JP7063209B2 - Printhead and liquid discharge device - Google Patents

Description

The present invention relates to a print head and a liquid ejection device.

A liquid ejection device such as an inkjet printer ejects a liquid such as ink filled in a cavity from a nozzle by driving a piezoelectric element provided in a print head with a drive signal, and prints characters and images on a recording medium. Form. In such a liquid discharge device, if a defect occurs in the print head, there is a possibility that a discharge abnormality may occur in which the liquid cannot be normally discharged from the nozzle. When such an ejection abnormality occurs, the ejection accuracy of the ink ejected from the nozzles may deteriorate, and the quality of the image formed on the recording medium may deteriorate.

Patent Document 1 has a self-diagnosis function in which the head unit (printhead) itself determines whether or not dots satisfying normal print quality can be formed according to a plurality of signals input to the printhead. Disclosed is a liquid ejection device that is a print head and in which a signal for executing the self-diagnosis function and a signal for executing a printing process of ejecting ink from a nozzle are propagated by a common signal path. ..

Japanese Unexamined Patent Publication No. 2017-114020

However, when the signal for executing the self-diagnosis function and the signal for executing the printing process of ejecting ink from the nozzle are propagated by a common signal path, the self-diagnosis circuit for executing the self-diagnosis function Due to the influence, the waveform of the signal for executing the printing process may be distorted, and as a result, the ink ejection accuracy may be deteriorated. That is, when the signal for executing the self-diagnosis function and the signal for executing the printing process are propagated by a common signal path, the self-diagnosis function of the printhead is normally executed and the ink ejection accuracy is increased. There is a risk that it will be difficult to achieve compatibility with executing the printing process by reducing the risk of deterioration.

One aspect of the print head according to the present invention is
The first drive element that discharges the liquid from the nozzle by driving based on the drive signal,
A diagnostic circuit that diagnoses whether or not normal liquid discharge is possible based on the first diagnostic signal, the second diagnostic signal, the third diagnostic signal, and the fourth diagnostic signal.
The first terminal to which the first diagnostic signal is input, the second terminal to which the second diagnostic signal is input, the third terminal to which the third diagnostic signal is input, and the fourth terminal to which the fourth diagnostic signal is input. A connector having a terminal and a fifth terminal into which the drive signal is input,
The board on which the connector is provided and
A first drive signal selection circuit that selects the waveform of the drive signal and supplies it to the first drive element.
Equipped with
The first terminal also serves as a terminal to which a first print data signal defining the waveform selection of the drive signal in the first drive signal selection circuit is input.
The board has a first wiring, a second wiring, a third wiring, a fourth wiring, a fifth wiring, a sixth wiring, a seventh wiring, an eighth wiring, and a ninth wiring.
The first wiring electrically connects the first terminal and the diagnostic circuit.
The second wiring electrically connects the second terminal and the diagnostic circuit.
The third wiring electrically connects the third terminal and the diagnostic circuit.
The fourth wiring electrically connects the fourth terminal and the diagnostic circuit.
The fifth wiring electrically connects the first terminal and the first drive signal selection circuit.
The sixth wiring electrically connects the fifth terminal and the first drive signal selection circuit.
The seventh wiring is electrically connected to the second wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.
The eighth wiring is electrically connected to the third wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.
The ninth wiring is electrically connected to the fourth wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.

In one aspect of the printhead
The first drive element group including the first drive element and
A second drive element that discharges liquid from the nozzle by driving based on the drive signal, and
A second drive signal selection circuit that selects the waveform of the drive signal based on the second print data signal and supplies it to the second drive element.
The second drive element group including the second drive element and
Equipped with
The shortest distance between the first drive element group and the connector is
It may be shorter than the shortest distance between the second drive element group and the connector.

In one aspect of the printhead
It has a plurality of drive element groups including the first drive element group and the second drive element group.
The other drive element group may not be located between the first drive element group and the connector.

In one aspect of the printhead
The connector and the diagnostic circuit may be provided on the same surface of the substrate.

In one aspect of the printhead
The second terminal may also serve as a terminal to which a signal defining the discharge timing of the liquid is input.

In one aspect of the printhead
The third terminal may also serve as a terminal to which a signal defining the waveform switching timing of the drive signal is input.

In one aspect of the printhead
The fourth terminal may also serve as a terminal to which a clock signal is input.

One aspect of the liquid discharge device according to the present invention is
One aspect of the print head and
The drive signal generation circuit that generates the drive signal and
To prepare for.

It is a figure which shows the schematic structure of the liquid discharge device. It is a block diagram which shows the electric structure of a liquid discharge device. It is a figure which shows an example of the waveform of the drive signal COM. It is a figure which shows an example of the waveform of the drive signal VOUT. It is a figure which shows the structure of the drive signal selection circuit. It is a figure which shows the decoding content in a decoder. It is a figure which shows the structure of the selection circuit corresponding to one discharge part. It is a figure for demonstrating operation of a drive signal selection circuit. It is a figure which shows the structure of the temperature abnormality detection circuit. It is a perspective view which shows the structure of a print head. It is a top view which shows the structure of the ink ejection surface. It is a figure which shows the schematic structure of one of the plurality of ejection parts included in a head. It is a top view when the substrate is seen from the surface 322. It is a top view when the substrate is seen from the surface 321. It is a figure which shows the structure of the connector 350, 360. It is a figure which shows the other structure of the connector 350, 360. It is sectional drawing when the print head is seen from the Y direction. It is a figure for demonstrating the detail of the signal input to a connector 350. It is a figure for demonstrating the detail of the signal input to a connector 360. It is a figure which shows an example of the wiring formed on the surface 321 of a substrate. It is a block diagram which shows the electric structure of the liquid discharge device in 2nd Embodiment. It is a perspective view which shows the structure of the print head in 2nd Embodiment. It is a top view which shows the ink ejection surface of the head in 2nd Embodiment. It is a top view when the substrate in 2nd Embodiment is seen from the surface 322. It is a top view when the substrate in 2nd Embodiment is seen from the surface 321. It is a figure which shows the structure of the connector 370, 380 in the 2nd Embodiment. It is sectional drawing when the print head in 2nd Embodiment is seen from the Y direction. It is a figure for demonstrating the detail of the signal input to the connector 350 in 2nd Embodiment. It is a figure for demonstrating the detail of the signal input to a connector 360 in 2nd Embodiment. It is a figure for demonstrating the detail of the signal input to the connector 370 in the 2nd Embodiment. It is a figure for demonstrating the detail of the signal input to the connector 380 in the 2nd Embodiment. It is a figure which shows an example of the wiring formed on the surface 321 of the substrate 320 in 2nd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The drawings used are for convenience of explanation. The embodiments described below do not unreasonably limit the content of the present invention described in the claims. Moreover, not all of the configurations described below are essential constituent requirements of the present invention.

1 First Embodiment 1.1 Outline of the liquid discharge device FIG. 1 is a diagram showing a schematic configuration of the liquid discharge device 1. In the liquid ejection device 1, a carriage 20 on which a print head 21 for ejecting ink as an example of a liquid is mounted reciprocates and ejects ink to a medium P to be conveyed, thereby producing an image with respect to the medium P. It is a serial printing type inkjet printer that forms the above. In the following description, the direction in which the carriage 20 moves is the X direction, the direction in which the medium P is conveyed is the Y direction, and the direction in which the ink is ejected is the Z direction. In addition, the X direction, the Y direction, and the Z direction will be described as being orthogonal to each other. Further, as the medium P, any printing target such as printing paper, resin film, or cloth can be used.

