Head unit, liquid discharge device and control device

Abstract

To provide a head unit that can appropriately cool a driving circuit in operation.SOLUTION: The head unit is provided with a head mounting part which is mounted with a head including a discharge part for discharging liquid, and a control part that controls a driving circuit that generates a driving signal of the head mounted on the head mounting part and a fan for cooling the driving circuit respectively. the control part controls the fan, on the basis of driving method information associated with a temperature detected by a temperature detecting part that detects a temperature of the driving circuit and rotation speed of the fan detected by a rotation speed detecting part that detects the rotation speed, of a plurality of pieces of driving method information showing a driving method of the fan.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a head unit, a liquid ejection device, and a control device. [Background technology]

[0002] 2. Description of the Related Art Research and development is ongoing into liquid ejection devices that eject liquid onto a medium and form an image on the medium.

[0003] In this regard, there is known a liquid ejection device that is equipped with a head unit to which various heads can be attached and that includes a drive circuit that generates drive signals for the attached heads (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-034637 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a liquid ejection device such as that described in Patent Document 1, the drive circuit of the head unit generates heat during operation. For this reason, the liquid ejection device has a structure that efficiently cools the drive circuit using a fan. Here, it is known that the temperature of the drive circuit during operation varies depending on the type of head, the mounting position of the head, and the like. For this reason, when the head mounted on the head unit is replaced with a new head, the liquid ejection device may not be able to sufficiently cool the drive circuit during operation. [Means for solving the problem]

[0006] One aspect of a head unit according to the present disclosure is a head unit comprising: a head attachment section for attaching a head including an ejection section for ejecting liquid; a drive circuit for generating a drive signal for the head attached to the head attachment section; and a control section for controlling a fan for cooling the drive circuit, wherein the control section controls the fan based on drive method information among a plurality of drive method information indicating a drive method for the fan, the drive method information being associated with the temperature detected by a temperature detection section that detects the temperature of the drive circuit and the rotation speed detected by a rotation speed detection section that detects the rotation speed of the fan.

[0007] Moreover, one aspect of a liquid ejection device according to the present disclosure is a liquid ejection device including the head unit described above and a transport section that transports a medium.

[0008] Furthermore, one aspect of the control device according to the present disclosure is a control device that includes a control unit that controls both a drive circuit that generates a drive signal for a head including an ejection unit that ejects liquid, and a fan that cools the drive circuit, and the control unit controls the fan based on drive method information, among a plurality of drive method information indicating a drive method for the fan, which is associated with the temperature detected by a temperature detection unit that detects the temperature of the drive circuit and the rotation speed detected by a rotation speed detection unit that detects the rotation speed of the fan. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a schematic configuration of a liquid ejection device 1. FIG. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a discharge unit 5. [Diagram 3] 2 is a perspective view showing an example of the structure of a head driving module 10. FIG. [Figure 4] FIG. 11 is a diagram showing an example of driving method information. [Diagram 5] FIG. 11 is a diagram illustrating an example of correspondence information. [Figure 6] 4 is a diagram showing an example of the flow of a calibration process performed by the control circuit 100. FIG. [Figure 7]7 is a diagram showing an example of a flow of processing in which the control circuit 100 controls the fan FN based on the drive method information selected by the control circuit 100 through the processing of the flowchart shown in FIG. 6. [Figure 8] 7 is a diagram showing an example of the flow of processing in which the control circuit 100 detects whether or not an error has occurred in the control of the fan FN based on the drive method information selected by the control circuit 100 through the processing of the flowchart shown in FIG. 6. [Figure 9] FIG. 1 is a diagram showing an example of a functional configuration of the control circuit 100 relating to a function that allows a user to change the detection sensitivity of the rotation speed of a fan FN, among the functions of the control circuit 100. [Figure 10] 11 is a diagram for explaining a method for calculating the rotation speed of the fan FN by the calculation unit 105 using a second clock signal. FIG. [Figure 11] 11 is a diagram showing an example of a processing flow in which a second clock generating unit 104 generates a second clock signal. FIG. [Figure 12] 10 is a diagram showing an example of a flow of a process in which the control circuit 100 detects the rotation speed of the fan FN. [Figure 13] 1 is a diagram illustrating a plurality of head units HU configured as a line head in a liquid ejection device 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the drawings. The drawings used are for convenience of explanation. Note that the embodiments described below do not unduly limit the contents of the present disclosure described in the claims. In addition, not all of the configurations described below are necessarily essential components of the present disclosure.

[0011] 1. Embodiment 1.1 Configuration of the liquid ejection device Fig. 1 is a diagram showing a schematic configuration of a liquid ejection device 1. As shown in Fig. 1, the liquid ejection device 1 is a so-called line-type inkjet printer that ejects ink, which is an example of a liquid, at a desired timing onto a medium P transported by a transport unit 4, thereby forming a desired image on the medium P. Here, in the following description, the direction in which the medium P is transported is sometimes referred to as the transport direction, and the width direction of the transported medium P is sometimes referred to as the main scanning direction.

[0012] As shown in FIG. 1, the liquid ejection device 1 includes a control unit 2, a liquid container 3, a transport unit 4, and a plurality of ejection units 5.

[0013] The control unit 2 includes processing circuits such as a CPU (Central Processing Unit) and an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory. The control unit 2 outputs signals to control each element of the liquid ejection device 1 based on image data supplied from an external device such as a host computer (not shown) provided outside the liquid ejection device 1. For example, the control unit 2 outputs an image information signal IP based on the image data to each of the multiple ejection units 5.

[0014] The liquid container 3 stores one or more types of liquid to be supplied to the discharge unit 5. For example, the liquid container 3 stores ink to be supplied to the discharge unit 5. Specifically, the liquid container 3 stores ink of multiple colors to be discharged onto the medium P, such as black, cyan, magenta, yellow, red, gray, etc. Of course, the liquid container 3 may store only black ink, or may store liquid other than ink.

[0015] The transport unit 4 has a transport motor 41 and a transport roller 42. A transport control signal Ctrl-T output by the control unit 2 is input to the transport unit 4. In the transport unit 4, the transport motor 41 operates based on the input transport control signal Ctrl-T, and the transport roller 42 is rotationally driven in accordance with the operation of the transport motor 41, thereby transporting the medium P in the transport direction. The transport unit 4 is an example of a transport section.

[0016] Each of the multiple ejection units 5 has a head driving module 10 and a liquid ejection module 20. An image information signal IP output by the control unit 2 is input to each of the multiple ejection units 5, and ink stored in the liquid container 3 is supplied to each of the multiple ejection units 5. In each of the multiple ejection units 5, the head driving module 10 controls the operation of the liquid ejection module 20 based on the image information signal IP input from the control unit 2, and the liquid ejection module 20 ejects the ink supplied from the liquid container 3 onto the medium P under the control of the head driving module 10.

[0017] Furthermore, the liquid ejection modules 20 of each of the multiple ejection units 5 are positioned, for example, lined up along the main scanning direction so as to be equal to or greater than the width of the medium P, so that ink can be ejected to the entire area in the width direction of the transported medium P. In this way, the liquid ejection device 1 constitutes a line-type inkjet printer. Note that the liquid ejection device 1 is not limited to a line-type inkjet printer.

[0018] Next, a description will be given of a schematic configuration of the discharge unit 5. Fig. 2 is a diagram showing a schematic configuration of the discharge unit 5. As shown in Fig. 2, the discharge unit 5 has a head driving module 10 and a liquid discharge module 20. In the discharge unit 5, the head driving module 10 and the liquid discharge module 20 are electrically connected by one or more wiring members 30.

[0019] The wiring member 30 is a flexible member for electrically connecting the head driving module 10 and the liquid ejection module 20, and is, for example, a flexible printed circuit (FPC: Flexible Printed Circuits).

[0020] The head driving module 10 has a control circuit 100, driving signal output circuits 50-1 to 50-m, and a conversion circuit 120. Here, m may be any integer equal to or greater than 1. The head driving module 10 may have a control device. In this case, the control device of the head driving module 10 includes the control circuit 100. The control device may or may not include the conversion circuit 120.

[0021] The control circuit 100 has a CPU, an FPGA, a non-volatile memory such as a flash memory, a volatile memory such as a RAM (Random Access Memory), a register, and the like. An image information signal IP output by the control unit 2 is input to the control circuit 100. The control circuit 100 outputs a signal for controlling each element of the discharge unit 5 based on the input image information signal IP. For convenience of explanation, the non-volatile memory included in the control circuit 100 will be referred to as a first storage unit in the following description. Also, for convenience of explanation, the register included in the control circuit 100 will be referred to as a second storage unit in the following description.

[0022] The control circuit 100 generates a base data signal dDATA for controlling the operation of the liquid ejection module 20 based on the image information signal IP, and outputs the base data signal dDATA to the conversion circuit 120. The conversion circuit 120 converts the base data signal dDATA into a differential signal such as LVDS (Low Voltage Differential Signaling), and outputs the signal as data signal DATA to the liquid ejection module 20. The conversion circuit 120 may convert the base data signal dDATA into a differential signal of a high-speed transfer method other than LVDS, such as LVPECL (Low Voltage Positive Emitter Coupled Logic) or CML (Current Mode Logic), and output the signal as data to the liquid ejection module 20, or may output a part or all of the base data signal dDATA to the liquid ejection module 20 as a single-ended data signal DATA.

[0023] The control circuit 100 also outputs base drive signals dA1, dB1, and dC1 to the drive signal output circuit 50-1. The drive signal output circuit 50-1 has drive circuits 52a, 52b, and 52c. The base drive signal dA1 is input to the drive circuit 52a. The drive circuit 52a performs digital / analog conversion on the base drive signal dA1 input thereto, and then performs class D amplification to generate a drive signal COMA1, which is output to the liquid ejection module 20. The base drive signal dB1 is input to the drive circuit 52b. The drive circuit 52b performs digital / analog conversion on the base drive signal dB1 input thereto, and then performs class D amplification to generate a drive signal COMB1, which is output to the liquid ejection module 20. The base drive signal dC1 is input to the drive circuit 52c. The drive circuit 52c performs digital / analog conversion on the input basic drive signal dC1, and then performs class D amplification to generate a drive signal COMC1.

