Large-sized printer and relay circuit board

Abstract

To provide a large-sized printer capable of reducing adverse effects caused by an overshoot voltage.SOLUTION: A large-sized printer has a print head for discharging a liquid by supplying a driving signal output by a control unit, and a relay circuit board for transmitting the driving signal output by the control unit to the print head, where the relay circuit board has an input connector to which the driving signal is input, an output connector for outputting the driving signal, a first restriction circuit which includes a first diode and a first capacitor and restricts a voltage value of a first driving signal, a second restriction circuit which includes a second diode and a second capacitor and restricts a voltage value of a second driving signal, and a wiring board; the input connector, the first restriction circuit and the second restriction circuit are provided on a first surface; the output connector is provided on a second surface; the first diode and the first capacitor are positioned adjacent to each other; and the second diode and the second capacitor are positioned adjacent to each other.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a large-format printer and a relay circuit board. [Background technology]

[0002] Known large format printers that print images or documents on media with a short side width of A3 or more by ejecting ink use piezoelectric elements. The piezoelectric elements are provided in correspondence with each of a number of nozzles in the print head that ejects the ink. The print head ejects a predetermined amount of ink from the nozzles at a predetermined timing by driving each of the multiple piezoelectric elements in accordance with a drive signal. In this way, the large format printer prints the desired image or document on the medium.

[0003] For example, Patent Document 1 discloses a technique in which a clamp circuit is mounted on a head (print head) that ejects ink to deal with an overshoot voltage of a drive signal that is generated due to a flexible flat cable that transmits the drive signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-170768 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 is not sufficient in terms of reducing adverse effects caused by overshoot voltage in large-format printers, and there is room for further improvement. [Means for solving the problem]

[0006] One aspect of the large format printer according to the present invention is a head unit that ejects liquid when a drive signal is supplied thereto; a control unit that outputs a first drive signal and a second drive signal as the drive signals; Equipped with The head unit includes: a print head that ejects liquid when the drive signal is supplied; a relay circuit board that transmits the drive signal output by the control unit to the print head; having The relay circuit board includes: an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; having the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface; the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other; The second diode and the second capacitor are positioned adjacent to each other.

[0007] One aspect of the relay circuit board according to the present invention is as follows: a print head that ejects liquid when a drive signal is supplied; a control unit that outputs a first drive signal and a second drive signal as the drive signals; In a large format printer equipped with a relay circuit board that transmits the drive signal output by the control unit to the print head, an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; Equipped with the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface; the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other; The second diode and the second capacitor are positioned adjacent to each other. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a large format printer. [Diagram 2] FIG. 2 illustrates an example of the functional configuration of a large format printer. [Diagram 3] FIG. 4 is a diagram showing an example of a structure of a discharge portion. [Figure 4] 4 is a diagram showing an example of signal waveforms of drive signals COMA, COMB, and a drive signal VOUT. [Diagram 5] FIG. 2 is a diagram illustrating an example of the structure of a head unit. [Figure 6] FIG. 2 is a diagram illustrating an example of a configuration of an ink ejection surface. [Figure 7] FIG. 2 is a diagram showing an example of the structure of a head substrate. [Figure 8] FIG. 2 is a diagram illustrating an example of a configuration of a clamp circuit. [Figure 9] 13 is a diagram showing an example of a signal waveform of a drive signal COM before being propagated through an FFC. FIG. [Figure 10] 13 is a diagram showing an example of a signal waveform of a drive signal COM input to a print head 23 after being propagated through an FFC 15. FIG. [Figure 11] 1 is a diagram showing an example of a configuration of a relay circuit board when the wiring board is viewed from the front surface side; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Preferred embodiments of the present invention will be described below with reference to the drawings. The drawings are used for the convenience of explanation. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0010] 1. Overview of large format printers 1 is a diagram showing a schematic configuration of a large format printer 1. The large format printer 1 of this embodiment is a serial printing type inkjet printer in which a carriage 21 equipped with a head unit 20 that ejects ink as an example of liquid moves back and forth, and the head unit 20 ejects ink onto the transported medium P to form a desired image on the medium P. Here, the large format printer 1 is a printing device that prints on a medium P such as printing paper or roll paper with a short side width of A3 or more, and is sometimes called a large format printer (LFP). Note that the medium P used in the large format printer 1 is not limited to printing paper or roll paper, and may be a resin film, fabric, or the like.

[0011] In the following description, the direction in which the carriage 21 moves may be referred to as the main scanning direction, the direction in which the medium P is transported may be referred to as the transport direction, and the direction in which the ink is ejected may be referred to as the ejection direction. Note that in the following description, the main scanning direction, the transport direction, and the ejection direction are assumed to be perpendicular to one another, but this is not limited to the case where the various components included in the large format printer 1 are arranged perpendicular to one another.

[0012] As shown in FIG. 1, the large format printer 1 includes a liquid container 2, a control unit 10, a head unit 20, a carriage 21, a moving unit 30, and a transport unit 40.

[0013] The liquid container 2 stores a plurality of types of ink to be ejected onto the medium P. Examples of the colors of ink stored in the liquid container 2 include black, cyan, magenta, yellow, red, and gray. The liquid container 2 in which the ink is stored may be an ink cartridge, a bag-shaped ink pack formed of a flexible film, or an ink tank that can be refilled with ink.

[0014] The control unit 10 includes processing circuits such as a CPU (Central Processing Unit) and an FPGA (Field Programmable Gate Array) and storage circuits such as semiconductor memory, and controls each element of the large format printer 1. Specifically, the control unit 10 generates control signals Ctrl-H, Ctrl-C, and Ctrl-T that control the operation of various components of the large format printer 1, and outputs them to the corresponding components.

[0015] The head unit 20 is mounted on a carriage 21. A control signal Ctrl-H is input from the control unit 10 to the head unit 20, and ink is supplied from the liquid container 2. The head unit 20 ejects the ink supplied from the liquid container 2 based on the control signal Ctrl-H. Note that the liquid container 2 may be mounted on the carriage 21 together with the head unit 20.

[0016] The moving unit 30 includes a carriage motor 31 and an endless belt 32. The control signal Ctrl-C is input to the carriage motor 31 of the moving unit 30. The carriage motor 31 drives based on the input control signal Ctrl-C. The endless belt 32 rotates according to the operation of the carriage motor 31. The carriage 21 is fixed to the endless belt 32. As a result, the carriage 21 fixed to the endless belt 32 moves in the main scanning direction as the endless belt 32 rotates. The control signal Ctrl-C may be converted into a signal in a format suitable for the operation of the carriage motor 31 by a carriage motor driver (not shown).

[0017] The transport unit 40 includes a transport motor 41 and a transport roller 42. The control signal Ctrl-T is input to the transport motor 41 of the transport unit 40. The transport motor 41 is driven based on the input control signal Ctrl-T. The transport roller 42 rotates in accordance with the operation of the transport motor 41. The medium P is transported in the transport direction in accordance with the rotation of the transport roller 42. Note that the control signal Ctrl-T may be converted into a signal in a format suitable for the operation of the transport motor 41 by a transport motor driver (not shown).

[0018] In the large format printer 1 configured as described above, the head unit 20 mounted on the carriage 21 ejects ink in conjunction with the transport of the medium P by the transport unit 40 and the movement of the carriage 21 by the movement unit 30. In this way, the large format printer 1 forms a desired image on the medium P.

[0019] 2. Functional configuration of large format printer Next, it will be described about the functional configuration of the large format printer 1. Fig. 2 is a diagram showing an example of the functional configuration of the large format printer 1. As shown in Fig. 2, the large format printer 1 includes a control unit 10, a head unit 20, a movement unit 30, and a transport unit 40.

[0020] The control unit 10 includes a control circuit 100, a power supply circuit 55, drive circuits 50-1 to 50-n, and reference voltage output circuits 52-1 to 52-n.

[0021] The power supply circuit 55 generates a DC voltage signal VHV, which is a constant voltage value of, for example, 42 V, from the commercial AC power source input to the large format printer 1 and is used in the large format printer 1, and outputs it as a control signal Ctrl-H to the head unit 20. The voltage signal VHV output by the power supply circuit 55 is also input to various components of the large format printer 1, including the drive circuits 50-1 to 50-n. Note that, in addition to the voltage signal VHV, the power supply circuit 55 may also generate DC voltage signals according to voltage values ​​used in various components of the large format printer 1, and output them to the corresponding components.

[0022] The control circuit 100 includes, for example, a processor such as a microcontroller and storage circuits such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The control circuit 100 generates various signals for controlling the large format printer 1 based on image information signals including image data and the like input from an external device such as a host computer, and outputs the signals to the corresponding components.

[0023] Specifically, the control circuit 100 generates a control signal Ctrl-C based on an image information signal input from an external device, and outputs it to the moving unit 30. The moving unit 30 controls the movement of the carriage 21 carrying the head unit 20 based on the input control signal Ctrl-H. The control circuit 100 also generates a control signal Ctrl-T based on the image information signal input from the external device, and outputs it to the transport unit 40. The transport unit 40 controls the transport of the medium P based on the input control signal Ctrl-T. That is, the control circuit 100 controls the movement of the head unit 20 and the transport of the medium P based on the image information signal input from the external device.

[0024] Furthermore, the control circuit 100 generates ejection control signals DATA1 to DATAn that control the operation of the head unit 20 based on image data included in an image information signal input from an external device, and outputs the signals as a control signal Ctrl-H to the head unit 20. Each of the ejection control signals DATA1 to DATAn output by the control circuit 100 includes a signal that specifies the amount of ink ejected from each of nozzles 651 (described later) that the head unit 20 has, a signal that specifies the ejection timing at which ink is ejected from the nozzles 651, and the like. That is, the control circuit 100 controls the amount and timing of ink ejection from the head unit 20 based on an image information signal input from an external device.

[0025] Here, the ejection control signals DATA1 to DATAn output by the control circuit 100 may be differential signals. In this case, the control circuit 100 may include a conversion circuit that converts the ejection control signals DATA1 to DATAn into differential signals, and the head unit 20 described later may include a restoration circuit that restores the input differential signals. Furthermore, the control circuit 100 may output, as the differential signals, differential signals of a high-speed transfer method such as a differential signal of a LVDS (Low Voltage Differential Signaling) transfer method, a differential signal of a LVPECL (Low Voltage Positive Emitter Coupled Logic) transfer method, or a differential signal of a CML (Current Mode Logic) transfer method.

[0026] The control circuit 100 also generates basic drive signals dA1-dAn, dB1-dBn, which are digital signals that are the basis of drive signals COMA1-COMAn, COMB1-COMBn that drive the piezoelectric elements 60 of the head unit 20 (described later), and outputs them to the corresponding drive circuits 50-1-50-n. The basic drive signals dA1 and dB1 are input to the drive circuit 50-1. The drive circuit 50-1 performs digital / analog conversion on the input basic drive signal dA1 and performs class D amplification on the converted analog signal according to the voltage signal VHV to generate the drive signal COMA1, and performs digital / analog conversion on the input basic drive signal dB1 and performs class D amplification on the converted analog signal according to the voltage signal VHV to generate the drive signal COMB1. The drive circuit 50-1 then outputs the generated drive signals COMA1 and COMB1 to the head unit 20 as a control signal Ctrl-H.

[0027] Similarly, the basic drive signals dAi, dBi (i = any one of 2 to n) are input to the drive circuit 50-i. The drive circuit 50-i performs digital / analog conversion on the input basic drive signal dAi and performs class D amplification on the converted analog signal according to the voltage signal VHV to generate the drive signal COMAi, and performs digital / analog conversion on the input basic drive signal dBi and performs class D amplification on the converted analog signal according to the voltage signal VHV to generate the drive signal COMBi. The drive circuit 50-i then outputs the generated drive signals COMAi, COMBi to the head unit 20 as a control signal Ctrl-H.

[0028] That is, each of the driving circuits 50-1 to 50-n includes two class D amplifier circuits, and generates driving signals COMA1 to COMAn, COMB1 to COMBn by class D amplifying the signal waveforms defined by the basic driving signals dA1 to dAn, dB1 to dBn input from the control circuit 100 according to the voltage signal VHV, and outputs them to the head unit 20 as a control signal Ctrl-H. Here, the basic driving signals dA1 to dAn, dB1 to dBn output by the control circuit 100 may be analog signals as long as they can define the signal waveforms of the corresponding driving signals COMA1 to COMAn, COMB1 to COMBn. Also, each of the driving circuits 50-1 to 50-n may include a class A amplifier circuit, a class B amplifier circuit, or a class AB amplifier circuit instead of or in addition to the class D amplifier circuit, as long as it can amplify the signal waveforms defined by the basic driving signals dA1 to dAn, dB1 to dBn according to the voltage signal VHV.

[0029] The reference voltage output circuits 52-1 to 52-n generate reference voltage signals VBS1 to VBSn that are the reference for driving the piezoelectric element 60 based on the drive signals COMA1 to COMAn and COMB1 to COMBn, respectively, and output them to the head unit 20 as a control signal Ctrl-H. Specifically, the reference voltage output circuit 52-1 generates a reference voltage signal VBS1 that is the reference for driving the piezoelectric element 60 based on the drive signals COMA1 and COMB1, and outputs it to the head unit 20. Similarly, the reference voltage output circuit 52-i generates a reference voltage signal VBSi that is the reference for driving the piezoelectric element 60 based on the drive signals COMAi and COMBi, and outputs it to the head unit 20. Each of these reference voltage signals VBS1 to VBSn may be, for example, a constant signal at ground potential, or may be a DC voltage signal with a constant voltage value of 5.5V, 6V, or the like.

[0030] As described above, the control unit 10 generates the voltage signal VHV, the ejection control signals DATA1-DATAn, and the drive signals COMA1-COMAn, COMB1-COMBn as the control signal Ctrl-H for controlling the operation of the head unit 20, and outputs them to the head unit 20. Furthermore, in addition to the signals described above, the control unit 10 may output various signals for controlling the operation of the head unit 20 and a ground signal GND indicating the ground potential of the large format printer 1 to the head unit 20 as the control signal Ctrl-H.

[0031] Here, the discharge control signals DATA1 to DATAn output by the control circuit 100 are all of the same signal configuration, and may be simply referred to as discharge control signals DATA when there is no need to distinguish them. Also, the drive circuits 50-1 to 50-n of the control unit 10 are all of the same configuration, and may be simply referred to as drive circuits 50 when there is no need to distinguish them. In this case, the drive circuit 50 may be described as receiving basic drive signals dA and dB and outputting drive signals COMA and COMB. Also, the reference voltage output circuits 52-1 to 52-n of the control unit 10 are all of the same configuration, and may be simply referred to as reference voltage output circuits 52 when there is no need to distinguish them. In this case, the reference voltage output circuit 52 may be described as outputting a reference voltage signal VBS that is a reference for driving the piezoelectric element 60 based on the drive signals COMA and COMB.

[0032] The head unit 20 includes a relay circuit board 22 and a print head 23 .

[0033] The relay circuit board 22 is electrically connected to the control unit 10 via a slidable FFC (Flexible Flat Cable) 15, and is also electrically connected to the print head 23 via a BtoB (Board to Board) connector 24. The relay circuit board 22 propagates the voltage signal VHV, the ejection control signal DATA, and the drive signals COMA and COMB input via the FFC 15, and outputs them to the print head 23 via the BtoB connector 24. In other words, the relay circuit board 22 relays the voltage signal VHV, the ejection control signal DATA, and the drive signals COMA and COMB output from the control unit 10 to the print head 23.

[0034] Here, the head unit 20 having the relay circuit board 22 is mounted on the carriage 21 which moves under the control of the moving unit 30. Therefore, the relative positional relationship between the head unit 20 and the control unit 10, that is, the relative positional relationship between the relay circuit board 22 and the control unit 10 changes. By electrically connecting the relay circuit board 22 and the control unit 10, whose relative positional relationship changes, using the FFC 15 having sliding properties, even if the relative positional relationship between the relay circuit board 22 and the control unit 10 changes with the movement of the carriage 21, the FFC 15 deforms and the electrical connection between the relay circuit board 22 and the control unit 10 can be maintained. Here, the relay circuit board 22 and the control unit 10 may be electrically connected by a plurality of FFCs 15 depending on the number of signals transmitted between the head unit 20 and the control unit 10, the voltage value of the signal, and the like.