The liquid discharge device 1 includes a liquid container 2, a control mechanism 10, a carriage 20, a moving mechanism 30, and a transport mechanism 40.

A plurality of types of ink discharged to the medium P are stored in the liquid container 2. Examples of the color of the ink stored in the liquid container 2 include black, cyan, magenta, yellow, red, and gray. As the liquid container 2 in which such ink is stored, an ink cartridge, a bag-shaped ink pack made of a flexible film, an ink tank capable of replenishing ink, and the like are used.

The control mechanism 10 includes, for example, 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, and controls each element of the liquid discharge device 1.

A print head 21 is mounted on the carriage 20. Further, the carriage 20 is fixed to the endless belt 32 included in the moving mechanism 30. The liquid container 2 may also be mounted on the carriage 20.

The control signal Ctrl-H for controlling the printhead 21 and one or a plurality of drive signals COM for driving the printhead 21 output by the control mechanism 10 are input to the printhead 21. Then, the print head 21 ejects the ink supplied from the liquid container 2 based on the control signal Ctrl-H and the drive signal COM.

The moving mechanism 30 includes a carriage motor 31 and an endless belt 32. The carriage motor 31 operates based on the control signal Ctrl-C input from the control mechanism 10. The endless belt 32 rotates according to the operation of the carriage motor 31. As a result, the carriage 20 fixed to the endless belt 32 reciprocates in the X direction.

The transport mechanism 40 includes a transport motor 41 and a transport roller 42. The transfer motor 41 operates based on the control signal Ctrl-T input from the control mechanism 10. The transfer roller 42 rotates according to the operation of the transfer motor 41. The medium P is conveyed in the Y direction as the conveyor 42 rotates.

As described above, the liquid ejection device 1 ejects ink from the print head 21 mounted on the carriage 20 in conjunction with the conveying of the medium P by the conveying mechanism 40 and the reciprocating movement of the carriage 20 by the moving mechanism 30. Ink is landed at an arbitrary position on the surface of the medium P to form a desired image on the medium P.

1.2 Electrical Configuration of Liquid Discharge Device FIG. 2 is a block diagram showing an electrical configuration of the liquid discharge device 1. The liquid discharge device 1 includes a control mechanism 10, a print head 21, a carriage motor 31, a transfer motor 41, and a linear encoder 90.

The control mechanism 10 includes a drive signal generation circuit 50, a control circuit 100, and a power supply circuit 110. The control circuit 100 includes a processor such as a microcontroller. Then, the control circuit 100 generates and outputs data and various signals for controlling the liquid discharge device 1 based on various signals such as image data input from the host computer.

Specifically, the control circuit 100 grasps the scanning position of the print head 21 based on the detection signal input from the linear encoder 90. Then, the control circuit 100 generates and outputs various signals according to the scanning position of the print head 21. Specifically, the control circuit 100 generates a control signal Ctrl-C for controlling the reciprocating motion of the print head 21, and outputs the control signal Ctrl-C to the carriage motor 31. Further, the control circuit 100 generates a control signal Ctrl-T for controlling the transfer of the medium P, and outputs the control signal Ctrl-T to the transfer motor 41. The control signal Ctrl-C may be input to the carriage motor 31 after being signal-converted via a carriage motor driver (not shown). Similarly, the control signal Ctrl-T is a transport motor driver (not shown). After the signal is converted via the above, the signal may be input to the transfer motor 41.

Further, the control circuit 100 uses the print data signal SI1 as a control signal Ctrl-H for controlling the printhead 21 based on various signals such as image data input from the host computer and the scanning position of the printhead 21. ~ SIn, change signal CH, latch signal LAT, and clock signal SCK are generated and output to the printhead 21.

Further, the control circuit 100 generates diagnostic signals DIG-A to DIG-D for diagnosing whether or not the print head 21 can normally discharge the liquid, and outputs the diagnostic signals to the print head 21. Here, in the liquid discharge device 1 according to the first embodiment, each of the diagnostic signals DIG-A to DIG-D and each of the latch signal LAT, the clock signal SCK, the change signal CH, and the print data signal SI1 are propagated in common. It is input to the print head 21 via the path. Specifically, the diagnostic signal DIG-A and the latch signal LAT are input via a common propagation path, and the diagnostic signal DIG-B and the clock signal SCK are input via a common propagation path, and the diagnostic signal DIG is input. -C and the change signal CH are input via a common propagation path, and the diagnostic signal DIG-D and the print data signal SI1 are input via a common propagation path.

Further, the control circuit 100 outputs a drive control signal dA, which is a digital signal, to the drive signal generation circuit 50.

The drive signal generation circuit 50 includes a drive circuit 50a. The drive control signal dA is input to the drive circuit 50a. The drive circuit 50a converts the drive control signal dA into a digital / analog signal, and then amplifies the converted analog signal to class D to generate a drive signal COM. That is, the drive control signal dA is a digital signal that defines the waveform of the drive signal COM, and the drive circuit 50a generates the drive signal COM by amplifying the waveform defined by the drive control signal dA in class D. Therefore, the drive control signal dA may be any signal that can define the waveform of the drive signal COM, and for example, the drive control signal dA may be an analog signal. The drive circuit 50a may be configured as long as it can amplify the waveform defined by the drive control signal dA, and may be composed of, for example, a class A amplifier circuit, a class B amplifier circuit, a class AB amplifier circuit, or the like.

Further, the drive signal generation circuit 50 outputs a reference voltage signal CGND indicating the reference potential of the drive signal COM. The reference voltage signal CGND may be, for example, a signal having a ground potential having a voltage value of 0 V, or a signal having a DC voltage having a voltage value of 6 V or the like.

The drive signal COM and the reference voltage signal CGND are branched by the control mechanism 10 and then output to the print head 21. Specifically, the drive signal COM is branched into n drive signals COM1 to COMn corresponding to each of the n drive signal selection circuits 200 described later in the control mechanism 10, and then output to the print head 21. .. Similarly, the reference voltage signal CGND is branched into n reference voltage signals CGND1 to CGNDn in the control mechanism 10 and then output to the print head 21. The drive signal COM including the drive signals COM1 to COMn is an example of the drive signal.

The power supply circuit 110 generates and outputs the voltage VHV, VDD1, VDD2 and the ground signal GND. The voltage VHV is a signal having a DC voltage having a voltage value of, for example, 42 V. Further, the voltages VDD1 and VDD2 are signals having a DC voltage having a voltage value of, for example, 3.3V. Further, the ground signal GND is a signal indicating a reference potential of the voltages VHV, VDD1, VDD2, and is, for example, a signal having a ground potential having a voltage value of 0V. The voltage VHV is used as a voltage for amplification in the drive signal generation circuit 50, and each of the voltages VDD1 and VDD2 is used as a power supply voltage, a control voltage, and the like of various configurations in the control mechanism 10. Further, the voltage VHV, VDD1, VDD2 and the ground signal GND are also output to the print head 21. The voltage values of the voltages VHV, VDD1, VDD2 and the ground signal GND are not limited to the above-mentioned 42V, 3.3V and 0V. Further, the power supply circuit 110 may generate a signal having a plurality of voltage values other than the voltage VHV, VDD1, VDD2 and the ground signal GND.

The print head 21 includes a drive signal selection circuit 200-1 to 200-n, a temperature detection circuit 210, a diagnostic circuit 240, a temperature abnormality detection circuit 250-1 to 250-n, and a plurality of discharge units 600. ..