[0024] Here, each of the drive circuits 52a, 52b, and 52c may generate the drive signals COMA1, COMB1, and COMC1 by amplifying the waveforms defined by the input basic drive signals dA1, dB1, and dC1, and may include a class A amplifier circuit, a class B amplifier circuit, or a class AB amplifier circuit, etc., instead of or in addition to the class D amplifier circuit. Also, each of the basic drive signals dA1, dB1, and dC1 may be an analog signal, as long as it can define the waveforms of the corresponding drive signals COMA1, COMB1, and COMC1.

[0025] The drive signal output circuit 50-1 also has a reference voltage output circuit 53. The reference voltage output circuit 53 generates a reference voltage signal VBS1 of a constant potential indicating a reference potential of a piezoelectric element 60 (described later) included in the liquid ejection module 20, and outputs it to the liquid ejection module 20. This reference voltage signal VBS1 may be, for example, a ground potential or a constant potential such as 5.5 V or 6 V. Here, the constant potential includes cases where the potential can be considered to be substantially constant when considering variations due to errors such as potential variations caused by the operation of peripheral circuits, potential variations caused by variations in circuit elements, and potential variations caused by temperature characteristics of circuit elements.

[0026] The drive signal output circuits 50-2 to 50-m have the same configuration as the drive signal output circuit 50-1, except that the input and output signals are different. That is, the drive signal output circuit 50-j (j is any of 1 to m) includes a circuit equivalent to the drive circuits 52a, 52b, and 52c, and a circuit equivalent to the reference voltage output circuit 53, and generates drive signals COMAj, COMBj, and COMCj and a reference voltage signal VBSj based on the basic drive signals dAj, dBj, and dCj input from the control circuit 100, and outputs them to the liquid ejection module 20.

[0027] In the following description, the drive signal output circuits 50-1 to 50-m have the same configuration, and when there is no need to distinguish between them, they may be simply referred to as drive signal output circuits 50. In the following description, the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j have the same configuration, and when there is no need to distinguish between them, they may be simply referred to as drive circuits 52. In this case, the drive circuit 52 will be described as generating and outputting a drive signal COM based on a basic drive signal do. On the other hand, when distinguishing between the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j, the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-1 may be referred to as drive circuits 52a1, 52b1, and 52c1, and the drive circuits 52a, 52b, and 52c included in the drive signal output circuit 50-j may be referred to as drive circuits 52aj, 52bj, and 52cj.

[0028] The liquid ejection module 20 includes a restoration circuit 220 and ejection modules 23-1 to 23-m.

[0029] The restoration circuit 220 restores the data signal DATA to a single-ended signal, separates it into signals corresponding to the respective discharge modules 23-1 to 23-m, and outputs them to the corresponding discharge modules 23-1 to 23-m.

[0030] Specifically, the restoration circuit 220 restores and separates the data signal DATA to generate a clock signal SCK1, a print data signal SI1, and a latch signal LAT1 corresponding to the ejection module 23-1, and outputs them to the ejection module 23-1. In addition, the restoration circuit 220 restores and separates the data signal DATA to generate a clock signal SCKj, a print data signal SIj, and a latch signal LATj corresponding to the ejection module 23-j, and outputs them to the ejection module 23-j.

[0031] As described above, the restoration circuit 220 restores the data signal DATA of the differential signal output by the head driving module 10, and separates the restored signal into signals corresponding to the ejection modules 23-1 to 23-m. As a result, the restoration circuit 220 generates the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm corresponding to the ejection modules 23-1 to 23-m, respectively, and outputs them to the corresponding ejection modules 23-1 to 23-m. Note that, among the signals output by the restoration circuit 220, any of the clock signals SCK1 to SCKm, the print data signals SI1 to SIm, and the latch signals LAT1 to LATm corresponding to the ejection modules 23-1 to 23-m, respectively, may be a common signal for the ejection modules 23-1 to 23-m.

[0032] Considering that the restoration circuit 220 restores and separates the data signal DATA to generate the clock signals SCK1-SCKm, the print data signals SI1-SIm, and the latch signals LAT1-LATm, the data signal DATA output by the control circuit 100 is a differential signal corresponding to the clock signals SCK1-SCKm, the print data signals SI1-SIm, and the latch signals LAT1-LATm, and the base data signal dDATA on which the data signal DATA is based includes signals corresponding to the clock signals SCK1-SCKm, the print data signals SI1-SIm, and the latch signals LAT1-LATm. That is, the base data signal dDATA includes signals for controlling the operation of the ejection modules 23-1-23-m of the liquid ejection module 20.

[0033] The ejection module 23-1 has a drive signal selection circuit 200 and a plurality of ejection units 600. Each of the plurality of ejection units 600 includes a piezoelectric element 60.

[0034] The discharge module 23-1 receives the drive signals COMA1, COMB1, and COMC1, the reference voltage signal VBS1, the clock signal SCK1, the print data signal SI1, and the latch signal LAT1. The drive signals COMA1, COMB1, and COMC1, the clock signal SCK1, the print data signal SI1, and the latch signal LAT1 are input to a drive signal selection circuit 200 included in the discharge module 23-1. The drive signal selection circuit 200 generates a drive signal VOUT by selecting or deselecting each of the drive signals COMA1, COMB1, and COMC1 based on the input clock signal SCK1, the print data signal SI1, and the latch signal LAT1, and supplies the drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding discharge section 600. At this time, the reference voltage signal VBS1 is supplied to the other end of the piezoelectric element 60. The piezoelectric elements 60 are driven by the potential difference between a drive signal VOUT supplied to one end and a reference voltage signal VBS1 supplied to the other end, causing the corresponding ejection portions 600 to eject ink.

[0035] Similarly, the ejection module 23-j has a drive signal selection circuit 200 and a plurality of ejection units 600. Each of the plurality of ejection units 600 includes a piezoelectric element 60.

[0036] The discharge module 23-j receives the drive signals COMAj, COMBj, and COMCj, the reference voltage signal VBSj, the clock signal SCKj, the print data signal SIj, and the latch signal LATj. The drive signals COMAj, COMBj, and COMCj, the clock signal SCKj, the print data signal SIj, and the latch signal LATj are input to a drive signal selection circuit 200 included in the discharge module 23-j. The drive signal selection circuit 200 generates a drive signal VOUT by selecting or not selecting each of the drive signals COMAj, COMBj, and COMCj based on the input clock signal SCKj, the print data signal SIj, and the latch signal LATj, and supplies the drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding discharge section 600. At this time, the reference voltage signal VBSj is supplied to the other end of the piezoelectric element 60. The piezoelectric elements 60 are driven by the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBSj supplied to the other end, causing the corresponding ejection portions 600 to eject ink.

[0037] In the liquid ejection device 1 of the embodiment configured as described above, the control unit 2 controls the transport of the medium P by the transport unit 4 based on image data supplied from a host computer (not shown) or the like, and also controls the ejection of ink from the liquid ejection module 20 of the ejection unit 5. In this way, the liquid ejection device 1 can land a desired amount of ink at a desired position on the medium P, and form a desired image on the medium P.

[0038] Here, the discharge modules 23-1 to 23-m of the liquid discharge module 20 have the same configuration, but only the signals input thereto are different. Therefore, in the following description, when there is no need to distinguish between the discharge modules 23-1 to 23-m, they may be simply referred to as the discharge modules 23. In this case, the drive signals COMA1 to COMAm input to the discharge modules 23 may be referred to as drive signals COMA, the drive signals COMB1 to COMBm as drive signals COMB, the drive signals COMC1 to COMCm as drive signals COMC, the reference voltage signals VBS1 to VBSm as reference voltage signals VBS, the clock signals SCK1 to SCKm as clock signals SCK, the print data signals SI1 to SIm as print data signals SI, and the latch signals LAT1 to LATm as latch signals LAT.

[0039] That is, the ejection module 23 receives the drive signals COMA, COMB, and COMC, the reference voltage signal VBS, the clock signal SCK, the print data signal SI, and the latch signal LAT. The drive signals COMA, COMB, and COMC, the clock signal SCK, the print data signal SI, and the latch signal LAT are input to a drive signal selection circuit 200 included in the ejection module 23. The drive signal selection circuit 200 generates a drive signal VOUT by selecting or not selecting each of the drive signals COMA, COMB, and COMC based on the input clock signal SCK, the print data signal SI, and the latch signal LAT, and supplies the drive signal VOUT to one end of the piezoelectric element 60 included in the corresponding ejection section 600. At this time, the reference voltage signal VBS is supplied to the other end of the piezoelectric element 60. Then, the piezoelectric element 60 is driven by the potential difference between the drive signal VOUT supplied to one end and the reference voltage signal VBS supplied to the other end, and ink is ejected from the corresponding ejection section 600.

[0040] As described above, the liquid ejection device 1 in this embodiment includes the liquid ejection module 20 including the ejection module 23 that ejects ink in response to the driving of the piezoelectric element 60, the head driving module 10 including the drive signal output circuits 50-1 to 50-m that output the drive signals COMA, COMB, and COMC, and the wiring member 30 having one end electrically connected to the head driving module 10 and the other end electrically connected to the liquid ejection module 20. Here, in this embodiment, the control circuit 100 is an example of a control unit. Also, in this embodiment, the ejection unit 600 of the ejection module 23 that ejects ink in response to the driving of the piezoelectric element 60 is an example of an ejection unit. Also, in this embodiment, the head driving module 10 is an example of a head unit. Also, in this embodiment, the liquid ejection module 20 including the ejection module 23 is an example of a head. In this embodiment, each of the drive signal output circuits 50-1 to 50-m that output the drive signals COMA, COMB, and COMC, or each of the drive circuits 52a, 52b, and 52c included in the drive signal output circuits 50-1 to 50-m, is an example of a drive circuit.