[0035] Furthermore, a BtoB connector 24 is used as a connection member that electrically connects the relay circuit board 22 and the print head 23. Specifically, the BtoB connector 24 has a plug provided on one of the relay circuit board 22 and the print head 23, and a socket provided on the other of the relay circuit board 22 and the print head 23. The plug and the socket are directly engaged with each other, so that the BtoB connector 24 electrically connects the relay circuit board 22 and the print head 23. This allows the relay circuit board 22 to be easily attached and detached from the print head 23, and makes it possible to miniaturize the head unit 20 including the relay circuit board 22 without the need to use a cable. In the following description, the plug of the BtoB connector 24 is provided on the relay circuit board 22, and the socket of the BtoB connector 24 is provided on the print head 23, but this is not limited to the above. The relay circuit board 22 also has a clamp circuit 300. One end of the clamp circuit 300 is electrically connected to the wiring pattern through which the voltage signal VHV propagates, and the other end is electrically connected to the wiring pattern through which the ground potential propagates. The drive signals COMA1-COMAn and COMB1-COMBn output by the control unit 10 are input to the clamp circuit 300. The clamp circuit 300 limits the voltage value of the overshoot voltage generated in each of the drive signals COMA1-COMAn and COMB1-COMBn. The clamp circuit 300 and the relay circuit board 22 having the clamp circuit 300 will be described in detail later.

[0036] The print head 23 has ejection heads 25-1 to 25-n.

[0037] The discharge head 25-1 is input with a voltage signal VHV, a discharge control signal DATA1, drive signals COMA1, COMB1, and a reference voltage signal VBS1. The discharge head 25-1 also has a drive signal selection circuit 200 and a plurality of discharge units 600, each of which has a piezoelectric element 60.

[0038] The drive signal selection circuit 200 of the ejection head 25-1 receives the voltage signal VHV, the ejection control signal DATA1, and the drive signals COMA1 and COMB1. The drive signal selection circuit 200 of the ejection head 25-1 generates the drive signal VOUT1 corresponding to each of the ejection sections 600 of the ejection head 25-1 by selecting or deselecting the signal waveforms of the drive signals COMA1 and COMB1 based on the signal that specifies the amount of ink ejected, which is included in the ejection control signal DATA1, at a timing that is specified by the signal that specifies the ejection timing that is included in the ejection control signal DATA1. The drive signal selection circuit 200 of the ejection head 25-1 then supplies the generated drive signal VOUT1 corresponding to each of the ejection sections 600 to one end of the piezoelectric element 60 of the corresponding ejection section 600. At this time, the reference voltage signal VBS1 is commonly supplied to the other end of the piezoelectric element 60 of each of the ejection sections 600 of the ejection head 25-1. Each of the piezoelectric elements 60 is driven in response to the potential difference between the voltage value of the drive signal VOUT1 supplied to one end and the voltage value of the reference voltage signal VBS1 supplied to the other end.

[0039] Similarly, the discharge head 25-i is supplied with a voltage signal VHV, a discharge control signal DATAi, drive signals COMAi, COMBi, and a reference voltage signal VBSi. The discharge head 25-i also includes a drive signal selection circuit 200 and a plurality of discharge units 600, each of which includes a piezoelectric element 60.

[0040] The drive signal selection circuit 200 of the ejection head 25-i receives the voltage signal VHV, the ejection control signal DATAi, and the drive signals COMAi and COMBi. The drive signal selection circuit 200 of the ejection head 25-i generates drive signals VOUTi corresponding to each of the ejection units 600 of the ejection head 25-i by selecting or deselecting the signal waveforms of the drive signals COMAi and COMBi based on a signal that specifies the amount of ink ejected, which is included in the ejection control signal DATAi, at a timing that is specified by a signal that specifies the ejection timing, which is included in the ejection control signal DATAi. The drive signal selection circuit 200 of the ejection head 25-i then supplies the generated drive signals VOUTi corresponding to each of the ejection units 600 to one end of the piezoelectric element 60 of the corresponding ejection unit 600. At this time, a reference voltage signal VBSi is commonly supplied to the other end of the piezoelectric element 60 of each of the ejection units 600 of the ejection head 25-i. Each of the piezoelectric elements 60 is driven in response to the potential difference between the voltage value of a drive signal VOUTi supplied to one end and the voltage value of a reference voltage signal VBSi supplied to the other end.

[0041] Here, the ejection heads 25-1 to 25-n all have the same configuration, and when there is no need to distinguish between them, they may be simply referred to as ejection heads 25. In this case, the ejection heads 25 may be described as receiving an ejection control signal DATA, drive signals COMA and COMB, and a reference voltage signal VBS, and a drive signal selection circuit 200 included in the ejection head 25 generates a drive signal VOUT based on the drive signals COMA and COMB, and supplies it to the piezoelectric element 60 of the corresponding ejection section 600.

[0042] Next, an example of the structure of the ejection section 600 of the ejection head 25 will be described. Fig. 3 is a diagram showing an example of the structure of the ejection section 600. In addition to the configuration of the ejection section 600, Fig. 3 also shows a reservoir 641 that supplies ink to the ejection section 600, and a supply port 661 that supplies ink to the reservoir 641.

[0043] As shown in FIG. 3, the ejection section 600 includes a piezoelectric element 60 , a vibration plate 621 , a cavity 631 , and a nozzle 651 .

[0044] The cavity 631 communicates with a reservoir 641. Thus, the cavity 631 is filled with ink stored in the reservoir 641. The nozzle 651 communicates with the cavity 631 and is an opening formed in the nozzle plate 632. The vibration plate 621 is located below the cavity 631 in FIG. 3. A piezoelectric element 60 is provided above the vibration plate 621 in FIG. 3. The piezoelectric element 60 has a piezoelectric body 601 and a pair of electrodes 611 and 612 positioned to sandwich the piezoelectric body 601. A drive signal VOUT is supplied to one of the electrodes 611 and 612 of the piezoelectric element 60, and a reference voltage signal VBS is supplied to the other of the electrodes 611 and 612. The piezoelectric body 601 is displaced so that the central portion bends in the vertical direction in FIG. 3 according to the potential difference between the voltage of the electrode 611 and the voltage of the electrode 612. That is, the piezoelectric element 60 is driven to bend in the vertical direction shown in Fig. 3 in response to the potential difference between the drive signal VOUT input to one of the electrodes 611, 612 and the reference voltage signal VBS input to the other of the electrodes 611, 612. Then, by driving the piezoelectric element 60, the diaphragm 621 is displaced in the vertical direction shown in Fig. 3, and the internal volume of the cavity 631 expands and contracts with the displacement of the diaphragm 621. That is, the diaphragm 621 functions as a diaphragm that changes the internal volume of the cavity 631.

[0045] In the ejection section 600 configured as above, when the piezoelectric element 60 is driven to bend in the upward direction shown in FIG. 3, the vibration plate 621 is also displaced in the upward direction shown in FIG. 3. As a result, the internal volume of the cavity 631 is expanded. Therefore, the ink stored in the reservoir 641 is drawn into the cavity 631. On the other hand, when the piezoelectric element 60 is driven to bend in the downward direction shown in FIG. 3, the vibration plate 621 is also displaced in the downward direction shown in FIG. 3. As a result, the internal volume of the cavity 631 is reduced. Therefore, the ink stored in the cavity 631 is ejected from the nozzle 651.

[0046] The structure of the piezoelectric element 60 of the ejection section 600 need only be a structure that can be driven to eject ink from the nozzle 651, and is not limited to the bending vibration structure shown in FIG. 3, but may be, for example, a longitudinal vibration structure.

[0047] As described above, the large format printer 1 of this embodiment comprises a head unit 20 that ejects ink when supplied with a drive signal VOUT based on the drive signals COMA and COMB, and a control unit 10 that outputs the drive signals COMA and COMB. The head unit 20 has a print head 23 that ejects ink when supplied with a drive signal VOUT based on the drive signals COMA and COMB, and a relay circuit board 22 that transmits the drive signals COMA and COMB output by the control unit 10 to the print head 23.

[0048] 3. Example of a drive signal waveform Next, an example of the signal waveform of the drive signals COMA, COMB output by the drive circuit 50 and an example of the signal waveform of the drive signal VOUT output by the drive signal selection circuit 200 based on the drive signals COMA, COMB will be described. Fig. 4 is a diagram showing an example of the signal waveforms of the drive signals COMA, COMB, and the drive signal VOUT. Fig. 4 also shows, as the ejection control signal DATA output by the control circuit 100, a latch signal LAT that specifies the ejection timing of ink from the nozzle 651, a change signal CH, and a print data signal SI that specifies the ejection amount of ink ejected from the nozzle 651.

[0049] As shown in Fig. 4, the drive signal COMA is a signal waveform formed by successively forming a trapezoidal waveform Adp1 arranged in a period t1 from when the latch signal LAT rises until when the change signal CH rises, and a trapezoidal waveform Adp2 arranged in a period t2 from when the change signal CH rises until when the latch signal LAT rises again. The trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 are signal waveforms for discharging a predetermined amount of ink from the nozzle 651 of the discharge section 600 including the piezoelectric element 60, when each of them is supplied to one end of the piezoelectric element 60. Note that Fig. 4 illustrates a case in which the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 are substantially the same signal waveform, but this is not limited thereto.

[0050] The drive signal COMB is a signal waveform in which the trapezoidal waveform Bdp1 arranged in the above-mentioned period t1 and the trapezoidal waveform Bdp2 arranged in the above-mentioned period t2 are consecutively arranged. The trapezoidal waveform Bdp1 is a signal waveform for preventing an increase in ink viscosity by slightly vibrating the ink near the nozzle opening of the ejection section 600, and when this trapezoidal waveform Bdp1 is supplied to one end of the piezoelectric element 60, ink is not ejected from the nozzle 651 of the ejection section 600 including the piezoelectric element 60. Moreover, the trapezoidal waveform Bdp2 is a signal waveform for ejecting an amount of ink less than the above-mentioned predetermined amount from the nozzle 651 of the ejection section 600 including the piezoelectric element 60 when supplied to one end of the piezoelectric element 60.

[0051] 4, the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 all start and end at the voltage Vc. That is, the voltage values ​​at the start and end timings of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 are all common to the voltage Vc.

[0052] In the following description, when the trapezoidal waveforms Adp1, Adp2 are supplied to the piezoelectric element 60, the predetermined amount of ink ejected from the corresponding nozzle 651 will be referred to as a medium amount, and when the trapezoidal waveform Bdp2 is supplied to the piezoelectric element 60, the amount of ink smaller than the predetermined amount ejected from the corresponding nozzle 651 will be referred to as a small amount.

[0053] The drive signal selection circuit 200 switches between whether to select the trapezoidal waveform Adp1 included in the drive signal COMA and whether to select the trapezoidal waveform Bdp1 included in the drive signal COMB in period t1 in accordance with the print data signal SI, and switches between whether to select the trapezoidal waveform Adp2 included in the drive signal COMA and whether to select the trapezoidal waveform Bdp2 included in the drive signal COMB in period t2. In this way, the drive signal selection circuit 200 generates the drive signal VOUT and outputs it to the corresponding ejection section 600.

[0054] Specifically, the print data signal SI includes information that defines the dot sizes to be formed on the medium P as “large dot LD,” “medium dot MD,” “small dot SD,” and “non-printing ND” corresponding to each of the multiple ejection sections 600.

[0055] When the input print data signal SI includes information defining a "large dot LD", the drive signal selection circuit 200 selects the trapezoidal waveform Adp1 in period t1 and selects the trapezoidal waveform Adp2 in period t2 as the drive signal VOUT to be output to the corresponding ejection unit 600. As a result, the drive signal selection circuit 200 generates a drive signal VOUT having a signal waveform in which the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 are connected, and outputs it to the corresponding ejection unit 600. The ejection unit 600 to which the drive signal VOUT having a signal waveform in which the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 are connected is input ejects a medium amount of ink in period t1 and ejects a medium amount of ink in period t2. That is, the ejection unit 600 ejects a medium amount of ink twice in the cycle ta. Then, a medium amount of ink ejected from the ejection section 600 in period t1 and a medium amount of ink ejected from the ejection section 600 in period t2 combine on the medium P to form a large dot LD on the medium P in the cycle ta.

[0056] Furthermore, when the input print data signal SI includes information defining a "medium dot MD", the drive signal selection circuit 200 selects the trapezoidal waveform Adp1 in period t1 and the trapezoidal waveform Bdp2 in period t2 as the drive signal VOUT to be output to the corresponding ejection unit 600. As a result, the drive signal selection circuit 200 generates a drive signal VOUT having a signal waveform in which the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 are connected, and outputs it to the corresponding ejection unit 600. The ejection unit 600 to which the drive signal VOUT having a signal waveform in which the trapezoidal waveform Adp1 and the trapezoidal waveform Adp2 are connected is input ejects a medium amount of ink in period t1 and ejects a small amount of ink in period t2. That is, the ejection unit 600 ejects a medium amount of ink and a small amount of ink once each in the cycle ta. Then, a medium amount of ink ejected from the ejection section 600 in period t1 and a small amount of ink ejected from the ejection section 600 in period t2 combine on the medium P, forming a medium dot MD that is smaller than the large dot LD on the medium P in the period ta.

[0057] Furthermore, when the input print data signal SI includes information defining a "small dot SD", the drive signal selection circuit 200 does not select the trapezoidal waveform Adp1 or the trapezoidal waveform Bdp1 in the period t1 as the drive signal VOUT to be output to the corresponding ejection unit 600, and selects the trapezoidal waveform Bdp2 in the period t2. As a result, the drive signal selection circuit 200 generates a drive signal VOUT having a signal waveform in which a constant signal waveform and a trapezoidal waveform Bdp2 are successively connected at a voltage Vc, and outputs the drive signal VOUT to the corresponding ejection unit 600. The ejection unit 600 to which the drive signal VOUT having a signal waveform in which a constant signal waveform and a trapezoidal waveform Adp2 are successively connected at a voltage Vc is input does not eject ink in the period t1, and ejects a small amount of ink in the period t2. That is, the ejection unit 600 ejects a small amount of ink only once in the cycle ta. Then, a small amount of ink ejected from the ejection section 600 during period t2 lands on the medium P, forming small dots SD smaller than the medium dots MD on the medium P during the cycle ta.

[0058] In addition, when the input print data signal SI includes information specifying "non-recording ND", the drive signal selection circuit 200 selects the trapezoidal waveform Bdp1 as the drive signal VOUT to be output to the corresponding ejection unit 600 in the period t1, and does not select the trapezoidal waveform Adp1 or the trapezoidal waveform Bdp2 in the period t2. As a result, the drive signal selection circuit 200 generates a drive signal VOUT having a signal waveform in which the trapezoidal waveform Bdp1 and a constant signal waveform at the voltage Vc are connected, and outputs it to the corresponding ejection unit 600. The ejection unit 600 to which the drive signal VOUT having a signal waveform in which the trapezoidal waveform Bdp1 and a constant signal waveform at the voltage Vc are connected only vibrates the ink near the nozzle opening of the corresponding ejection unit 600 slightly in the period t1, and does not eject ink in the period t2. That is, the ejection unit 600 does not eject ink in the cycle ta. As a result, no dots are formed on the medium P in the cycle ta. At this time, the ink near the nozzle opening of the corresponding ejection unit 600 vibrates slightly, thereby reducing the risk of an increase in the viscosity of the ink in that ejection unit 600. This operation of reducing the risk of an increase in the viscosity of the ink by slightly vibrating the ink near the nozzle opening of the corresponding ejection unit 600 is sometimes referred to as micro-vibration.

[0059] As described above, the drive signal COMA includes the trapezoidal waveforms Adp1 and Adp2, and the drive signal COMB includes the trapezoidal waveforms Bdp1 and Bdp2. The drive signal selection circuit 200 selects or deselects 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 for each of the multiple ejection sections 600 at a timing determined by the latch signal LAT and the change signal CH included in the ejection control signal DATA based on the print data signal SI included in the ejection control signal DATA, thereby generating a drive signal VOUT corresponding to the ejection amount of ink ejected from each of the multiple ejection sections 600 and outputting it to the corresponding ejection section 600.

[0060] In other words, the print data signal SI is the size of the dots formed on the medium P, and is a signal that specifies the amount of ink ejected from the nozzle 651 of the ejection section 600, and the latch signal LAT that specifies the period ta corresponding to the dot formation period at which dots are formed on the medium P and the change signal CH that specifies the switching timing of the signal waveforms of the drive signals COMA and COMB and specifies the timing of waveform selection in the drive signal selection circuit 200 correspond to the signals that specify the timing of forming dots on the medium P and the ejection timing of ink from the ejection section 600.

[0061] Note that the signal waveforms of the drive signals COMA and COMB and the signal waveform of the drive signal VOUT shown in Figure 4 are just examples, and various combinations of signal waveforms may be used depending on the moving speed of the carriage 21 on which the head unit 20 is mounted, the physical properties of the ink ejected from the head unit 20, and the type of medium P on which the ink lands, etc.