The diagnostic circuit 240 is printed with the diagnostic signal DIG-A and the latch signal LAT, the diagnostic signal DIG-B and the clock signal SCK, the diagnostic signal DIG-C and the change signal CH, and the diagnostic signal DIG-D propagated by the common wiring. The data signal SI1 is input. Then, the diagnostic circuit 240 diagnoses whether or not normal ink ejection is possible based on the diagnostic signals DIG-A to DIG-D.

For example, the diagnostic circuit 240 detects whether or not the voltage values of any of the input diagnostic signals DIG-A to DIG-D or all the signals are normal, and based on the detection result. Then, it may be diagnosed whether or not the print head 21 and the control mechanism 10 are normally connected. Further, the diagnostic circuit 240 is a drive signal selection circuit included in the printhead 21 according to the combination of the logical levels of any of the input diagnostic signals DIG-A to DIG-D or all the signals. Arbitrary configurations such as 200-1 to 200-n and the piezoelectric element 60 are operated, it is detected whether or not the voltage value caused by the operation is normal, and the print head 21 is normal based on the detection result. It may be diagnosed whether or not it can be operated. That is, the print head 21 performs a self-diagnosis as to whether or not normal ink ejection is possible based on the diagnosis result of the diagnostic circuit 240.

When the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the printhead 21, the diagnostic circuit 240 changes the latch signal LAT, the clock signal SCK, and the change signal CH to the latch signal cLAT, the clock signal cSK, and the change. It is output as a signal cCH. Here, the diagnostic signal DIG-D and the print data signal SI1 are branched at the print head 21, and one of the branched branches is input to the diagnostic circuit 240 and the other is input to the drive signal selection circuit 200-1.

The change signal cCH, latch signal cLAT, and clock signal cSCK output by the diagnostic circuit 240 may be signals having the same waveform as the change signal CH, latch signal LAT, and clock signal SCK input to the diagnostic circuit 240. That is, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the terminal of the diagnostic circuit 240 to which each of the latch signal LAT, the clock signal SCK, and the change signal CH is input and the latch. The terminals of the diagnostic circuit 240 from which each of the signal cLAT, the clock signal cSCK, and the change signal cCH is output are electrically connected inside the diagnostic circuit 240. Each of the change signal cCH, the latch signal cLAT, and the clock signal cSK may be a signal having a waveform corrected by each of the change signal CH, the latch signal LAT, and the clock signal SCK in the diagnostic circuit 240.

Further, the diagnostic circuit 240 generates a diagnostic signal DIG-E indicating the diagnostic result in the diagnostic circuit 240 and outputs it to the control circuit 100. Here, the diagnostic circuit 240 in the first embodiment is configured as, for example, one or a plurality of integrated circuit (IC) devices.

Voltages VHV, VDD1, drive signals COM1 to COMn, print data signals SI1 to SIn, clock signal cSCK, latch signal cLAT, and change signal cCH are input to each of the drive signal selection circuits 200-1 to 200-n. The voltages VHV and VDD1 function as power supply voltages and control voltages of the drive signal selection circuits 200-1 to 200-n, respectively. Then, each of the drive signal selection circuits 200-1 to 200-n selects or does not select the drive signals COM1 to COMn based on the print data signals SI1 to SIn, the clock signal cSCK, the latch signal cLAT, and the change signal cCH. By doing so, drive signals VOUT1 to VOUTn are generated.

The drive signals VOUT1 to VOUTn generated by each of the drive signal selection circuits 200-1 to 200-n are supplied to the piezoelectric element 60 included in the corresponding discharge unit 600. The piezoelectric element 60 is displaced by being supplied with drive signals VOUT1 to VOUTn. Then, an amount of ink corresponding to the displacement is ejected from the ejection unit 600.

Specifically, the drive signal COM1, the print data signal SI1, the latch signal cLAT, the change signal cCH, and the clock signal cSCK are input to the drive signal selection circuit 200-1. Then, the drive signal selection circuit 200-1 generates the drive signal VOUT1 by selecting or not selecting the waveform of the drive signal COM1 based on the print data signal SI1, the latch signal cLAT, the change signal cCH, and the clock signal cSCK. .. The drive signal VOUT1 is supplied to one end of the piezoelectric element 60 of the corresponding discharge unit 600. Further, a reference voltage signal CGND1 is supplied to the other end of the piezoelectric element 60. Then, the piezoelectric element 60 is displaced due to the potential difference between the drive signal VOUT1 and the reference voltage signal CGND1.

Similarly, the drive signal COMi, the print data signal SIi, the latch signal cLAT, the change signal cCH, and the clock signal cSCK are input to the drive signal selection circuit 200-i (i is any one of 1 to n). Then, the drive signal selection circuit 200-i generates the drive signal VOUTi by selecting or not selecting the waveform of the drive signal COMi based on the print data signal SIi, the latch signal cLAT, the change signal cCH, and the clock signal cSCK. .. The drive signal VOUTi is supplied to one end of the piezoelectric element 60 of the corresponding discharge unit 600. Further, a reference voltage signal CGNDi is supplied to the other end of the piezoelectric element 60. Then, the piezoelectric element 60 is displaced due to the potential difference between the drive signal VOUTi and the reference voltage signal CGNDi.

Further, the print head 21 has a plurality of piezoelectric elements 60 corresponding to each of the n drive signal selection circuits 200-1 to 200-n. In other words, the printhead 21 is formed by a drive element group formed by a plurality of piezoelectric elements 60 corresponding to the drive signal selection circuit 200-1 and a plurality of piezoelectric elements 60 corresponding to the drive signal selection circuit 200-2. It has a plurality of drive element groups including the drive element group to be driven.

Here, the drive signal selection circuit 200-1 is an example of the first drive signal selection circuit in the first embodiment. The print data signal SI1 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-1 is an example of the first print data signal in the first embodiment, and is output by the drive signal selection circuit 200-1. The drive element group formed by the plurality of piezoelectric elements 60 driven by the drive signal VOUT1 is an example of the first drive element group in the first embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT1 is used. , Is an example of the first driving element in the first embodiment. Similarly, the drive signal selection circuit 200-2 is an example of the second drive signal selection circuit in the first embodiment. The print data signal SI2 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-2 is an example of the second print data signal in the first embodiment, and is output by the drive signal selection circuit 200-2. The drive element group formed by the plurality of piezoelectric elements 60 driven by the drive signal VOUT2 is an example of the second drive element group in the first embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT2 , Is an example of the second drive element in the first embodiment.

Here, each of the drive signal selection circuits 200-1 to 200-n has a similar circuit configuration. Therefore, when it is not necessary to distinguish the drive signal selection circuits 200-1 to 200-n in the following description, the drive signal selection circuit 200 is referred to. Further, in this case, the drive signals COM1 to COMn input to the drive signal selection circuit 200 are referred to as drive signals COM, the print data signals SI1 to SIn are referred to as print data signal SI, and are output from the drive signal selection circuit 200. The drive signals VOUT1 to VOUTn are referred to as drive signals VOUT. The details of the operation of the drive signal selection circuit 200 will be described later. Here, each of the drive signal selection circuits 200-1 to 200-i is configured as, for example, an integrated circuit device.