[0041] 1.2 Structure and operation of the head drive module Next, the structure and operation of the head driving module 10 will be described with reference to FIG. 3. FIG. 3 is a perspective view showing an example of the structure of the head driving module 10. Here, FIG. 3 shows arrows indicating the X2 direction, the Y2 direction, and the Z2 direction, which are directions independent of the X1 direction, the Y1 direction, and the Z1 direction described above and perpendicular to each other. In the description of FIG. 3, the starting point side of the arrow indicating the X2 direction may be referred to as the -X2 side, and the tip side as the +X2 side, the starting point side of the arrow indicating the Y2 direction may be referred to as the -Y2 side, and the tip side as the +Y2 side, and the starting point side of the arrow indicating the Z2 direction may be referred to as the -Z2 side, and the tip side as the +Z2 side. In FIG. 3, as an example, the case where the Z2 direction is the direction opposite to the direction of gravity, that is, the upward direction, will be described. In FIG. 3, as an example, the case where the direction opposite to the Z2 direction is the direction of gravity, that is, the downward direction, will be described. In FIG. 3, as an example, the case where the direction opposite to the X2 direction is the transport direction will be described. In addition, in FIG. 3, as an example, a case where a direction parallel to the Y2 direction is the main scanning direction will be described. In the following, as an example, a case where m=6 will be described. For convenience of explanation, the direction in which liquid is ejected from the liquid ejection module 20 will be referred to as the first direction, and the direction opposite to the first direction will be referred to as the second direction. In addition, in this embodiment, as an example, a case where the first direction coincides with the downward direction will be described. In addition, in this embodiment, as an example, a case where the control circuit 100 and the conversion circuit 120 are included in a common FPGA will be described. In addition, the conversion circuit 120 may be configured not to be included in the FPGA.

[0042] As shown in FIG. 3, the head driving module 10 has a first substrate B1, a second substrate B2, a fan FN, a control circuit 100, a conversion circuit 120, a heat sink HS1, six driving circuit sections DRV, and a first connector CN1 to a fourth connector CN4. The head driving module 10 can be fitted with a type of fan desired by a user of the liquid ejection device 1 as the fan FN. For this reason, the head driving module 10 does not include the fan FN, and the fan is attached from the outside. The head driving module 10 may be configured to include the fan FN. Even in this case, the head driving module 10 can replace the fan attached as the fan FN with a fan desired by the user.

[0043] The first substrate B1 is a power supply board that supplies power to each component included in the head driving module 10. The first substrate B1 is a rectangular flat substrate in which the longitudinal direction of each of the two surfaces, a first surface M1 and a second surface M2, of the first substrate B1 extends in the Z2 direction, and the lateral direction of each of the first surface M1 and the second surface M2 extends in the Y2 direction.

[0044] Here, in this embodiment, the longitudinal or lateral direction of a certain member extending toward a certain direction may mean that the member extends in that direction or that the member extends in a direction oblique to that direction. In the following, as an example, as shown in FIG. 3, a case will be described in which the first substrate B1 is a rectangular flat substrate in which the longitudinal direction of each of the first surface M1 and the second surface M2 extends in the Z2 direction and the lateral direction of each of the first surface M1 and the second surface M2 extends in the Y2 direction. In this case, each of the first surface M1 and the second surface M2 is a surface parallel to the first direction as shown in FIG. 3. In addition, when the longitudinal direction of each of the first surface M1 and the second surface M2 extends in a direction oblique to the Z2 direction, each of the first surface M1 and the second surface M2 is a surface oblique to the first direction.

[0045] The first substrate B1 may be configured to be connected to the liquid ejection module 20 via the wiring member 30, or may be configured to be connected to the liquid ejection module 20 in a BtoB manner without the wiring member 30 being interposed therebetween.

[0046] Six drive circuit units DRV, a second substrate B2, etc. are mounted on the first surface M1 of the first substrate B1. In the following, for convenience of explanation, these six drive circuit units DRV will be referred to as drive circuit units DRV1 to DRV6. A first connector CN1 is provided at an end on the -Z2 side of the first surface M1 of the first substrate B1. A second connector CN2 and a third connector CN3 are provided at an end on the +Z2 side of the second surface M2 of the first substrate B1. Thus, the first substrate B1 has the first connector CN1, the second connector CN2, and the third connector CN3.

[0047] The first connector CN1 is a connector to which a transmission cable is connected to transmit a drive signal output from each of the drive circuits 52a, 52b, and 52c included in the drive circuit unit DRV described later. The liquid ejection module 20 or the wiring member 30 connected to the liquid ejection module 20 is connected to the first connector CN1. Therefore, the drive signal output from the drive circuit unit DRV is output to the liquid ejection module 20 via the first connector CN1. In the example shown in FIG. 3, the first connector CN1 is provided on a first surface M1 of the two surfaces of the first substrate B1. The first connector CN1 may be configured to be provided on a second surface M2 of the first substrate B1. The first connector CN1 is an example of a head attachment unit.

[0048] The second connector CN2 is a connector to which a power cable that supplies power to the fan FN is connected. The second connector CN2 is provided on the second surface M2 of the first substrate B1. The second connector CN2 may be configured to be provided on the first surface M1 of the first substrate B1.

[0049] The third connector CN3 is a connector to which a power cable that supplies power to the first substrate B1, which is a power supply board, is connected. The third connector CN3 is provided on the second surface M2 of the first substrate B1. The third connector CN3 may be configured to be provided on the first surface M1 of the first substrate B1.

[0050] The i-th drive circuit unit DRVi of the six drive circuit units DRV is provided on the first surface M1 of the first substrate B1. In other words, the drive circuit unit DRVi is connected onto the first surface M1 of the first substrate B1. The drive circuit unit DRVi includes a drive signal output circuit 50-i. That is, the drive circuit unit DRVi includes three drive circuits, ie, a drive circuit 52a, a drive circuit 52b, and a drive circuit 52c, not shown in FIG. 3, and a reference voltage output circuit 53. Here, i is an integer of 1 to 6.

[0051] The driving circuit unit DRVi includes a third substrate B3 on which the driving signal output circuit 50-i is mounted, a temperature detection unit S1, and a heat sink HS2. The head driving module 10 may be configured so that the driving circuit 52 included in the driving signal output circuit 50-i can be replaced with a driving circuit desired by the user. In this case, the head driving module 10 may be configured so that the driving circuit 52 included in the driving signal output circuit 50-i itself is replaceable, the entire driving signal output circuit 50-i together with the driving circuit is replaceable, or the entire driving circuit unit DRVi including the driving signal output circuit 50-i together with the driving circuit is replaceable. In this case, the head driving module 10 may be configured so that it does not include a driving circuit connected to the head driving module 10 as the driving circuit 52 included in the driving signal output circuit 50-i, it may be configured so that it does not include the driving signal output circuit 50-i including the driving circuit, or it may be configured so that it does not include the driving circuit unit DRVi including the driving signal output circuit 50-i.

[0052] Here, as shown in FIG. 3, the third substrate B3 is connected to the first substrate B1 in a BtoB manner and stands upright relative to the first substrate B1. Therefore, all connections between the third substrate B3 and other substrates are made via the BtoB connection with the first substrate B1. The third substrate B3 is a rectangular flat substrate, and the drive signal output circuit 50-i is mounted on it. Note that, for example, three integrated circuits, three field effect transistors, three coils, one electrolytic capacitor, etc. constituting the drive circuits 52a, 52b, and 52c as class D amplifier circuits are mounted on the third substrate B3 of the drive circuit unit DRVi, but this is not limited thereto. Here, the field effect transistor mounted on the third substrate B3 of the drive circuit unit DRVi is a field effect transistor included in the drive signal output circuit 50-i. This field effect transistor generates heat while the drive signal output circuit 50-i is operating, that is, while the drive circuit unit DRVi is operating. The above-mentioned fan FN cools the drive circuit section DRVi, whose temperature rises due to this heat, thereby cooling the drive signal output circuit 50-i.

[0053] The temperature detection unit S1 is a temperature sensor that detects the temperature of the drive signal output circuit 50-i, the temperature of which increases in this way, and is, for example, a thermistor, but is not limited to this. The temperature of the drive signal output circuit 50-i may be referred to as the temperature of the drive circuit unit DRVi. Here, the temperature detection unit S1 is included in each of the drive circuit units DRV1 to DRV6. In the following, for convenience of explanation, the temperature detection unit S1 included in the drive circuit unit DRVi will be referred to as the temperature detection unit S1i. The temperature detection unit S1i may have any configuration as long as it is capable of detecting the temperature of the drive signal output circuit 50-i. The position of the temperature detection unit S1 inside the drive circuit unit DRVi is preferably as close as possible to the field effect transistor included in the drive signal output circuit 50-i inside the drive circuit unit DRVi. This is because the field effect transistor is one of the heat sources that generate the most heat inside the drive circuit unit DRVi. The temperature detection unit S1i outputs temperature information indicating the detected temperature to the control circuit 100. In order to avoid the diagram becoming complicated, the temperature detection units S1 included in each of the drive circuit units DRV2, DRV3, DRV5, and DRV6 are omitted in Fig. 3.

[0054] A fifth connector (not shown) is provided at the end of the third substrate B3 of the drive circuit unit DRV1 on the -X2 side. The fifth connector is connected to a connector (not shown) provided on the first substrate B1. This allows the drive circuit unit DRV1 to be connected to the first substrate B1 in a BtoB manner. As a result, the drive circuit unit DRV1 is connected to the first substrate B1 so as to extend in a direction intersecting with the first substrate B1. In the example shown in FIG. 3, the drive circuit unit DRV1 is connected to the first substrate B1 in a BtoB manner so as to extend in the X2 direction, which is a direction perpendicular to the first substrate B1. The fifth connector is a connector for outputting drive signals output from the drive circuits 52a, 52b, and 52c included in the drive circuit unit DRV1 to the liquid ejection module 20 via the first substrate B1.