[0062] 4.Head unit structure Next, a specific example of the structure of the head unit 20 will be described. FIG. 5 is a diagram showing an example of the structure of the head unit 20. Here, in the following description, the description will be given using the X-axis, Y-axis, and Z-axis that are mutually orthogonal. When defining the directions of the X-axis, Y-axis, and Z-axis, the starting point side of the arrow along the illustrated X-axis may be referred to as the -X side, and the tip side as the +X side, the starting point side of the arrow along the illustrated Y-axis may be referred to as the -Y side, and the tip side as the +Y side, and the starting point side of the arrow along the illustrated Z-axis may be referred to as the -Z side, and the tip side as the +Z side. In addition, the head unit 20 of this embodiment will be described assuming a case where it is mounted on the large format printer 1 so that the X-axis is located along the above-mentioned main scanning direction, the Y-axis is located along the above-mentioned transport direction, and the Z-axis is located along the above-mentioned ejection direction. Note that the mounting direction of the head unit 20 on the large format printer 1 is not limited to this.

[0063] In the following description, the head unit 20 is described as having twelve ejection heads 25 and two relay circuit boards 22. In the following description, when the twelve ejection heads 25 are to be distinguished, they may be referred to as ejection heads 25-1 to 25-12, and when the two relay circuit boards 22 are to be distinguished, they may be referred to as relay circuit boards 22a and 22b. In this case, the BtoB connector 24 that electrically connects the relay circuit board 22a and the print head 23 may be referred to as the BtoB connector 24a, and the BtoB connector 24 that electrically connects the relay circuit board 22b and the print head 23 may be referred to as the BtoB connector 24b. Therefore, the head unit 20 described below receives control signals Ctrl-H including ejection control signals DATA1 to DATA12, drive signals COMA1 to COMA12, COMB1 to COMB12, and reference voltage signals VBS1 to VBS12 from the control unit 10.

[0064] As shown in FIG. 5, the head unit 20 has a print head 23 and relay circuit boards 22a and 22b.

[0065] The relay circuit board 22a has a wiring board 220a, four FFC connectors 260a, and a BtoB plug 242a. The four FFC connectors 260a are located on the -Z side surface of the wiring board 220a. Some of the above-mentioned multiple FFCs 15 are attached to each of the four FFC connectors 260a. The BtoB plug 242a is located on the +Z side surface of the wiring board 220a. The BtoB plug 242a corresponds to the plug of the above-mentioned BtoB connector 24a, and is electrically connected to the print head 23. The relay circuit board 22a configured as above relays a signal input from the control unit 10 via the four FFC connectors 260a, and outputs the signal to the print head 23 via the BtoB connector 24a including the BtoB plug 242a. That is, relay circuit board 22a has four FFC connectors 260a electrically connected to control unit 10, and BtoB plug 242a electrically connected to print head 23. In the following description, the surface on the -Z side of wiring board 220a may be referred to as the front surface of wiring board 220a, and the surface on the +Z side of wiring board 220a may be referred to as the back surface of wiring board 220a.

[0066] The relay circuit board 22b has a wiring board 220b, four FFC connectors 260b, and a BtoB plug 242b. The four FFC connectors 260b are located on the -Z side of the wiring board 220b. Some of the above-mentioned multiple FFCs 15 are attached to each of the four FFC connectors 260b. The BtoB plug 242b is located on the +Z side of the wiring board 220b. The BtoB plug 242b corresponds to the plug of the BtoB connector 24b described above, and is electrically connected to the print head 23. The relay circuit board 22b configured as above relays a signal input from the control unit 10 via the four FFC connectors 260b, and outputs the signal to the print head 23 via the BtoB connector 24b including the BtoB plug 242b. That is, relay circuit board 22b has four FFC connectors 260b electrically connected to control unit 10, and BtoB plug 242b electrically connected to print head 23. In the following description, the surface on the -Z side of wiring board 220b may be referred to as the front surface of wiring board 220b, and the surface on the +Z side of wiring board 220b may be referred to as the back surface of wiring board 220b.

[0067] The print head 23 includes a head substrate 230 and an ejection head module 250 .

[0068] The head substrate 230 has a surface 235 located on the -Z side and a surface 236 located on the +Z side different from the surface 235. A BtoB socket 241a and a BtoB socket 241b are located on the surface 235 of the head substrate 230. Then, the BtoB socket 241a is fitted into the BtoB plug 242a of the relay circuit substrate 22a, so that the BtoB connector 24a electrically connects the relay circuit substrate 22a to the head substrate 230, and the BtoB socket 241b is fitted into the BtoB plug 242b of the relay circuit substrate 22b, so that the BtoB connector 24b electrically connects the relay circuit substrate 22b to the head substrate 230. As a result, the control signal Ctrl-H relayed by the relay circuit substrates 22a and 22b is input to the head substrate 230.

[0069] The ejection head module 250 is located on the surface 236 of the head substrate 230. The above-mentioned ejection heads 25-1 to 25-12 are provided inside this ejection head module 250. In other words, the ejection head module 250 has the ejection heads 25-1 to 25-12. An ink ejection surface 252 is located on the +Z side of the ejection head module 250. Nozzles 651 of a plurality of ejection units 600 of each of the ejection heads 25-1 to 25-12 are exposed from this ink ejection surface 252.

[0070] Fig. 6 is a diagram showing an example of the configuration of the ink ejection surface 252. As shown in Fig. 6, the ink ejection surface 252 has nozzle rows L1 to L12 formed thereon.

[0071] The nozzle row L1 is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L2 is located on the −X side of the nozzle row L1, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L3 is located on the −X side of the nozzle row L2, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L4 is located on the −X side of the nozzle row L3, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L5 is located on the −X side of the nozzle row L4, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L6 is located on the −X side of the nozzle row L5, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L7 is located on the -X side of the nozzle row L6, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L8 is located on the -X side of the nozzle row L7, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L9 is located on the -X side of the nozzle row L8, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L10 is located on the -X side of the nozzle row L9, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L11 is located on the -X side of the nozzle row L10, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis. The nozzle row L12 is located on the -X side of the nozzle row L11, and is configured by arranging a plurality of nozzles 651 formed in the nozzle plate 632 in parallel along the Y axis.

[0072] That is, on the ink ejection surface 252, nozzle rows L1 to L12 each configured by arranging a plurality of nozzles 651 in parallel along the Y axis are arranged from the -X side to the +X side along the X axis in the order of nozzle rows L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, and L12. Note that, although Fig. 6 illustrates an example in which the plurality of nozzles 651 are arranged in a single row along the Y axis in each of the nozzle rows L1 to L12, the plurality of nozzles 651 may be arranged in two or more rows along the Y axis in each of the nozzle rows L1 to L12.

[0073] Here, in the head unit 20 of this embodiment, the multiple nozzles 651 constituting the nozzle row L1 are constituted by the multiple nozzles 651 possessed by the ejection head 25-1, and similarly, the multiple nozzles 651 constituting the nozzle row Lj (j is any of 2 to 12) are constituted by the multiple nozzles 651 possessed by the ejection head 25-j. That is, the multiple nozzles 651 constituting the nozzle row L1 eject ink in response to the ejection control signal DATA1, the drive signals COMA1, COMB1, and the reference voltage signal VBS1, and the multiple nozzles 651 constituting the nozzle row Lj eject ink in response to the ejection control signal DATAj, the drive signals COMAj, COMBj, and the reference voltage signal VBSj.

[0074] Next, an example of the configuration of the head substrate 230 will be described. FIG. 7 is a diagram showing an example of the structure of the head substrate 230. FIG. 7 shows the head substrate 230 viewed from the surface 235 side. The head substrate 230 is rectangular and includes a side 231 extending along the X axis, a side 232 facing the side 231 and extending along the X axis, a side 233 extending along the Y axis, and a side 234 facing the side 233 and extending along the Y axis. The shape of the head substrate 230 is not limited to a rectangular shape, and may be a polygon such as a hexagon or an octagon, and may further include a notch, an arc, or the like.

[0075] The head substrate 230 has insertion holes 237a to 237f and electrode groups 238-1 to 238-12.

[0076] Each of the electrode groups 238-1 to 238-12 has a plurality of electrodes arranged side by side along the Y axis. The electrode groups 238-1 to 238-12 are arranged in the order of the electrode groups 238-1, 238-2, 238-3, 238-4, 238-5, 238-6, 238-7, 238-8, 238-9, 238-10, 238-11, and 238-12 from the side 233 to the side 234.

[0077] The through holes 237a to 237f are through holes penetrating the surface 235 and the surface 236 of the head substrate 230. The through hole 237a is located between the electrode group 238-1 and the electrode group 238-2 in the direction along the X axis. The through hole 237b is located between the electrode group 238-3 and the electrode group 238-4 in the direction along the X axis. The through hole 237c is located between the electrode group 238-5 and the electrode group 238-6 in the direction along the X axis. The through hole 237d is located between the electrode group 238-7 and the electrode group 238-8 in the direction along the X axis. The through hole 237e is located between the electrode group 238-9 and the electrode group 238-10 in the direction along the X axis. The insertion hole 237f is located between the electrode group 238-11 and the electrode group 238-12 in the direction along the X-axis.

[0078] In the head substrate 230 configured as above, one end of a flexible printed circuit (FPC: Flexible Printed Circuit) (not shown) is electrically connected to each of the electrode groups 238-1 to 238-12. The other end of the FPC electrically connected to the electrode group 238-1 and the other end of the FPC electrically connected to the electrode group 238-2 are inserted through the insertion hole 237a and electrically connected to the ejection head module 250. The other end of the FPC electrically connected to the electrode group 238-3 and the other end of the FPC electrically connected to the electrode group 238-4 are inserted through the insertion hole 237b and electrically connected to the ejection head module 250. The other end of the FPC electrically connected to the electrode group 238-5 and the other end of the FPC electrically connected to the electrode group 238-6 are inserted through the insertion hole 237c and electrically connected to the ejection head module 250. Moreover, the other end of the FPC electrically connected to electrode group 238-7 and the other end of the FPC electrically connected to electrode group 238-8 are inserted through insertion hole 237d and electrically connected to the ejection head module 250. Moreover, the other end of the FPC electrically connected to electrode group 238-9 and the other end of the FPC electrically connected to electrode group 238-10 are inserted through insertion hole 237e and electrically connected to the ejection head module 250. Moreover, the other end of the FPC electrically connected to electrode group 238-11 and the other end of the FPC electrically connected to electrode group 238-12 are inserted through insertion hole 237f and electrically connected to the ejection head module 250.

[0079] Specifically, the other end of the FPC electrically connected to the electrode group 238-1 and inserted through the insertion hole 237a is electrically connected to the ejection head 25-1 of the ejection head module 250. The FPC electrically connected to the electrode group 238-1 transmits to the ejection head 25-1 an ejection control signal DATA1, drive signals COMA1 and COMB1, and a reference voltage signal VBS1 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L1. This controls the ejection of ink from the ejection head 25-1, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L1.

[0080] Similarly, the other end of the FPC electrically connected to the electrode group 238-2 and inserted through the insertion hole 237a is electrically connected to the ejection head 25-2 of the ejection head module 250. The FPC electrically connected to the electrode group 238-2 transmits to the ejection head 25-2 an ejection control signal DATA2, drive signals COMA2 and COMB2, and a reference voltage signal VBS2 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L2. This controls the ejection of ink from the ejection head 25-2, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L2.

[0081] Similarly, the other end of the FPC electrically connected to the electrode group 238-3 and inserted through the insertion hole 237b is electrically connected to the ejection head 25-3 of the ejection head module 250. The FPC electrically connected to the electrode group 238-3 transmits to the ejection head 25-3 an ejection control signal DATA3, drive signals COMA3 and COMB3, and a reference voltage signal VBS3 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L3. This controls the ejection of ink from the ejection head 25-3, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L3.

[0082] Similarly, the other end of the FPC electrically connected to the electrode group 238-4 and inserted through the insertion hole 237b is electrically connected to the ejection head 25-4 of the ejection head module 250. The FPC electrically connected to the electrode group 238-4 transmits to the ejection head 25-4 an ejection control signal DATA4, drive signals COMA4, COMB4, and a reference voltage signal VBS4 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L4. This controls the ejection of ink from the ejection head 25-4, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L4.

[0083] Similarly, the other end of the FPC electrically connected to the electrode group 238-5 and inserted through the insertion hole 237c is electrically connected to the ejection head 25-5 of the ejection head module 250. The FPC electrically connected to the electrode group 238-5 transmits to the ejection head 25-5 an ejection control signal DATA5, drive signals COMA5 and COMB5, and a reference voltage signal VBS5 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L5. This controls the ejection of ink from the ejection head 25-5, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L5.

[0084] Similarly, the other end of the FPC electrically connected to the electrode group 238-6 and inserted through the insertion hole 237c is electrically connected to the ejection head 25-6 of the ejection head module 250. The FPC electrically connected to the electrode group 238-6 transmits to the ejection head 25-6 an ejection control signal DATA6, drive signals COMA6, COMB6, and a reference voltage signal VBS6 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L6. This controls the ejection of ink from the ejection head 25-6, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L6.

[0085] Similarly, the other end of the FPC electrically connected to the electrode group 238-7 and inserted through the insertion hole 237d is electrically connected to the ejection head 25-7 of the ejection head module 250. The FPC electrically connected to the electrode group 238-7 transmits to the ejection head 25-7 an ejection control signal DATA7, drive signals COMA7 and COMB7, and a reference voltage signal VBS7 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L7. This controls the ejection of ink from the ejection head 25-7, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L7.

[0086] Similarly, the other end of the FPC electrically connected to the electrode group 238-8 and inserted through the insertion hole 237d is electrically connected to the ejection head 25-8 of the ejection head module 250. The FPC electrically connected to the electrode group 238-8 transmits to the ejection head 25-8 an ejection control signal DATA8, drive signals COMA8, COMB8, and a reference voltage signal VBS8 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L8. This controls the ejection of ink from the ejection head 25-8, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L8.

[0087] Similarly, the other end of the FPC electrically connected to the electrode group 238-9 and inserted through the insertion hole 237e is electrically connected to the ejection head 25-9 of the ejection head module 250. The FPC electrically connected to the electrode group 238-9 transmits to the ejection head 25-9 an ejection control signal DATA9, drive signals COMA9, COMB9, and a reference voltage signal VBS9 that control the ejection of ink from the multiple nozzles 651 that make up the nozzle row L9. This controls the ejection of ink from the ejection head 25-9, that is, the ejection of ink from the multiple nozzles 651 that make up the nozzle row L9.

[0088] Similarly, the other end of the FPC electrically connected to the electrode group 238-10 and inserted through the insertion hole 237e is electrically connected to the ejection head 25-10 of the ejection head module 250. The FPC electrically connected to the electrode group 238-10 transmits to the ejection head 25-10 an ejection control signal DATA10, drive signals COMA10, COMB10, and a reference voltage signal VBS10 that control the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L10. This controls the ejection of ink from the ejection head 25-10, that is, the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L10.

[0089] Similarly, the other end of the FPC electrically connected to the electrode group 238-11 and inserted through the insertion hole 237f is electrically connected to the ejection head 25-11 of the ejection head module 250. The FPC electrically connected to the electrode group 238-11 transmits to the ejection head 25-11 an ejection control signal DATA11, drive signals COMA11, COMB11, and a reference voltage signal VBS11 that control the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L11. This controls the ejection of ink from the ejection head 25-11, that is, the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L11.

[0090] Similarly, the other end of the FPC electrically connected to the electrode group 238-12 and inserted through the insertion hole 237f is electrically connected to the ejection head 25-12 of the ejection head module 250. The FPC electrically connected to the electrode group 238-12 transmits to the ejection head 25-12 an ejection control signal DATA12, drive signals COMA12, COMB12, and a reference voltage signal VBS12 that control the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L12. This controls the ejection of ink from the ejection head 25-12, that is, the ejection of ink from the multiple nozzles 651 that constitute the nozzle row L12.

[0091] As described above, the head substrate 230 branches the control signals Ctrl-H, which include the ejection control signals DATA1 to DATA12, the drive signals COMA1 to COMA12, COMB1 to COMB12, and the reference voltage signals VBS1 to VBS12 input from the control unit 10 via the relay circuit substrates 22a, 22b, into signals corresponding to each of the ejection heads 25-1 to 25-12, and supplies them to the corresponding ejection heads 25-1 to 25-12.

[0092] Here, the drive signal selection circuit 200 provided in each of the ejection heads 25-1 to 25-12 may be configured with one or more integrated circuits, and may be mounted by COF (Chip On Film) on the FPC corresponding to each of the ejection heads 25-1 to 25-12.

