Liquid discharge device

Abstract

To provide a liquid discharge device which can radiate heat of an internal space of a carriage and cool a driving circuit housed in the carriage without agitating gas around the carriage.SOLUTION: A liquid discharge device includes: a driving circuit for generating a driving signal; a print head to which the driving signal is input and which has a discharge section for discharging liquid; a carriage that houses the driving circuit and the print head in an internal space; a first blast pipe through which gas flowing into or out of the internal space of the carriage passes; and a support guide member which is connected to the carriage, supports the first blast pipe and guides the first blast pipe to the carriage.SELECTED DRAWING: Figure 13

Description

[Technical field]

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

[0002] Patent Document 1 discloses a liquid ejection device in which a plurality of airflow generating units are provided along a carriage movement area in order to cool a head drive circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6943254 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid ejection device described in Patent Document 1, when the moving range of the carriage becomes large, the number of airflow generating units must be increased accordingly, and the airflow generating units must be controlled according to the movement of the carriage, which tends to lead to an increase in costs. In addition, in the liquid ejection device described in Patent Document 1, the air inside the housing is significantly agitated by the multiple airflow generating units, which causes problems such as unstable ink ejection due to the influence of the agitated airflow, and ink mist generated by ink ejection being carried by the airflow and adhering to various places inside the housing, which require improvement. In view of the above situation, the present inventor has found a configuration that solves at least one of the above problems. [Means for solving the problem]

[0005] One aspect of the liquid ejection device according to the present invention is to A drive circuit for generating a drive signal; a print head having an ejection section to which the drive signal is input and which ejects liquid; a carriage that houses the drive circuit and the print head in an internal space; a first air duct through which gas flows into or out of the internal space of the carriage; a support and guide member connected to the carriage for supporting and guiding the first blower duct to the carriage; Equipped with. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a liquid ejection device. [Diagram 2] FIG. 2 is a diagram illustrating an example of a functional configuration of a control unit and a head unit. [Diagram 3] FIG. 4 is a diagram illustrating an example of a configuration of a discharge unit. [Figure 4] 4 is a diagram showing an example of signal waveforms of drive signals COMA and COMB. FIG. [Diagram 5] 4 is a diagram showing an example of a signal waveform of a drive signal VOUT. [Figure 6] FIG. 4 is a diagram illustrating a functional configuration of a drive signal selection circuit. [Figure 7] FIG. 2 is a diagram showing an example of the decoded content in a decoder. [Figure 8] FIG. 2 is a diagram illustrating a configuration of a selection circuit. [Figure 9] 5 is a diagram for explaining the operation of a drive signal selection circuit. FIG. [Figure 10] FIG. 2 is a side view showing the structure of a head unit and a carriage. [Figure 11] FIG. 2 is a perspective view showing the structure of a head unit and a carriage. [Figure 12] FIG. [Figure 13] FIG. 13 is a diagram showing a state in which the support guide member is connected to the carriage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Preferred embodiments of the present invention will be described below with reference to the drawings. The drawings are used for the convenience of explanation. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0008] In the following description, an inkjet printer is taken as an example of a liquid ejection device according to the present invention. However, the liquid ejection device is not limited to an inkjet printer, and may be, for example, a color material ejection device used in manufacturing color filters for liquid crystal displays and the like, an electrode material ejection device used in forming electrodes for organic electroluminescence displays, surface-emitting displays and the like, a bioorganic material ejection device used in manufacturing biochips, etc.

[0009] 1. Embodiment 1-1. Functional configuration of the liquid ejection device 1 is a diagram showing a schematic configuration of a liquid ejection device 1. The liquid ejection device 1 of this embodiment is a so-called inkjet printer that ejects ink at a desired timing onto a transported medium P to form a desired image on the surface of the medium P. Here, in the following description, the direction in which the medium P is transported may be referred to as the transport direction.

[0010] As shown in FIG. 1, the liquid ejection device 1 includes a control unit 2, a head unit 3, a transport motor 4, a transport roller 5, a carriage motor 6, a carriage guide shaft 7, and a carriage 8.

[0011] The control unit 2 generates and outputs to each part a control signal for controlling each part of the liquid ejection device 1 based on image data DATA supplied from an external device such as a host computer (not shown) provided outside the liquid ejection device 1. The control unit 2 also generates a voltage signal VDC used as a power supply voltage for each part of the liquid ejection device 1 from the commercial AC voltage VAC supplied to the liquid ejection device 1, and supplies the voltage signal VDC to each part of the liquid ejection device 1.

[0012] Specifically, the control unit 2 generates a transport control signal Ctrl-T as one of the control signals and outputs it to the transport motor 4. The transport motor 4 drives based on the input transport control signal Ctrl-T. The transport roller 5 is driven to rotate in conjunction with the driving of the transport motor 4. The medium P is transported in the transport direction by the driving force generated by the rotational driving of the transport roller 5.

[0013] Furthermore, the control unit 2 generates a carriage control signal Ctrl-C as one of the control signals and outputs it to the carriage motor 6. The carriage motor 6 drives based on the input carriage control signal Ctrl-C. The driving force generated by the driving of the carriage motor 6 is transmitted to the carriage 8 supported by a carriage guide shaft 7 via a timing belt (not shown). The carriage guide shaft 7 extends in a direction intersecting with the transport direction, and supports the carriage 8. The driving force generated by the driving of the carriage motor 6 moves the carriage 8 supported by the carriage guide shaft 7 along the carriage guide shaft 7.

[0014] The control unit 2 also generates a print data signal pDATA as one of the control signals and outputs it to the head unit 3. The head unit 3 has a discharge control module 10 and a plurality of liquid discharge modules 20. Furthermore, each of the plurality of liquid discharge modules 20 has a drive circuit module 50 and a print head 30. In other words, the head unit 3 has a plurality of pairs of drive circuit modules 50 and print heads 30. Such a head unit 3 is mounted on a carriage 8, and moves as the carriage 8 moves along a carriage guide shaft 7.

[0015] The print data signal pDATA output by the control unit 2 is input to the ejection control module 10. The ejection control module 10 generates a control signal for controlling the operation of each of the liquid ejection modules 20 based on the print data signal pDATA, and outputs the control signal to the corresponding liquid ejection module 20. The control signal output by the ejection control module 10 is input to the corresponding drive circuit module 50. The drive circuit module 50 is electrically connected to the corresponding print head 30, and drives the print head 30 so that the amount of ink specified by the control signal is ejected at the timing specified by the control signal. As a result, the print head 30 ejects a predetermined amount of ink at a predetermined timing. That is, the head unit 3 ejects a predetermined amount of ink from the print head 30 at a predetermined timing in response to the print data signal pDATA output by the control unit 2.

[0016] 1, the liquid ejection device 1 includes an ink container 9 and a plurality of ink tubes 91. The ink container 9 stores a plurality of types of ink to be ejected from the plurality of print heads 30. The plurality of ink tubes 91 are connected to the ink container 9 and are also connected to the plurality of print heads 30. Each ink tube 91 supplies each ink stored in the ink container 9 to each print head 30 connected thereto. As such an ink container 9, for example, an ink cartridge, a bag-shaped ink pack formed of a flexible film, an ink tank that can be refilled with ink, or the like can be used.

[0017] As described above, in the liquid ejection device 1, the control unit 2 controls the transportation of the medium P, the movement of the carriage 8, and the timing of ink ejection from the print head 30 mounted on the carriage 8. This allows the ink to land at a desired position on the medium P, and as a result, a desired image is formed on the medium P.

[0018] Each of the drive circuit modules 50 consumes a large amount of power and generates a large amount of heat. The large amount of heat generated by the drive circuit modules 50 easily causes the internal space of the carriage 8 to become hot. If the internal space of the carriage 8 becomes hot, the operation of the head unit 3 housed in the internal space of the carriage 8 may become unstable. In this embodiment, the liquid ejection device 1 includes a compressor 40, a first air duct 41, and a second air duct 42 to release heat from the internal space of the carriage 8 and to cool the drive circuit modules 50. The liquid ejection device 1 also includes a housing 300 that houses the control unit 2, the head unit 3, the transport motor 4, the transport roller 5, the carriage motor 6, the carriage guide shaft 7, the carriage 8, the ink container 9, the ink tube 91, the compressor 40, the first air duct 41, and the second air duct 42 in its internal space.

[0019] The compressor 40 takes in air and sends out compressed air. The first air duct 41 connects the compressor 40 and the carriage 8. The second air duct 42 connects the carriage 8 and an opening O2 provided in the housing 300. The first air duct 41 allows air to flow in or out of the internal space of the carriage 8. The second air duct 42 allows air to flow in or out of the internal space of the carriage 8. That is, the first air duct 41 allows air to flow in to the internal space of the carriage 8, and the second air duct 42 allows air to flow out from the internal space of the carriage 8. Alternatively, the first air duct 41 allows air to flow out from the internal space of the carriage 8, and the second air duct 42 allows air to flow in to the internal space of the carriage 8.

[0020] For example, the compressor 40 may take in air from outside the housing 300 through the opening O1 of the housing 300 and send the compressed air to the first air duct 41. In this case, the compressed air sent out from the compressor 40 is sucked into the internal space of the carriage 8 through the first air duct 41. Meanwhile, the air in the internal space of the carriage 8 is discharged to the second air duct 42. The air discharged from the internal space of the carriage 8 to the second air duct 42 is discharged to the outside of the housing 300 through the opening O2 of the housing 300 through the second air duct 42. In this way, the first air duct 41 may be an intake duct through which the air sucked into the internal space of the carriage 8 passes, and the second air duct 42 may be an exhaust duct through which the air discharged from the internal space of the carriage 8 passes.