The temperature abnormality detection circuits 250-1 to 250-n are provided corresponding to the drive signal selection circuits 200-1 to 200-n, respectively. Then, the temperature abnormality detection circuits 250-1 to 250-n diagnose the presence or absence of the temperature abnormality of the corresponding drive signal selection circuits 200-1 to 200-n. Specifically, the temperature abnormality detection circuits 250-1 to 250-n operate using the voltage VDD2 as the power supply voltage. Then, when each of the temperature abnormality detection circuits 250-1 to 250-n detects the temperature of the corresponding drive signal selection circuits 200-1 to 200-n and diagnoses that the temperature is normal, a high level ( The abnormal signal XHOT of (H level) is generated and output to the control circuit 100. On the other hand, each of the temperature abnormality detection circuits 250-1 to 250-n has a low level (L level) abnormality signal when it is diagnosed that the temperature of the corresponding drive signal selection circuits 200-1 to 200-n is abnormal. XHOT is generated and output to the control circuit 100.

Here, each of the temperature abnormality detection circuits 250-1 to 250-n has a similar circuit configuration. Therefore, when it is not necessary to distinguish between the temperature abnormality detection circuits 250-1 to 250-n in the following description, the temperature abnormality detection circuit 250 is referred to. The diagnostic signal DIG-E and the abnormal signal XHOT are propagated to the control circuit 100 via a common propagation path. The details of the temperature abnormality detection circuit 250 will be described later. Here, each of the temperature abnormality detection circuits 250-1 to 250-i is configured as, for example, an integrated circuit device. Further, the temperature abnormality detection circuit 250-i and the drive signal selection circuit 200-i may be configured as one integrated circuit device.

The temperature detection circuit 210 includes a temperature detection element such as a thermistor. Then, based on the detection signal detected by the temperature detection element, the temperature signal TH of the analog signal including the temperature information of the print head 21 is generated and output to the control circuit 100.

1.3 Example of drive signal waveform Here, an example of the waveform of the drive signal COM generated by the drive signal generation circuit 50 and an example of the waveform of the drive signal VOUT supplied to the piezoelectric element 60 are shown in FIGS. 3 and 4. Will be described using.

FIG. 3 is a diagram showing an example of the waveform of the drive signal COM. As shown in FIG. 3, the drive signal C
The OM has a trapezoidal waveform Adp1 arranged in the period T1 from the rise of the latch signal LAT to the rise of the change signal CH, and a trapezoidal waveform arranged in the period T2 after the period T1 until the next change signal CH rises. It is a waveform in which Adp2 and the trapezoidal waveform Adp3 arranged in the period T3 until the next latch signal LAT rises after the period T2 are continued. Then, when the trapezoidal waveform Adp1 is supplied to one end of the piezoelectric element 60, a medium amount of ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60. Further, when the trapezoidal waveform Adp2 is supplied to one end of the piezoelectric element 60, a small amount of ink, which is smaller than a medium amount, is ejected from the ejection unit 600 corresponding to the piezoelectric element 60. Further, when the trapezoidal waveform Adp3 is supplied to one end of the piezoelectric element 60, the ink is not ejected from the ejection unit 600 corresponding to the piezoelectric element 60. The trapezoidal waveform Adp3 is a waveform for slightly vibrating the ink in the vicinity of the nozzle opening portion of the ejection portion 600 to prevent an increase in ink viscosity.

Here, the period Ta from the rise of the latch signal LAT shown in FIG. 3 to the rise of the latch signal LAT corresponds to the printing cycle for forming new dots on the medium P. As described above, the latch signal LAT and the latch signal cLAT are signals that define the ejection timing of the ink from the print head 21, and the change signal CH and the change signal cCH are trapezoidal waveforms Adp1 and Adp2 included in the drive signal COM. , Adp3 is a signal that defines the waveform switching timing.

Further, the voltages at the start timing and the end timing of the trapezoidal waveforms Adp1, Adp2, and Adp3 are all common to the voltage Vc. That is, each of the trapezoidal waveforms Adp1, Adp2, and Adp3 is a waveform that starts at the voltage Vc and ends at the voltage Vc. The drive signal COM may be a signal having a continuous waveform of one or two trapezoidal waveforms in the period Ta, or may be a signal having a continuous waveform of four or more trapezoidal waveforms.

FIG. 4 is a diagram showing an example of the waveform of the drive signal VOUT corresponding to each of “large dot”, “medium dot”, “small dot”, and “non-recording”.

As shown in FIG. 4, the drive signal VOUT corresponding to the “large dot” is arranged in the trapezoidal waveform Adp1 arranged in the period T1, the trapezoidal waveform Adp2 arranged in the period T2, and the period T3 in the period Ta. It is a waveform that is continuous with a constant waveform at the voltage Vc. When this drive signal VOUT is supplied to one end of the piezoelectric element 60, a medium amount of ink and a small amount of ink are ejected from the ejection unit 600 corresponding to the piezoelectric element 60 in the period Ta. .. Therefore, large dots are formed on the medium P by landing and coalescing the respective inks.

The drive signal VOUT corresponding to the "medium dot" is a waveform in which the trapezoidal waveform Adp1 arranged in the period T1 and a constant waveform with the voltage Vc arranged in the periods T2 and T3 are continuous in the period Ta. There is. When this drive signal VOUT is supplied to one end of the piezoelectric element 60, a medium amount of ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60 in the period Ta. Therefore, this ink lands on the medium P to form medium dots.

The drive signal VOUT corresponding to the "small dot" is a waveform in which a constant waveform at the voltage Vc arranged in the periods T1 and T3 and a trapezoidal waveform Adp2 arranged in the period T2 are continuous in the period Ta. There is. When this drive signal VOUT is supplied to one end of the piezoelectric element 60, a small amount of ink is ejected from the ejection unit 600 corresponding to the piezoelectric element 60 in the period Ta. Therefore, this ink lands on the medium P to form small dots.

The drive signal VOUT corresponding to "non-recording" is a waveform in which a constant waveform at the voltage Vc arranged in the periods T1 and T2 and a trapezoidal waveform Adp3 arranged in the period T3 are continuous in the period Ta. There is. When this drive signal VOUT is supplied to one end of the piezoelectric element 60, the ink in the vicinity of the nozzle opening portion of the ejection portion 600 corresponding to the piezoelectric element 60 only slightly vibrates in the period Ta, and the ink is not ejected. Therefore, the ink does not land on the medium P and dots are not formed.

Here, the constant waveform at the voltage Vc is from the voltage at which the immediately preceding voltage Vc is held by the capacitive component of the piezoelectric element 60 when none of the trapezoidal waveforms Adp1, Adp2, and Adp3 are selected as the drive signal VOUT. It is a waveform. Therefore, when none of the trapezoidal waveforms Adp1, Adp2, and Adp3 is selected as the drive signal VOUT, the voltage Vc is supplied to the piezoelectric element 60 as the drive signal VOUT.

The drive signal COM and the drive signal VOUT shown in FIGS. 3 and 4 are merely examples, and the moving speed of the carriage 20 on which the print head 21 is mounted, the physical characteristics of the ink supplied to the print head 21, and the medium P. Various combinations of waveforms may be used depending on the material and the like.

1.4 Configuration of Drive Signal Selection Circuit Next, the configuration and operation of the drive signal selection circuit 200 will be described with reference to FIGS. 5 to 8. FIG. 5 is a diagram showing the configuration of the drive signal selection circuit 200. As shown in FIG. 5, the drive signal selection circuit 200 includes a selection control circuit 220 and a plurality of selection circuits 230.