[0093] Furthermore, on a surface 235 of the head substrate 230, BtoB sockets 241a and 241b are provided.

[0094] The BtoB socket 241a is located on the side 233 side of the insertion holes 237a to 237f and the electrode groups 238-1 to 238-12 in the head substrate 230. The BtoB socket 241b is located on the side 234 side of the insertion holes 237a to 237f and the electrode groups 238-1 to 238-12 in the head substrate 230. Therefore, in the head unit 20, the relay circuit board 22a, which is electrically connected to the head substrate 230 via the BtoB connector 24a including the BtoB socket 241a, is located on the side 233 side of the insertion holes 237a to 237f and the electrode groups 238-1 to 238-12, and the relay circuit board 22b, which is electrically connected to the head substrate 230 via the BtoB connector 24b including the BtoB socket 241b, is located on the side 234 side of the insertion holes 237a to 237f and the electrode groups 238-1 to 238-12.

[0095] In the head unit 20 configured as above, the control signals Ctrl-H including the ejection control signals DATA1-DATA12, the drive signals COMA1-COMA12, COMB1-COMB12, and the reference voltage signals VBS1-VBS12 output by the control unit 10 are input to the relay circuit boards 22a and 22b. Then, the control signals Ctrl-H including the ejection control signals DATA1-DATA12, the drive signals COMA1-COMA12, COMB1-COMB12, and the reference voltage signals VBS1-VBS12 are relayed by the relay circuit boards 22a and 22b, and then input to the head board 230 of the print head 23 via the BtoB connectors 24a and 24b. The head substrate 230 propagates the control signal Ctrl-H, which includes the input ejection control signals DATA1 to DATA12, the drive signals COMA1 to COMA12, COMB1 to COMB12, and the reference voltage signals VBS1 to VBS12, and branches the signals corresponding to the ejection heads 25-1 to 25-12, and supplies the branched signals to the corresponding ejection heads 25-1 to 25-12. This controls the ejection of ink from each of the ejection heads 25-1 to 25-12.

[0096] At this time, among the control signals Ctrl-H including the ejection control signals DATA1 to DATA12, the drive signals COMA1 to COMA12, COMB1 to COMB12, and the reference voltage signals VBS1 to VBS12 output by the control unit 10, it is preferable that the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 input to the ejection heads 25-1 to 25-6 are relayed by the relay circuit board 22a and then input to the head substrate 230, and it is preferable that the ejection control signals DATA7 to DATA12, the drive signals COMA7 to COMA12, COMB7 to COMB12, and the reference voltage signals VBS7 to VBS12 input to the ejection heads 25-7 to 25-12 are relayed by the relay circuit board 22b and then input to the head substrate 230.

[0097] In the head substrate 230, insertion holes 237a to 237c through which the FPCs corresponding to the ejection heads 25-1 to 25-6 are inserted are positioned closer to side 233 than insertion holes 237d to 237f through which the FPCs corresponding to the ejection heads 25-7 to 25-12 are inserted. In other words, the ejection heads 25-1 to 25-6 are electrically connected to the head substrate 230 closer to side 233 than the ejection heads 25-7 to 25-12. For such a head substrate 230, the relay circuit board 22a electrically connected to the head substrate 230 on the side 233 side of the head substrate 230 relays the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 input to the ejection heads 25-1 to 25-6, thereby shortening the propagation paths of the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 in the head substrate 230. As a result, the risk of noise being superimposed on the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 is reduced, and the signal accuracy of the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 input to the ejection heads 25-1 to 25-6 is improved.

[0098] Similarly, in the head substrate 230, insertion holes 237d to 237f, through which the FPCs corresponding to the ejection heads 25-7 to 25-12 are inserted, are positioned closer to side 234 than insertion holes 237a to 237c, through which the FPCs corresponding to the ejection heads 25-1 to 25-6 are inserted. In other words, the ejection heads 25-7 to 25-12 are electrically connected to the head substrate 230 closer to side 234 than the ejection heads 25-1 to 25-6. For such a head substrate 230, the relay circuit board 22b electrically connected to the head substrate 230 on the side 234 of the head substrate 230 relays the ejection control signals DATA7 to DATA12, drive signals COMA7 to COMA12, COMB7 to COMB12, and reference voltage signals VBS7 to VBS12 input to the ejection heads 25-7 to 25-12, thereby shortening the propagation paths of the ejection control signals DATA7 to DATA12, drive signals COMA7 to COMA12, COMB7 to COMB12, and reference voltage signals VBS7 to VBS12 in the head substrate 230. As a result, the risk of noise being superimposed on the ejection control signals DATA7 to DATA12, the drive signals COMA7 to COMA12, COMB7 to COMB12, and the reference voltage signals VBS7 to VBS12 is reduced, and the signal accuracy of the ejection control signals DATA7 to DATA12, the drive signals COMA7 to COMA12, COMB7 to COMB12, and the reference voltage signals VBS7 to VBS12 input to the ejection heads 25-7 to 25-12 is improved.

[0099] 5. Clamp circuit configuration and operation In the large format printer 1 configured as described above, the carriage 21 carrying the head unit 20 moves over the width of the medium P. Therefore, the FFC 15 electrically connecting the control unit 10 and the head unit 20, the wiring length of the FFC 15 transmitting the drive signals COMA and COMB to the head unit 20, may exceed 2 m. Therefore, the inductance component of the FFC 15 transmitting the drive signals COMA and COMB to the head unit 20 becomes large. As a result, in the large format printer 1 as described in the present embodiment, there is a risk that an overshoot voltage of a large voltage value may occur in the drive signals COMA and COMB, which may reduce the stability of the operation of the large format printer 1. Furthermore, when the overshoot voltage occurs in the drive signals COMA and COMB, the overshoot voltage may distort the signal waveform of the drive signals COMA and COMB, which may result in a deterioration in the accuracy of ink ejection from the head unit 20.

[0100] Here, if the voltage value of the overshoot voltage occurring in the drive signals COMA and COMB is constant, it may be possible to reduce the voltage value of the overshoot voltage by correcting the voltage value of the drive signals COMA and COMB output in the drive circuit 50. However, in the case of a so-called serial type large format printer 1 in which the carriage 21 mounted with the head unit 20 as shown in this embodiment moves, the FFC 15 deforms with the movement of the carriage 21, so that the inductance component occurring in the FFC 15 propagating the drive signals COMA and COMB also changes, and as a result, the voltage value of the overshoot voltage occurring in the drive signals COMA and COMB also changes. Furthermore, if the number of piezoelectric elements 60 driven by the drive signal VOUT based on the drive signals COMA and COMB changes, the amount of current occurring with the propagation of the drive signals COMA and COMB changes. The voltage value of the overshoot voltage occurring in the drive signals COMA and COMB is the change in the amount of current occurring with the propagation of the drive signals COMA and COMB, and also changes due to the change in the amount of current propagated by the FFC 15. For this reason, it is not easy for the drive circuit 50 to correct the voltage values ​​of the drive signals COMA and COMB to be output and to reduce the voltage value of the overshoot voltage occurring in the drive signals COMA and COMB.

[0101] In contrast, in the large format printer 1 of this embodiment, the relay circuit board 22a and the relay circuit board 22b each have a clamp circuit 300 that limits the overshoot voltage generated in the drive signals COMA, COMB. This clamp circuit 300 limits the voltage value of the overshoot voltage generated in the drive signals COMA, COMB, thereby reducing the risk of a decrease in the stability of the operation of the large format printer 1 and a decrease in the accuracy of ink ejection from the head unit 20.

[0102] An example of the configuration of the clamp circuit 300 that limits the voltage value of the overshoot voltage generated in the drive signals COMA and COMB will be described. In the large format printer 1 of this embodiment, the relay circuit board 22a and the relay circuit board 22b have the same configuration, except that the signals input thereto are different. Therefore, the clamp circuit 300 of the relay circuit board 22a and the clamp circuit 300 of the relay circuit board 22b have the same configuration. Therefore, in the following explanation, only the configuration of the clamp circuit 300 of the relay circuit board 22a will be explained, and an explanation of the configuration of the clamp circuit 300 of the relay circuit board 22b will be omitted. In other words, only the configuration and operation of the clamp circuit 300 of the relay circuit board 22a that propagates the ejection control signals DATA1 to DATA6, drive signals COMA1 to COMA6, COMB1 to COMB6, and reference voltage signals VBS1 to VBS6 input to the ejection heads 25-1 to 25-6 will be explained, and an explanation of the configuration and operation of the clamp circuit 300 of the relay circuit board 22b that propagates the ejection control signals DATA7 to DATA12, drive signals COMA7 to COMA12, COMB7 to COMB12, and reference voltage signals VBS7 to VBS12 input to the ejection heads 25-7 to 25-12 will be omitted.

[0103] 8 is a diagram showing an example of a configuration of the clamp circuit 300. The clamp circuit 300 has limiting circuits 310a1 to 310a6 and 310b1 to 310b6.

[0104] The limiting circuit 310a1 includes a diode Da1 and a capacitor Ca1. The anode terminal of the diode Da1 is electrically connected to the wiring Wa1 through which the drive signal COMA1 propagates. The cathode terminal of the diode Da1 is electrically connected to the wiring WH through which the voltage signal VHV propagates. One end of the capacitor Ca1 is electrically connected to the wiring WH. The other end of the capacitor Ca1 is electrically connected to the wiring WG at the ground potential. The limiting circuit 310a1 configured as described above limits the voltage value of an overshoot voltage that may occur in the drive signal COMA1. In other words, the limiting circuit 310a1 includes the diode Da1 and the capacitor Ca1, and limits the voltage value of the drive signal COMA1.

[0105] The limiting circuit 310b1 includes a diode Db1 and a capacitor Cb1. The anode terminal of the diode Db1 is electrically connected to the wiring Wb1 through which the drive signal COMB1 propagates. The cathode terminal of the diode Db1 is electrically connected to the wiring WH. One end of the capacitor Cb1 is electrically connected to the wiring WH. The other end of the capacitor Cb1 is electrically connected to the wiring WG. The limiting circuit 310b1 configured as described above limits the voltage value of an overshoot voltage that may occur in the drive signal COMB1. In other words, the limiting circuit 310b1 includes the diode Db1 and the capacitor Cb1, and limits the voltage value of the drive signal COMB1.

[0106] Similarly, the limiting circuit 310ak (k is any one of 1 to 6) includes a diode Dak and a capacitor Cak. The anode terminal of the diode Dak is electrically connected to the wiring Wak through which the drive signal COMAk propagates. The cathode terminal of the diode Dak is electrically connected to the wiring WH. One end of the capacitor Cak is electrically connected to the wiring WH. The other end of the capacitor Cak is electrically connected to the wiring WG. The limiting circuit 310ak configured as above limits the voltage value of an overshoot voltage that may occur in the drive signal COMAk. In other words, the limiting circuit 310ak is provided on the surface 225 of the wiring board 220a, includes a diode Dak and a capacitor Cak, and limits the voltage value of the drive signal COMAk.

[0107] Similarly, the limiting circuit 310bk includes a diode Dbk and a capacitor Cbk. The anode terminal of the diode Dbk is electrically connected to the wiring Wbk through which the drive signal COMBk propagates. The cathode terminal of the diode Dbk is electrically connected to the wiring WH. One end of the capacitor Cbk is electrically connected to the wiring WH. The other end of the capacitor Cbk is electrically connected to the wiring WG. The limiting circuit 310bk configured as above limits the voltage value of an overshoot voltage that may occur in the drive signal COMBk. In other words, the limiting circuit 310bk is provided on the surface 225 of the wiring board 220a, includes a diode Dbk and a capacitor Cbk, and limits the voltage value of the drive signal COMBk.

[0108] That is, the clamp circuit 300 has limiting circuits 310a1-310a6, 310b1-310b6 corresponding to the drive signals COMA1-COMA6, COMB1-COMB6, respectively. Each of the limiting circuits 310a1-310a6, 310b1-310b6 has diodes Da1-Da6, Db1-Db6 whose anode terminals are electrically connected to the wiring pattern through which the corresponding drive signals COMA1-COMA6, COMB1-COMB6 propagate and whose cathode terminals are electrically connected to the wiring pattern through which the voltage signal VHV propagates, and capacitors Ca1-Ca6 whose one end is electrically connected to the wiring pattern through which the voltage signal VHV propagates and whose other end is electrically connected to the wiring pattern at ground potential. That is, one ends of the capacitors Ca1 to Ca6 and Cb1 to Cb6 are electrically connected, and the other ends of the capacitors Ca1 to Ca6 and Cb1 to Cb6 are electrically connected in the clamp circuit 300. In other words, the capacitors Ca1 to Ca6 and Cb1 to Cb6 are connected in parallel between the wiring pattern through which the voltage signal VHV propagates and the wiring pattern of the ground potential.

[0109] As described above, the limiting circuits 310a1-310a6 and 310b1-310b6 have the same configuration. Therefore, in the following description, when there is no need to distinguish between the limiting circuits 310a1-310a6 and 310b1-310b6, they may be simply referred to as limiting circuits 310. In this case, the limiting circuit 310 will be described as having a diode D and a capacitor C.

[0110] Next, the operation of limiting the voltage value of the overshoot voltage generated by the drive signals COMA and COMB in the limiting circuit 310 will be described. Here, in describing the operation of limiting the voltage value of the overshoot voltage generated by the drive signals COMA and COMB in the limiting circuit 310, the following description will be given using the drive signal COM, which is a simplified signal waveform of the drive signals COMA and COMB. In this case, the description will be given assuming that the drive signal COM propagates through the wiring Wc, which is the wirings Wa1 to Wa6 and Wb1 to Wb6. In other words, the description will be given assuming that the drive signal COM propagates through the wiring Wc to which the anode terminal of the diode D is connected.

[0111] Fig. 9 is a diagram showing an example of the signal waveform of the drive signal COM, which is a simplification of the drive signals COMA and COMB output by the drive circuit 50, and is a diagram showing an example of the signal waveform of the drive signal COM before it is propagated through the FFC 15. Fig. 10 is a diagram showing an example of the signal waveform of the drive signal COM input to the print head 23 after it has propagated through the FFC 15.

[0112] As shown in Fig. 9, the drive signal COM output by the drive circuit 50 before it propagates through the FFC 15 includes a signal waveform whose voltage value changes between voltage Vcmax and voltage Vcmin. No overshoot voltage occurs in the signal waveform included in this drive signal COM. However, in the large format printer 1, the FFC 15 that electrically connects the control unit 10 and the head unit 20 is very long, and therefore the inductance component caused by the FFC 15 is very large. Therefore, a very large overshoot voltage occurs in the signal waveform of the drive signal COM that has propagated through the FFC 15 and is input to the print head 23, as shown in Fig. 10.

[0113] Voltage Vos, which is the maximum voltage value of the overshoot voltage generated in the signal waveform of this type of drive signal COM, may exceed the absolute maximum rated voltage of the integrated circuits that make up the drive signal selection circuit 200. If voltage Vos exceeds the absolute maximum rated voltage of the integrated circuits that make up the drive signal selection circuit 200, the stability of the operation of the integrated circuits that make up the drive signal selection circuit 200 decreases, and as a result, the stability of the operation of the large format printer 1 decreases.

[0114] In contrast, in the large format printer 1 of this embodiment, the clamp circuit 300 limits the voltage value of the overshoot voltage to the sum of voltage Vh, which is the voltage value of the voltage signal VHV, and voltage Vf, which is the forward drop voltage of diode D.

[0115] Specifically, when the voltage value of the overshoot voltage exceeds the sum of voltages Vh and Vf, a current flows through diode D. As a result, the voltage value of the drive signal COM is limited to the sum of voltages Vh and Vf. That is, diode D functions as a clamp diode that clamps the voltage value of the drive signal COM to be equal to or lower than the sum of voltages Vh and Vf.

[0116] At this time, the capacitor C smoothes the current flowing into the wiring WH via the diode D by regenerating the current into the wiring WG, which is at ground potential. This reduces the risk that the voltage value of the voltage signal VHV will fluctuate due to the current flowing through the diode D, and stabilizes the voltage value of the voltage signal VHV. In other words, the capacitor C functions as a stabilizing capacitor that stabilizes the voltage value of the voltage signal VHV, and also functions as a regenerative capacitor that regenerates the current flowing into the wiring WH.

[0117] It is preferable that such a capacitor C has a large capacitance so that a current caused by an overshoot voltage can flow. In the clamp circuit 300 of this embodiment, the capacitors Ca1 to Ca6 and Cb1 to Cb6 are connected in parallel between the wiring pattern through which the voltage signal VHV propagates and the wiring pattern of the ground potential. This ensures a large capacitance when viewed as a whole of the clamp circuit 300, further reducing the risk of the voltage value of the voltage signal VHV fluctuating.