[0021] Also, for example, air in the internal space of the carriage 8 may be discharged to the first air duct 41, and the air discharged from the internal space of the carriage 8 to the first air duct 41 may be sucked out by the compressor 40 through the first air duct 41. In this case, the compressor 40 sucks out air from the first air duct 41, takes in the sucked air, compresses it, and releases the compressed air to the outside of the housing 300 through the opening O1 of the housing 300. Meanwhile, the second air duct 42 takes in air from the outside of the housing 300 through the opening O2 of the housing 300, and the air taken in by the second air duct 42 is sucked into the internal space of the carriage 8 through the second air duct 42. In this way, the first air duct 41 may be an exhaust duct through which air discharged from the internal space of the carriage 8 passes, and the second air duct 42 may be an intake duct through which air sucked into the internal space of the carriage 8 passes.

[0022] The compressor 40 can generate a large airflow in the internal space of the carriage 8, which can efficiently dissipate heat in the internal space of the carriage 8 and cool the multiple drive circuit modules 50. In this way, the compressor 40, the first air duct 41, and the second air duct 42 reduce the risk that the internal space of the carriage 8 will become too hot, causing the operation of the head unit 3 to become unstable.

[0023] 1-2. Functional configuration of the control unit and head unit Next, a detailed description will be given of the functional configuration of the control unit 2 and head unit 3 provided in the liquid ejection device 1. Fig. 2 is a diagram showing an example of the functional configuration of the control unit 2 and head unit 3. As shown in Fig. 2, the control unit 2 and the ejection control module 10 of the head unit 3 are electrically connected by a cable 120. Since the head unit 3 is mounted on a carriage 8 that moves along a carriage guide shaft 7, the cable 120 may be a FFC (Flexible Flat Cable) that deforms in accordance with the movement of the carriage 8.

[0024] 2, the control unit 2 has a main control circuit 16 and a power supply voltage output circuit 18. The main control circuit 16 includes a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory. The main control circuit 16 performs predetermined signal processing on image data DATA supplied from an external device such as a host computer (not shown) provided outside the liquid ejection device 1, generates a print data signal pDATA, and outputs it to the ejection control module 10 via a cable 120.

[0025] The power supply voltage output circuit 18 includes an AC / DC converter such as a flyback circuit, and a DC / DC converter such as a step-down circuit or a step-up circuit. The power supply voltage output circuit 18 generates a voltage signal VHV, which is a DC voltage signal with a voltage value of, for example, 42 V, and a voltage signal VMV, which is a DC voltage signal with a voltage value of, for example, 24 V, as a voltage signal VDC from a commercial voltage VAC input from outside the liquid ejection device 1, and outputs them to the ejection control module 10 via a cable 120.

[0026] 2, the head unit 3 has a discharge control module 10 and a plurality of liquid discharge modules 20. Here, the plurality of liquid discharge modules 20 all have the same configuration, but when describing the plurality of liquid discharge modules 20 separately, they may be referred to as liquid discharge modules 20-1 to 20-n. That is, the head unit 3 shown in FIG. 2 may be described as having liquid discharge modules 20-1 to 20-n as n liquid discharge modules 20.

[0027] The ejection control module 10 operates using, as a power supply voltage, the voltage signals VHV, VMV output by the power supply voltage output circuit 18 or a DC voltage signal generated from the voltage signals VHV, VMV. The ejection control module 10 generates control signals for controlling the operation of the n liquid ejection modules 20 based on the print data signal pDATA output by the control unit 2, and outputs the control signals to the corresponding liquid ejection modules 20.

[0028] The ejection control module 10 includes a head control circuit 12 and a cooling fan drive circuit 14. The print data signal pDATA is input to the head control circuit 12 included in the ejection control module 10. Based on the print data signal pDATA, the head control circuit 12 generates and outputs a clock signal SCK commonly input to the n liquid ejection modules 20, differential print data signals Dp1 to Dpn corresponding to each of the n liquid ejection modules 20, and differential drive data signals Dd1 to Ddn corresponding to each of the n liquid ejection modules 20.

[0029] Specifically, the print data signal pDATA is a differential signal generated based on the image data DATA, and includes a clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn in series. The head control circuit 12 generates the clock signal SCK by deserializing and restoring the print data signal pDATA, and generates the differential print data signals Dp1-Dpn and differential drive data signals Dd1-Ddn corresponding to each of the n liquid ejection modules 20 by deserializing the print data signal pDATA. The head control circuit 12 then outputs the generated clock signal SCK, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn to the corresponding liquid ejection modules 20.

[0030] Here, in the following description, it is assumed that the differential print data signal Dp1 and the differential drive data signal Dd1 are signals corresponding to the liquid ejection module 20-1, and the differential print data signal Dpn and the differential drive data signal Ddn are signals corresponding to the liquid ejection module 20-n. That is, it is assumed that the clock signal SCK, the differential print data signal Dp1, and the differential drive data signal Dd1 are input to the liquid ejection module 20-1, and the clock signal SCK, the differential print data signal Dpn, and the differential drive data signal Ddn are input to the liquid ejection module 20. It is also assumed that the clock signal SCK, the differential print data signal Dp, and the differential drive data signal Dd are input to the liquid ejection module 20.

[0031] The head control circuit 12 also generates a fan control signal Fc that controls the operation of the cooling fan drive circuit 14, and outputs it to the cooling fan drive circuit 14. In addition to the fan control signal Fc, a voltage signal VMV is input to the cooling fan drive circuit 14. The cooling fan drive circuit 14 switches whether or not to output the voltage signal VMV as the fan drive signals Fp1 to Fpn based on the fan control signal Fc.

[0032] The fan drive signals Fp1 to Fpn output by the cooling fan drive circuit 14 are output to the corresponding liquid discharging modules 20. In the following description, it is assumed that the fan drive signal Fp1 corresponds to the liquid discharging module 20-1, and the fan drive signal Fpn corresponds to the liquid discharging module 20-n. That is, the fan drive signal Fp1 is input to the liquid discharging module 20-1, and the fan drive signal Fpn is input to the liquid discharging module 20-n. In addition, it is assumed that the fan drive signal Fp is input to the liquid discharging module 20.

[0033] The cooling fan drive circuit 14 may convert the voltage signal VMV to a predetermined voltage value based on the fan control signal Fc, and output the converted signals as the fan drive signals Fp1 to Fpn.

[0034] Furthermore, the voltage signals VHV and VMV supplied from the power supply voltage output circuit 18 are propagated through the discharge control module 10 and are supplied to each of the liquid discharge modules 20-1 to 20-n.

[0035] The liquid ejection module 20-1 receives the clock signal SCK, differential print data signal Dp1, differential drive data signal Dd1, fan drive signal Fp1, and voltage signals VHV and VMV output by the ejection control module 10. The liquid ejection module 20-1 operates using the voltage signals VHV and VMV, or a DC voltage generated from the voltage signals VHV and VMV, as a power supply voltage, and ejects an amount of ink defined by the differential print data signal Dp1 and the differential drive data signal Dd1 onto the medium P at a timing defined by the differential print data signal Dp1 and the differential drive data signal Dd1.

[0036] The liquid ejection module 20-1 has a drive circuit module 50 and a print head 30. The drive circuit module 50 also includes an ejection control circuit 51, drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m, a capacitor 53, an abnormality detection circuit 54, an abnormality notification circuit 55, a temperature detection circuit 56, a voltage conversion circuit 58, and a cooling fan 59.

[0037] A clock signal SCK, a differential print data signal Dp1, and a differential drive data signal Dd1 are input to the discharge control circuit 51. The discharge control circuit 51 then analyzes the differential print data signal Dp1 and the differential drive data signal Dd1 to generate and output a differential print data signal Dpt that controls the operation of the print head 30, basic drive signals dA1-dAm that are the basis for drive signals COMA1-COMAm (described later), and basic drive signals dB1-dBm that are the basis for drive signals COMB1-COMBm (described later).

[0038] Specifically, the discharge control circuit 51 analyzes the differential print data signal Dp1 based on the clock signal SCK. Then, the discharge control circuit 51 generates a differential print data signal Dpt, which is a differential signal according to the analysis result of the differential print data signal Dp1, and outputs it to the print head 30. At this time, the discharge control circuit 51 may output the differential print data signal Dp1 as the differential print data signal Dpt according to the analysis result of the differential print data signal Dp1, or may output a signal obtained by performing a predetermined signal processing on the differential print data signal Dp1 as the differential print data signal Dpt. Furthermore, the discharge control circuit 51 may output a signal including predetermined information read from a storage circuit (not shown) according to the analysis result of the differential print data signal Dp1 as the differential print data signal Dpt.

[0039] Furthermore, the discharge control circuit 51 restores the differential drive data signal Dd1 to a single-ended signal and analyzes it based on the clock signal SCK. The discharge control circuit 51 then generates basic drive signals dA1-dAm, dB1-dBm according to the analysis results and outputs them to the corresponding drive signal output circuits 52a-1-52a-m, 52b-1-52b-m. Here, the discharge control circuit 51 may read information stored in a storage circuit (not shown) based on the analysis results of the single-ended signal restored from the differential drive data signal Dd1, generate basic drive signals dA1-dAm, dB1-dBm including the read information, and output them to the corresponding drive signal output circuits 52a-1-52a-m, 52b-1-52b-m. In addition, the discharge control circuit 51 may generate a single-ended signal by restoring the differential drive data signal Dd1, and then deserialize the single-ended signal to generate base drive signals dA1 to dAm, dB1 to dBm, and output them to the corresponding drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m.