[0055] The heat sink HS2 is a heat sink for cooling the drive signal output circuit 50-i. The heat sink HS2 is provided on the third substrate B3 so as to sandwich the drive signal output circuit 50-i mounted on the third substrate B3 together with the third substrate B3. Here, in the example shown in FIG. 3, the outer shape of the drive circuit unit DRVi is a substantially rectangular parallelepiped shape. Such an outer shape of the drive circuit unit DRVi is formed by the third substrate B3 and the heat sink HS2 included in the drive circuit unit DRVi. The heat sink HS2 does not substantially obstruct the airflow flowing in the first direction or the second direction. Therefore, the airflow flowing in the first direction or the second direction can efficiently dissipate heat from the drive circuit unit DRVi.

[0056] As shown in FIG. 3, the second substrate B2 is a rectangular flat substrate, and is an interface board on which the control circuit 100 and the conversion circuit 120 are mounted. More specifically, the second substrate B2 is mounted on the first surface M1 of the first substrate B1 on the +Z2 side of the six drive circuit units DRV. In the example shown in FIG. 3, the second substrate B2 is connected to the first substrate B1 in a BtoB manner. The second substrate B2 may be connected to the first substrate B1 in a manner different from the BtoB connection. A fourth connector CN4 is provided at the end of the second substrate B2 on the +Z2 side.

[0057] The fourth connector CN4 is a connector to which a transmission cable for transmitting signals such as an image information signal IP input to the control circuit 100 is connected. Therefore, the image information signal IP is input to the control circuit 100 via the fourth connector CN4. The fourth connector CN4 is also a connector for receiving a control signal input to the conversion circuit 120. Therefore, the control signal is input to the conversion circuit 120 via the fourth connector CN4. Here, the second board B2 is connected to the first board B1 in a BtoB manner. Therefore, the conversion circuit 120 operates by power supplied from the first board B1 to the second board B2. On the other hand, the control signal is received by the fourth connector CN4 without passing through the first board B1. That is, the conversion circuit 120 receives the control signal through the fourth connector CN4 without passing through the first board B1.

[0058] In the example shown in FIG. 3, a fan mounting portion (not shown) on which the fan FN is mounted is mounted on the second substrate B2. More specifically, in this example, the fan FN is mounted on a fan mounting portion mounted on the end of the second substrate B2 on the -Z2 side. That is, the fan FN is mounted on the first substrate B1 via the fan mounting portion on the second substrate B2. This makes it possible for the head drive module 10 to suppress the transmission of vibrations generated by the rotation of the fan FN mounted on the fan mounting portion to the first substrate B1, compared to a case in which the fan mounting portion is directly mounted on the first substrate B1, and as a result, to suppress the transmission of the vibrations to each of the drive circuits 52a, 52b, and 52c. In addition, although the fan mounting portion is mounted on the first substrate B1 via the second substrate B2, the fan FN is supplied with power from the first substrate B1 using a cable (not shown). That is, the power supplied from the second connector CN2 is supplied to the fan FN via the first board B1, not via the second board B2. In other words, the fan FN operates with the power supplied from the first board B1. Note that the fan mounting portion may be directly mounted on the first board B1, instead of being mounted on the second board B2. Also, the fan mounting portion may not be mounted on either the first board B1 or the second board B2, and may be mounted by another method, such as by being screwed to the frame.

[0059] The fan FN is a blower that generates air to blow on the drive circuits 52a, 52b, and 52c of the drive signal output circuits 50-1 to 50-6. More specifically, the fan FN has fins that rotate around a predetermined rotation axis, and is a blower that blows air in a direction parallel to the rotation axis. The fan FN stands upright on the first board B1 via a fan mounting portion on the second board B2. In the example shown in FIG. 3, the predetermined rotation axis is an axis parallel to the first direction and is approximately parallel to the surface of the third board B3. Therefore, the fan FN can generate an airflow parallel to the first direction and the surface of the third board B3 so that resistance to the flow of the airflow is small. As a result, the fan FN can more reliably dissipate heat from the heat sink HS2 of the drive circuit unit DRV and the heat sink HS1 described later by the airflow generated by the fan FN. That is, the head driving module 10 can efficiently cool at least a part of the driving circuits 52a, 52b, and 52c of the driving signal output circuits 50-1 to 50-6. In the following, as an example, a case will be described in which the fan FN blows air to create an air current that flows in a second direction opposite to the first direction. Note that the fan FN may be configured to blow air to create an air current that flows in the first direction.

[0060] Moreover, a heat sink HS1 is provided on the FPGA (not shown) including the control circuit 100 and the conversion circuit 120 on the second substrate B2. The heat sink HS1 is a heat sink for cooling the FPGA and the like. Moreover, in the example shown in FIG. 3, the FPGA is mounted on the second substrate B2, next to the fan FN on the +Z2 side, between the heat sink HS2 and the second substrate B2. This allows the head drive module 10 to more reliably pass the airflow created by the fan FN to flow in the first direction through the heat sink HS1. As a result, the head drive module 10 can improve the cooling efficiency of the FPGA.

[0061] 1.3 Process by which the control circuit controls the fan Next, a process of the control circuit 100 controlling the fan FN will be described. The control circuit 100 controls the fan attached to the head driving module 10 as the fan FN based on the temperature detected by the temperature detection unit S1 and the driving method information stored in the first storage unit of the control circuit 100. The driving method information is information indicating a method for driving the fan. More specifically, the driving method information is information including information that associates, for example, temperature range information indicating the temperature range of the temperature of the driving circuit unit DRV with duty ratio information indicating the duty ratio for PWM (Pulse Width Modulation) control of the fan. The driving method information may be configured to include other information. Note that the driving method information may be information including information that associates the temperature range information with other control values ​​that control the fan. The driving method information is generated based on, for example, a prior experiment, a simulation, or the like.

[0062] Here, FIG. 4 is a diagram showing an example of the driving method information. In the example shown in FIG. 4, the driving method information is information in a lookup table format. Note that the driving method information may be information in another format instead of the lookup table format. Also, in FIG. 4, the temperature detected by the temperature detection unit S1 is indicated by a "TH detection value". The driving method information shown in FIG. 4 includes six pieces of temperature range information. These six pieces of temperature range information are identified by levels indicating the levels of the temperatures detected by the temperature detection unit S1. In this example, the temperature range indicated by the temperature range information identified by level 1 is a temperature range below -5°C. In this example, the temperature range indicated by the temperature range information identified by level 2 is a temperature range of -5°C or more and less than 40°C. In this example, the temperature range indicated by the temperature range information identified by level 3 is a temperature range of 40°C or more and less than 70°C. In this example, the temperature range indicated by the temperature range information identified by level 4 is a temperature range of 70°C or more and less than 85°C. In this example, the temperature range indicated by the temperature range information identified by level 5 is a temperature range of 85° C. or more and less than 90° C. In this example, the temperature range indicated by the temperature range information identified by level 6 is a temperature range of 90° C. or more.

[0063] In the example shown in FIG. 4, each piece of temperature range information is associated with rotation speed range information about the rotation speed of the fan FN, unit information indicating the unit of the rotation speed, and duty ratio information indicating the duty ratio for the PWM control of the fan FN. However, in FIG. 4, the duty ratio information is indicated by "PWM Duty." For example, the temperature range information of level 1 is associated with rotation speed range information indicating a rotation speed range of 2800 rpm (revolution per minute) or more and less than 24000 rpm, and duty ratio information indicating the duty ratio of 8%. For example, the temperature range information of level 4 is associated with rotation speed range information indicating a rotation speed range of 8750 rpm or more and less than 24000 rpm, and duty ratio information indicating the duty ratio of 33%.

[0064] For example, the control circuit 100 specifies a statistical value such as an average value or a maximum value of the temperature detected by each of the temperature detection units S1 included in each drive circuit unit DRV as the temperature of each drive circuit unit DRV. After specifying the temperature, the control circuit 100 specifies temperature range information including the temperature based on the drive method information, and specifies duty ratio information associated with the specified temperature range information. After specifying the duty ratio information, the control circuit 100 controls the fan FN by PWM control of the duty ratio indicated by the specified duty ratio information. This allows the control circuit 100 to change the rotation speed of the fan FN according to the temperature of the hottest drive circuit unit DRV. Note that these are examples of how to use the drive method information. Therefore, the use of the drive method information is not limited to these.

[0065] However, the temperature of the drive circuit unit DRV during operation also changes depending on the type of the liquid ejection module 20, the mounting position of the liquid ejection module 20, and the like. In addition, the temperature of the drive circuit unit DRV during operation also changes depending on the type of the fan FN, the mounting position of the fan FN, and the like. The mounting position of the liquid ejection module 20 may be rephrased as the relative arrangement position of the liquid ejection module 20 with respect to the head driving module 10. In addition, the mounting position of the fan FN may be rephrased as the relative arrangement position of the fan FN with respect to the head driving module 10. For these reasons, when the liquid ejection module 20 is replaced with a new liquid ejection module 20, when the fan FN is replaced with a new fan FN, and the like, the control circuit 100 may not be able to properly cool the drive circuit unit DRV during operation in the method using the drive method information as described above. In other words, in these cases, the control circuit 100 may not be able to properly cool the drive signal output circuit 50 during operation.

[0066] Therefore, the control circuit 100 controls the fan FN based on the drive method information associated with the temperature detected by the temperature detection unit S1 and the rotation speed of the fan FN, among a plurality of different drive method information. This allows the control circuit 100 to appropriately cool the drive circuit unit DRV during operation.