A print data signal SI, a latch signal cLAT, a change signal cCH, and a clock signal cSCK are input to the selection control circuit 220. Further, the selection control circuit 220 is provided with a set of a shift register (S / R) 222, a latch circuit 224, and a decoder 226 corresponding to each of the plurality of discharge units 600. That is, the drive signal selection circuit 200 includes a set of a shift register 222, a latch circuit 224, and a decoder 226 having the same number as the total number m of the corresponding discharge units 600. Here, the print data signal SI is a signal that defines the waveform selection of the drive signal COM, and the clock signal SCK and the clock signal cSCK are clock signals for defining the timing at which the print data signal SI is input.

Specifically, the print data signal SI is a signal synchronized with the clock signal cSCK, and is a “large dot”, a “medium dot”, a “small dot”, and a “small dot” for each of the m ejection units 600. It is a signal of 2 m bits in total including 2 bits of print data [SIH, SIL] for selecting any of "non-recording". The print data signal SI corresponds to the ejection unit 600 and is held in the shift register 222 for each of the two bits of print data [SIH, SIL] included in the print data signal SI. Specifically, the m-stage shift registers 222 corresponding to the ejection unit 600 are vertically connected to each other, and the serially input print data signal SI is sequentially transferred to the subsequent stage according to the clock signal cSK. In addition, in FIG. 5, in order to distinguish the shift register 222, it is described as 1st stage, 2nd stage, ..., M stage in order from the upstream side where the print data signal SI is input.

Each of the m latch circuits 224 latches the 2-bit print data [SIH, SIL] held by each of the m shift registers 222 at the rising edge of the latch signal cLAT.

Each of the m decoders 226 decodes the 2-bit print data [SIH, SIL] latched by each of the m latch circuits 224. Then, the decoder 226 outputs the selection signal S for each period T1, T2, T3 defined by the latch signal cLAT and the change signal cCH.

FIG. 6 is a diagram showing the contents of decoding in the decoder 226. The decoder 226 outputs the selection signal S according to the latched 2-bit print data [SIH, SIL]. For example, when the 2-bit print data [SIH, SIL] is [1,0], the decoder 226 outputs the logic level of the selection signal S as H, H, L levels in each of the periods T1, T2, and T3. do.

The selection circuit 230 is provided corresponding to each of the discharge portions 600. That is, the number of selection circuits 230 included in the drive signal selection circuit 200 is the same as the total number m of the corresponding discharge units 600. FIG. 7 is a diagram showing a configuration of a selection circuit 230 corresponding to one discharge unit 600. As shown in FIG. 7, the selection circuit 230 has an inverter 232 and a transfer gate 234 which are NOT circuits.

The selection signal S is input to the positive control end not marked with a circle in the transfer gate 234, while is logically inverted by the inverter 232 and input to the negative control end marked with a circle in the transfer gate 234. To. Further, a drive signal COM is supplied to the input end of the transfer gate 234. Specifically, the transfer gate 234 makes conduction (ON) between the input end and the output end when the selection signal S is H level, and the input end and the output end when the selection signal S is L level. The interval is non-conducting (off). Then, the drive signal VOUT is output from the output end of the transfer gate 234.

Here, the operation of the drive signal selection circuit 200 will be described with reference to FIG. FIG. 8 is a diagram for explaining the operation of the drive signal selection circuit 200. The print data signal SI is serially input in synchronization with the clock signal cSK, and is sequentially transferred in the shift register 222 corresponding to the ejection unit 600. Then, when the input of the clock signal cSCK is stopped, the 2-bit print data [SIH, SIL] corresponding to each of the ejection units 600 is held in each shift register 222. The print data signal SI is input in the order corresponding to the m-stage, ..., 2-stage, and 1-stage ejection unit 600 of the shift register 222.

Then, when the latch signal cLAT rises, each of the latch circuits 224 latches the 2-bit print data [SIH, SIL] held in the shift register 222 all at once. In FIG. 8, LT1, LT2, ..., LTm are 2-bit print data [SIH, SIL] latched by the latch circuit 224 corresponding to the shift register 222 of the 1st stage, 2nd stage, ..., M stage. show.

The decoder 226 shows the logic level of the selection signal S in each of the periods T1, T2, and T3 according to the dot size defined by the latched 2-bit print data [SIH, SIL], as shown in FIG. Output with.

Specifically, when the print data [SIH, SIL] is [1,1], the decoder 226 sets the selection signal S to the H, H, L levels in the periods T1, T2, and T3. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 in the period T1, selects the trapezoidal waveform Adp2 in the period T2, and does not select the trapezoidal waveform Adp3 in the period T3. As a result, the drive signal VOUT corresponding to the "large dot" shown in FIG. 4 is generated.

Further, when the print data [SIH, SIL] is [1,0], the decoder 226 sets the selection signal S to the H, L, L level in the periods T1, T2, and T3. In this case, the selection circuit 230 selects the trapezoidal waveform Adp1 in the period T1, does not select the trapezoidal waveform Adp2 in the period T2, and does not select the trapezoidal waveform Adp3 in the period T3. As a result, the drive signal VOUT corresponding to the "middle dot" shown in FIG. 4 is generated.

Further, when the print data [SIH, SIL] is [0,1], the decoder 226 sets the selection signal S to the L, H, L level in the periods T1, T2, and T3. In this case, the selection circuit 230 does not select the trapezoidal waveform Adp1 in the period T1, selects the trapezoidal waveform Adp2 in the period T2, and does not select the trapezoidal waveform Adp3 in the period T3. As a result, the drive signal VOUT corresponding to the "small dot" shown in FIG. 4 is generated.

Further, when the print data [SIH, SIL] is [0,0], the decoder 226 sets the selection signal S to the L, L, H levels in the periods T1, T2, and T3. In this case, the selection circuit 230 does not select the trapezoidal waveform Adp1 in the period T1, does not select the trapezoidal waveform Adp2 in the period T2, and selects the trapezoidal waveform Adp3 in the period T3. As a result, the drive signal VOUT corresponding to the "non-recording" shown in FIG. 4 is generated.

As described above, the drive signal selection circuit 200 selects the waveform of the drive signal COM based on the print data signal SI, the latch signal cLAT, the change signal cCH, and the clock signal cSCK, and outputs the drive signal VOUT. In other words, the drive signal selection circuit 200 selects the waveform of the drive signal COM and supplies it to the piezoelectric element 60.

1.5 Configuration of Temperature Abnormality Detection Circuit Next, the temperature abnormality detection circuit 250 will be described with reference to FIG. FIG. 9 is a diagram showing the configuration of the temperature abnormality detection circuit 250. As shown in FIG. 9, the temperature anomaly detection circuit 250 includes a comparator 251, a reference voltage generation circuit 252, a transistor 253, a plurality of diodes 254, and resistors 255 and 256. As described above, the temperature abnormality detection circuits 250-1 to 250-n all have the same configuration. Therefore, in FIG. 9, the detailed configuration of the temperature abnormality detection circuits 250-2 to 250-n is not shown.

The voltage VDD2 is input to the reference voltage generation circuit 252. Then, the reference voltage generation circuit 252 generates a voltage Vref by transforming the voltage VDD2 and supplies it to the + side input terminal of the comparator 251. The reference voltage generation circuit 252 is composed of, for example, a voltage regulator circuit or the like.