[0040] The basic drive signals dA1 to dAm are input to the drive signal output circuits 52a-1 to 52a-m, respectively, and the basic drive signal dB1 is input to the drive signal output circuits 52b-1 to 52b-m, respectively. The drive signal output circuits 52a-1 to 52a-m, 52b-1 to 52b-m then perform digital-to-analog conversion on the basic drive signals dA1 to dAm, dB1 to dBm, respectively, and generate drive signals COMA1 to COMAm, COMB1 to COMBm by class D amplification, and output them to the print head 30. At this time, the basic drive signals dA1 to dAm, dB1 to dBm are signals that are the basis of the drive signals COMA1 to COMAm, COMB1 to COMBm, respectively, and are signals that define the signal waveforms of the drive signals COMA1 to COMAm, COMB1 to COMBm.

[0041] The drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m may have the same configuration, but only the input and output signals are different. The drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m may generate the drive signals COMA1 to COMAm and COMB1 to COMBm by amplifying the signal waveforms defined by the basic drive signals dA1 to dAm and dB1 to dBm in class A, class B, or class AB. However, the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m consume a large amount of power, and therefore generate a large amount of heat. From the viewpoint of reducing power consumption and suppressing the amount of heat generation, it is required for such drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m to generate the drive signals COMA1 to COMAm and COMB1 to COMBm with high efficiency. In view of this, it is preferable that the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m are configured to include a class D amplifier capable of amplifying the signal waveforms defined by the basic drive signals dA1 to dAm and dB1 to dBm with high efficiency.

[0042] Further, each of the drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m generates and outputs a reference voltage signal VBS. At this time, the drive circuit module 50 stabilizes the voltage value of the reference voltage signal VBS output by the drive signal output circuit 52a-1 using the capacitor 53. That is, the drive circuit module 50 has a capacitor 53 for reducing fluctuations in the voltage value of the reference voltage signal VBS. After the voltage value of the reference voltage signal VBS is stabilized by the capacitor 53, it is branched and output to the print head 30. The wiring through which the reference voltage signal VBS output by each of the drive signal output circuits 52a-2 to 52a-m and 52b-1 to 52b-m propagates is opened.

[0043] The reference voltage signal VBS functions as a reference potential for driving the piezoelectric element 60 of the print head 30, which will be described later. If a voltage value fluctuation occurs in the reference voltage signal VBS functioning as such a reference potential, the driving characteristics of the piezoelectric element 60 change. In contrast, by making the reference voltage signal VBS output by the driving signal output circuit 52a-1 the only reference voltage signal VBS supplied to the piezoelectric element 60, even if the voltage values ​​of the reference voltage signals VBS output by the driving signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m vary due to circuit variations or the like, the risk of the voltage value of the reference voltage signal VBS supplied to the piezoelectric element 60 fluctuating is reduced. This improves the driving accuracy of the piezoelectric element 60.

[0044] The temperature detection circuit 56 acquires the environmental temperature of the drive circuit module 50. For example, a thermistor element or an IC temperature sensor element can be used as the temperature detection circuit 56. Here, the environmental temperature of the drive circuit module 50 does not mean the temperature of the components of the drive circuit module 50 itself, but includes the spatial temperature of the drive circuit module 50, which changes with an increase in the temperature of the components. The temperature detection circuit 56 then generates a temperature information signal Tt including temperature information corresponding to the acquired environmental temperature, and outputs the signal to the head control circuit 12.

[0045] The head control circuit 12 estimates the temperature of the drive circuit module 50 based on the input temperature information signal Tt. Then, the head control circuit 12 corrects the clock signal SCK, the differential print data signals Dp1-Dpn, and the differential drive data signals Dd1-Ddn according to the estimated temperature of the drive circuit module 50, and outputs the corrected clock signal SCK, the differential print data signals Dp1-Dpn, and the differential drive data signals Dd1-Ddn.

[0046] Furthermore, if the estimated temperature of the drive circuit module 50 is equal to or higher than a predetermined threshold, the head control circuit 12 determines that a temperature abnormality has occurred or is likely to occur in the drive circuit module 50. In this case, the head control circuit 12 may generate a clock signal SCK for stopping the operation of the drive circuit module 50, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn, and output them to the drive circuit module 50.

[0047] Furthermore, the head control circuit 12 may notify the user of the temperature information acquired by the temperature detection circuit 56, which is information corresponding to the estimated temperature of the drive circuit module 50, via a notification unit (not shown) such as a display.

[0048] Further, voltage signals VHV and VMV are input to the drive circuit module 50. The voltage signal VHV propagates inside the drive circuit module 50 and is also supplied to the print head 30. The voltage signal VMV propagates inside the drive circuit module 50 and is also supplied to a voltage conversion circuit 58. The voltage conversion circuit 58 generates and outputs a voltage signal VDD by stepping down the voltage signal VMV. The voltage signal VDD output by the voltage conversion circuit 58 is used as a power supply voltage for various circuits in the drive circuit module 50 and is also supplied to the print head 30. Such a voltage signal VDD is, for example, a DC voltage of 5 V or 3.3 V.

[0049] The abnormality detection circuit 54 detects an abnormality occurring in the drive circuit module 50, and generates an abnormality information signal Te and an abnormality notification signal De according to the detection result. Such an abnormality detection circuit 54 is a comparator that compares whether the detection target is equal to or higher than a predetermined threshold, and is configured to include, for example, a comparator. For example, when the abnormality detection circuit 54 detects that the voltage values ​​of the voltage signal VHV and the voltage signal VDD are lower than the normal value, it may determine that the voltage values ​​of the voltage signal VHV and the voltage signal VDD are not normal, and generate an abnormality notification signal De to alert the user.

[0050] The abnormality information signal Te output by the abnormality detection circuit 54 is input to the head control circuit 12. When the abnormality information signal Te includes information indicating an abnormality in the drive circuit module 50, the head control circuit 12 generates a clock signal SCK for stopping the operation of the drive circuit module 50, differential print data signals Dp1-Dpn, and differential drive data signals Dd1-Ddn, and outputs them to the drive circuit module 50. This causes the operation of the drive circuit module 50 to stop.

[0051] The abnormality notification signal De output by the abnormality detection circuit 54 is input to an abnormality notification circuit 55. The abnormality notification circuit 55 includes a light-emitting element such as a light-emitting diode. The abnormality notification circuit 55 notifies the user whether or not an abnormality has occurred in the drive circuit module 50 by turning on, off, or blinking the light-emitting element based on the input abnormality notification signal De.

[0052] The cooling fan 59 receives a fan drive signal Fp1 output by the cooling fan drive circuit 14. The cooling fan 59 is driven by the fan drive signal Fp1 to generate an airflow in the drive circuit module 50. The airflow generated by the cooling fan 59 cools the drive circuit module 50. The head control circuit 12 may output a fan control signal Fc based on a temperature information signal Tt output by the temperature detection circuit 56. As a result, the drive state of the cooling fan 59 is controlled according to the temperature status of the drive circuit module 50, which is the temperature detection result by the temperature detection circuit 56. As a result, the power consumption of the liquid ejection device 1 is reduced by reducing the risk of an increase in power consumption due to excessive driving of the cooling fan 59, and the risk of temperature abnormalities occurring in the drive circuit module 50 is also reduced.

[0053] The print head 30 includes a restoration circuit 31 and ejection modules 32-1 to 32-m. The restoration circuit 31 operates using the voltage signals VHV and VDD, or a DC voltage generated from the voltage signals VHV and VDD, as a power supply voltage. The restoration circuit 31 restores the differential print data signal Dpt, which is a differential signal output by the ejection control circuit 51, to a single-ended signal. Specifically, a clock signal SCK and a differential print data signal Dpt are input to the restoration circuit 31. The restoration circuit 31 restores the differential print data signal Dpt to a single-ended signal based on the clock signal SCK, and deserializes the restored signal to generate a latch signal LAT, a change signal CH, and print data signals SI1 to SIm. The restoration circuit 31 outputs the clock signal SCK and the generated latch signal LAT, change signal CH, and print data signals SI1 to SIm to the corresponding ejection modules 32-1 to 32-m.

[0054] The ejection module 32-1 includes a drive signal selection circuit 200 and a plurality of ejection units 600. The drive signal selection circuit 200 receives the latch signal LAT, the change signal CH, the print data signal SI1, the clock signal SCK, and the drive signals COMA1 and COMB1 output by the restoration circuit 31. The drive signal selection circuit 200 operates using the voltage signals VHV and VDD, or a DC voltage generated from the voltage signals VHV and VDD, as a power supply voltage, and generates and outputs drive signals VOUT corresponding to each of the plurality of ejection units 600 by selecting or not selecting a signal waveform included in the drive signal COMA1 and selecting or not selecting a signal waveform included in the drive signal COMB1 based on the print data signal SI1 during each of the periods defined by the latch signal LAT and the change signal CH. For example, if the ejection module 32-1 has p ejection sections 600, the drive signal selection circuit 200 generates p drive signals VOUT corresponding to each of the p ejection sections 600, and outputs them to the corresponding ejection sections 600.

[0055] Each of the ejection sections 600 includes a piezoelectric element 60. A corresponding drive signal VOUT output by the drive signal selection circuit 200 is supplied to one end of the piezoelectric element 60. A reference voltage signal VBS is commonly supplied to the other end of the piezoelectric elements 60 included in each of the ejection sections 600. The piezoelectric elements 60 included in each of the ejection sections 600 are displaced by the potential difference between the drive signal VOUT and the reference voltage signal VBS. An amount of ink corresponding to the displacement of the piezoelectric element 60 is ejected from the corresponding ejection section 600. The ink ejected from the ejection section 600 lands on the medium P, forming an image on the medium P.