[0118] The clamp circuit 300 and limiting circuit 310 configured as described above can limit the voltage value of the overshoot voltage generated in the drive signal COM to less than or equal to the absolute maximum rated voltage of the integrated circuits that make up the drive signal selection circuit 200. As a result, the risk of a decrease in the stability of the operation of the integrated circuits that make up the drive signal selection circuit 200 is reduced, which in turn reduces the risk of a decrease in the stability of the operation of the large format printer 1, as well as reducing the risk of distortion of the signal waveform of the drive signal COM and reducing the risk of a decrease in the accuracy of ink ejection from the print head 23.

[0119] Moreover, it is preferable that the voltage Vf, which is the forward drop voltage of the diode D of the limiting circuit 310, is set lower than the forward drop voltage of a parasitic diode that is parasitic between the wiring Wc through which the drive signal COM propagates and the wiring WH through which the voltage signal VHV propagates, inside the integrated circuit that constitutes the drive signal selection circuit 200. This further reduces the risk of current flowing through the parasitic diode inside the integrated circuit that constitutes the drive signal selection circuit 200, and further reduces the risk of the integrated circuit that constitutes the drive signal selection circuit 200 failing. As such a diode D, a Schottky diode with a small forward drop voltage can be used.

[0120] 6. Clamp circuit layout on relay circuit board Next, a specific example of the arrangement of the clamp circuit 300 in the relay circuit board 22a will be described. Fig. 11 is a diagram showing an example of the configuration of the relay circuit board 22a when the wiring board 220a is viewed from the front side. As shown in Fig. 11, the relay circuit board 22a has a wiring board 220a, FFC connectors 260a-1 to 260a-4, diodes Da1 to Da6, Db1 to Db6, and capacitors Ca1 to Ca6, Cb1 to Cb6. Although not shown in Fig. 11, the relay circuit board 22a has a BtoB plug 242a provided on the back side of the wiring board 220a. That is, in the relay circuit board 22a, the FFC connectors 260a-1 to 260a-4, the limiting circuits 310a1 to 310a6, 310b1 to 310b6 including the diodes Da1 to Da6, Db1 to Db6, and the capacitors Ca1 to Ca6, Cb1 to Cb6, and the BtoB plug 242a are provided on the wiring board 220a. At this time, the FFC connectors 260a-1 to 260a-4, the limiting circuits 310a1 to 310a6, 310b1 to 310b6 including the diodes Da1 to Da6, Db1 to Db6, and the capacitors Ca1 to Ca6, Cb1 to Cb6 are provided on the front surface of the wiring board 220a, and the BtoB plug 242a is provided on the back surface of the wiring board 220a.

[0121] The wiring board 220a includes sides 221 to 224 and faces 225 and 226. The face 225 corresponds to the front surface of the wiring board 220a described above, and the face 226 corresponds to the back surface of the wiring board 220a described above. The sides 221 and 222 face each other, and the sides 223 and 224 face each other. At this time, the side 221 is longer than the sides 223 and 224 and intersects with both the sides 223 and 224, and the side 222 is longer than the sides 223 and 224 and intersects with both the sides 223 and 224. That is, the wiring board 220a includes the face 225 and the face 226 different from the face 225, and is a substantially rectangular shape in which the sides 221 and 222 are long sides and the sides 223 and 224 are short sides. In other words, the wiring board 220a includes a side 221, a side 222 facing the side 221, a side 223, a side 224 facing the side 223, a surface 225, and a surface 226 different from the surface 225, and the side 223 intersects with both the side 221 and the side 222, and the side 224 intersects with both the side 221 and the side 222. The wiring board 220a is not limited to a rectangular shape, and may be a polygon such as a hexagon or an octagon, and may further include a notch, an arc, or the like. Such a wiring board 220a is attached to the head substrate 230 so that the side 221 and the side 222 extend along the side 233 of the head substrate 230.

[0122] The FFC connector 260a-1 has terminals 261a-1 to 261a-24. The FFC connector 260a-1 is provided on the surface 225 of the wiring board 220a such that the terminals 261a-1 to 261a-24 are arranged in the order of terminal 261a-1, terminal 261a-2, ..., terminal 261a-23, and terminal 261a-24 from the side 223 to the side 224. That is, the terminals 261a-1 to 261a-24 of the FFC connector 260a-1 are arranged in the direction from the side 223 to the side 224, along the longitudinal direction of the wiring board 220a. The terminals 261a-1 to 261a-24 of the FFC connector 260a-1 may be arranged in two rows or in a staggered manner along the direction from the side 223 to the side 224.

[0123] FFC connector 260a-2 has terminals 262a-1 to 262a-24. FFC connector 260a-2 is located on side 222 of FFC connector 260a-1 on surface 225 of wiring board 220a, and terminals 262a-1 to 262a-24 are arranged side by side from side 223 to side 224 in the order of terminal 262a-1, terminal 262a-2, ..., terminal 262a-23, terminal 262a-24. In other words, terminals 262a-1 to 262a-24 of FFC connector 260a-2 are arranged side by side along the longitudinal direction of wiring board 220a in the direction from side 223 to side 224. The terminals 262a-1 to 262a-24 of the FFC connector 260a-2 may be arranged in two rows along the direction from the side 223 to the side 224, or may be arranged in a staggered pattern.

[0124] FFC connector 260a-3 has terminals 263a-1 to 263a-24. FFC connector 260a-3 is located on side 224 of FFC connector 260a-1 on surface 225 of wiring board 220a, and terminals 263a-1 to 263a-24 are arranged side by side from side 223 to side 224 in the order of terminal 263a-1, terminal 263a-2, ..., terminal 263a-23, terminal 263a-24. In other words, terminals 263a-1 to 263a-24 of FFC connector 260a-3 are arranged side by side along the longitudinal direction of wiring board 220a in the direction from side 223 to side 224. The terminals 263a-1 to 263a-24 of the FFC connector 260a-3 may be arranged in two rows along the direction from the side 223 to the side 224, or may be arranged in a staggered pattern.

[0125] FFC connector 260a-4 has terminals 264a-1 to 264a-24. FFC connector 260a-4 is located on side 224 of FFC connector 260a-2 on surface 225 of wiring board 220a, and terminals 264a-1 to 264a-24 are arranged side by side from side 223 to side 224 in the order of terminal 264a-1, terminal 264a-2, ..., terminal 264a-23, terminal 264a-24. In other words, terminals 264a-1 to 264a-24 of FFC connector 260a-4 are arranged side by side along the longitudinal direction of wiring board 220a in the direction from side 223 to side 224. The terminals 264a-1 to 264a-24 of the FFC connector 260a-4 may be arranged in two rows along the direction from the side 223 to the side 224, or may be arranged in a staggered pattern.

[0126] A plurality of FFCs 15 are attached to each of the FFC connectors 260a-1 to 260a-4 arranged as described above, which transmit the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6 output by the control unit 10. That is, the FFC connectors 260a-1 to 260a-4 are electrically connected to the control unit 10, and receive the ejection control signals DATA1 to DATA6, the drive signals COMA1 to COMA6, COMB1 to COMB6, and the reference voltage signals VBS1 to VBS6.

[0127] Specifically, among the FFC connectors 260a-1 to 260a-4, the FFC connectors 260a-1 and 260a-2 located on the side 223 side are input with ejection control signals DATA1 to DATA6, various power supply voltage signals including a voltage signal VHV with a constant voltage value, and ground potential signals. On the other hand, among the FFC connectors 260a-1 to 260a-4, the FFC connectors 260a-3 and 260a-4 located on the side 224 side are input with drive signals COMA1 to COMA6, COMB1 to COMB6, and reference voltage signals VBS1 to VBS6 supplied to the piezoelectric element 60 of the print head 23.

[0128] Each of the ejection heads 25 has several hundred piezoelectric elements 60. That is, the drive signals COMA1 to COMA6, COMB1 to COMB6 and the reference voltage signals VBS1 to VBS6 are supplied to and drive several hundred piezoelectric elements 60. Therefore, a large current flows as the drive signals COMA1 to COMA6, COMB1 to COMB6 and the reference voltage signals VBS1 to VBS6 are propagated. The driving signals COMA1-COMA6, COMB1-COMB6, and reference voltage signals VBS1-VBS6 that generate such a large current are input to the relay circuit board 22a via the FFC connectors 260a-3 and 260a-4, and various power supply voltage signals including the discharge control signals DATA1-DATA6, which are logic signals with a small voltage value, and the voltage signal VHV, which has a constant voltage value, and the ground potential signal are input to the relay circuit board 22a via the FFC connectors 260a-1 and 260a-2, which are different from the FFC connectors 260a-3 and 260a-4, thereby reducing the possibility that the current generated by the propagation of the driving signals COMA1-COMA6, COMB1-COMB6, and the reference voltage signals VBS1-VBS6 will be superimposed on the discharge control signals DATA1-DATA6, which are logic signals with a small voltage value, and various power supply voltage signals including the voltage signal VHV, which has a constant voltage value. As a result, the signal accuracy of the discharge control signals DATA1-DATA6 and the voltage signal VHV is improved.

[0129] The clamp circuit 300, which limits the overshoot voltage generated in the drive signals COMA1 to COMA6, COMB1 to COMB6, is disposed on the surface 225 of the wiring board 220a near the FFC connectors 260a-3, 260a-4 to which the drive signals COMA1 to COMA6, COMB1 to COMB6 and the reference voltage signals VBS1 to VBS6 are input.

[0130] Specifically, the diode Da1 and capacitor Ca1 included in the limiting circuit 310a1 that limits the voltage value of the overshoot voltage generated in the drive signal COMA1 are positioned adjacent to each other in the vicinity of the FFC connector 260a to which the drive signal COMA1 is input, and the diode Db1 and capacitor Cb1 included in the limiting circuit 310b1 that limits the voltage value of the overshoot voltage generated in the drive signal COMB1 are positioned adjacent to each other in the vicinity of the FFC connector 260a to which the drive signal COMB1 is input. Similarly, the diode Dak and capacitor Cak included in the limiting circuit 310ak that limits the voltage value of the overshoot voltage generated in the drive signal COMAk are located adjacent to each other in the vicinity of the FFC connector 260a to which the drive signal COMAk is input, and the diode Dbk and capacitor Cbk included in the limiting circuit 310bk that limits the voltage value of the overshoot voltage generated in the drive signal COMBk are located adjacent to each other in the vicinity of the FFC connector 260a to which the drive signal COMBk is input.

[0131] In detail, the drive signal COMA1 is input to the terminals 263a-1 and 263a-3 of the FFC connector 260a-3. The terminals 263a-1 and 263a-3 are electrically connected to the wiring Wa1. The wiring Wa1 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA1 input to the terminals 263a-1 and 263a-3 propagates through the wiring Wa1 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0132] Furthermore, the diode Da1 and capacitor Ca1 of the limiting circuit 310a1 that limits the voltage value of the overshoot voltage of the drive signal COMA1 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMA1 is input, with the diode Da1 on the side 223 and the capacitor Ca1 on the side 224. In other words, the diode Da1 and the capacitor Ca1 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0133] The wiring Wa1 through which the drive signal COMA1 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Da1. The cathode terminal of the diode Da1 is electrically connected to the wiring WH located on the side 221 side of the wiring Wa1. One end of the capacitor Ca1 is electrically connected to the wiring WH. The other end of the capacitor Ca1 is electrically connected to the wiring WG located between the wiring Wa1 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMA1 in the wiring Wa1, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0134] At this time, in the FFC connector 260a-3, a reference voltage signal VBS1 corresponding to the drive signal COMA1 is input to the terminals 263a-2 and 263a-4 adjacent to the terminals 263a-1 and 263a-3 to which the drive signal COMA1 is input. The reference voltage signal VBS1 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS1 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0135] The drive signal COMB2 is input to the terminals 263a-5 and 263a-7 of the FFC connector 260a-3. The terminals 263a-5 and 263a-7 are electrically connected to the wiring Wb2. The wiring Wb2 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB2 input to the terminals 263a-5 and 263a-7 propagates through the wiring Wb2 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0136] Furthermore, the diode Db2 and capacitor Cb2 of the limiting circuit 310b2 that limits the voltage value of the overshoot voltage of the drive signal COMB2 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMB2 is input, and on the side 224 of the limiting circuit 310a1, with the diode Db2 on the side 223 and the capacitor Cb2 on the side 224. In other words, the diode Db2 and the capacitor Cb2 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Db2 and the capacitor Ca1 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0137] The wiring Wb2 through which the drive signal COMB2 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Db2. The cathode terminal of the diode Db2 is electrically connected to the wiring WH located on the side 221 side of the wiring Wb2. One end of the capacitor Cb2 is electrically connected to the wiring WH. The other end of the capacitor Cb2 is electrically connected to the wiring WG located between the wiring Wb2 and the wiring WH. As a result, even if an overshoot voltage occurs in the drive signal COMB2 in the wiring Wb2, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0138] At this time, in the FFC connector 260a-3, a reference voltage signal VBS2 corresponding to the drive signal COMB2 is input to the terminals 263a-6 and 263a-8 adjacent to the terminals 263a-5 and 263a-7 to which the drive signal COMB2 is input. The reference voltage signal VBS2 propagates through the wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS2 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0139] The drive signal COMA3 is input to the terminals 263a-9 and 263a-11 of the FFC connector 260a-3. The terminals 263a-9 and 263a-11 are electrically connected to the wiring Wa3. The wiring Wa3 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA3 input to the terminals 263a-9 and 263a-11 is propagated through the wiring Wa3 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0140] Furthermore, the diode Da3 and capacitor Ca3 of the limiting circuit 310a3 that limits the voltage value of the overshoot voltage of the drive signal COMA3 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMA3 is input, and on the side 224 of the limiting circuit 310b2, with the diode Da3 on the side 223 and the capacitor Ca3 on the side 224. That is, the diode Da3 and the capacitor Ca3 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Da3 and the capacitor Cb2 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0141] The wiring Wa3 through which the drive signal COMA3 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Da3. The cathode terminal of the diode Da3 is electrically connected to the wiring WH located on the side 221 side of the wiring Wa3. One end of the capacitor Ca3 is electrically connected to the wiring WH. The other end of the capacitor Ca3 is electrically connected to the wiring WG located between the wiring Wa3 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMA3 in the wiring Wa3, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0142] At this time, in the FFC connector 260a-3, a reference voltage signal VBS3 corresponding to the drive signal COMA3 is input to the terminals 263a-10 and 263a-12 adjacent to the terminals 263a-9 and 263a-11 to which the drive signal COMA3 is input. The reference voltage signal VBS3 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS3 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0143] The drive signal COMB4 is input to the terminals 263a-13 and 263a-15 of the FFC connector 260a-3. The terminals 263a-13 and 263a-15 are electrically connected to the wiring Wb4. The wiring Wb4 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB4 input to the terminals 263a-13 and 263a-15 propagates through the wiring Wb4 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0144] Furthermore, the diode Db4 and capacitor Cb4 of the limiting circuit 310b4 that limits the voltage value of the overshoot voltage of the drive signal COMB4 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMB4 is input, and on the side 224 of the limiting circuit 310a3, with the diode Db4 on the side 223 and the capacitor Cb4 on the side 224. In other words, the diode Db4 and the capacitor Cb4 are positioned adjacent to each other in the direction from the side 223 to the side 224, and the diode Db4 and the capacitor Ca3 are positioned adjacent to each other in the direction from the side 223 to the side 224.