[0067] Here, each of the plurality of driving method information is associated with information identification information for identifying each of the plurality of driving method information. The information identification information associated with a certain driving method information is, for example, an ID (Identifier) ​​indicating the driving method information, but is not limited thereto. Each of the plurality of driving method information is stored in the first storage unit together with the correspondence information. The correspondence information is information in which temperature range information indicating a temperature range for the temperature detected by the temperature detection unit S1, rotation speed range information indicating a rotation speed range for the rotation speed of the fan FN, and information identification information are associated with each other. FIG. 5 is a diagram illustrating an example of the correspondence information. In the example shown in FIG. 5, the correspondence information is information in a lookup table format. Note that the correspondence information may be information in another format instead of the lookup table format. FIG. 5 shows three pieces of correspondence information (a) to (c). As shown in FIG. 5, in the correspondence information, the temperature range information, the rotation speed range information, and the information identification information are associated with each other. In the correspondence information shown in Fig. 5(a), for example, temperature range information indicated by -5°C≦T<20°C, rotation speed range information indicated by 3800 rpm≦R<5000 rpm, and information identification information indicated by xxx1 are associated with each other. In addition, in the correspondence information shown in Fig. 5(b), for example, temperature range information indicated by 20°C≦T<40°C, rotation speed range information indicated by 5000 rpm≦R<6000 rpm, and information identification information indicated by xxx2 are associated with each other. In addition, in the correspondence information shown in Fig. 5(c), for example, temperature range information indicated by 40°C≦T<60°C, rotation speed range information indicated by 2800 rpm≦R<3800 rpm, and information identification information indicated by xxx3 are associated with each other.

[0068] The control circuit 100 selects drive method information to be used for controlling the fan FN from among a plurality of pieces of drive method information, for example, by a calibration process. The calibration process is a process in which the drive circuit unit DRV is controlled based on a predetermined image information signal IP while controlling the fan FN based on reference drive method information from among the plurality of pieces of drive method information, thereby causing the discharge unit 600 of the liquid discharge module 20 to discharge liquid, and selects drive method information associated with the temperature detected by the temperature detection unit S1 and the number of revolutions of the fan FN from among the plurality of pieces of drive method information, based on the read-out correspondence information, during the period in which the discharge unit 600 discharges liquid. In the following, for convenience of explanation, the reference drive method information will be referred to as reference drive method information.

[0069] For example, the control circuit 100 performs the following process in the calibration process. First, the control circuit 100 receives head identification information for identifying the liquid ejection module 20 from an external device such as a host computer (not shown) provided outside the liquid ejection device 1 via the control unit 2. The head identification information may be any information that can identify the liquid ejection module 20, for example, an ID, but is not limited to this. The control circuit 100 reads out the reference driving method information associated with the received head identification information from the first storage unit. For this reason, the first storage unit stores a plurality of mutually different reference driving method information in advance. Then, each of the plurality of reference driving information is associated with a mutually different head identification information. That is, the reference driving method information associated with a certain head identification information is the reference driving method information used in the calibration process when the liquid ejection module 20 identified by the head identification information is attached to the head driving module 10. After reading out the reference driving method information from the first storage unit, the control circuit 100 controls the fan FN based on the read out reference driving method information while controlling the driving circuit unit DRV based on a predetermined image information signal IP. As a result, the control circuit 100 causes the discharge unit 600 of the liquid discharge module 20 to discharge liquid, and selects driving method information associated with the temperature detected by the temperature detection unit S1 and the rotation speed of the fan FN from among the multiple driving method information based on the correspondence information previously read out from the first storage unit during the period in which the discharge unit 600 discharges liquid. The image information signal IP is an image information signal used in the calibration process. The image information signal IP is, for example, an image information signal for test printing, but may be an image information signal other than that for test printing, or may be another image information signal. In the following, for convenience of explanation, the image information signal IP is referred to as a test image information signal. Here, the control circuit 100 may detect the rotation speed of the fan FN in any way. For example, the control circuit 100 detects the rotation speed of the fan FN based on the signal output from the signal output unit S3 shown in FIG.The signal output unit S3 is a sensor that outputs a signal according to the rotation of the fan FN, but is not limited thereto. For example, the signal output unit S3 is a fan pulse sensor that outputs a square wave of one period as a signal for one rotation of the fan FN. When the control circuit 100 detects the rotation speed of the fan FN based on the signal output from the signal output unit S3, the control circuit 100 detects the rotation speed of the fan FN based on the signal acquired from the signal output unit S3 and a clock signal generated by the control circuit 100. In this case, among the functions of the control circuit 100, the function of detecting the rotation speed of the fan FN based on the signal and the clock signal functions as a rotation speed detection unit that detects the rotation speed of the fan FN in the control circuit 100. Note that the signal output unit S3 may be a rotation speed detection unit that detects the rotation speed of the fan FN. In this case, the signal output unit S3 is, for example, a hall sensor, etc., which detects the rotation speed of the fan FN and outputs a signal including rotation speed information indicating the detected rotation speed to the control circuit 100. After selecting the drive method information associated with the temperature detected by the temperature detection unit S1 and the rotation speed of the fan FN, the control circuit 100 sets the selected drive method information in the first storage unit as the drive method information to be used in normal times. For example, the control circuit 100 associates the selected drive method information with information indicating that the drive method information is the drive method information to be used in normal times and stores it in the first storage unit. This allows the control circuit 100 to control the fan FN by a drive method suitable for the liquid ejection module 20 attached to the head drive module 10, and as a result, the drive circuit unit DRV in operation can be appropriately cooled. The control circuit 100 performs the above-mentioned processing as a calibration process.

[0070] Fig. 6 is a diagram showing an example of the flow of the calibration process performed by the control circuit 100. In the following, as an example, a case will be described in which the control circuit 100 receives, via the control unit 2, a process start operation for starting the calibration process at a timing before the process of step S110 shown in Fig. 6 is performed. In addition, in the following, as an example, a case will be described in which the control circuit 100 receives, via the control unit 2, head identification information at that timing from an external device communicably connected to the liquid ejection device 1.

[0071] After receiving the processing start operation, the control circuit 100 reads out the test image information signal from the first storage unit (step S110). Note that in step S110, the control circuit 100 may be configured to obtain the test image information signal from another information processing device, another server, or the like that is communicably connected to the liquid ejection device 1.

[0072] Next, the control circuit 100 reads out from the first storage unit, among the plurality of pieces of driving method information stored in the first storage unit, reference driving method information associated with the head identification information previously received (step S120). Note that the process of step S120 may be performed in the reverse order to the process of step S110, or may be performed in parallel with the process of step S110.

[0073] Next, based on the test image information signal read out in step S110, the control circuit 100 starts printing an image on the medium P, acquiring temperature information output from the temperature detection unit S1, and acquiring a signal output from the signal output unit S3 (step S130).

[0074] Next, the control circuit 100 waits until the printing started in step S130 is completed (step S140).

[0075] When the control circuit 100 determines that the printing started in step S130 has ended (step S140-YES), it ends both the acquisition of the temperature information started in step S130 and the acquisition of the signal started in step S130 (step S150). Note that the control circuit 100 may be configured to end at least one of the acquisition of the temperature information and the acquisition of the signal during printing.

[0076] Next, the control circuit 100 detects the temperature of each drive circuit section DRV and the rotation speed of the fan FN based on the temperature information and the signal acquired by the processing of steps S130 to S150 (step S160). More specifically, in step S160, the control circuit 100 detects, for example, statistical values ​​such as the average value and maximum value of the temperature indicated by the temperature information as the temperature of each drive circuit section DRV. Also, in step S160, the control circuit 100 detects, for example, statistical values ​​such as the average value and maximum value of the rotation speed of the fan FN during the period in which the processing of steps S130 to S150 is performed based on the signal as the rotation speed of the fan FN.

[0077] Next, the control circuit 100 reads out the correspondence information from the first storage unit, and identifies information identification information associated with temperature range information indicating a temperature range including the temperature detected in step S160 and rotation speed information indicating a rotation speed range including the rotation speed detected in step S160 based on the read out correspondence information. Then, the control circuit 100 selects the driving method information associated with the identified information identification information from the multiple driving method information stored in the first storage unit (step S170).

[0078] Next, the control circuit 100 sets the driving method information selected in step S170 in the first storage unit as driving method information to be used in normal times (step S180), and ends the process of the flowchart shown in FIG.

[0079] As described above, the control circuit 100 selects, from among a plurality of pieces of drive method information, drive method information associated with the temperature detected by the temperature detection unit S1 and the rotation speed detected by the rotation speed detection unit. This allows the control circuit 100 to control the fan FN based on drive method information suitable for the liquid ejection module 20 attached to the head drive module 10. As a result, the control circuit 100 can suitably cool the drive circuit unit DRV during operation.

[0080] Here, Fig. 7 is a diagram showing an example of a process flow in which the control circuit 100 controls the fan FN based on the drive method information selected by the control circuit 100 through the process of the flowchart shown in Fig. 6. In the following, as an example, a case will be described in which the control unit 2 of the liquid ejection device 1 receives image data from an external device at a timing before the process of step S210 shown in Fig. 7 is performed. In addition, in the following, as an example, a case will be described in which the control unit 2 of the liquid ejection device 1 receives a print start operation from the external device to cause the liquid ejection device 1 to start printing at that timing.

[0081] After the control unit 2 of the liquid ejection device 1 accepts a print start operation, the control circuit 100 sets the lowest duty ratio among the duty ratios indicated by each of the multiple duty ratio information included in the drive method information set as the drive method information used in normal times as the duty ratio to be used for PWM control of the fan FN (step S210). Note that the control circuit 100 may be configured to set a duty ratio other than the lowest duty ratio among the duty ratios indicated by each of the multiple duty ratio information included in the drive method information set as the drive method information used in normal times as the duty ratio to be used for PWM control of the fan FN in step S210.