[0056] Here, the ejection modules 32-2 to 32-m of the print head 30 have the same configuration as the ejection module 32-1, and perform the same operation, except that the input signals are different. Therefore, detailed description of the ejection modules 32-2 to 32-m is omitted. That is, the ejection modules 32-2 to 32-m each include a drive signal selection circuit 200 and a plurality of ejection units 600. Then, the drive signal selection circuit 200 of each of the ejection modules 32-2 to 32-m selects or deselects the signal waveform included in the corresponding drive signal COMA2 to COMAm and selects or deselects the signal waveform included in the corresponding drive signal COMB2 to COMBm based on the corresponding print data signal SI2 to SIm during each period defined by the input latch signal LAT and change signal CH, thereby outputting the drive signal VOUT corresponding to each of the plurality of ejection units 600. As a result, an amount of ink according to the potential difference between the input drive signal VOUT and reference voltage signal VBS is ejected from each of the multiple ejection sections 600 in each of the ejection modules 32-2 to 32-m.

[0057] In the following description, when there is no need to distinguish between the discharge modules 32-1 to 32-m, they may be simply referred to as the discharge modules 32. In addition, the discharge modules 32 may be described as receiving a print data signal SI as the print data signals SI1 to SIm, a drive signal COMA as the drive signals COMA1 to COMAm, and a drive signal COMB as the drive signals COMB1 to COMBm.

[0058] As described above, the liquid ejection module 20-1 has a drive circuit module 50 and a print head 30, and operates based on the clock signal SCK, differential print data signal Dp1, differential drive data signal Dd1, fan drive signal Fp1, and voltage signals VHV, VMV output by the ejection control module 10, thereby ejecting an amount of ink specified by the differential print data signal Dp1 and the differential drive data signal Dd1 onto the medium P at a timing specified by the differential print data signal Dp1 and the differential drive data signal Dd1.

[0059] Here, the liquid ejection modules 20-2 to 20-n have the same configuration as the liquid ejection module 20-1, and perform the same operation, except that the input signals are different. Therefore, detailed description of the liquid ejection modules 20-2 to 20-n is omitted. That is, each of the liquid ejection modules 20-2 to 20-n has a drive circuit module 50 and a print head 30, and operates based on the clock signal SCK, the corresponding differential print data signals Dp2 to Dpn, the corresponding differential drive data signals Dd2 to Ddn, the corresponding fan drive signals Fp2 to Fpn, and the voltage signals VHV and VMV output by the ejection control module 10, thereby ejecting an amount of ink specified by the corresponding differential print data signals Dp2 to Dpn and the corresponding differential drive data signals Dd2 to Ddn onto the medium P at a timing specified by the corresponding differential print data signals Dp2 to Dpn and the corresponding differential drive data signals Dd2 to Ddn.

[0060] As described above, the liquid ejection device 1 includes the print head 30 that ejects ink, the drive circuit module 50 electrically connected to the print head 30, and the control unit 2 and head control circuit 12 that control the operation of the print head 30 and the drive circuit module 50. The head unit 3 included in the liquid ejection device 1 and having the ejection control module 10, the print head 30, and the drive circuit module 50 is driven using the voltage signals VHV, VMV input from the control unit 2 as a power supply voltage, and ejects ink at a timing based on the print data signal pDATA, thereby forming an image on the medium P that corresponds to the print data signal pDATA and that is in accordance with the image data DATA.

[0061] 1-3.Discharge section structure Next, a description will be given of the structure of the discharge part 600. Fig. 3 is a diagram showing an example of the configuration of the discharge part 600 included in the discharge module 32. In addition to the discharge part 600, a nozzle plate 632, a reservoir 641, and a supply port 661 are also shown in Fig. 3.

[0062] As shown in FIG. 3, the ejection section 600 includes a piezoelectric element 60, a vibration plate 621, a cavity 631, and a nozzle 651. The piezoelectric element 60 includes a piezoelectric body 601 and electrodes 611 and 612. The electrodes 611 and 612 are positioned so as to sandwich the piezoelectric body 601, thereby forming the piezoelectric element 60. The piezoelectric element 60 is driven so that the central portion is displaced in the vertical direction in response to the potential difference between the voltage supplied to the electrode 611 and the voltage supplied to the electrode 612. Specifically, a drive signal VOUT based on the drive signal COM is supplied to the electrode 611, and a reference voltage signal VBS is supplied to the electrode 612. When the voltage value of the drive signal VOUT supplied to the electrode 611 changes, the potential difference between the drive signal VOUT supplied to the electrode 611 and the reference voltage signal VBS supplied to the electrode 612 changes, and the piezoelectric element 60 is driven so that the central portion is displaced in the vertical direction.

[0063] The diaphragm 621 is located below the piezoelectric element 60 in Fig. 3. In other words, the piezoelectric element 60 is formed on the upper surface of the diaphragm 621 in Fig. 3. Such a diaphragm 621 is displaced in the vertical direction as the piezoelectric element 60 is driven in the vertical direction.

[0064] A cavity 631 is located below the vibration plate 621 in FIG. 3. Ink is supplied to the cavity 631 from a reservoir 641. In addition, ink stored in the ink container 9 is introduced into the reservoir 641 via a supply port 661. That is, the inside of the cavity 631 is filled with ink stored in the ink container 9. The internal volume of the cavity 631 expands or contracts with the vertical displacement of the vibration plate 621. That is, the vibration plate 621 functions as a diaphragm that changes the internal volume of the cavity 631, and the cavity 631 functions as a pressure chamber in which the internal pressure changes with the vertical displacement of the vibration plate 621.

[0065] The nozzle 651 is an opening provided in the nozzle plate 632, and communicates with the cavity 631. When the internal volume of the cavity 631 changes, the ink filled inside the cavity 631 is ejected from the nozzle 651 in accordance with the change in the internal volume.

[0066] In the ejection unit 600 configured as above, when the piezoelectric element 60 is driven to bend upward, the vibration plate 621 is displaced upward. This causes the internal volume of the cavity 631 to expand, and as a result, the ink stored in the reservoir 641 is drawn into the cavity 631. On the other hand, when the piezoelectric element 60 is driven to bend downward, the vibration plate 621 is displaced downward. This causes the internal volume of the cavity 631 to shrink, and as a result, an amount of ink corresponding to the degree of shrinkage of the internal volume of the cavity 631 is ejected from the nozzle 651. That is, an amount of ink corresponding to the voltage value of the drive signal VOUT is ejected from each of the multiple ejection units 600 included in the ejection module 32 of the print head 30.

[0067] Note that the piezoelectric element 60 is not limited to the structure shown in FIG. 3 as long as it is driven by the supply of the drive signal VOUT corresponding to the drive signal COM and is configured to eject ink from the nozzle 651 by being driven.

[0068] 1-4. Functional configuration of the drive signal selection circuit Next, a description will be given of the configuration and operation of the drive signal selection circuit 200. In describing the configuration and operation of the drive signal selection circuit 200, an example of the signal waveforms of the drive signals COMA and COMB input to the drive signal selection circuit 200 and an example of the signal waveform of the drive signal VOUT output from the drive signal selection circuit 200 will be described.

[0069] Fig. 4 is a diagram showing an example of the signal waveforms of the drive signals COMA and COMB. As shown in Fig. 4, the drive signal COMA is a signal waveform in which a trapezoidal waveform Adp1 arranged in a period t1 from when the latch signal LAT rises until when the change signal CH rises, and a trapezoidal waveform Adp2 arranged in a period t2 from when the change signal CH rises until when the latch signal LAT rises are successively arranged. In addition, the trapezoidal waveform Adp1 is a signal waveform that, when supplied to the piezoelectric element 60 included in the discharge section 600, causes the discharge section 600 to discharge a predetermined amount of ink, and the trapezoidal waveform Adp2 is a signal waveform that, when supplied to the piezoelectric element 60 included in the discharge section 600, causes the discharge section 600 to discharge an amount of ink greater than the predetermined amount. In the following description, the amount of ink ejected from the ejection section 600 when the trapezoidal waveform Adp1 is supplied to the piezoelectric element 60 included in the ejection section 600 may be referred to as a small amount, and the amount of ink ejected from the ejection section 600 when the trapezoidal waveform Adp2 is supplied to the piezoelectric element 60 included in the ejection section 600 may be referred to as a medium amount.

[0070] 4, the drive signal COMB is a signal waveform in which a trapezoidal waveform Bdp1 arranged in a period t1 and a trapezoidal waveform Bdp2 arranged in a period t2 are consecutively arranged. The trapezoidal waveform Bdp1 is a signal waveform that, when supplied to the piezoelectric element 60 included in the ejection section 600, does not cause the ejection section 600 to eject ink, and the trapezoidal waveform Bdp2 is a signal waveform that, when supplied to the piezoelectric element 60 included in the ejection section 600, causes the ejection section 600 to eject a small amount of ink. Here, the trapezoidal waveform Bdp1 is a signal waveform for preventing an increase in ink viscosity by vibrating the ink near the nozzle opening included in the ejection section 600 to an extent that the ink is not ejected. In the following description, the operation of vibrating the ink near the nozzle opening when the trapezoidal waveform Bdp1 is supplied to the piezoelectric element 60 of the ejection section 600 may be referred to as micro-vibration.