[0145] The wiring Wb4 through which the drive signal COMB4 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Db4. The cathode terminal of the diode Db4 is electrically connected to the wiring WH located on the side 221 side of the wiring Wb4. One end of the capacitor Cb4 is electrically connected to the wiring WH. The other end of the capacitor Cb4 is electrically connected to the wiring WG located between the wiring Wb4 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMB4 in the wiring Wb4, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0146] At this time, in the FFC connector 260a-3, a reference voltage signal VBS4 corresponding to the drive signal COMB4 is input to the terminals 263a-14, 263a-16 adjacent to the terminals 263a-13, 263a-15 to which the drive signal COMB4 is input. The reference voltage signal VBS4 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS4 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0147] The drive signal COMA5 is input to the terminals 263a-17 and 263a-19 of the FFC connector 260a-3. The terminals 263a-17 and 263a-19 are electrically connected to the wiring Wa5. The wiring Wa5 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA5 input to the terminals 263a-17 and 263a-19 is propagated through the wiring Wa5 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0148] Furthermore, the diode Da5 and capacitor Ca5 of the limiting circuit 310a5 that limits the voltage value of the overshoot voltage of the drive signal COMA5 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMA5 is input, and on the side 224 of the limiting circuit 310b4, with the diode Da5 on the side 223 and the capacitor Ca5 on the side 224. That is, the diode Da5 and the capacitor Ca5 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Da5 and the capacitor Cb4 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0149] The wiring Wa5 through which the drive signal COMA5 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Da5. The cathode terminal of the diode Da5 is electrically connected to the wiring WH located on the side 221 side of the wiring Wa5. One end of the capacitor Ca5 is electrically connected to the wiring WH. The other end of the capacitor Ca5 is electrically connected to the wiring WG located between the wiring Wa5 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMA5 in the wiring Wa5, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0150] At this time, in the FFC connector 260a-3, a reference voltage signal VBS5 corresponding to the drive signal COMA5 is input to the terminals 263a-18, 263a-20 adjacent to the terminals 263a-17, 263a-19 to which the drive signal COMA5 is input. The reference voltage signal VBS5 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS5 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0151] The drive signal COMB6 is input to the terminals 263a-21 and 263a-23 of the FFC connector 260a-3. The terminals 263a-21 and 263a-23 are electrically connected to the wiring Wb6. The wiring Wb6 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB6 input to the terminals 263a-21 and 263a-23 propagates through the wiring Wb6 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0152] Furthermore, the diode Db6 and capacitor Cb6 of the limiting circuit 310b6 that limits the voltage value of the overshoot voltage of the drive signal COMB6 are positioned adjacent to each other on the side 221 of the FFC connector 260a-3 to which the drive signal COMB6 is input, and on the side 224 of the limiting circuit 310a5, with the diode Db6 on the side 223 and the capacitor Cb6 on the side 224. In other words, the diode Db6 and the capacitor Cb6 are positioned adjacent to each other in the direction from the side 223 to the side 224, and the diode Db6 and the capacitor Ca5 are positioned adjacent to each other in the direction from the side 223 to the side 224.

[0153] The wiring Wb6 through which the drive signal COMB6 propagates extends to the side 221 of the FFC connector 260a-3 and is electrically connected to the anode terminal of the diode Db6. The cathode terminal of the diode Db6 is electrically connected to the wiring WH located on the side 221 side of the wiring Wb6. One end of the capacitor Cb6 is electrically connected to the wiring WH. The other end of the capacitor Cb6 is electrically connected to the wiring WG located between the wiring Wb6 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMB6 in the wiring Wb6, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0154] At this time, in the FFC connector 260a-3, a reference voltage signal VBS6 corresponding to the drive signal COMB6 is input to the terminals 263a-22, 263a-24 adjacent to the terminals 263a-21, 263a-23 to which the drive signal COMB6 is input. The reference voltage signal VBS6 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS6 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0155] The drive signal COMB1 is input to the terminals 264a-1 and 264a-3 of the FFC connector 260a-4. The terminals 264a-1 and 264a-3 are electrically connected to the wiring Wb1. The wiring Wb1 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB1 input to the terminals 264a-1 and 264a-3 propagates through the wiring Wb1 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0156] Furthermore, the diode Db1 and capacitor Cb1 of the limiting circuit 310b1 that limits the voltage value of the overshoot voltage of the drive signal COMB1 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMB1 is input, with the diode Db1 on the side 223 and the capacitor Cb1 on the side 224. In other words, the diode Db1 and the capacitor Cb1 are positioned adjacent to each other in the direction from the side 223 to the side 224.

[0157] The wiring Wb1 through which the drive signal COMB1 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Db1. The cathode terminal of the diode Db1 is electrically connected to the wiring WH located on the side 222 of the wiring Wb1. One end of the capacitor Cb1 is electrically connected to the wiring WH. The other end of the capacitor Cb1 is electrically connected to the wiring WG located between the wiring Wb1 and the wiring WH. As a result, even if an overshoot voltage occurs in the drive signal COMB1 in the wiring Wb1, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0158] At this time, in the FFC connector 260a-4, a reference voltage signal VBS1 corresponding to the drive signal COMB1 is input to the terminals 264a-2, 264a-4 adjacent to the terminals 264a-1, 264a-3 to which the drive signal COMB1 is input. The reference voltage signal VBS1 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS1 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0159] The drive signal COMA2 is input to the terminals 264a-5 and 264a-7 of the FFC connector 260a-4. The terminals 264a-5 and 264a-7 are electrically connected to the wiring Wa2. The wiring Wa2 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA2 input to the terminals 264a-5 and 264a-7 propagates through the wiring Wa2 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0160] Furthermore, the diode Da2 and capacitor Ca2 of the limiting circuit 310a2 that limits the voltage value of the overshoot voltage of the drive signal COMA2 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMA2 is input, and on the side 224 of the limiting circuit 310b1, with the diode Da2 on the side 223 and the capacitor Ca2 on the side 224. That is, the diode Da2 and the capacitor Ca2 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Da2 and the capacitor Cb1 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0161] The wiring Wa2 through which the drive signal COMA2 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Da2. The cathode terminal of the diode Da2 is electrically connected to the wiring WH located on the side 222 of the wiring Wa2. One end of the capacitor Ca2 is electrically connected to the wiring WH. The other end of the capacitor Ca2 is electrically connected to the wiring WG located between the wiring Wb2 and the wiring WH. As a result, even if an overshoot voltage occurs in the drive signal COMA2 in the wiring Wa2, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0162] At this time, in the FFC connector 260a-4, a reference voltage signal VBS2 corresponding to the drive signal COMA2 is input to the terminals 264a-6 and 264a-8 adjacent to the terminals 264a-5 and 264a-7 to which the drive signal COMA2 is input. The reference voltage signal VBS2 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS2 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0163] The drive signal COMB3 is input to the terminals 264a-9 and 264a-11 of the FFC connector 260a-4. The terminals 264a-9 and 264a-11 are electrically connected to the wiring Wb3. The wiring Wb3 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB3 input to the terminals 264a-9 and 264a-11 propagates through the wiring Wb3 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0164] Furthermore, the diode Db3 and capacitor Cb3 of the limiting circuit 310b3 that limits the voltage value of the overshoot voltage of the drive signal COMB3 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMB3 is input, and on the side 224 of the limiting circuit 310a2, with the diode Db3 on the side 223 and the capacitor Cb3 on the side 224. In other words, the diode Db3 and the capacitor Cb3 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Db3 and the capacitor Ca2 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0165] The wiring Wb3 through which the drive signal COMB3 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Db3. The cathode terminal of the diode Db3 is electrically connected to the wiring WH located on the side 222 of the wiring Wb3. One end of the capacitor Cb3 is electrically connected to the wiring WH. The other end of the capacitor Cb3 is electrically connected to the wiring WG located between the wiring Wa3 and the wiring WH. As a result, even if an overshoot voltage occurs in the drive signal COMB3 in the wiring Wb3, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0166] At this time, in the FFC connector 260a-4, a reference voltage signal VBS3 corresponding to the drive signal COMB3 is input to the terminals 264a-10, 264a-12 adjacent to the terminals 264a-9, 264a-11 to which the drive signal COMB3 is input. The reference voltage signal VBS3 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS3 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0167] The drive signal COMA4 is input to the terminals 264a-13 and 264a-15 of the FFC connector 260a-4. The terminals 264a-13 and 264a-15 are electrically connected to the wiring Wa4. The wiring Wa4 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA4 input to the terminals 264a-13 and 264a-15 propagates through the wiring Wa4 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0168] Furthermore, the diode Da4 and capacitor Ca4 of the limiting circuit 310a4 that limits the voltage value of the overshoot voltage of the drive signal COMA4 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMA4 is input, and on the side 224 of the limiting circuit 310b3, with the diode Da4 on the side 223 and the capacitor Ca4 on the side 224. That is, the diode Da4 and the capacitor Ca4 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Da4 and the capacitor Cb3 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0169] The wiring Wa4 through which the drive signal COMA4 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Da4. The cathode terminal of the diode Da4 is electrically connected to the wiring WH located on the side 222 of the wiring Wa4. One end of the capacitor Ca4 is electrically connected to the wiring WH. The other end of the capacitor Ca4 is electrically connected to the wiring WG located between the wiring Wa4 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMA4 in the wiring Wa4, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0170] At this time, in the FFC connector 260a-4, a reference voltage signal VBS4 corresponding to the drive signal COMA4 is input to the terminals 264a-14, 264a-16 adjacent to the terminals 264a-13, 264a-15 to which the drive signal COMA4 is input. The reference voltage signal VBS4 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS4 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0171] The drive signal COMB5 is input to the terminals 264a-17 and 264a-19 of the FFC connector 260a-4. The terminals 264a-17 and 264a-19 are electrically connected to the wiring Wb5. The wiring Wb5 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMB5 input to the terminals 264a-17 and 264a-19 is propagated through the wiring Wb5 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0172] Furthermore, the diode Db5 and capacitor Cb5 of the limiting circuit 310b5 that limits the voltage value of the overshoot voltage of the drive signal COMB5 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMB5 is input, and on the side 224 of the limiting circuit 310a4, with the diode Db5 on the side 223 and the capacitor Cb5 on the side 224. In other words, the diode Db5 and the capacitor Cb5 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Db5 and the capacitor Ca4 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0173] The wiring Wb5 through which the drive signal COMB5 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Db5. The cathode terminal of the diode Db5 is electrically connected to the wiring WH located on the side 222 side of the wiring Wb5. One end of the capacitor Cb5 is electrically connected to the wiring WH. The other end of the capacitor Cb5 is electrically connected to the wiring WG located between the wiring Wb5 and the wiring WH. As a result, even if an overshoot voltage occurs in the driving signal COMB5 in the wiring Wb5, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0174] At this time, in the FFC connector 260a-4, a reference voltage signal VBS5 corresponding to the drive signal COMB5 is input to the terminals 264a-18, 264a-20 adjacent to the terminals 264a-17, 264a-19 to which the drive signal COMB5 is input. The reference voltage signal VBS5 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS5 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0175] The drive signal COMA6 is input to the terminals 264a-21 and 264a-23 of the FFC connector 260a-4. The terminals 264a-21 and 264a-23 are electrically connected to the wiring Wa6. The wiring Wa6 is provided with a via wiring (not shown) that electrically connects the surface 225 and the surface 226 of the wiring board 220a. The drive signal COMA6 input to the terminals 264a-21 and 264a-23 propagates through the wiring Wa6 and the via wiring, and is output to the print head 23 via the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0176] Furthermore, the diode Da6 and capacitor Ca6 of the limiting circuit 310a6 that limits the voltage value of the overshoot voltage of the drive signal COMA6 are positioned adjacent to each other on the side 222 of the FFC connector 260a-4 to which the drive signal COMA6 is input, and on the side 224 of the limiting circuit 310b5, with the diode Da6 on the side 223 and the capacitor Ca6 on the side 224. That is, the diode Da6 and the capacitor Ca6 are positioned adjacent to each other along the direction from the side 223 to the side 224, and the diode Da6 and the capacitor Cb5 are positioned adjacent to each other along the direction from the side 223 to the side 224.

[0177] The wiring Wa6 through which the drive signal COMA6 propagates extends to the side 222 of the FFC connector 260a-4 and is electrically connected to the anode terminal of the diode Da6. The cathode terminal of the diode Da6 is electrically connected to the wiring WH located on the side 222 of the wiring Wa6. In addition, one end of the capacitor Ca6 is electrically connected to the wiring WH.

[0178] The other end of the capacitor Ca6 is electrically connected to the wiring WG located between the wiring Wa6 and the wiring WH. As a result, even if an overshoot voltage occurs in the drive signal COMA6 in the wiring Wa6, the voltage value of the overshoot voltage is limited by the sum of the voltages Vh and Vf.

[0179] At this time, in the FFC connector 260a-4, a reference voltage signal VBS6 corresponding to the drive signal COMA6 is input to the terminals 264a-22, 264a-24 adjacent to the terminals 264a-21, 264a-23 to which the drive signal COMA6 is input. The reference voltage signal VBS6 propagates through a wiring pattern provided on the wiring board 220a, and is then supplied to the surface 226 of the wiring board 220a through via wiring (not shown). The reference voltage signal VBS6 is then output to the print head 23 through the BtoB plug 242a provided on the surface 226 of the wiring board 220a.

[0180] In the relay circuit board 22a configured as above, the drive signals COMA1, COMB2, COMA3, COMB4, COMA5, and COMB6 are input from the FFC connector 260a-3, and the drive signals COMB1, COMA2, COMB3, COMA4, COMB5, and COMA6 are input from the FFC connector 260a-4. In other words, the relay circuit board 22a has the FFC connector 260a-3 to which the drive signals COMA1, COMB2, COMA3, COMB4, COMA5, and COMB6 are input, and the FFC connector 260a-4 to which the drive signals COMB1, COMA2, COMB3, COMA4, COMB5, and COMA6 are input. At this time, the FFC connector 260a-3 and the FFC connector 260a-4 are positioned adjacent to each other along the direction from the side 221 to the side 222, with the FFC connector 260a-3 on the side 221 side and the FFC connector 260a-4 on the side 222 side.

[0181] Limiting circuits 310a1, 310b2, 310a3, 310b4, 310a5, and 310b6 that limit the voltage values ​​of each of the drive signals COMA1, COMB2, COMA3, COMB4, COMA5, and COMB6 input from FFC connector 260a-3 are located on the side 221 of FFC connector 260a-3, and limiting circuits 310b1, 310a2, 310b3, 310a4, 310b5, and 310a6 that limit the voltage values ​​of each of the drive signals COMB1, COMA2, COMB3, COMA4, COMB5, and COMA6 input from FFC connector 260a-4 are located on the side 224 of FFC connector 260a-4.

[0182] That is, the limiting circuits 310a1, 310b2, 310a3, 310b4, 310a5, 310b6, the limiting circuits 310b1, 310a2, 310b3, 310a4, 310b5, 310a6, the FFC connector 260a-3, and the FFC connector 260a-4 are positioned in the following order along the direction from side 221 to side 222: limiting circuits 310a1, 310b2, 310a3, 310b4, 310a5, 310b6, FFC connector 260a-3, FFC connector 260a-4, limiting circuits 310b1, 310a2, 310b3, 310a4, 310b5, 310a6. In other words, limiting circuits 310a1, 310b2, 310a3, 310b4, 310a5, and 310b6 are located closer to FFC connector 260a-3 than to FFC connector 260a-4, and limiting circuits 310b1, 310a2, 310b3, 310a4, 310b5, and 310a6 are located closer to FFC connector 260a-4 than to FFC connector 260a-3.

[0183] This makes it possible to shorten the wiring pattern for limiting the overshoot voltage generated in the drive signals COMA1-COMA6, COMB1-COMB6. This reduces the effect of the impedance components caused by the wiring pattern, improving the accuracy of limiting the voltage value of the overshoot voltage generated in the drive signals COMA1-COMA6, COMB1-COMB6. As a result, the risk of a decrease in the stability of the operation of the large format printer 1 is further reduced, and the risk of a decrease in the accuracy of ink ejection from the print head 23 is further reduced.

[0184] In the relay circuit board 22a configured as described above, in the FFC connector 260a-3, the terminals 263a-1, 263a-3 to which the drive signal COMA1 is input, the terminals 263a-5, 263a-7 to which the drive signal COMB2 is input, the terminals 263a-9, 263a-11 to which the drive signal COMA3 is input, the terminals 263a-13, 263a-15 to which the drive signal COMB4 is input, the terminals 263a-17, 263a-19 to which the drive signal COMA5 is input, and the terminals 263a-21, 263a-23 to which the drive signal COMB6 is input are arranged in the following order from the side 223 to the side 224: the terminals 263a-1, 263a-3, 263a-5, 263a-7, 263a-9, 263a-11, 263a- 13, terminal 263a-15, terminal 263a-17, terminal 263a-19, terminal 263a-21, and terminal 263a-23 are located in that order, and the limiting circuit 310a1 that limits the voltage value of drive signal COMA1, the limiting circuit 310b2 that limits the voltage value of drive signal COMB2, the limiting circuit 310a3 that limits the voltage value of drive signal COMA3, the limiting circuit 310b4 that limits the voltage value of drive signal COMB4, the limiting circuit 310a5 that limits the voltage value of drive signal COMA5, and the limiting circuit 310b6 that limits the voltage value of drive signal COMB6 are located in the order of limiting circuit 310a1, limiting circuit 310b2, limiting circuit 310a3, limiting circuit 310b4, limiting circuit 310a5, and limiting circuit 310b6 along the direction from side 223 to side 224.