[0082] Next, the control circuit 100 starts printing on the medium P an image indicated by the image data received in advance (step S220). The control circuit 100 also starts controlling the fan FN in step S220. That is, the control circuit 100 starts rotating the fan FN in step S220. The process of step S220 may be performed in the reverse order to the process of step S210, or may be performed in parallel with the process of step S210.

[0083] Next, the control circuit 100 repeats the processes of steps S240 to S270 every time a predetermined first update period elapses (step S230). The first update period is, for example, about several seconds, but may instead be several hundred milliseconds or another period.

[0084] When it is determined in step S230 that the first update period has elapsed, the control circuit 100 acquires, from the temperature detection unit S1, temperature information output from the temperature detection unit S1. Then, the control circuit 100 identifies temperature range information indicating a temperature range including the temperature indicated by the acquired temperature information from among the driving method information set as driving method information used in normal times (step S240).

[0085] Next, the control circuit 100 specifies duty ratio information associated with the temperature range information specified in step S240 from among the driving method information set as driving method information to be used in normal times (step S250). Note that the process of step S250 may be combined with the process of step S240.

[0086] Next, the control circuit 100 changes the duty ratio set as the duty ratio used for the PWM control of the fan FN to the duty ratio indicated by the duty ratio information identified in step S250 (step S260). This allows the control circuit 100 to rotate the fan FN at a rotation speed according to the temperature of each drive circuit unit DRV.

[0087] Next, the control circuit 100 determines whether the printing started in step S220 has ended (step S270). The method by which the control circuit 100 determines whether the printing has ended may be a known method or a method to be developed in the future.

[0088] When the control circuit 100 determines in step S220 that the printing started has not ended (step S270-NO), the control circuit 100 transitions to step S230 and waits until the next first update period has elapsed.

[0089] On the other hand, if the control circuit 100 determines that the printing started in step S220 has ended (step S270-YES), it ends the repeated process of steps S220 to S270, stops the rotation of the fan FN, and then ends the process of the flowchart shown in FIG. 7.

[0090] As described above, the control circuit 100 controls the fan FN based on the drive method information selected by the processing of the flowchart shown in Fig. 6. This allows the control circuit 100 to suitably cool the drive circuit unit DRV during operation.

[0091] The control circuit 100 can also perform a process of detecting whether an error has occurred in the control of the fan FN based on the drive method information selected by the control circuit 100 through the process of the flowchart shown in Fig. 6. Fig. 8 is a diagram showing an example of a process flow in which the control circuit 100 detects whether an error has occurred in the control of the fan FN based on the drive method information selected by the control circuit 100 through the process of the flowchart shown in Fig. 6. In the following, as an example, a case will be described in which the control circuit 100 starts the process of the flowchart shown in Fig. 8 at the timing when the fan FN starts to rotate in step S220 shown in Fig. 7.

[0092] The control circuit 100 repeats the processes of steps S320 to S340 every time a predetermined second update period elapses (step S310). The second update period is, for example, about several seconds, but may instead be several hundred milliseconds or another period. The second update period may be the same period as the first update period, or may be a period different from the first update period.

[0093] If it is determined in step S310 that the second update period has elapsed, the control circuit 100 acquires the temperature information output from the temperature detection unit S1 and the signal output from the signal output unit S3. Then, the control circuit 100 detects the temperature indicated by the acquired temperature information as the current temperature of each drive circuit unit DRV, and detects the rotation speed detected based on the acquired signal as the current rotation speed of the fan FN (step S320).

[0094] Next, the control circuit 100 identifies temperature range information indicating a temperature range including the temperature detected in step S320 from among the driving method information set as driving method information to be used normally (step S330).

[0095] Next, the control circuit 100 judges whether an error has occurred in the control of the fan FN (step S340). In FIG. 8, the process of step S340 is indicated by "Error?". For example, the control circuit 100 judges whether an error has occurred in the control of the fan FN by judging whether the rotation speed detected in step S320 is included in the rotation speed range indicated by the rotation speed range information associated with the temperature range information identified in step S330. In this case, if the control circuit 100 judges that the rotation speed detected in step S320 is included in the rotation speed range indicated by the rotation speed range information associated with the temperature range information identified in step S330, it judges that no error has occurred in the control of the fan FN. On the other hand, if the control circuit 100 judges that the rotation speed detected in step S320 is not included in the rotation speed range indicated by the rotation speed range information associated with the temperature range information identified in step S330, it judges that an error has occurred in the control of the fan FN. That is, the temperature range information is, for example, information used to judge whether an error has occurred in the control of the fan FN. The control circuit 100 may be configured to determine whether or not an error has occurred in the control of the fan FN using another method based on the rotation speed detected in step S320.

[0096] When it is determined that no error has occurred in the control of the fan FN (step S340-NO), the control circuit 100 transitions to step S310 and waits until the next second update period has elapsed.

[0097] On the other hand, if the control circuit 100 determines that an error has occurred in the control of the fan FN (step S340-YES), it stops the currently executing printing of the image on the medium P (step S350) and ends the processing of the flowchart shown in Fig. 7 along with the processing of the flowchart shown in Fig. 8. At this time, the control circuit 100 may be configured to output information indicating that an error has occurred in the control of the fan FN to an external device.

[0098] As described above, the control circuit 100 detects whether an error occurs in the control of the fan FN. This allows the control circuit 100 to prevent the printing of the image on the medium P from continuing in a state where an error occurs in the control of the fan FN, and as a result, the liquid ejection device 1 can be prevented from further malfunctioning. Note that the control circuit 100 may be configured to continue printing without stopping it and reduce the number of rotations of the fan FN in step S350, for example. In this case, the control circuit 100 can prevent the number of rotations of the fan FN from increasing too much, and as a result, prevent the amount of power consumption from increasing. However, when the process of step S350 is performed in this manner, it is desirable that the upper limit value of the range of rotation speeds included in the drive method information is set to a value sufficiently lower than the maximum value of the achievable number of rotations of the fan FN. Furthermore, when the process of step S350 is performed in this manner, the control circuit 100 can more reliably cool each drive circuit unit DRV by setting all the upper limits of the range of rotation speeds included in each drive method information to the maximum value.

[0099] 1.4 Process by which the control circuit controls the fan As described above, the head driving module 10 can attach and detach the liquid ejection module 20. Here, when a user of the liquid ejection device 1 attaches a certain type of liquid ejection module 20 to the head driving module 10, it is desirable to replace the fan currently attached as the fan FN to the head driving module 10 with a fan that corresponds to the performance of the liquid ejection module 20 of that type. This is because, as described above, the temperature of the driving circuit unit DRV during operation changes depending on the type of the liquid ejection module 20, and the required cooling capacity of the fan changes. In addition, when replacing the fan FN, it is preferable for the user to select a fan that is suitable in terms of shape and size from among fans that satisfy the required cooling capacity. However, when the type of fan attached to the head driving module 10 as the fan FN is changed in this way, the control circuit 100 may not be able to accurately control the fan FN unless the detection sensitivity of the rotation speed of the fan FN is also changed according to the replacement of the fan FN. This leads to the fan not being cooled appropriately. This is undesirable because it may increase the power consumption of the fan or may cause the drive circuit units DRV to be unable to be sufficiently cooled.

[0100] Therefore, the control circuit 100 has a function that allows the user to change the detection sensitivity of the rotation speed of the fan FN. Fig. 9 is a diagram showing an example of the functional configuration of the control circuit 100 related to the function that allows the user to change the detection sensitivity of the rotation speed of the fan FN, among the functions of the control circuit 100.

[0101] 9, the control circuit 100 includes a first clock generating unit 101, a second storage unit 102, a receiving unit 103, a second clock generating unit 104, and a calculation unit 105. The control circuit 100 may be configured to include other functional units as functional units related to a function for allowing a user to change the detection sensitivity of the rotation speed of the fan FN.

[0102] The first clock generating unit 101 is an oscillation circuit of the control circuit 100, and generates a first clock signal.

[0103] The second storage unit 102 is an example of a second storage unit included in the control circuit 100, and is, for example, a register as described above. The second storage unit 102 stores value information indicating the value of n for dividing the first clock signal generated by the first clock generation unit 101 by n. n may be any integer equal to or greater than 1. Note that the second storage unit 102 may be any storage device, instead of a register, as long as the storage device is capable of updating the stored value information to other value information via a connected external device.

[0104] The reception unit 103 is a connection unit, for example a connector, to which an external device or the like is connected via a cable or the like. The reception unit 103 has the second storage unit 102 connected to the other end. The reception unit 103 receives value information from the connected external device. The reception unit 103 stores the received value information in the second storage unit 102.

[0105] The second clock generating unit 104 generates a second clock signal by dividing the first clock signal by n based on the value information stored in the second storage unit 102. The method of dividing the first clock signal by n by the second clock generating unit 104 may be a known method or a method to be developed in the future. The second clock generating unit 104 may be a software function unit or a hardware function unit. In the following, as an example, a case where the second clock generating unit 104 is a hardware function unit of an FPGA included in the control circuit 100 will be described.

[0106] The calculation unit 105 calculates the rotation speed of the fan FN based on the value information stored in the second storage unit 102, the signal output by the signal output unit S3, and the second clock signal generated by the second clock generation unit 104. The calculation unit 105 is, for example, a counter circuit, but is not limited to this.

[0107] Here, FIG. 10 is a diagram for explaining a method of calculating the rotation speed of the fan FN by the calculation unit 105 using the second clock signal. The waveform WV1 shown in FIG. 10 is an example of the waveform of the signal output from the signal output unit S3. The waveform WV2 shown in FIG. 10 is an example of the waveform of the second clock signal generated by the second clock generation unit 104. The period PD1 shown in FIG. 10 is an example of a waveform for one cycle included in the signal of the waveform WV1. The calculation unit 105 calculates the number of pulses of the second clock signal of the waveform WV2 included in each cycle of the signal of the waveform WV1 as the rotation speed of the fan FN. For example, the calculation unit 105 calculates the number of pulses included in the period PD1, that is, 7, as the rotation speed of the fan FN. Since such a method of calculating the rotation speed of the fan FN is a known method, further detailed description will be omitted.