[0071] 4, the voltage values ​​at the start and end timings of each of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 are all common to voltage Vc. That is, each of the trapezoidal waveforms Adp1, Adp2, Bdp1, and Bdp2 starts and ends at voltage Vc. A cycle tp consisting of periods t1 and t2 corresponds to a printing cycle for forming new dots on the medium P.

[0072] 4 illustrates a case where the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 are the same signal waveform, but the trapezoidal waveform Adp1 and the trapezoidal waveform Bdp2 may be different signal waveforms. In addition, in the case where the trapezoidal waveform Adp1 is supplied to the piezoelectric element 60 included in the discharge section 600 and in the case where the trapezoidal waveform Bdp2 is supplied to the piezoelectric element 60 included in the discharge section 600, a small amount of ink is discharged from the discharge section 600 in both cases, but this is not limited to the case. In other words, the signal waveforms of the drive signals COMA and COMB are not limited to the signal waveforms shown in FIG. 4, and various combinations of signal waveforms may be used depending on the properties of the ink discharged from the discharge section 600 and the material of the medium P on which the discharged ink lands.

[0073] In addition, FIG. 4 illustrates an example in which the timing at which the trapezoidal waveforms Adp1 and Adp2 contained in the drive signal COMA are switched, and the timing at which the trapezoidal waveforms Bdp1 and Bdp2 contained in the drive signal COMB are switched are determined by a single change signal CH; however, the change signal CH that determines the timing at which the trapezoidal waveforms Adp1 and Adp2 contained in the drive signal COMA are switched and the change signal CH that determines the timing at which the trapezoidal waveforms Bdp1 and Bdp2 contained in the drive signal COMB are switched may be different signals.

[0074] FIG. 5 is a diagram showing an example of the signal waveform of the drive signal VOUT when the sizes of dots formed on the medium P are large dots LD, medium dots MD, small dots SD, and non-printing ND.

[0075] 5, the drive signal VOUT when a large dot LD is formed on the medium P has a signal waveform in which a trapezoidal waveform Adp1 arranged in period t1 of the cycle tp and a trapezoidal waveform Adp2 arranged in period t2 of the cycle tp are successively formed. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection section 600, a small amount of ink and a medium amount of ink are ejected from the corresponding ejection section 600. Then, each ink lands on the medium P and combines, forming a large dot LD on the medium P in the cycle tp.

[0076] The drive signal VOUT when a medium dot MD is formed on the medium P has a signal waveform consisting of a continuous trapezoidal waveform Adp1 arranged in period t1 of the cycle tp and a trapezoidal waveform Bdp2 arranged in period t2 of the cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection section 600, a small amount of ink is ejected twice from the corresponding ejection section 600. Then, each ink droplet lands on the medium P and combines, forming a medium dot MD on the medium P in the cycle tp.

[0077] The drive signal VOUT when a small dot SD is formed on the medium P has a signal waveform that is a succession of a trapezoidal waveform Adp1 arranged in period t1 of the cycle tp and a constant signal waveform of voltage Vc arranged in period t2 of the cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection section 600, a small amount of ink is ejected once from the corresponding ejection section 600. Then, when this ink lands on the medium P, a small dot SD is formed on the medium P in the cycle tp.

[0078] The drive signal VOUT corresponding to the non-recording ND that does not form dots on the medium P has a signal waveform consisting of a trapezoidal waveform Bdp1 arranged in period t1 of the cycle tp and a constant signal waveform of voltage Vc arranged in period t2 of the cycle tp. When this drive signal VOUT is supplied to the piezoelectric element 60 included in the ejection section 600, the ink near the nozzle opening of the corresponding ejection section 600 only vibrates slightly, and no ink is ejected from the ejection section 600. Therefore, no dots are formed on the medium P in the cycle tp.

[0079] Here, the constant signal waveform of voltage Vc in the drive signal VOUT means that when none of the trapezoidal waveforms Adp1, Adp2, Bdp1, Bdp2 is selected as the drive signal VOUT, the voltage Vc immediately before the trapezoidal waveforms Adp1, Adp2, Bdp1, Bdp2 corresponds to the voltage value held by the capacitive component of the piezoelectric element 60 included in the ejection section 600. In other words, when none of the trapezoidal waveforms Adp1, Adp2, Bdp1, Bdp2 is selected as the drive signal VOUT, the voltage Vc that was supplied immediately before is supplied to the piezoelectric element 60 included in the ejection section 600 as the drive signal VOUT.

[0080] Here, the drive signal selection circuit 200 selects or deselects the trapezoidal waveforms Adp1, Adp2 contained in the drive signal COMA and the trapezoidal waveforms Bdp1, Bdp2 contained in the drive signal COMB, thereby generating drive signals VOUT corresponding individually to each of the multiple ejection sections 600, as shown in Figure 5, and outputs them to the piezoelectric elements 60 included in the corresponding ejection sections 600.

[0081] Fig. 6 is a diagram showing a functional configuration of the drive signal selection circuit 200. As shown in Fig. 6, the drive signal selection circuit 200 includes a selection control circuit 210 and a plurality of selection circuits 230. Fig. 6 also shows a plurality of ejection units 600 to which the drive signal VOUT output from the drive signal selection circuit 200 is supplied. In the following description, the ejection module 32 including the drive signal selection circuit 200 and the plurality of ejection units 600 will be described as having p ejection units 600 as the plurality of ejection units 600.

[0082] A print data signal SI, a clock signal SCK, a latch signal LAT, and a change signal CH are input to the selection control circuit 210. The selection control circuit 210 is provided with a set of a register 212, a latch circuit 214, and a decoder 216 corresponding to each of the p ejection units 600. In other words, the selection control circuit 210 includes sets of the register 212, the latch circuit 214, and the decoder 216 in a number equal to at least the p ejection units 600.

[0083] The print data signal SI is a signal synchronized with the clock signal SCK, and is a signal of 2p bits in total that serially includes 2-bit print data [SIH, SIL] for selecting one of large dots LD, medium dots MD, small dots SD, and non-recording ND for each of the p ejection units 600. The print data signal SI is held in the register 212 for each of the print data [SIH, SIL] included in the print data signal SI, corresponding to the p ejection units 600.

[0084] Specifically, in the selection control circuit 210, the registers 212 are connected in cascade to each other to form a p-stage shift register. The print data [SIH, SIL] input serially as the print data signal SI is transferred to the registers 212 in the following stages in sequence in accordance with the clock signal SCK. When the supply of the clock signal SCK is stopped, the print data [SIH, SIL] corresponding to each of the p ejection units 600 is held in the registers 212 corresponding to each of the p ejection units 600. In the following description, in order to distinguish the p registers 212 that form the shift register, they may be referred to as 1st stage, 2nd stage, ..., pth stage from the upstream side to the downstream side along which the print data signal SI is propagated.

[0085] Each of the p latch circuits 214 is provided corresponding to the p registers 212. Each of the latch circuits 214 simultaneously latches the print data [SIH, SIL] held in each of the p registers 212 at the rising edge of the latch signal LAT, and outputs the data to the corresponding decoder 216.

[0086] Fig. 7 is a diagram showing an example of the decoded contents in the decoder 216. The decoder 216 generates and outputs the selection signals S1 and S2 by decoding the print data [SIH, SIL] latched by the latch circuit 214 with the contents shown in Fig. 7. For example, when the input print data [SIH, SIL] is [1, 0], the decoder 216 outputs the logical level of the selection signal S1 to the selection circuit 230 as H and L levels during periods t1 and t2, and outputs the logical level of the selection signal S2 to the selection circuit 230 as L and H levels during periods t1 and t2.

[0087] The selection circuits 230 are provided corresponding to each of the p discharge sections 600. That is, the drive signal selection circuit 200 has p selection circuits 230, the same number as at least the p discharge sections 600. Fig. 8 is a diagram showing the configuration of a selection circuit 230 corresponding to one discharge section 600. As shown in Fig. 8, the selection circuit 230 includes inverters 232a and 232b, which are NOT circuits, and transfer gates 234a and 234b.

[0088] The selection signal S1 is input to a positive control terminal of the transfer gate 234a that is not marked with a circle, and is logically inverted by the inverter 232a and input to a negative control terminal of the transfer gate 234a that is marked with a circle. A drive signal COMA is supplied to an input terminal of the transfer gate 234a. The selection signal S2 is input to a positive control terminal of the transfer gate 234b that is not marked with a circle, and is logically inverted by the inverter 232b and input to a negative control terminal of the transfer gate 234b that is marked with a circle. A drive signal COMB is supplied to an input terminal of the transfer gate 234b. An output terminal of the transfer gate 234a and an output terminal of the transfer gate 234b are commonly connected. A signal at a connection terminal where the output terminal of the transfer gate 234a and the output terminal of the transfer gate 234b are commonly connected is output as a drive signal VOUT.

[0089] Specifically, when the selection signal S1 is at H level, the input terminal and the output terminal of the transfer gate 234a are electrically connected, and when the selection signal S1 is at L level, the input terminal and the output terminal of the transfer gate 234a are electrically disconnected. When the selection signal S2 is at H level, the input terminal and the output terminal of the transfer gate 234b are electrically connected, and when the selection signal S2 is at L level, the input terminal and the output terminal of the transfer gate 234b are electrically disconnected. That is, the selection circuit 230 switches the electrical connection state between the input terminal and the output terminal of the transfer gate 234a, 234b based on the selection signals S1, S2 to select or not select the signal waveforms of the drive signals COMA, COMB supplied to the input terminals of the transfer gates 234a, 234b, and outputs the drive signal VOUT to the connection terminal to which the output terminal of the transfer gate 234a and the output terminal of the transfer gate 234b are commonly connected.

