a wiring substrate provided with the second connector, the reference voltage signal output circuit, and the electrolytic capacitor;

[0483] The wiring substrate is a rigid-flexible substrate including a plurality of rigid components on which the reference voltage signal output circuit and the electrolytic capacitor are provided, and a flexible component that is softer than the plurality of rigid components.

[0484] The flexible component includes a first surface, a second surface opposite to the first surface, a first region, a second region, and a third region.

[0485] The third area is located between the first area and the second area.

[0486] The plurality of rigid components include a first rigid component, a second rigid component, and a third rigid component,

[0487] The first rigid component includes a first surface, and the first surface is laminated on the first surface of the first region in a manner extending along the first surface.

[0488] The second rigid component includes a second surface, and the second surface is laminated on the first surface of the second region in a manner extending along the first surface.

[0489] The third rigid component includes a third surface, and the third surface is laminated on the second surface of the second region in a manner extending along the second surface.

[0490] The reference voltage signal output circuit is provided on the first rigid component,

[0491] The electrolytic capacitor is arranged on the second rigid component,

[0492] The second connector is provided on the third rigid component,

[0493] The first rigid component and the second rigid component are located at positions where a normal direction of the first surface intersects a normal direction of the second surface due to the bending of the flexible component in the third region.

[0494] According to this liquid ejection device, an electrolytic capacitor for reducing fluctuations in the voltage value of a reference voltage signal is provided in the second rigid component laminated on the first surface of the second region of the flexible component. A second connector electrically connected to the printhead is provided in the third rigid component laminated on the second surface of the second region of the flexible component. Specifically, the electrolytic capacitor for reducing fluctuations in the voltage value of the reference voltage signal is provided near the second connector supplied to the printhead. This improves the stability of the voltage value of the reference voltage signal VBS supplied to the printhead. Consequently, the displacement accuracy of the first piezoelectric element is improved, and the ejection accuracy of ink ejected from the first ejection portion due to the displacement of the first piezoelectric element is improved.

[0495] In one embodiment of the liquid ejection device,

[0496] The substrate unit has a first drive circuit, the first drive circuit includes an integrated circuit, and outputs the first drive signal.

[0497] The integrated circuit is arranged on the first rigid component,

[0498] At least a portion of the reference voltage signal output circuit is included in the integrated circuit.

[0499] According to the liquid ejection device, the reference voltage signal output circuit that outputs the reference voltage signal is included in a part of the integrated circuit of the first drive circuit that outputs the first drive signal, so there is no need to set up a separate reference voltage signal output circuit, which can achieve miniaturization of the wiring substrate.

[0500] In one embodiment of the liquid ejection device,

[0501] The print head includes a second ejection portion, the second ejection portion including a second piezoelectric element that is displaced based on a second drive signal whose voltage value is changed by the third electrode and the reference voltage signal supplied to the fourth electrode, and ejects liquid by the displacement of the second piezoelectric element.

[0502] The substrate unit includes a second drive circuit that outputs the second drive signal.

[0503] According to the liquid ejection device, the print head includes a first ejection part and a second ejection part, the first ejection part includes a first piezoelectric element that is displaced based on the voltage value of the first drive signal, and ejects liquid through the displacement of the first piezoelectric element, and the second ejection part includes a second piezoelectric element that is displaced based on the voltage value of the second drive signal, and ejects liquid through the displacement of the second piezoelectric element. In this case, the second electrode of the first piezoelectric element and the fourth electrode of the second piezoelectric element are supplied with a common reference voltage signal, so the difference between the ejection amount of ink ejected from the first ejection part and the ejection amount of ink ejected from the second ejection part is reduced, resulting in that the ejection accuracy of the liquid from the first ejection part and the second ejection part is improved.