[0185] This makes it possible to shorten the wiring pattern for limiting the overshoot voltage generated in the drive signals COMA1, COMB2, COMA3, COMB4, COMA5, and COMB6. This reduces the effect of the impedance components caused by the wiring pattern, and improves the accuracy of limiting the voltage value of the overshoot voltage generated in the drive signals COMA1, COMB2, COMA3, COMB4, COMA5, and COMB6. As a result, the risk of a decrease in the stability of the operation of the large format printer 1 is further reduced, and the risk of a decrease in the accuracy of ink ejection from the print head 23 is further reduced.

[0186] Similarly, in the relay circuit board 22a, in the FFC connector 260a-4, terminals 264a-1, 264a-3 to which the drive signal COMB1 is input, terminals 264a-5, 264a-7 to which the drive signal COMA2 is input, terminals 264a-9, 264a-11 to which the drive signal COMB3 is input, terminals 264a-13, 264a-15 to which the drive signal COMA4 is input, terminals 264a-17, 264a-19 to which the drive signal COMB5 is input, and terminals 264a-21, 264a-23 to which the drive signal COMA6 is input are arranged in the following order from the side 223 to the side 224: terminal 264a-1, terminal 264a-3, terminal 264a-5, terminal 264a-7, terminal 264a-9, terminal 264a-11, terminal 264a-13, terminal 264a-15, terminal 264a-17, terminal 264a-19, terminal 264a-21, and terminal 264a-23 are located in that order, and limiting circuit 310b1 that limits the voltage value of drive signal COMB1, limiting circuit 310a2 that limits the voltage value of drive signal COMA2, limiting circuit 310b3 that limits the voltage value of drive signal COMB3, limiting circuit 310a4 that limits the voltage value of drive signal COMA4, limiting circuit 310b5 that limits the voltage value of drive signal COMB5, and limiting circuit 310a6 that limits the voltage value of drive signal COMA6 are located in the order of limiting circuit 310b1, limiting circuit 310a2, limiting circuit 310b3, limiting circuit 310a4, limiting circuit 310b5, limiting circuit 310a6 along the direction from side 223 to side 224.

[0187] This makes it possible to shorten the wiring pattern for limiting the overshoot voltage generated in the drive signals COMB1, COMA2, COMB3, COMA4, COMB5, and COMA6. This reduces the effect of the impedance components caused by the wiring pattern, and improves the accuracy of limiting the voltage value of the overshoot voltage generated in the drive signals COMB1, COMA2, COMB3, COMA4, COMB5, and COMA6. As a result, the risk of a decrease in the stability of the operation of the large format printer 1 is further reduced, and the risk of a decrease in the accuracy of ink ejection from the print head 23 is further reduced.

[0188] Furthermore, in the relay circuit board 22a configured as described above, the wiring board 220a includes wiring Wa1 to Wa6 through which the drive signals COMA1 to COMA6 are propagated, respectively, wiring Wb1 to Wb6 through which the drive signals COMB1 to COMB6 are propagated, and wiring WH1 and WH2 as wiring WH through which the voltage signal VHV is propagated.

[0189] The limiting circuit 310a1, which is located closer to the side 221 than the FFC connectors 260a-3 and 260a-4, has a diode Da1 whose anode terminal is electrically connected to the wiring Wa1 and a cathode terminal whose cathode terminal is electrically connected to the wiring WH1. The limiting circuit 310b2 has a diode Db2 whose anode terminal is electrically connected to the wiring Wb2 and a cathode terminal whose cathode terminal is electrically connected to the wiring WH1. The limiting circuit 310a3 has a diode Da3 whose anode terminal is electrically connected to the wiring Wa3 and a cathode terminal whose cathode terminal is electrically connected to the wiring WH2. The limiting circuit 310b4 has a diode Db4 having an anode terminal electrically connected to the wiring Wb4 and a cathode terminal electrically connected to the wiring WH1, the limiting circuit 310a5 has a diode Da5 having an anode terminal electrically connected to the wiring Wa5 and a cathode terminal electrically connected to the wiring WH1, and the limiting circuit 310b6 has a diode Db6 having an anode terminal electrically connected to the wiring Wb6 and a cathode terminal electrically connected to the wiring WH1.

[0190] In this case, the wiring WH1 is located closer to the side 221 than the FFC connectors 260a-3 and 260a-4 and closer to the side 221 than the diodes Da1, Db2, Da3, Db4, Da5, and Db6, and extends along the side 221.

[0191] The limiting circuit 310b1, which is located closer to the side 222 than the FFC connectors 260a-3 and 260a-4, has a diode Db1 whose anode terminal is electrically connected to the wiring Wb1 and a cathode terminal which is electrically connected to the wiring WH2. The limiting circuit 310a2 has a diode Da2 whose anode terminal is electrically connected to the wiring Wa2 and a cathode terminal which is electrically connected to the wiring WH2. The limiting circuit 310b3 has a diode Db3 whose anode terminal is electrically connected to the wiring Wb3 and a cathode terminal which is electrically connected to the wiring WH3. The limiting circuit 310a4 has a diode Da4 electrically connected at its anode terminal to the wiring Wa4 and at its cathode terminal to the wiring WH2, the limiting circuit 310a4 has a diode Db5 electrically connected at its anode terminal to the wiring Wb5 and at its cathode terminal to the wiring WH2, and the limiting circuit 310a6 has a diode Da6 electrically connected at its anode terminal to the wiring Wa6 and at its cathode terminal to the wiring WH2.

[0192] In this case, the wiring WH2 is located closer to the side 222 than the FFC connectors 260a-3 and 260a-4 and closer to the side 222 than the diodes Da1, Db2, Da3, Db4, Da5, and Db6, and extends along the side 221.

[0193] That is, the wiring WH1, WH2 that propagates the voltage signal VHV with a constant voltage value is located at an end of the wiring board 220a than the FFC connectors 260a-3, 260a-4 to which the drive signals COMA1-COMA6, COMB1-COMB6 are input, and the limiting circuits 310a1-310a6, 310b1-310b6 that limit the voltage values ​​of the drive signals COMA1-COMA6, COMB1-COMB6. This allows the wiring WH1, WH2 that propagates the voltage signal VHV with a constant voltage value to function as shield wiring. As a result, the signal accuracy of the drive signals COMA1-COMA6, COMB1-COMB6 input to the FFC connectors 260a-3, 260a-4 is improved, and the stability of the operation of the limiting circuits 310a1-310a6, 310b1-310b6 is improved.

[0194] Here, the drive signals COMA and COMB output by the control unit 10 are an example of a drive signal, and considering that the drive signal VOUT is generated by selecting the signal waveforms of the drive signals COMA and COMB, the drive signal VOUT is also an example of a drive signal. Also, the drive signal COMA1 of the drive signals COMA is an example of a first drive signal, the drive signal COMB1 of the drive signals COMB is an example of a second drive signal, and the drive signal COMB2 of the drive signals COMB is an example of a third drive signal.

[0195] In addition, the relay circuit board 22a of the head unit 20 is an example of a relay circuit board, the multiple FFC connectors 260a of the relay circuit board 22a are an example of input connectors, the FFC connector 260a-3 of the multiple FFC connectors 260a is an example of a first input connector, and the FFC connector 260a-4 of the multiple FFC connectors 260a is an example of a second input connector. Furthermore, terminals 263a-1 to 263a-24 of FFC connector 260a-3 are an example of a plurality of first terminals, terminals 264a-1 to 264a-24 of FFC connector 260a-4 are an example of a plurality of second terminals, of the terminals 263a-1 to 263a-24, at least one of terminals 263a-1, 263a-3 to which drive signal COMA1 is input is an example of a first drive signal input terminal, of the terminals 264a-1 to 264a-24, at least one of terminals 264a-1, 264a-3 to which drive signal COMB1 is input is an example of a second drive signal input terminal, and of the terminals 263a-1 to 263a-24, at least one of terminals 263a-5, 263a-7 to which drive signal COMB2 is input is an example of a third drive signal input terminal. The BtoB connector 24a that outputs the drive signals COMA and COMB to the print head 23, and the BtoB plug 242a that constitutes at least a part of the BtoB connector 24a are examples of output connectors.

[0196] Moreover, side 221 of wiring board 220a is an example of a first side, side 222 is an example of a second side, side 223 is an example of a third side, side 224 is an example of a fourth side, face 225 is an example of a first face, and face 226 is an example of a second face. Furthermore, wiring Wa1 provided on wiring board 220a is an example of a first drive signal propagation wiring, wiring Wb1 is an example of a second drive signal propagation wiring, wiring WH1 is an example of a first constant voltage wiring, and wiring WH2 is an example of a second constant voltage wiring.

[0197] In addition, the limiting circuit 310a1 is an example of a first limiting circuit, the diode Da1 possessed by the limiting circuit 310a1 is an example of a first diode, the capacitor Ca1 possessed by the limiting circuit 310a1 is an example of a first capacitor, the limiting circuit 310b1 is an example of a second limiting circuit, the diode Db1 possessed by the limiting circuit 310b1 is an example of a second diode, the capacitor Cb1 possessed by the limiting circuit 310b1 is an example of a second capacitor, the limiting circuit 310b2 is an example of a third limiting circuit, the diode Db2 possessed by the limiting circuit 310b2 is an example of a third diode, and the capacitor Cb2 possessed by the limiting circuit 310b2 is an example of a third capacitor.

[0198] In addition, in the relay circuit board 22a, the direction from the side 221 to the side 222 is an example of a first direction, and the direction from the side 223 to the side 224 is an example of a second direction.

[0199] 7. Effects In the large format printer 1 of this embodiment configured as described above, the relay circuit board 22 that transmits the drive signals COMA1 and COMB1 output by the control unit 10 to the print head 23 includes a limiting circuit 310a1 that includes a diode Da1 and a capacitor Ca1 and limits the voltage value of the drive signal COMA1, and a limiting circuit 310b1 that includes a diode Db1 and a capacitor Cb1 and limits the voltage value of the drive signal COMB1, so that even if an overshoot voltage occurs in the drive signals COMA1 and COMB1 input to the head unit 20, the voltage value of the overshoot voltage is limited by the limiting circuits 310a1 and 310b1. This reduces the risk that the stability of the operation of the print head 23 will decrease due to the overshoot voltage occurring in the drive signals COMA1 and COMB1.

[0200] Furthermore, in the large format printer 1 of this embodiment, the limiting circuit 310a1 that limits the voltage value of the drive signal COMA1, and the limiting circuit 310b1 that limits the voltage value of the drive signal COMB1 are provided on the relay circuit board 22a, so that the voltage value of the overshoot voltage generated in the drive signal COMA1 that allows input to the print head 23, and the voltage value of the overshoot voltage generated in the drive signal COMB1 can be adjusted without changing the specifications of the print head 23. As a result, even if the specifications of the large format printer 1 dictate that the overshoot voltage is large or that a large overshoot voltage cannot occur, it becomes possible to determine whether or not the limiting circuit 310a1 should limit the voltage value of the overshoot voltage occurring in the drive signal COMA1 and to adjust the voltage value of the overshoot voltage occurring in the drive signal COMA1 limited by the limiting circuit 310a1, without changing the specifications of the print head 23, and it becomes possible to determine whether or not the limiting circuit 310b1 should limit the voltage value of the overshoot voltage occurring in the drive signal COMB1 and to adjust the voltage value of the overshoot voltage occurring in the drive signal COMB1 limited by the limiting circuit 310b1. This makes it possible to increase the versatility of the print head 23 used in the large format printer 1.

[0201] Furthermore, in the relay circuit board 22a, the diode Da1 and the capacitor Ca1 of the limiting circuit 310a1 are positioned adjacent to each other, so that the current corresponding to the overshoot voltage limited by the limiting circuit 310a1 can be regenerated in a short path, and similarly, the diode Db1 and the capacitor Cb1 of the limiting circuit 310b1 are positioned adjacent to each other, so that the current corresponding to the overshoot voltage limited by the limiting circuit 310b1 can be regenerated in a short path. This improves the accuracy of the voltage value of the overshoot voltage generated in the drive signal COMA1 limited by the limiting circuit 310a1, and the accuracy of the voltage value of the overshoot voltage generated in the drive signal COMB1 limited by the limiting circuit 310b1. This further reduces the risk of the stability of the operation of the print head 23 decreasing due to the overshoot voltage generated in the drive signals COMA1 and COMB1.

[0202] Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments, and can be embodied in various forms without departing from the spirit of the present invention. For example, the above embodiments can be appropriately combined.

[0203] The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations with the same functions, methods and results, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments or that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0204] The following can be derived from the above-described embodiment.

[0205] One embodiment of the large format printer is a head unit that ejects liquid when a drive signal is supplied thereto; a control unit that outputs a first drive signal and a second drive signal as the drive signals; Equipped with The head unit includes: a print head that ejects liquid when the drive signal is supplied; a relay circuit board that transmits the drive signal output by the control unit to the print head; having The relay circuit board includes: an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; having the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface; the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other; The second diode and the second capacitor are positioned adjacent to each other.

[0206] According to this large format printer, the relay circuit board has a first limiting circuit that limits the voltage value of the first drive signal, and a second limiting circuit that limits the voltage value of the second drive signal, thereby reducing the risk of the stability of the print head's operation being reduced by overshoot voltages generated in the first drive signal and the second drive signal.

[0207] Furthermore, with this large format printer, the first limiting circuit and the second limiting circuit are provided on a relay circuit board separate from the print head, making it possible to adjust the limit value of the overshoot voltage generated in the first drive signal and the second drive signal without changing the specifications of the print head, and it is possible to switch whether or not to limit the overshoot voltage generated in the first drive signal and the second drive signal depending on the specifications of the large format printer, thereby increasing the versatility of the print head used in large format printers.

[0208] Furthermore, in this large format printer 1, the first limiting circuit that limits the voltage value of the first drive signal has a first diode and a first capacitor that are positioned adjacent to each other, so that a current corresponding to an overshoot voltage occurring in the first drive signal can be regenerated via a short path, and the second limiting circuit that limits the voltage value of the second drive signal has a second diode and a second capacitor that are positioned adjacent to each other, so that a current corresponding to an overshoot voltage occurring in the second drive signal can be regenerated via a short path. This improves the accuracy of the voltage value of the overshoot voltage occurring in the first drive signal that is limited by the first limiting circuit, and the voltage value of the overshoot voltage occurring in the second drive signal that is limited by the second limiting circuit. This further reduces the risk of the stability of the print head operation being reduced due to the overshoot voltage occurring in the first drive signal and the second drive signal.

[0209] In one embodiment of the large format printer, the relay circuit board has, as the input connectors, a first input connector to which the first drive signal is input and a second input connector to which the second drive signal is input; The first limiting circuit, the second limiting circuit, the first input connector, and the second input connector may be positioned in a line in a first direction from the first side to the second side in the following order: first limiting circuit, first input connector, second input connector, second limiting circuit.

[0210] With this large format printer, it is possible to shorten the path from the first input connector, where the first drive signal is input, to the first limiting circuit, and similarly, it is possible to shorten the path from the second input connector, where the second drive signal is input, to the second limiting circuit. This improves the accuracy with which the first limiting circuit limits the overshoot voltage generated in the first drive signal, and improves the accuracy with which the second limiting circuit limits the overshoot voltage generated in the second drive signal.

[0211] In one embodiment of the large format printer, the wiring board includes a third side and a fourth side facing the third side, the third side intersects with the first side and the second side, the fourth side intersects with the first side and the second side, the first input connector has a plurality of first terminals including a first drive signal input terminal to which the first drive signal is input; the second input connector has a plurality of second terminals including a second drive signal input terminal to which the second drive signal is input; The plurality of first terminals are arranged in parallel along a second direction from the third side toward the fourth side, The plurality of second terminals are arranged in parallel along the second direction, the first diode and the first capacitor are positioned adjacent to each other along the second direction, The second diode and the second capacitor may be positioned adjacent to each other along the second direction.

[0212] In one embodiment of the large format printer, The control unit further outputs a third drive signal as the drive signal; the relay circuit board has a third limiting circuit including a third diode and a third capacitor, and limiting a voltage value of the third drive signal; the third limiting circuit is provided on the first surface, the third diode and the third capacitor are positioned adjacent to each other, The third diode and the first capacitor may be located adjacent to each other.

[0213] In one embodiment of the large format printer, the first input connector includes, as the plurality of first terminals, a third drive signal input terminal to which the third drive signal is input; the first drive signal input terminal and the third drive signal input terminal are located in this order along the second direction; The first limiting circuit and the third limiting circuit may be positioned in the second direction in the order of the first limiting circuit, the third limiting circuit.