[0090] The operation of the drive signal selection circuit 200 will be described with reference to FIG. 9. FIG. 9 is a diagram for explaining the operation of the drive signal selection circuit 200. The print data [SIH, SIL] included in the print data signal SI is input serially in synchronization with the clock signal SCK. Then, the print data [SIH, SIL] is sequentially transferred by the register 212 constituting a shift register corresponding to p ejection units 600 in synchronization with the clock signal SCK. Thereafter, the supply of the clock signal SCK is stopped, and the print data [SIH, SIL] corresponding to each of the p ejection units 600 is held in each of the registers 212. Note that the print data [SIH, SIL] included in the print data signal SI is input in the order corresponding to the ejection units 600 of the pth stage, ..., 2nd stage, and 1st stage of the register 212 constituting the shift register.

[0091] Then, when the latch signal LAT rises, the latch circuits 214 simultaneously latch the print data [SIH, SIL] held in the registers 212. In addition, in Fig. 9, LS1, LS2, ..., LSp indicate the print data [SIH, SIL] latched by the latch circuits 214 corresponding to the 1st, 2nd, ..., pth stages of the registers 212.

[0092] The decoder 216 outputs the logic levels of the selection signals S1, S2 as shown in FIG. 7 during each of the periods t1, t2, according to the dot size defined by the latched print data [SIH, SIL].

[0093] Specifically, when the input print data [SIH, SIL] is [1, 1], the decoder 216 sets the logic level of the selection signal S1 to H, H level during periods t1 and t2, and sets the logic level of the selection signal S2 to L, L level during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1, and selects the trapezoidal waveform Adp2 during period t2. As a result, the drive signal VOUT corresponding to the large dot LD shown in FIG. 5 is generated at the output terminal of the selection circuit 230.

[0094] Furthermore, when the input print data [SIH, SIL] is [1, 0], the decoder 216 sets the logic levels of the selection signal S1 to H, L levels during periods t1 and t2, and sets the logic levels of the selection signal S2 to L, H levels during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1, and selects the trapezoidal waveform Bdp2 during period t2. As a result, a drive signal VOUT corresponding to the medium dot MD shown in FIG. 5 is generated at the output terminal of the selection circuit 230.

[0095] Furthermore, when the input print data [SIH, SIL] is [0, 1], the decoder 216 sets the logic level of the selection signal S1 to H, L levels during periods t1 and t2, and sets the logic level of the selection signal S2 to L, L levels during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 during period t1, and does not select either of the trapezoidal waveforms Adp2 or Bdp2 during period t2. As a result, a drive signal VOUT corresponding to the small dot SD shown in FIG. 5 is generated at the output terminal of the selection circuit 230.

[0096] Furthermore, when the input print data [SIH, SIL] is [0, 0], the decoder 216 sets the logic level of the selection signal S1 to L, L level during periods t1 and t2, and sets the logic level of the selection signal S2 to H, L level during periods t1 and t2. In this case, the selection circuit 230 selects the trapezoidal waveform Bdp1 during period t1, and does not select either of the trapezoidal waveforms Adp2 or Bdp2 during period t2. As a result, the drive signal VOUT corresponding to the non-printing ND shown in FIG. 5 is generated at the output terminal of the selection circuit 230.

[0097] As described above, the drive signal selection circuit 200 generates and outputs the drive signal VOUT by selecting the signal waveforms of the drive signals COMA and COMB based on the print data signal SI, the clock signal SCK, the latch signal LAT, and the change signal CH.

[0098] 1-5.Head unit and carriage structure Next, the structure of the head unit 3 and the carriage 8 will be described. FIG. 10 is a side view showing the structure of the head unit 3 and the carriage 8. FIG. 11 is a perspective view showing the structure of the head unit 3 and the carriage 8. Here, in the following description, the X-axis, Y-axis, and Z-axis, which are perpendicular to each other, are illustrated and described. In addition, in the following description, the starting point side of the illustrated arrow along the X-axis may be referred to as the -X side, and the tip side as the +X side, the starting point side of the illustrated arrow along the Y-axis may be referred to as the -Y side, and the tip side as the +Y side, and the starting point side of the illustrated arrow along the Z-axis may be referred to as the -Z side, and the tip side as the +Z side. In addition, in the following description, the plane formed by the X-axis and the Y-axis may be referred to as the XY plane, the plane formed by the X-axis and the Z-axis may be referred to as the XZ plane, and the plane formed by the Y-axis and the Z-axis may be referred to as the YZ plane.

[0099] As shown in FIG. 10 and FIG. 11, the carriage 8 includes a carriage body 81, a carriage cover 82, and a storage case 83. The carriage body 81 includes a mounting portion 85 and a fixing portion 86. The mounting portion 85 is a plate-like member extending along the XY plane, and the fixing portion 86 is a plate-like member extending along the YZ plane from the end of the mounting portion 85 on the -Y side toward the -Z side. That is, the carriage body 81 has an L-shaped cross section when viewed along the X axis. The carriage cover 82 is located on the -Z side of the carriage body 81 and is detachably attached to the carriage body 81. At this time, the carriage body 81 and the carriage cover 82 form a closed space. The storage case 83 is a substantially rectangular parallelepiped shape capable of housing various components therein, but has no surface on the +Y side and is open. The +Y side end of the storage case 83 is fixed to the -Z side end of the fixing part 86 on the -Y side of the carriage body 81. With this structure, the carriage body 81, the carriage cover 82, and the storage case 83 form a closed space.

[0100] Furthermore, a carriage support part 87 is formed on the -Y side surface of the fixed part 86 included in the carriage body 81. The carriage support part 87 is movably supported on the carriage guide shaft 7 by fitting the guide rail 72 formed on the +Y side of the carriage guide shaft 7 into the carriage support part 87. This enables the carriage 8 to move along the carriage guide shaft 7.

[0101] The internal space of the carriage 8 configured as above, which is a closed space formed by the carriage body 81, the carriage cover 82, and the storage case 83, accommodates the discharge control module 10, the multiple liquid discharge modules 20, and the multiple cables 21 and the multiple cables 22 corresponding to the multiple liquid discharge modules 20. Here, the liquid discharge device 1 of this embodiment will be described as having five liquid discharge modules 20. That is, five liquid discharge modules 20, five cables 21, and five cables 22 are accommodated in the internal space of the carriage 8 of this embodiment. The number of liquid discharge modules 20 included in the liquid discharge device 1 is not limited to five.

[0102] The ejection control module 10 is accommodated inside a housing case 83. The ejection control module 10 includes a control circuit board 100 and an integrated circuit 110 mounted on the control circuit board 100. The integrated circuit 110 constitutes a part or the whole of the head control circuit 12 described above.

[0103] The five cables 21 and the five cables 22 are provided corresponding to the five liquid ejection modules 20. Specifically, one end of each of the five cables 21 and one end of each of the five cables 22 are electrically connected to the control circuit board 100. The other end of each of the five cables 21 and the other end of each of the five cables 22 are electrically connected to the corresponding liquid ejection modules 20. As such cables 21 and 22, for example, flexible flat cables (FFC: Flexible Flat Cables) can be used.

[0104] Each of the five liquid ejection modules 20 has a drive circuit module 50 and a print head 30, and is housed in a space formed by a carriage body 81 and a carriage cover 82. The five liquid ejection modules 20 are mounted on a mounting portion 85 at equal intervals along the X-axis.

[0105] The other end of the cable 21 and the other end of the cable 22 are electrically connected to the drive circuit module 50 on the -Z side of the drive circuit module 50 of the corresponding liquid ejection module 20. In addition, the print head 30 is located on the +Z side of the drive circuit module 50. The print head 30 is mounted on the mounting part 85 at equal intervals along the X axis. At this time, a plurality of ejection parts 600 of the print head 30 are exposed from the -Z side of the mounting part 85. As a result, ink ejected from the plurality of ejection parts 600 of the print head 30 is ejected onto the medium P without being blocked by the carriage 8.

[0106] In the liquid ejection module 20, the print head 30 and the drive circuit module 50 are electrically connected by a connector CN1. As such a connector CN1, it is preferable to use a board-to-board (BtoB: Board to Board) connector.

[0107] A BtoB connector is a connector in which two connectors directly fit together, allowing a configuration that has one of the two connectors to be electrically connected to a configuration that has the other of the two connectors without the need for a cable.

[0108] In the head unit 3 configured as above, the print data signal pDATA and the voltage signals VHV and VMV output by the control unit 2 are propagated through the cable 120 and input to the discharge control module 10. The discharge control module 10 generates a clock signal SCK, a differential print data signal Dp, and a differential drive data signal Dd corresponding to each of the five liquid discharge modules 20 based on the input print data signal pDATA and the voltage signals VHV and VMV, and also generates a fan drive signal Fp corresponding to the liquid discharge module 20. Then, the discharge control module 10 outputs the generated clock signal SCK, differential print data signal Dp, differential drive data signal Dd, and fan drive signal Fp, as well as the voltage signals VHV and VMV, to the cables 21 and 22.

[0109] The clock signal SCK, differential print data signal Dp, differential drive data signal Dd, and fan drive signal Fp, as well as the voltage signals VHV and VMV, output by the ejection control module 10, are propagated through cables 21 and 22 and input to a drive circuit module 50 included in the liquid ejection module 20. The drive circuit module 50 operates based on the input clock signal SCK, differential print data signal Dp, and differential drive data signal Dd, as well as the voltage signals VHV and VMV, to generate a clock signal SCK, a differential print data signal Dpt, and a plurality of drive signals COM for controlling the operation of the print head 30, and supply them to the print head 30 via the connector CN1. As a result, ink is ejected from an ejection unit 600 included in the print head 30.