The plurality of diodes 254 are connected in series with each other. The voltage VDD2 is supplied to the anode terminal of the diode 254 located on the highest potential side among the plurality of diodes 254 connected in series via the resistor 255, and the cathode of the diode 254 located on the lowest potential side is supplied. A ground signal GND is supplied to the terminal. Specifically, the temperature abnormality detection circuit 250 has diodes 254-1,254-2, 254-3, 254-4 as a plurality of diodes 254. The voltage VDD2 is supplied to the anode terminal of the diode 254-1 via the resistor 255, and is connected to the-side input terminal of the comparator 251. The cathode terminal of the diode 254-1 is connected to the anode terminal of the diode 254-2. The cathode terminal of the diode 254-2 is connected to the anode terminal of the diode 254-2. The cathode terminal of the diode 254-3 is connected to the anode terminal of the diode 254-4. A ground signal GND is supplied to the cathode terminal of the diode 254-4. With the resistance 255 and the plurality of diodes 254 configured as described above, the voltage Vdet, which is the sum of the forward voltages of the plurality of diodes 254, is supplied to the-side input terminal of the comparator 251. The number of the plurality of diodes 254 is not limited to four.

The comparator 251 operates by the potential difference between the voltage VDD2 and the ground signal GND. Then, the comparator 251 compares the voltage Vref supplied to the + side input terminal with the voltage Vdet supplied to the − side input terminal, and outputs a signal based on the comparison result from the output terminal.

The voltage VDD2 is supplied to the drain terminal of the transistor 253 via the resistor 256. Further, the gate terminal of the transistor 253 is connected to the output terminal of the comparator 251 and the ground signal GND is supplied to the source terminal. The voltage supplied to the drain terminal of the transistor 253 connected as described above is output from the temperature abnormality detection circuit 250 as an abnormality signal XHOT.

The voltage value of the voltage Vref generated by the reference voltage generation circuit 252 is smaller than the voltage Vdet when the temperature of the plurality of diodes 254 is within a predetermined range. In this case, the comparator 251 outputs an L level signal. Therefore, the transistor 253 is controlled to be off, and as a result, the temperature abnormality detection circuit 250 outputs an H level abnormality signal XHOT.

The forward voltage of the diode 254 has the property of decreasing as the temperature rises. Therefore, when a temperature abnormality occurs in the print head 21, the temperature of the diode 254 rises, and the voltage Vdet drops accordingly. Then, when the voltage Vdet falls below the voltage Vref due to the temperature rise, the output signal of the comparator 251 changes from the L level to the H level. Therefore, the transistor 253 is controlled on. As a result, the temperature abnormality detection circuit 250 outputs an L-level abnormality signal XHOT.

Further, as shown in FIG. 9, the outputs of n temperature abnormality detection circuits 250-1 to 250-n are commonly connected. Then, when a temperature abnormality occurs in any of the temperature abnormality detection circuits 250-1 to 250-n, the transistor 253 corresponding to the temperature abnormality detection circuit 250 in which the temperature abnormality has occurred is controlled to be turned on. As a result, the ground signal GND is supplied to the node to which the abnormal signal XHOT is output via the transistor 253. Therefore, the abnormality signal XHOT output by the temperature abnormality detection circuits 250-1 to 250-n is controlled to the L level. That is, the temperature abnormality detection circuits 250-1 to 250-n are wired or connected. As a result, even when a plurality of temperature abnormality detection circuits 250 are provided in the printhead 21, the presence or absence of the temperature abnormality of the printhead 21 is shown without increasing the number of wires for propagating the abnormality signal XHOT. The anomaly signal XHOT can be propagated.

1.6 Configuration of the print head Next, the configuration of the print head 21 will be described. FIG. 10 is a perspective view showing the configuration of the print head 21. As shown in FIG. 10, the print head 21 has a head 310 and a substrate 320. Further, an ink ejection surface 311 on which a plurality of ejection portions 600 are formed is located on the lower surface of the head 310 in the Z direction. In the following description, it is assumed that the printhead 21 of the first embodiment includes six drive signal selection circuits 200-1 to 200-6. That is, in the print head 21 of the first embodiment, the six print data signals SI1 to SI6 corresponding to each of the six drive signal selection circuits 200-1 to 200-6 and the six drive signals COM1 to COM6 and six reference voltage signals CGND1 to CGND6 are input.

FIG. 11 is a plan view showing the configuration of the ink ejection surface 311. As shown in FIG. 11, the ink ejection surface 311 is provided with six nozzle plates 632 having nozzles 651 included in the plurality of ejection portions 600 arranged side by side in the X direction. Further, in each of the nozzle plates 632, the nozzles 651 are provided side by side in the Y direction. That is, six nozzle rows L1 to L6 are formed on the ink ejection surface 311. In addition, in FIG. 11, in the nozzle rows L1 to L6 formed on each nozzle plate 632, the nozzles 651 are provided side by side in one row in the Y direction, but the nozzles 651 are provided in two or more rows in the Y direction. It may be provided side by side.

The nozzle rows L1 to L6 are provided corresponding to each of the drive signal selection circuits 200-1 to 200-6. Specifically, the drive signal VOUT1 output by the drive signal selection circuit 200-1 based on the print data signal SI1 is supplied to one end of the piezoelectric element 60 included in the plurality of ejection portions 600 provided in the nozzle row L1. A reference voltage signal CGND1 is supplied to the other end of the piezoelectric element 60. Similarly, the drive signals VOUT2 to VOUT6 output by the drive signal selection circuits 200-2 to 200-6 based on the print data signals SI2 to SI6 are included in the plurality of ejection units 600 provided in each of the nozzle rows L2 to L6. It is supplied to one end of the piezoelectric element 60, and each of the reference voltage signals CGND2 to CGND6 is supplied to the other end of the corresponding piezoelectric element 60.

Next, the configuration of the discharge unit 600 included in the head 310 will be described with reference to FIG. FIG. 12 is a diagram showing a schematic configuration of one of the plurality of ejection portions 600 included in the head 310. As shown in FIG. 12, the head 310 includes a discharge unit 600 and a reservoir 641.

The reservoir 641 is provided corresponding to each of the nozzle rows L1 to L6. Then, ink is introduced into the reservoir 641 from the ink supply port 661.

The discharge unit 600 includes a piezoelectric element 60, a diaphragm 621, a cavity 631, and a nozzle 651. The diaphragm 621 is deformed with the displacement of the piezoelectric element 60 provided on the upper surface in FIG. 12. The diaphragm 621 functions as a diaphragm that expands / reduces the internal volume of the cavity 631. The inside of the cavity 631 is filled with ink. The cavity 631 functions as a pressure chamber whose internal volume changes due to the displacement of the piezoelectric element 60. The nozzle 651 is an opening portion formed in the nozzle plate 632 and communicating with the cavity 631. Then, the ink stored in the cavity 631 is ejected from the nozzle 651 according to the change in the internal volume of the cavity 631.

The piezoelectric element 60 has a structure in which the piezoelectric body 601 is sandwiched between a pair of electrodes 611 and 612. In the piezoelectric body 601 having this structure, the central portions of the electrodes 611 and 612 and the diaphragm 621 bend in the vertical direction in FIG. 12 with respect to both end portions in response to the voltage supplied to the electrodes 611 and 612. Specifically, the drive signal VOUT is supplied to the electrode 611, and the reference voltage signal CGND is supplied to the electrode 612. When the voltage of the drive signal VOUT increases, the central portion of the piezoelectric element 60 bends upward, and when the voltage of the drive signal VOUT decreases, the central portion of the piezoelectric element 60 bends downward. That is, if the piezoelectric element 60 bends upward, the internal volume of the cavity 631 expands. Therefore, the ink is drawn from the reservoir 641. Further, if the piezoelectric element 60 bends downward, the internal volume of the cavity 631 is reduced. Therefore, an amount of ink corresponding to the degree of reduction of the internal volume of the cavity 631 is ejected from the nozzle 651. As described above, the piezoelectric element 60 is driven by the drive signal VOUT based on the drive signal COM. Then, by driving the piezoelectric element 60, ink is ejected from the nozzle 651. The piezoelectric element 60 is not limited to the structure shown in the figure, and may be any type as long as it can eject ink as the piezoelectric element 60 is displaced. Further, the piezoelectric element 60 is not limited to bending vibration, and may be configured to use longitudinal vibration.