[0504] In one embodiment of the liquid ejection device,

[0505] The wiring substrate includes:

[0506] a first reference voltage wiring electrically connecting the reference voltage signal output circuit and the electrolytic capacitor;

[0507] a second reference voltage wiring electrically connecting the electrolytic capacitor and the second connector and branching from the first reference voltage wiring to transmit the reference voltage signal supplied to the second electrode;

[0508] a third reference voltage wiring electrically connecting the electrolytic capacitor and the second connector and branching from the first reference voltage wiring to transmit the reference voltage signal supplied to the fourth electrode;

[0509] a first drive signal wiring, electrically connecting the first drive circuit and the second connector for transmitting the first drive signal;

[0510] a second drive signal wiring, electrically connecting the second drive circuit to the second connector for transmitting the second drive signal; and

[0511] Ground wiring for ground signal transmission...

Claims

1. A liquid ejection device, characterized in that: have: a print head, which ejects liquid; and a substrate unit, electrically connected to the print head, The print head has: The first ejection unit includes a first piezoelectric element that is displaced based on a first drive signal whose voltage value varies and is supplied to the first electrode, and a reference voltage signal whose voltage value is fixed and is supplied to the second electrode, and ejects liquid by the displacement of the first piezoelectric element; as well as a first connector electrically connected to the substrate unit, The substrate unit comprises: a second connector, engaged with the first connector, thereby being electrically connected to the print head; A reference voltage signal output circuit, outputting the reference voltage signal; an electrolytic capacitor, used to reduce a variation in a voltage value of the reference voltage signal; as well as a wiring substrate provided with the second connector, the reference voltage signal output circuit, and the electrolytic capacitor; The wiring substrate is a rigid-flexible substrate including a plurality of rigid components on which the reference voltage signal output circuit and the electrolytic capacitor are provided, and a flexible component that is softer than the plurality of rigid components. The flexible component includes a first surface, a second surface opposite to the first surface, a first region, a second region, and a third region. The third area is located between the first area and the second area. The plurality of rigid components include a first rigid component, a second rigid component, and a third rigid component, The first rigid component includes a first surface, and the first surface is laminated on the first surface of the first region in a manner extending along the first surface. The second rigid component includes a second surface, and the second surface is laminated on the first surface of the second region in a manner extending along the first surface. The third rigid component includes a third surface, and the third surface is laminated on the second surface of the second region in a manner extending along the second surface. The reference voltage signal output circuit is provided on the first rigid component, The electrolytic capacitor is arranged on the second rigid component, The second connector is provided on the third rigid component, The first rigid component and the second rigid component are located at positions where a normal direction of the first surface intersects a normal direction of the second surface due to the bending of the flexible component in the third region.

2. The liquid ejection device according to claim 1, wherein have: The substrate unit has a first drive circuit, the first drive circuit includes an integrated circuit, and outputs the first drive signal. The integrated circuit is arranged on the first rigid component, At least a portion of the reference voltage signal output circuit is included in the integrated circuit.

3. The liquid ejection device according to claim 2, wherein: The print head includes a second ejection portion, the second ejection portion including a second piezoelectric element that is displaced based on a second drive signal whose voltage value is changed by the third electrode and the reference voltage signal supplied to the fourth electrode, and ejects liquid by the displacement of the second piezoelectric element. The substrate unit includes a second drive circuit that outputs the second drive signal.

4. The liquid ejection device according to claim 3, wherein: The wiring substrate includes: a first reference voltage wiring electrically connecting the reference voltage signal output circuit and the electrolytic capacitor; a second reference voltage wiring electrically connecting the electrolytic capacitor and the second connector and branching from the first reference voltage wiring to transmit the reference voltage signal supplied to the second electrode; a third reference voltage wiring electrically connecting the electrolytic capacitor and the second connector and branching from the first reference voltage wiring to transmit the reference voltage signal supplied to the fourth electrode; a first drive signal wiring, electrically connecting the first drive circuit and the second connector for transmitting the first drive signal; a second drive signal wiring, electrically connecting the second drive circuit to the second connector for transmitting the second drive signal; and Ground wiring for ground signal transmission, A portion of the first drive signal wiring is provided adjacent to the second reference voltage wiring, and another portion is provided adjacent to the ground wiring. A portion of the second drive signal wiring is provided adjacent to the third reference voltage wiring, and a different portion is provided adjacent to the ground wiring.

5. The liquid ejection device according to any one of claims 1 to 4, characterized in that The first connector and the second connector constitute a BtoB connector.

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