[0108] Next, a process in which the second clock generating unit 104 generates a second clock signal will be described. Fig. 11 is a diagram showing an example of a flow of a process in which the second clock generating unit 104 generates a second clock signal. In the following, as an example, a case will be described in which value information is stored in the second storage unit 102 via the receiving unit 103 at a timing before the process of step S410 shown in Fig. 11 is performed.

[0109] When generating the second clock signal, the second clock generating unit 104 reads the value information stored in the second storage unit 102 from the second storage unit 102 (step S410).

[0110] Next, the second clock generating unit 104 divides the first clock signal generated by the first clock generating unit 101 by n based on the n indicated by the value information read in step S410 to generate a second clock signal (step S420). Then, the second clock generating unit 104 ends the process of the flowchart shown in FIG.

[0111] As described above, the control circuit 100 can generate the second clock signal based on the value information stored in the second storage unit 102. Therefore, the user of the liquid ejection device 1 can adjust the clock count of the second clock signal to a desired clock count by updating the value information of the second storage unit 102 by operating an external device connected to the reception unit 103. As a result, the user can change the detection sensitivity of the rotation speed of the fan FN by the control circuit 100 to a detection sensitivity desired by the user. This change in detection sensitivity may be an increase in the detection sensitivity or a decrease in the detection sensitivity. However, such a change in detection sensitivity is a relative change in detection sensitivity before and after the change in the clock count.

[0112] Next, a process in which the control circuit 100 detects the rotation speed of the fan FN will be described. Fig. 12 is a diagram showing an example of the flow of a process in which the control circuit 100 detects the rotation speed of the fan FN. For example, the control circuit 100 detects the rotation speed of the fan FN by the process of the flowchart shown in Fig. 12 in the process of step S160 shown in Fig. 6 and the process of step S320 shown in Fig. 8.

[0113] When detecting the rotation speed of the fan FN, the calculation unit 105 acquires the signal output from the signal output unit S3 (step S510). Here, the control circuit 100 continues to acquire the signal from the timing when the control circuit 100 starts acquiring the signal output from the signal output unit S3 in step S510 until the time when the fan FN rotates at least once has elapsed.

[0114] Next, the calculation unit 105 calculates the rotation speed of the fan FN based on the signal acquired in step S510, the second clock signal generated by the processing of the flowchart shown in FIG. 11, and the value information stored in the second storage unit 102. Then, the control circuit 100 detects the rotation speed of the fan FN calculated by the calculation unit 105 as the current rotation speed of the fan FN (step S520). After that, the control circuit 100 ends the processing of the flowchart shown in FIG. 12. Note that the calculation unit 105 may be configured to calculate the rotation speed of the fan FN without using the value information in step S520. Alternatively, the calculation unit 105 may be configured to calculate the rotation speed of the fan FN based on the first clock signal, the value information, and the signal in step S520. In this case, the control circuit 100 may be configured not to include the second clock generation unit 104.

[0115] As described above, the control circuit 100 detects the rotation speed of the fan FN based on the second clock signal generated by the processing of the flowchart shown in FIG. 11. This allows the control circuit 100 to detect the rotation speed of the fan FN with the detection sensitivity desired by the user. As a result, the control circuit 100 can precisely control the fan FN, and can appropriately cool each of the drive circuit units DRV during operation. Furthermore, as a result of being able to precisely control the fan FN, the control circuit 100 can also suppress an increase in power consumption.

[0116] The liquid ejection module 20 to which the head driving module 10 as described above is connected constitutes a head unit HU in the liquid ejection device 1 as shown in FIG. 13. That is, the liquid ejection device 1 includes a plurality of head units HU, each of which is a liquid ejection module 20 to which the head driving module 10 is connected. In the liquid ejection device 1, these plurality of head units HU constitute a line head. FIG. 13 is a diagram illustrating a plurality of head units HU configured as a line head in the liquid ejection device 1. In the example shown in FIG. 13, the head driving modules 10 of each head unit HU are connected to the liquid ejection module 20 via a wiring member 30. However, as described above, the head driving modules 10 of each head unit HU may be connected to the liquid ejection module 20 in a BtoB manner without the wiring member 30.

[0117] In the example shown in Fig. 13, the head units HU form three line heads. For ease of explanation, the three head units HU forming the first line head will be referred to as head unit HU11, head unit HU12, and head unit HU13. For ease of explanation, the three head units HU forming the second line head will be referred to as head unit HU21, head unit HU22, and head unit HU23. For ease of explanation, the three head units HU forming the third line head will be referred to as head unit HU31, head unit HU32, and head unit HU33.

[0118] The first line head is, for example, a line head made up of head units HU11 to HU13 including a liquid ejection module 20 that ejects magenta liquid. The second line head is, for example, a line head made up of head units HU21 to HU23 including a liquid ejection module 20 that ejects cyan liquid. The third line head is, for example, a line head made up of head units HU31 to HU33 including a liquid ejection module 20 that ejects yellow liquid.

[0119] In the example shown in FIG. 13, the head units HU11 to HU13 included in the first line head are arranged in the order of head unit HU11, head unit HU12, and head unit HU13 in the Y2 direction. The head units HU11 to HU13 included in the first line head may be arranged in a direction different from the Y2 direction. The same applies to the second and third line heads. For this reason, hereinafter, a description of the arrangement direction of the head units HU in the second and third line heads will be omitted. The head units HU11 to HU13 included in the first line head may be arranged in the order of head unit HU11, head unit HU12, and head unit HU13 in a direction inclined from the Y2 direction.

[0120] The drive method information selected by the control circuit 100 in some or all of the nine head units HU, head unit HU11, head unit HU12, head unit HU13, head unit HU21, head unit HU22, head unit HU23, head unit HU31, head unit HU32, and head unit HU33, is not necessarily the same as one another. This is because the temperature of each drive circuit section DRV during operation changes depending on the type and mounting position of the liquid ejection module 20 attached to the head drive module 10. In other words, the drive method information selected by the control circuit 100 in some or all of the nine head units HU may be different from one another or may be the same as one another.

[0121] Furthermore, the values ​​of n indicated by the value information stored in the second storage unit 102 of some or all of the nine head units HU, head unit HU11, head unit HU12, head unit HU13, head unit HU21, head unit HU22, head unit HU23, head unit HU31, head unit HU32, and head unit HU33, are not necessarily the same as each other. This is because the fans attached to the individual head driving modules 10 as fans FN are not necessarily the same as each other. In other words, the values ​​of n indicated by the value information stored in the second storage unit 102 of some or all of these nine head units HU may be different from each other or may be the same as each other.

[0122] The items described above may be combined in any manner.

[0123] Further, instead of being stored in the first storage unit, the plurality of pieces of driving method information described above may be stored in a server communicably connected to the control circuit 100. In this case, the control circuit 100 acquires each piece of driving method information from the server. The server may be a server on the cloud, a server in a LAN (Local Area Network), or a server on another network.

[0124] As described above, the head unit HU according to the embodiment includes the first connector CN1 to which the liquid ejection module 20 including the ejection unit 600 that ejects liquid is attached, the drive circuits 52a, 52b, 52c that generate drive signals for the liquid ejection module 20 attached to the first connector CN1, and the control circuit 100 that controls each of the fans FN that cool the drive circuits 52a, 52b, 52c, and the control circuit 100 controls the fan FN based on drive method information associated with the temperature detected by the temperature detection unit S1 that detects the temperature of the drive circuits 52a, 52b, 52c and the rotation speed detected by the rotation speed detection unit that detects the rotation speed of the fan FN, among a plurality of drive method information indicating the drive method of the fan FN. This allows the head unit HU to appropriately cool the drive circuit during operation.

[0125] Moreover, the control circuit according to the embodiment includes a control circuit 100 that controls the fan FN based on a signal output from a signal output unit S3 that outputs a signal corresponding to the rotation of the fan FN that cools the drive circuits 52a, 52b, 52c that generate a drive signal for the liquid ejection module 20 including an ejection unit 600 that ejects liquid. The control circuit 100 includes a first clock generation unit 101 that generates a first clock signal, a second memory unit 102 that stores value information indicating the value of n for dividing the first clock signal by n, a reception unit 103 that receives the value information and stores the received value information in the second memory unit 102, a second clock generation unit 104 that generates a second clock signal obtained by dividing the first clock signal by n based on the value information stored in the second memory unit 102, and a calculation unit 105 that calculates the rotation speed of the fan FN based on the value information stored in the second memory unit 102, the signal output by the signal output unit S3, and the second clock signal generated by the second clock generation unit 104. This allows the control device to suitably cool the drive circuit during operation.