That is, the plurality of piezoelectric elements 60 included in each of the nozzle rows L1 to L6 form a plurality of piezoelectric element groups. Specifically, the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 is an example of the first drive element group in the first embodiment, and the drive signal selection circuit 200-2. The plurality of piezoelectric elements 60 included in the nozzle row L2 corresponding to the above are examples of the second drive element group in the first embodiment.

Returning to FIG. 10, the substrate 320 has a surface 321 and a surface 322 facing the surface 321 with respect to the side 323, the side 324 facing the side 323 in the X direction, the side 325, and the side 325. It is a substantially rectangular shape formed by the sides 326 facing in the Y direction. The shape of the substrate 320 is not limited to a rectangle, and may be, for example, a polygon such as a hexagon or an octagon, and may have a notch, an arc, or the like formed in a part thereof. ..

Here, the configuration of the substrate 320 will be described with reference to FIGS. 13 and 14. FIG. 13 is a plan view of the substrate 320 when viewed from the surface 322. Further, FIG. 14 is a plan view of the substrate 320 when viewed from the surface 321.

As shown in FIG. 13, electrode groups 330a to 330f are provided on the surface 322 of the substrate 320. Specifically, each of the electrode groups 330a to 330f has a plurality of electrodes arranged side by side in the Y direction. Each of the electrode groups 330a to 330f is provided side by side in the order of the electrode groups 330a, 330b, 330c, 330d, 330e, 330f along the Y direction. Flexible printed circuit boards (FPCs) (not shown) are electrically connected to each of the electrode groups 330a to 330f provided as described above.

Further, as shown in FIGS. 13 and 14, FPC insertion holes 332a to 332c and ink supply path insertion holes 331a to 331f, which are through holes penetrating the surface 321 and the surface 322, are formed on the substrate 320. ing.

The FPC insertion hole 332a is located between the electrode group 330a and the electrode group 330b in the X direction, and the FPC electrically connected to the electrode group 330a and the FPC electrically connected to the electrode group 330b are inserted. Will be done. The FPC insertion hole 332b is located between the electrode group 330c and the electrode group 330d in the X direction, and the FPC electrically connected to the electrode group 330c and the FPC electrically connected to the electrode group 330d are inserted. Will be done. The FPC insertion hole 332c is located between the electrode group 330e and the electrode group 330f in the X direction, and the FPC electrically connected to the electrode group 330e and the FPC electrically connected to the electrode group 330f are inserted. Will be done.

The ink supply path insertion hole 331a is located on the side 323 side of the electrode group 330a in the X direction. The ink supply path insertion holes 331b and 331c are located between the electrode group 330b and the electrode group 330c in the X direction, the ink supply path insertion hole 331b is on the side 325 side, and the ink supply path insertion hole 331c is on the side 326 side. They are located side by side along the Y direction. The ink supply path insertion holes 331d and 331e are located between the electrode group 330d and the electrode group 330e in the X direction, the ink supply path insertion hole 331d is on the side 325 side, and the ink supply path insertion hole 331e is on the side 326 side. They are located side by side along the Y direction. The ink supply path insertion hole 331f is located on the side 324 side of the electrode group 330f in the X direction. Then, in each of the ink supply path insertion holes 331a to 331f, one of the ink supply paths (not shown) communicating with the ink supply port 661 for introducing ink into the ejection unit 600 corresponding to each of the nozzle rows L1 to L6. The part is inserted.

Further, as shown in FIGS. 13 and 14, the substrate 320 has fixing portions 346 to 349 for fixing the substrate 320 included in the print head 21 to the carriage 20 shown in FIG. Each of the fixing portions 346 to 349 is a through hole penetrating the surface 321 and the surface 322 of the substrate 320. Then, a screw (not shown) inserted through the fixing portions 346 to 349 is attached to the carriage 20, so that the substrate 320 is fixed to the carriage 20. The fixing portions 346 to 349 are not limited to the through holes formed in the substrate 320. For example, the fixing portions 346 to 349 may be configured to fix the substrate 320 to the carriage 20 by fitting them together.

The fixed portions 346 and 347 are located on the side 323 side of the ink supply path insertion hole 331a in the X direction, and are arranged along the Y direction so that the fixed portion 346 is on the side 325 side and the fixed portion 347 is on the side 326 side. It will be provided. Further, the fixed portions 348 and 349 are located on the side 324 side of the ink supply path insertion hole 331f in the X direction, along the Y direction so that the fixed portion 348 is on the side 325 side and the fixed portion 349 is on the side 326 side. It is installed side by side.

Further, as shown in FIG. 14, an integrated circuit 241 constituting the diagnostic circuit 240 shown in FIG. 2 is provided on the surface 321 of the substrate 320. Specifically, the integrated circuit 241 is provided on the surface 321 side of the substrate 320, between the fixed portion 347 and the fixed portion 349, and on the side 326 side of the electrode group 330a to the electrode group 330f.

Further, as shown in FIGS. 13 and 14, the substrate 320 is provided with connectors 350 and 360. The connector 350 is on the surface 321 side of the substrate 320 and is provided along the side 323. The connector 360 is on the surface 322 side of the substrate 320 and is provided along the side 323.

Here, the configurations of the connectors 350 and 360 will be described with reference to FIG. FIG. 15 is a diagram showing the configuration of the connectors 350 and 360. As shown in FIG.
The connector 350 has a housing 351 and a cable mounting portion 352 formed in the housing 351 and a plurality of terminals 353. The plurality of terminals 353 are arranged side by side along the side 323. Specifically, 26 terminals 353 are arranged side by side along the side 323. Here, the 26 terminals 353 are referred to as terminals 353-1,353-2, ..., 353-26 in order from the side 325 side to the side 326 side in the direction along the side 323. The cable mounting portion 352 is located on the substrate 320 of the plurality of terminals 353 in the Z direction. A propagation path such as a flexible flat cable is attached to the cable attachment portion 352.

The connector 360 has a housing 361, a cable mounting portion 362 formed in the housing 361, and a plurality of terminals 363. The plurality of terminals 363 are arranged side by side along the side 323. Specifically, 26 terminals 363 are arranged side by side along the side 323. Here, the 26 terminals 363 are referred to as terminals 363-1,363-2, ..., 363-26 in order from the side 325 side to the side 326 side in the direction along the side 323. The cable mounting portion 362 is located on the substrate 320 of the plurality of terminals 363 in the Z direction. A propagation path such as a flexible flat cable is attached to the cable attachment portion 362.

Various signals for controlling the operation of the printhead 21 are propagated to the cable as a propagation path of various control signals attached to the connectors 350 and 360. In other words, the printhead 21 operates based on various signals input via the connectors 350 and 360.