[0110] 1-6. Use of support guide members As described above, the first air duct 41 and the second air duct 42 are connected to the carriage 8, the ink tubes 91 are connected to the print heads 30 mounted on the carriage 8, and the cable 120 is connected to the discharge control module 10 mounted on the carriage 8. Therefore, when the print heads 30 discharge ink to form an image on the medium P, if large friction, twisting, bending, tension, etc. occurs in the cable 120, the ink tube 91, the first air duct 41, and the second air duct 42 as the carriage 8 moves, these may be damaged or smooth movement of the carriage 8 may be hindered. Therefore, in this embodiment, at least the first air duct 41 and the second air duct 42 are guided to the carriage 8 in a state where they are supported by being stored in the support guide member 400. Furthermore, in this embodiment, the ink tubes 91 are also guided to the carriage 8 in a state where they are supported by being stored in the support guide member 400. Furthermore, the cable 120 may also be guided to the carriage 8 while being supported by being housed in the support and guide member 400 .

[0111] Fig. 12 is a perspective view of the support guide member 400 that houses a plurality of ink tubes 91, the first air blower duct 41, the second air blower duct 42, and the cable 120. Fig. 13 is a view showing a state in which the support guide member 400 is connected to the carriage 8.

[0112] 12, the support guide member 400 has a chain-like structure in which a plurality of hollow link units 401 are rotatably connected. A plurality of ink tubes 91, a first air blowing duct 41, a second air blowing duct 42, and a cable 120 are housed in the hollow portion inside the support guide member 400.

[0113] As shown in FIG. 13, the support guide member 400 has one end E1 fixed to the housing 300 and the other end E2 fixed to the carriage 8. Therefore, for example, when the carriage 8 moves from the position shown by the solid line in FIG. 13 along the carriage guide shaft 7 to the position shown by the broken line, the end E1 of the support guide member 400 does not move, but the end E2 of the support guide member 400 moves. At this time, the support guide member 400 smoothly deforms with the movement of the carriage 8, so that the ink tubes 91, the first air blowing tube 41, the second air blowing tube 42, and the cable 120 housed in the support guide member 400 are unlikely to experience large friction, twisting, bending, tension, or the like. In addition, the risk that any of the ink tubes 91, the first air blowing tube 41, the second air blowing tube 42, and the cable 120 will be caught by any member present in the internal space of the housing 300, thereby hindering the smooth movement of the carriage 8, is reduced.

[0114] In this way, the support and guide member 400 stores and supports the multiple ink tubes 91, the first air blower duct 41, the second air blower duct 42, and the cable 120, and guides them to the carriage 8, thereby protecting the multiple ink tubes 91, the first air blower duct 41, the second air blower duct 42, and the cable 120 from wear and tear and enabling smooth movement even when the carriage 8 moves repeatedly. For example, the support and guide member 400 may be a Cablebear (registered trademark).

[0115] Incidentally, most of the ink ejected from the multiple print heads 30 lands on the medium P and remains on the medium P, but some of the ejected ink becomes mist before landing and floats in the air. In addition, the liquid that lands on the medium P also becomes mist again due to the flow of gas caused by the carriage 8 moving on the medium P and the medium P being transported before being absorbed and solidified. In this way, during the period when an image is formed on the medium P, the ink mist floats in the internal space of the housing 300. Therefore, it is preferable that the first air duct 41, the second air duct 42, and the multiple ink tubes 91 are each made of silicone. Silicone is resistant to attack and has excellent oil resistance, chemical resistance, solvent resistance, etc., so by using the first air duct 41, the second air duct 42, and the multiple ink tubes 91 made of silicone, deterioration of the first air duct 41, the second air duct 42, and the multiple ink tubes 91 caused by the adhesion of ink mist is reduced.

[0116] On the other hand, as described above, during the period when an image is formed on the medium P, the multiple drive circuit modules 50 generate a large amount of heat, so the internal space of the carriage 8 is likely to become hot, and it is necessary to dissipate the heat in the internal space of the carriage 8 and cool the multiple drive circuit modules 50. If the air inside the housing 300 is sent into the internal space of the carriage 8 to dissipate the heat from the internal space of the carriage 8 and to cool the multiple drive circuit modules 50, the ink mist floating inside the housing 300 will also be drawn into the internal space of the carriage 8, and this ink mist may cause an electrical malfunction in the head unit 3.

[0117] Therefore, in this embodiment, as described above, air outside the housing 300 is sent into the internal space of the carriage 8 by the first air duct 41 or the second air duct 42 through the openings O1, O2 of the housing 300. For example, the compressed air taken in by the compressor 40 from outside the housing 300 may be sent into the internal space of the carriage 8 by the first air duct 41, and high-temperature air in the internal space of the carriage 8 may be exhausted to the outside of the carriage 8 by the second air duct 42. Also, for example, the compressor 40 may suck out air in the internal space of the carriage 8 through the first air duct 41 and exhaust it to the outside of the housing 300, and air outside the housing 300 may be sent into the internal space of the carriage 8 by the second air duct 42. Furthermore, since the air in the internal space of the carriage 8 does not necessarily need to be exhausted to the outside of the housing 300, for example, in the former case, it is not necessary to use the second air duct 42 by providing a small opening in the carriage 8 for exhausting air.

[0118] In this embodiment, ink is an example of a "liquid", and the ink container 9 is an example of a "container for storing liquid". The ink tube 91 is an example of a "liquid supply tube". Air is an example of a "gas". The drive signal output circuits 52a-1 to 52a-m and 52b-1 to 52b-m are each an example of a "drive circuit that generates a drive signal".

[0119] 1-7.Effects As described above, in the liquid ejection device 1 of the present embodiment, it is necessary to prevent the internal space of the carriage 8 from becoming abnormally hot due to heat generated by the multiple drive circuit modules 50, but on the other hand, it is also necessary to prevent the head unit 3 from malfunctioning due to ink mist floating inside the housing 300 caused by ink ejection by the multiple print heads 30. In response to this, according to the liquid ejection device 1 of the present embodiment, air from outside the housing 300 is sent into the internal space of the carriage 8 by one of the first air blower duct 41 and the second air blower duct 42, and the high-temperature air in the internal space of the carriage 8 is exhausted to the outside of the housing 300 by the other of the first air blower duct 41 and the second air blower duct 42, so that it is possible to dissipate heat from the internal space of the carriage 8 and cool the multiple drive circuit modules 50. In addition, according to the liquid ejection device 1 of the present embodiment, it is not necessary to agitate the air around the carriage 8 in order to cool the carriage 8, so that the risk of ink mist entering the internal space of the carriage 8 and causing malfunction of the head unit 3 is reduced.

[0120] However, since the carriage 8 moves from near one end of the carriage guide shaft 7 to near the other end, the first air duct 41 and the second air duct 42 tend to be long and are prone to large friction, twisting, bending, tension, etc. In contrast, according to the liquid ejection device 1 of this embodiment, the first air duct 41 and the second air duct 42 are guided to the carriage 8 in a supported state by being stored in the support guide member 400, so that the first air duct 41 and the second air duct 42 are less likely to be subjected to large friction, twisting, bending, tension, etc., and the risk of the first air duct 41 or the second air duct 42 being damaged is reduced. Furthermore, according to the liquid ejection device 1 of this embodiment, the first air duct 41 and the second air duct 42 are guided to the carriage 8 while being supported by the support guide member 400, thereby reducing the risk that the first air duct 41 or the second air duct 42 will get caught on any member present in the internal space of the housing 300, thereby hindering the smooth movement of the carriage 8.

[0121] Furthermore, according to the liquid ejection device 1 of this embodiment, the ink tubes 91 and the cables 120 are also guided to the carriage 8 in a supported state by being stored in the support guide member 400, so that the ink tubes 91 and the cables 120 are less likely to be subjected to large friction, twisting, bending, tension, etc., and the ink tubes 91 and the cables 120 are less likely to be damaged, and the ink tubes 91 and the cables 120 are less likely to be caught on some member, hindering smooth movement of the carriage 8. Furthermore, the first air blowing tube 41, the second air blowing tube 42, the ink tubes 91, and the cables 120 are not stored separately in the support guide member 400, but one support guide member 400 is used for all of them, which is advantageous in reducing costs.

[0122] Furthermore, according to the liquid ejection device 1 of this embodiment, the compressor 40 can generate a large airflow in the internal space of the carriage 8, thereby efficiently dissipating heat in the internal space of the carriage 8 and cooling the multiple drive circuit modules 50.

[0123] 2. Variations The present invention is not limited to the present embodiment, and various modifications are possible within the scope of the present invention.

[0124] For example, in the above embodiment, the liquid ejection device 1 is exemplified in which the head control circuit 12 is mounted on the carriage 8, but the head control circuit 12 does not have to be mounted on the carriage 8. For example, the control unit 2 may have the head control circuit 12.

[0125] Also, for example, in the above embodiment, a liquid ejection device 1 in which multiple drive circuit modules 50 are mounted on a carriage 8 is exemplified, but the liquid ejection device 1 may also include a carriage on which a drive circuit board on which at least one drive signal output circuit is implemented, and a print head to which a drive signal generated by the drive signal output circuit is supplied are mounted.