[0126] <Appendix 1> [1] A head unit comprising: a head attachment portion for attaching a head including an ejection portion that ejects liquid; a drive circuit that generates a drive signal for the head attached to the head attachment portion; and a control portion that controls a fan that cools the drive circuit, wherein the control portion controls the fan based on drive method information among a plurality of drive method information indicating a drive method for the fan, the drive method information being associated with the temperature detected by a temperature detection portion that detects the temperature of the drive circuit and the rotation speed detected by a rotation speed detection portion that detects the rotation speed of the fan. [2] The control unit selects, from the plurality of pieces of driving method information, the driving method information that corresponds to the temperature detected by the temperature detection unit and the rotation speed detected by the rotation speed detection unit, and controls the fan based on the selected driving method information. [3] The head unit described in [2], wherein each of the plurality of driving method information is associated with information identification information that identifies each of the plurality of driving method information, and the control unit reads the correspondence information from a memory unit in which correspondence information is stored in which temperature range information indicating a temperature range for the temperature, rotation speed range information indicating a rotation speed range for the rotation speed, and the information identification information are associated, and based on the read correspondence information, selects from the plurality of driving method information the driving method information that is associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection unit and the rotation speed range information indicating the rotation speed range including the rotation speed detected by the rotation speed detection unit using the information identification information. [4] The control unit performs a calibration process for the control of the drive circuit and the fan in response to the received operation, and the calibration process is a process of controlling the drive circuit based on a predetermined image information signal while controlling the fan based on a reference drive method information among the plurality of drive method information, thereby causing the discharge section of the head to discharge the liquid, and selecting, from the plurality of drive method information, the drive method information associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection section and the rotation speed range information indicating the rotation speed range including the rotation speed detected by the rotation speed detection section, using the information identification information based on the correspondence information read out during a period in which the discharge section is discharging the liquid. [5] A head unit described in any one of [2] to [4], wherein each of the multiple driving method information includes multiple pieces of information correlating temperature range information indicating a temperature range for the temperature with duty ratio information indicating a duty ratio for PWM control of the fan, and the control unit, based on the selected driving method information, identifies the duty ratio information associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection unit, and controls the fan by PWM control based on the duty ratio indicated by the identified duty ratio information. [6] The head unit according to any one of [1] to [5], wherein the plurality of pieces of driving method information are stored in a server communicatively connected to the control unit. [7] The head unit described in any one of [1] to [5], further comprising a storage unit that stores the plurality of pieces of driving method information. [8] A head unit described in any one of [1] to [7], comprising the head. [9] A head unit described in any one of [1] to [8], comprising the fan.

[10] A head unit described in any one of [1] to [9], comprising the drive circuit.

[11] A liquid ejection device comprising: a head unit according to any one of [1] to

[10] ; and a transport unit that transports a medium.

[12] A liquid ejection device as described in

[11] , comprising the head units as a first head unit and a second head unit, wherein the drive method information selected by the control unit of the second head unit is different from the drive method information selected by the control unit of the first head unit.

[13] A control device comprising a control unit that controls both a drive circuit that generates a drive signal for a head including an ejection unit that ejects liquid, and a fan that cools the drive circuit, and the control unit controls the fan based on drive method information, among a plurality of drive method information indicating a drive method for the fan, which is associated with the temperature detected by a temperature detection unit that detects the temperature of the drive circuit and the rotation speed detected by a rotation speed detection unit that detects the rotation speed of the fan.

[0127] <Appendix 2> [1] a control unit that controls the fan based on a signal output from a signal output unit that outputs a signal corresponding to the rotation of a fan that cools a drive circuit that generates a drive signal for a head including an ejection unit that ejects liquid, the control unit comprising: a first clock signal generation unit that generates a first clock signal; a memory unit that stores value information indicating the value of n for dividing the first clock signal by n; a reception unit that receives the value information and stores the received value information in the memory unit; a second clock signal generation unit that generates a second clock signal obtained by dividing the first clock signal by n based on the value information stored in the memory unit; and a calculation unit that calculates a rotation speed of the fan based on the value information stored in the memory unit, the signal output by the signal output unit, and the second clock signal generated by the second clock signal generation unit. [2] The control device according to [1], wherein the memory unit is a register. [3] A liquid ejection device comprising: the control device according to [1] or [2]; a head unit including a head mounting part for mounting the head and the drive circuit; and a transport part for transporting a medium. [4] A liquid ejection device as described in [3], comprising the head units as a first head unit and a second head unit, wherein the value information stored in the memory unit of the second head unit is different from the value information stored in the memory unit of the first head unit. [5] a head unit comprising: a head attachment section for attaching a head including an ejection section that ejects liquid; a drive circuit that generates a drive signal for the head; a signal output section that outputs a signal corresponding to the rotation of a fan that cools the drive circuit; and a control section that controls the fan, wherein the control section comprises: a first clock signal generation section that generates a first clock signal; a memory section that stores value information indicating the value of n for dividing the first clock signal by n; a reception section that receives the value information and stores the received value information in the memory section; a second clock signal generation section that generates a second clock signal obtained by dividing the first clock signal by n based on the value information stored in the memory section; and a calculation section that calculates the rotation speed of the fan based on the value information stored in the memory section, the signal output by the signal output section, and the second clock signal generated by the second clock signal generation section.

[0128] Although an embodiment of the present disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and may be changed, substituted, deleted, etc. without departing from the gist of this disclosure.

[0129] In addition, a program for realizing the function of any of the components in the above-described device may be recorded in a computer-readable recording medium, and the program may be read and executed by a computer system. Here, the device may be, for example, the liquid ejection device 1, the head driving module 10, the liquid ejection module 20, the control circuit 100, etc. Note that the term "computer system" here includes hardware such as an operating system (OS) and peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and compact disks (CDs)-ROMs, and storage devices such as hard disks built into a computer system. Furthermore, the term "computer-readable recording medium" refers to a storage device that holds a program for a certain period of time, such as a volatile memory inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line.

[0130] The above program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has a function of transmitting information, such as a network such as the Internet or a communication line such as a telephone line. The above program may be for implementing some of the above functions. Furthermore, the above program may be a so-called differential file or differential program that can implement the above functions in combination with a program already recorded in the computer system. [Explanation of symbols]

[0131] 1...liquid ejection device, 2...control unit, 3...liquid container, 4...transport unit, 5...ejection unit, 10...head driving module, 20...liquid ejection module, 23, 23-1, 23-j, 23-m...ejection module, 30...wiring member, 41...transport motor, 42...transport roller, 50, 50-1, 50-2, 50-3, 50-4, 50-5, 50-6, 50-i, 50-j, 50-m...driving signal output circuit, 52, 52a, 52a1, 52aj, 52b, 52b1, 52bj, 52c, 52c1, 52cj...driving circuit, 53...reference voltage output circuit, 60...piezoelectric element, 100...control circuit, 101...first clock generation unit, 102...second memory unit, 103 ...reception unit, 104...second clock generation unit, 105...calculation unit, 120...conversion circuit, 200...drive signal selection circuit, 220...restoration circuit, 600...discharge unit, B1...first board, B2...second board, B3...third board, CN1...first connector, CN2...second connector, CN3...third connector, CN4...fourth connector, DRV, DRV1, DRV2, DRV3, DRV4, DRV5, DRV6, DRVi...drive circuit unit, FN...fan, HS1, HS2...heat sink, HU, HU11, HU12, HU13, HU21, HU22, HU23, HU31, HU32, HU33...head unit, P...medium, S1, S1i...temperature detection unit, S3...signal output unit

Claims

1. a head attachment part for attaching a head including a discharge part for discharging liquid; a control unit that controls a drive circuit that generates a drive signal for the head attached to the head attachment unit and a fan that cools the drive circuit; Equipped with the control unit controls the fan based on drive method information, among a plurality of drive method information indicating drive methods of the fan, which is associated with the temperature detected by a temperature detection unit that detects a temperature of the drive circuit and the number of rotations detected by a number of rotations detection unit that detects a number of rotations of the fan. Head unit.

2. the control unit selects, from the plurality of pieces of drive method information, the drive method information associated with the temperature detected by the temperature detection unit and the rotation speed detected by the rotation speed detection unit, and controls the fan based on the selected drive method information. The head unit according to claim 1 .

3. each of the plurality of pieces of driving method information is associated with information identification information that identifies each of the plurality of pieces of driving method information; the control unit reads out correspondence information from a storage unit in which temperature range information indicating a temperature range for the temperature, rotation speed range information indicating a rotation speed range for the rotation speed, and the information identification information are stored, and selects, based on the read correspondence information, from among the plurality of driving method information, the driving method information associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection unit and the rotation speed range information indicating the rotation speed range including the rotation speed detected by the rotation speed detection unit, using the information identification information. The head unit according to claim 2 .

4. The control unit performs a calibration process for the control of the fan in response to the received operation, the calibration process is a process of controlling the fan based on a reference driving method information among the plurality of driving method information, while controlling the driving circuit based on a predetermined image information signal to cause the ejection section of the head to eject the liquid, and selecting, from the plurality of driving method information based on the read correspondence information, using the information identification information, the driving method information associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection section and the rotation speed range information indicating the rotation speed range including the rotation speed detected by the rotation speed detection section during a period in which the ejection section is ejecting the liquid. The head unit according to claim 3 .

5. each of the plurality of pieces of drive method information includes information for associating temperature range information indicating a temperature range for the temperature with duty ratio information indicating a duty ratio for PWM control of the fan; the control unit, based on the selected driving method information, specifies the duty ratio information associated with the temperature range information indicating the temperature range including the temperature detected by the temperature detection unit, and controls the fan by PWM control based on the duty ratio indicated by the specified duty ratio information. The head unit according to claim 2 .

6. The plurality of pieces of driving method information are stored in a server communicably connected to the control unit. The head unit according to claim 1 .

7. Further comprising a storage unit that stores the plurality of pieces of driving method information. The head unit according to claim 1 .

8. The head is provided with The head unit according to claim 1 .

9. The fan is provided. The head unit according to claim 1 .

10. The drive circuit is provided. The head unit according to claim 1 .

11. A head unit according to any one of claims 1 to 10; A transport unit that transports the medium; A liquid ejection device comprising:

12. The head unit is provided as a first head unit and a second head unit, the driving method information selected by the control unit of the second head unit is different from the driving method information selected by the control unit of the first head unit; The liquid ejection device according to claim 11.

13. a control unit that controls a drive circuit that generates a drive signal for a head including an ejection unit that ejects liquid, and a fan that cools the drive circuit; the control unit controls the fan based on drive method information, among a plurality of drive method information indicating drive methods of the fan, which is associated with the temperature detected by a temperature detection unit that detects a temperature of the drive circuit and the number of rotations detected by a number of rotations detection unit that detects a number of rotations of the fan. Control device.

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