[0214] With this large format printer, even when a third drive signal is input from the first input connector in addition to the first drive signal, it is possible to shorten the path from the first drive signal input terminal of the first input connector to which the first drive signal is input, to the first limiting circuit, and similarly, it is possible to shorten the path from the third drive signal input terminal of the first input connector to which the third drive signal is input, to the third limiting circuit. This improves the accuracy with which the first limiting circuit limits the overshoot voltage generated in the first drive signal, and improves the accuracy with which the third limiting circuit limits the overshoot voltage generated in the third drive signal.

[0215] In one embodiment of the large format printer, one end of the first capacitor and one end of the third capacitor are electrically connected to each other; The other end of the first capacitor and the other end of the third capacitor may be electrically connected.

[0216] According to this large format printer, the first capacitor of the first limiting circuit and the third capacitor of the third limiting circuit are connected in parallel, thereby ensuring a large capacitance in the first limiting circuit and the third limiting circuit. This eliminates the need to increase the individual capacitances of the first capacitor and the third capacitor, making it possible to reduce the size of the wiring board of the relay circuit board, and reducing the risk of a decrease in the stability of print head operation even if a large overshoot voltage occurs in at least one of the first drive signal and the third drive signal.

[0217] In one embodiment of the large format printer, the wiring board includes a first drive signal propagation wiring through which the first drive signal propagates, a second drive signal propagation wiring through which the second drive signal propagates, a first constant voltage wiring through which a constant voltage signal propagates, and a second constant voltage wiring; an anode terminal of the first diode is electrically connected to the first drive signal transmission line; a cathode terminal of the first diode is electrically connected to the first constant voltage wiring; an anode terminal of the second diode is electrically connected to the second drive signal transmission line; a cathode terminal of the second diode is electrically connected to the second constant voltage wiring; the first constant voltage wiring is located along the first side on a side closer to the first side than the input connector; The second constant voltage wiring may be located along the second side, on the second side of the input connector.

[0218] According to this large format printer, the first limiting circuit, the second limiting circuit, and the input connector are located between the first constant voltage wiring, through which a constant voltage signal propagates, and the second constant voltage wiring, thereby reducing the risk of noise being superimposed on the first limiting circuit and the second limiting circuit, and also reducing the risk of noise being superimposed on the first drive signal and the second drive signal input from the input connector.

[0219] One aspect of the relay circuit board is as follows: a print head that ejects liquid when a drive signal is supplied; a control unit that outputs a first drive signal and a second drive signal as the drive signals; In a large format printer equipped with a relay circuit board that transmits the drive signal output by the control unit to the print head, an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; Equipped with the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface; the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other; The second diode and the second capacitor are positioned adjacent to each other.

[0220] This relay circuit board has a first limiting circuit that limits the voltage value of the first drive signal, and a second limiting circuit that limits the voltage value of the second drive signal, thereby reducing the risk that the operational stability of the connected print head will be reduced due to overshoot voltages generated in the first drive signal and the second drive signal.

[0221] Furthermore, with this relay circuit board, the first limiting circuit and the second limiting circuit are provided separately from the print head that ejects the liquid, making it possible to adjust the limit value of the overshoot voltage generated in the first drive signal and the second drive signal without changing the specifications of the print head, and it is possible to switch whether or not to limit the overshoot voltage generated in the first drive signal and the second drive signal depending on the specifications of the large format printer being used. Therefore, by using this relay circuit board, it is possible to increase the versatility of the print head used in large format printers.

[0222] Furthermore, according to this relay circuit board, the first limiting circuit that limits the voltage value of the first drive signal has a first diode and a first capacitor that are adjacent to each other, so that a current corresponding to an overshoot voltage occurring in the first drive signal can be regenerated in a short path, and the second limiting circuit that limits the voltage value of the second drive signal has a second diode and a second capacitor that are adjacent to each other, so that a current corresponding to an overshoot voltage occurring in the second drive signal can be regenerated in a short path. This improves the accuracy of the voltage value of the overshoot voltage occurring in the first drive signal that is limited by the first limiting circuit, and the voltage value of the overshoot voltage occurring in the second drive signal that is limited by the second limiting circuit. This further reduces the risk of the stability of the operation of the connected print head being reduced due to the overshoot voltage occurring in the first drive signal and the second drive signal.

[0223] In one aspect of the relay circuit board, the input connectors include a first input connector to which the first drive signal is input and a second input connector to which the second drive signal is input; The first limiting circuit, the second limiting circuit, the first input connector, and the second input connector may be positioned in a line in a first direction from the first side to the second side in the following order: first limiting circuit, first input connector, second input connector, second limiting circuit.

[0224] This relay circuit board can shorten the path from the first input connector to which the first drive signal is input to the first limiting circuit, and similarly, can shorten the path from the second input connector to which the second drive signal is input to the second limiting circuit, thereby improving the accuracy with which the first limiting circuit limits the overshoot voltage generated in the first drive signal, and the accuracy with which the second limiting circuit limits the overshoot voltage generated in the second drive signal.

[0225] In one aspect of the relay circuit board, the wiring board includes a third side and a fourth side facing the third side, the third side intersects with both the first side and the second side, the fourth side intersects with both the first side and the second side, the first input connector has a plurality of first terminals including a first drive signal input terminal to which the first drive signal is input; the second input connector has a plurality of second terminals including a second drive signal input terminal to which the second drive signal is input; The plurality of first terminals are arranged in parallel along a second direction from the third side toward the fourth side, The plurality of second terminals are arranged in parallel along the second direction, the first diode and the first capacitor are positioned adjacent to each other along the second direction, The second diode and the second capacitor may be positioned adjacent to each other along the second direction.

[0226] In one aspect of the relay circuit board, The control unit further outputs a third drive signal as the drive signal; a third limiting circuit including a third diode and a third capacitor, the third limiting circuit limiting a voltage value of the third driving signal; the third limiting circuit is provided on the first surface, the third diode and the third capacitor are positioned adjacent to each other, The third diode and the first capacitor may be located adjacent to each other.

[0227] In one aspect of the relay circuit board, the first input connector includes, as the plurality of first terminals, a third drive signal input terminal to which the third drive signal is input; the first drive signal input terminal and the third drive signal input terminal are located in this order along the second direction; The first limiting circuit and the third limiting circuit may be positioned in the second direction in the order of the first limiting circuit, the third limiting circuit.

[0228] According to this relay circuit board, even when the third drive signal is input from the first input connector in addition to the first drive signal, it is possible to shorten the path from the first drive signal input terminal of the first input connector to which the first drive signal is input, to the first limiting circuit, and similarly, it is possible to shorten the path from the third drive signal input terminal of the first input connector to which the third drive signal is input, to the third limiting circuit. This improves the accuracy with which the first limiting circuit limits the overshoot voltage generated in the first drive signal, and the accuracy with which the third limiting circuit limits the overshoot voltage generated in the third drive signal.

[0229] In one aspect of the relay circuit board, one end of the first capacitor and one end of the third capacitor are electrically connected to each other; The other end of the first capacitor and the other end of the third capacitor may be electrically connected.

[0230] According to this relay circuit board, the first capacitor of the first limiting circuit and the third capacitor of the third limiting circuit are connected in parallel, so that a large capacitance can be ensured in the first limiting circuit and the third limiting circuit. This eliminates the need to increase the individual capacitances of the first capacitor and the third capacitor, making it possible to reduce the size of the wiring board of the relay circuit board, and also reduces the risk of a decrease in the stability of the operation of the connected print head, even if a large overshoot voltage occurs in at least one of the first drive signal and the third drive signal.

[0231] In one aspect of the relay circuit board, the wiring board includes a first drive signal propagation wiring through which the first drive signal propagates, a second drive signal propagation wiring through which the second drive signal propagates, a first constant voltage wiring through which a constant voltage signal propagates, and a second constant voltage wiring; an anode terminal of the first diode is electrically connected to the first drive signal transmission line; a cathode terminal of the first diode is electrically connected to the first constant voltage wiring; an anode terminal of the second diode is electrically connected to the second drive signal transmission line; a cathode terminal of the second diode is electrically connected to the second constant voltage wiring; the first constant voltage wiring is located along the first side on a side closer to the first side than the input connector; The second constant voltage wiring may be located along the second side, on the second side of the input connector.

[0232] According to this relay circuit board, the first limiting circuit, the second limiting circuit, and the input connector are located between the first constant voltage wiring and the second constant voltage wiring, through which a constant voltage signal propagates, thereby reducing the risk of noise being superimposed on the first limiting circuit and the second limiting circuit, and also reducing the risk of noise being superimposed on the first drive signal and the second drive signal input from the input connector. [Explanation of symbols]

[0233] 1...large format printer, 2...liquid container, 10...control unit, 20...head unit, 21...carriage, 22, 22a, 22b...relay circuit board, 23...print head, 24, 24a, 24b...BtoB connector, 25...ejection head, 30...movement unit, 31...carriage motor, 32...endless belt, 40...transport unit, 41...transport motor, 42...transport roller, 50, 50-1 to 50-n...drive driving circuit, 52, 52-1 to 52-n...reference voltage output circuit, 55...power supply circuit, 60...piezoelectric element, 100...control circuit, 200...driving signal selection circuit, 220a, 220b...wiring board, 221 to 224...sides, 225, 226...faces, 230...head board, 231 to 234...sides, 235, 236...faces, 237a to 237f...insertion holes, 238-1 to 238-12...electrode group, 241a, 241b...BtoB socket, 242a , 242b...BtoB plug, 250...ejection head module, 252...ink ejection surface, 260a, 260a-1 to 260a-4, 260b...FFC connector, 261a-1 to 261a-24, 262a-1 to 262a-24, 263a-1 to 263a-24, 264a-1 to 264a-24...terminal, 300...clamp circuit, 310, 310a1 to 310a6, 310b1 to 310b6...limiting circuit, 60 0...discharge portion, 601...piezoelectric body, 611, 612...electrodes, 621...diaphragm, 631...cavity, 632...nozzle plate, 641...reservoir, 651...nozzle, 661...supply port, C, Ca1 to Ca6, Cb1 to Cb6...capacitors, D, Da1 to Da6, Db1 to Db6...diodes, L1 to L12...nozzle array, P...medium, WG, WH, WH1, WH2, Wa1 to Wa6, Wb1 to Wb6, Wc...wiring

Claims

1. a head unit that ejects liquid when a drive signal is supplied thereto; a control unit that outputs a first drive signal and a second drive signal as the drive signals; Equipped with The head unit includes: a print head that ejects liquid when the drive signal is supplied; a relay circuit board that transmits the drive signal output by the control unit to the print head; having The relay circuit board includes: an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; having the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface, the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other, The second diode and the second capacitor are located adjacent to each other. A large format printer that features

2. the relay circuit board has, as the input connectors, a first input connector to which the first drive signal is input and a second input connector to which the second drive signal is input; the first limiting circuit, the second limiting circuit, the first input connector, and the second input connector are arranged in the following order in a first direction from the first side to the second side: the first limiting circuit, the first input connector, the second input connector, and the second limiting circuit.

2. The large format printer according to claim 1.

3. the wiring board includes a third side and a fourth side facing the third side, the third side intersects with the first side and the second side, the fourth side intersects with the first side and the second side, the first input connector has a plurality of first terminals including a first drive signal input terminal to which the first drive signal is input; the second input connector has a plurality of second terminals including a second drive signal input terminal to which the second drive signal is input; The first terminals are arranged in parallel along a second direction from the third side toward the fourth side, The second terminals are arranged in parallel along the second direction, the first diode and the first capacitor are positioned adjacent to each other along the second direction, The second diode and the second capacitor are positioned adjacent to each other along the second direction.

3. The large format printer according to claim 2.

4. The control unit further outputs a third drive signal as the drive signal; the relay circuit board has a third limiting circuit including a third diode and a third capacitor, and limiting a voltage value of the third drive signal; the third limiting circuit is provided on the first surface, the third diode and the third capacitor are positioned adjacent to each other, The third diode and the first capacitor are located adjacent to each other.

4. The large format printer according to claim 3.

5. the first input connector includes, as the plurality of first terminals, a third drive signal input terminal to which the third drive signal is input; the first drive signal input terminal and the third drive signal input terminal are located in this order along the second direction; The first limiting circuit and the third limiting circuit are positioned in the second direction in the order of the first limiting circuit and the third limiting circuit.

5. The large format printer according to claim 4.

6. one end of the first capacitor and one end of the third capacitor are electrically connected to each other; The other end of the first capacitor and the other end of the third capacitor are electrically connected to each other.

6. The large format printer according to claim 5.

7. the wiring board includes a first drive signal propagation wiring through which the first drive signal propagates, a second drive signal propagation wiring through which the second drive signal propagates, a first constant voltage wiring through which a constant voltage signal propagates, and a second constant voltage wiring; an anode terminal of the first diode is electrically connected to the first drive signal transmission line; a cathode terminal of the first diode is electrically connected to the first constant voltage wiring; an anode terminal of the second diode is electrically connected to the second drive signal transmission line; a cathode terminal of the second diode is electrically connected to the second constant voltage wiring; the first constant voltage wiring is located along the first side on a side closer to the first side than the input connector; The second constant voltage wiring is located along the second side on the second side of the input connector.

7. The large format printer according to claim 1,

8. a print head that ejects liquid when a drive signal is supplied; a control unit that outputs a first drive signal and a second drive signal as the drive signals; In a large format printer equipped with a relay circuit board that transmits the drive signal output by the control unit to the print head, an input connector electrically connected to the control unit and receiving the drive signal; an output connector electrically connected to the print head and configured to output the drive signal; a first limiting circuit including a first diode and a first capacitor, the first limiting circuit limiting a voltage value of the first driving signal; a second limiting circuit including a second diode and a second capacitor, the second limiting circuit limiting a voltage value of the second driving signal; a wiring board on which the input connector, the output connector, the first limiting circuit, and the second limiting circuit are provided; Equipped with the wiring board includes a first side, a second side facing the first side, a first surface, and a second surface different from the first surface; the input connector, the first limiting circuit, and the second limiting circuit are provided on the first surface, the output connector is provided on the second surface, the first diode and the first capacitor are positioned adjacent to each other, The second diode and the second capacitor are located adjacent to each other. A relay circuit board comprising:

9. The input connectors include a first input connector to which the first drive signal is input and a second input connector to which the second drive signal is input, the first limiting circuit, the second limiting circuit, the first input connector, and the second input connector are arranged in the following order in a first direction from the first side to the second side: the first limiting circuit, the first input connector, the second input connector, and the second limiting circuit.

9. The relay circuit board according to claim 8.

10. the wiring board includes a third side and a fourth side facing the third side, the third side intersects with both the first side and the second side, the fourth side intersects with both the first side and the second side, the first input connector has a plurality of first terminals including a first drive signal input terminal to which the first drive signal is input; the second input connector has a plurality of second terminals including a second drive signal input terminal to which the second drive signal is input; The first terminals are arranged in parallel along a second direction from the third side toward the fourth side, The second terminals are arranged in parallel along the second direction, the first diode and the first capacitor are positioned adjacent to each other along the second direction, The second diode and the second capacitor are positioned adjacent to each other along the second direction.

10. The relay circuit board according to claim 9.

11. The control unit further outputs a third drive signal as the drive signal; a third limiting circuit including a third diode and a third capacitor, the third limiting circuit limiting a voltage value of the third driving signal; the third limiting circuit is provided on the first surface, the third diode and the third capacitor are positioned adjacent to each other, The third diode and the first capacitor are located adjacent to each other.

11. The relay circuit board according to claim 10.

12. the first input connector includes, as the plurality of first terminals, a third drive signal input terminal to which the third drive signal is input; the first drive signal input terminal and the third drive signal input terminal are located in the second direction in this order, The first limiting circuit and the third limiting circuit are positioned in the second direction in the order of the first limiting circuit and the third limiting circuit.

12. The relay circuit board according to claim 11.

13. one end of the first capacitor and one end of the third capacitor are electrically connected to each other; The other end of the first capacitor and the other end of the third capacitor are electrically connected to each other.

13. The relay circuit board according to claim 12.

14. the wiring board includes a first drive signal propagation wiring through which the first drive signal propagates, a second drive signal propagation wiring through which the second drive signal propagates, a first constant voltage wiring through which a constant voltage signal propagates, and a second constant voltage wiring; an anode terminal of the first diode is electrically connected to the first drive signal transmission line; a cathode terminal of the first diode is electrically connected to the first constant voltage wiring; an anode terminal of the second diode is electrically connected to the second drive signal transmission line; a cathode terminal of the second diode is electrically connected to the second constant voltage wiring; the first constant voltage wiring is located along the first side on a side closer to the first side than the input connector; The second constant voltage wiring is located along the second side on the second side of the input connector.

14. The relay circuit board according to claim 8, wherein the first and second electrodes are electrically connected to the first and second electrodes.

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