[0126] Also, for example, in the above embodiment, the air in the internal space of the carriage 8 is discharged to the outside of the housing 300 by one of the first air duct 41 and the second air duct 42, but the liquid ejection device 1 may be provided with an exhaust duct that discharges the air in the internal space of the carriage 8 to the outside of the housing 300. For example, compressed air sent out from the compressor 40 may be sent into the internal space of the carriage 8 by the first air duct 41, and high-temperature air in the internal space of the carriage 8 may be discharged to the outside of the housing 300 by the exhaust duct. In this case, the liquid ejection device 1 may not be provided with the second air duct 42. Also, for example, high-temperature air in the internal space of the carriage 8 may be sucked out to the outside of the housing 300 by the exhaust duct, and air outside the housing 300 may be sucked into the internal space of the carriage 8 through the first air duct 41. In this case, the liquid ejection device 1 may not be provided with the second air duct 42 and the compressor 40.

[0127] The present invention includes configurations that are substantially the same as the configurations described in this embodiment, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in this embodiment are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in this embodiment, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in this embodiment.

[0128] The above-described embodiment is merely an example, and the present invention is not limited to the above. For example, the embodiments can be appropriately combined.

[0129] The following can be derived from the above-described embodiment and modified examples.

[0130] One aspect of the liquid ejection device is A drive circuit for generating a drive signal; a print head having an ejection section to which the drive signal is input and which ejects liquid; a carriage that houses the drive circuit and the print head in an internal space; a first air duct through which gas flows into or out of the internal space of the carriage; a support and guide member connected to the carriage for supporting and guiding the first blower duct to the carriage; Equipped with.

[0131] In this liquid ejection device, the first air duct sends gas into the internal space of the carriage or expels high-temperature gas from the internal space of the carriage so that the internal space of the carriage does not become abnormally hot due to heat generated by the drive circuit. Therefore, this liquid ejection device can dissipate heat from the internal space of the carriage and cool the drive circuit without stirring the gas around the carriage. However, since the carriage moves, the first air duct is likely to become long and is likely to cause large friction, twisting, bending, tension, etc. In contrast, according to this liquid ejection device, the first air duct is guided to the carriage while being supported by a support guide member, so that the first air duct is unlikely to cause large friction, twisting, bending, tension, etc., and the risk of damaging the first air duct is reduced. Furthermore, according to this liquid ejection device, the first air duct is guided to the carriage while being supported by a support guide member, so that the risk of the first air duct getting caught on some member and hindering the smooth movement of the carriage is reduced.

[0132] One aspect of the liquid ejection device is The ventilation system may further include a compressor that sends the gas to the first blower duct or sucks the gas out of the first blower duct.

[0133] According to this liquid ejection device, a large air current can be generated in the internal space of the carriage by the compressor, so that heat can be efficiently dissipated in the internal space of the carriage and the drive circuit can be efficiently cooled.

[0134] In one aspect of the liquid ejection device, The first blower duct may be an intake duct through which the gas to be sucked into the internal space of the carriage passes.

[0135] According to this liquid ejection device, the risk of damaging the first blower duct for feeding gas into the internal space of the carriage is reduced, and the risk of impeding smooth movement of the carriage is also reduced.

[0136] In one aspect of the liquid ejection device, The first blower duct may be an exhaust duct through which the gas discharged from the internal space of the carriage passes.

[0137] According to this liquid ejection device, the risk of damaging the first blower duct for discharging high-temperature gas from the internal space of the carriage is reduced, and the risk of impeding smooth movement of the carriage is also reduced.

[0138] One aspect of the liquid ejection device is a second blower pipe through which the gas flows out or into the internal space of the carriage; The support and guide member may further support and guide the second blower duct to the carriage.

[0139] In this liquid ejection device, one of the first and second air ducts sends gas into the internal space of the carriage to prevent the internal space of the carriage from becoming abnormally hot due to heat generated by the drive circuit, and the other of the first and second air ducts expels the hot gas from the internal space of the carriage. Therefore, this liquid ejection device can dissipate heat from the internal space of the carriage and cool the drive circuit without stirring the gas around the carriage. However, since the carriage moves, the first and second air ducts tend to be long, and large friction, twisting, bending, tension, etc. tend to occur. In contrast, according to this liquid ejection device, the first and second air ducts are guided to the carriage while being supported by a support guide member, so large friction, twisting, bending, tension, etc. are unlikely to occur in the first or second air duct, and the risk of damage to the first and second air ducts is reduced. Furthermore, according to this liquid ejection device, the first and second air ducts are guided to the carriage while being supported by the support guide member, thereby reducing the risk of the first or second air duct getting caught on some member, thereby hindering the smooth movement of the carriage.

[0140] One aspect of the liquid ejection device is A container for storing the liquid; a liquid supply pipe for supplying the liquid to the print head; Equipped with The support and guide member may further support and guide the liquid supply pipe to the carriage.

[0141] According to this liquid ejection device, the liquid supply pipe is guided to the carriage while being supported by the support and guide member, so that the liquid supply pipe is less likely to be subjected to significant friction, twisting, bending, tension, etc., reducing the risk of damage to the liquid supply pipe and reducing the risk of the liquid supply pipe getting caught on some member and preventing smooth movement of the carriage. Furthermore, the first air supply pipe and the liquid supply pipe are not stored separately in two support and guide members, but one support and guide member is used for both, which is also advantageous in reducing costs.

[0142] One aspect of the liquid ejection device is a housing that houses the carriage, the first blower duct, the support guide member, and the compressor, The compressor may take in the gas to be sent to the first air duct from outside the housing, or may discharge the gas sucked from the first air duct to the outside of the housing.

[0143] According to this liquid ejection device, the compressor can generate a large air flow in the internal space of the carriage, so that the heat in the internal space of the carriage and the driving circuit can be efficiently dissipated. In addition, in this liquid ejection device, it is preferable that the compressor and the first air duct send gas from outside the housing into the internal space of the carriage, or discharge high-temperature gas in the internal space of the carriage to the outside of the housing, so that the driving circuit and the print head do not malfunction due to mist floating inside the housing caused by the ejection of liquid by the ejection unit. Since the carriage moves, the first air duct is likely to become long, and large friction, twisting, bending, tension, etc. are likely to occur. In contrast, according to this liquid ejection device, the first air duct is guided to the carriage while being supported by the support guide member, so that large friction, twisting, bending, tension, etc. are unlikely to occur in the first air duct, and the risk of damage to the first air duct is reduced.

[0144] In one aspect of the liquid ejection device, The first air duct may be made of silicone.

[0145] According to this liquid ejection device, by using a first air duct made of silicone, which is resistant to attack and has excellent oil, chemical and solvent resistance, deterioration of the first air duct caused by liquid adhesion is reduced. [Explanation of symbols]

[0146] 1...liquid ejection device, 2...control unit, 3...head unit, 4...transport motor, 5...transport roller, 6...carriage motor, 7...carriage guide shaft, 8...carriage, 9...ink container, 10...ejection control module, 12...head control circuit, 14...cooling fan drive circuit, 16...main control circuit, 18...power supply voltage output circuit, 20...liquid ejection module, 21, 22...cable, 30...print head, 31...restoration circuit, 32...ejection module, 40...compressor, 41...first air duct, 42...second air duct, 50...drive circuit module, 51...ejection control circuit, 52...drive signal output circuit, 53...capacitor, 54...abnormality detection circuit, 55...abnormality notification circuit, 56...temperature detection circuit, 58...voltage conversion circuit, 59...cooling fan, 60...piezoelectric element, 72...guide rail ball, 81...carriage body, 82...carriage cover, 83...accommodation case, 85...placement portion, 86...fixing portion, 87...carriage support portion, 91...ink tube, 100...control circuit board, 110...integrated circuit, 120...cable, 200...drive signal selection circuit, 210...selection control circuit, 212...register, 214...latch circuit, 216...decoder, 230...selection circuit, 232a, 232b...inverter, 234a, 234b...transfer gate, 300...housing, 400...support guide member, 401...link unit, 600...ejection portion, 601...piezoelectric body, 611, 612...electrodes, 621...diaphragm, 631...cavity, 632...nozzle plate, 641...reservoir, 651...nozzle, 661...supply port, CN1...connector, O1, O2...opening, P...medium

Claims

1. A drive circuit for generating a drive signal; a print head having an ejection section to which the drive signal is input and which ejects liquid; a carriage that houses the drive circuit and the print head in an internal space; a first blower pipe through which gas flows into or out of the internal space of the carriage; a support and guide member connected to the carriage for supporting and guiding the first blower duct to the carriage; Equipped with A liquid ejection device comprising:

2. The air conditioner further includes a compressor that sends the gas to the first air duct or sucks the gas out from the first air duct. The liquid ejection device according to claim 1 .

3. the first blower duct is an intake duct through which the gas to be sucked into the internal space of the carriage passes; The liquid ejection device according to claim 1 .

4. the first blower duct is an exhaust duct through which the gas discharged from the internal space of the carriage passes; The liquid ejection device according to claim 1 .

5. a second blower pipe through which the gas flows out of or into the internal space of the carriage; The support and guide member further supports and guides the second blower duct to the carriage. The liquid ejection device according to claim 1 .

6. A container for storing the liquid; a liquid supply pipe for supplying the liquid to the print head; Equipped with The support and guide member further supports and guides the liquid supply pipe to the carriage. The liquid ejection device according to claim 1 .

7. a housing that houses the carriage, the first blower duct, the support guide member, and the compressor, The compressor takes in the gas to be sent to the first air duct from outside the housing, or discharges the gas sucked from the first air duct to the outside of the housing. The liquid ejection device according to claim 2 .

8. The first air duct is made of silicone. The liquid ejection device according to claim 1 .

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