Here, in the connector 350 shown in FIG. 15, the cable mounting portion 352 is located on the substrate 320 side in the Z direction, and the plurality of terminals 353 are located on the ink ejection surface 311 side in the Z direction. Like the connector 350, it is preferable that the plurality of terminals 353 are located on the substrate 320 side in the Z direction, and the cable mounting portion 352 is located on the ink ejection surface 311 side in the Z direction. FIG. 16 is a diagram showing other configurations of the connectors 350 and 360.

In the liquid ejection device 1, most of the ink ejected from the nozzle 651 lands on the medium P to form an image. However, a part of the ink ejected from the nozzle 651 may become mist and float inside the liquid ejection device 1 before landing on the medium P. Further, even after the ink ejected from the nozzle 651 has landed on the medium P, the ink has landed on the medium P due to the movement of the carriage 20 on which the print head 21 is mounted and the air flow generated by the transport of the medium P. The ink may re-float inside the liquid ejection device 1. When the ink floating inside the liquid ejection device 1 adheres to the plurality of terminals 353 included in the connector 350, there is a possibility that the terminals will be short-circuited. As a result, the waveforms of various signals input to the print head 21 are distorted, which may deteriorate the ejection accuracy of the ink ejected from the print head 21.

Since the plurality of terminals 353 are located on the substrate 320 side in the Z direction as in the connector 350 shown in FIG. 16, when the cable is attached to the connector 350, the ink floating inside the liquid ejection device 1 adheres. A plurality of terminals 353 are not provided on the surface on the ink ejection surface 311 side, which is highly likely. Therefore, it is possible to reduce the possibility of a short circuit occurring between the plurality of terminals 353 included in the connector 350 due to the ink floating inside the liquid ejection device 1. Therefore, it is possible to reduce the possibility that the signal input to the print head 21 will be distorted.

In the print head 21 configured as described above, the drive signals COM1 to COM6, the reference voltage signals CGND1 to CGND6, the print data signals SI1 to SI6, the latch signal LAT, the change signal CH, and the clock signal SCK output from the control mechanism 10 are used. A plurality of signals including the above are input to the printhead 21 via the connectors 350 and 360. Then, it is propagated by the wiring pattern provided on the substrate 320 and input to each of the electrode groups 330a to 330f.

The various signals input to each of the electrode groups 330a to 330f are the drive signal selection circuits 200-corresponding to each of the nozzle rows L1 to L6 via the FPC electrically connected to each of the electrode groups 330a to 330f. It is input to 1 to 200-6. Then, the drive signal selection circuits 200-1 to 200-6 generate drive signals VOUT1 to VOUT6 based on the input signal and supply them to the piezoelectric elements 60 included in each of the nozzle rows L1 to L6. As a result, various signals input to the connectors 350 and 360 are supplied to the piezoelectric elements 60 included in the plurality of discharge units 600. Each of the drive signal selection circuits 200-1 to 200-6 may be provided inside the head 310, or may be COF (Chip On Film) mounted on the FPC.

FIG. 17 is a cross-sectional view of the print head 21 when viewed from the Y direction. As shown in FIG. 13, a plurality of nozzle rows L1 to L6 are provided side by side in the X direction. Specifically, the plurality of nozzle rows L1 to L6 are formed in the order of nozzle rows L1, L2, L3, L4, L5, L6 from the side 323 side where the connector 350 of the substrate 320 is provided toward the side 324 side. It is installed side by side. That is, the shortest distance between the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 and the connector 350 is a plurality of plurality included in the nozzle row L2 corresponding to the drive signal selection circuit 200-2. It is shorter than the shortest distance between the piezoelectric element 60 and the connector 350. Further, in this case, there are other nozzle rows L2 to L6 and nozzle rows L2 to L6 between the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 and the connector 350. The piezoelectric element 60 included in each is not located. In other words, the nozzle row L1 is located on the connector 350 side of the nozzle rows L1 to L6 formed on the ink ejection surface 311.

Although the details will be described later, the print data signal SI1 corresponding to the nozzle row L1 is input to the printhead 21 via the connector 350. Then, the print data signal SI1 is propagated by the wiring common to the diagnostic signal DIG-D and input to the diagnostic circuit 240, and is also input to the drive signal selection circuit 200-1. The print data signal is provided by providing the nozzle row L1 corresponding to the drive signal selection circuit 200-1 on the connector 350 side in which the print data signal SI1 is input among the nozzle rows L1 to L6 formed on the ink ejection surface 311. It is possible to shorten the wiring length of the wiring to which SI1 is propagated. Therefore, it is possible to reduce the possibility of noise interfering with the wiring in which the print data signal SI1 and the diagnostic signal DIG-D are propagated.

1.7 Details of the signal input to the print head In the liquid discharge device 1 configured as described above, the details of the signal input to the print head will be described with reference to FIGS. 18 and 19.

FIG. 18 is a diagram for explaining the details of the signal input to the connector 350. As shown in FIG. 18, the connector 350 has a terminal to which each of the drive signals COM1 to COM6 is input, a terminal to which each of the reference voltage signals CGND1 to CGND6 is input, a temperature signal TH, a latch signal LAT, and a clock signal. A terminal to which each of the SCK, the change signal CH, the print data signal SI1, and the abnormality signal XHOT is input, a terminal to which each of the diagnostic signals DIG-A to DIG-E is input, and a terminal to which the voltage VHV is input. , A plurality of terminals to which a plurality of ground signals GND are input.

Specifically, each of the drive signals COM1 to COM6 is input from each of the terminals 353-11, 353-9, 353-7, 353-5, 353-3, 353-1. Here, the terminal 353-11 to which the drive signal COM1 is input is an example of the fifth terminal. Further, the reference voltage signals CGND1 to CGND6 are input from terminals 353-12, 353-10, 353-8, 353-6, 353-4, 353-2, respectively.

The diagnostic signal DIG-A is input from terminals 353-23. Similarly, the latch signal LAT is also input from terminals 353-23. That is, the terminals 353-23 also serve as a terminal to which the diagnostic signal DIG-A is input and a terminal to which the latch signal LAT is input. Here, the diagnostic signal DIG-A is an example of the second diagnostic signal in the first embodiment, and the terminal 353-23 to which the diagnostic signal DIG-A is input is an example of the second terminal in the first embodiment.

The diagnostic signal DIG-B is input from terminals 353-21. Similarly, the clock signal SCK is also input from the terminal 353-6. That is, the terminals 353-21 also serve as a terminal to which the diagnostic signal DIG-B is input and a terminal to which the clock signal SCK is input. Here, the diagnostic signal DIG-B is an example of the fourth diagnostic signal in the first embodiment, and the terminal 353-21 to which the diagnostic signal DIG-B is input is an example of the fourth terminal in the first embodiment.

The diagnostic signal DIG-C is input from terminals 353-19. Similarly, the change signal CH is also input from the terminals 353-19. That is, the terminals 353-19 also serve as a terminal to which the diagnostic signal DIG-C is input and a terminal to which the change signal CH is input. Here, the diagnostic signal DIG-C is an example of the third diagnostic signal in the first embodiment, and the terminal 353-19 to which the diagnostic signal DIG-C is input is an example of the third terminal in the first embodiment.

The diagnostic signal DIG-D is input from terminals 353-17. Further, the print data signal SI1 is also input to the terminals 353-17 in the same manner. That is, the terminals 353-17 also serve as a terminal to which the diagnostic signal DIG-D is input and a terminal to which the print data signal SI1 is input. Here, the diagnostic signal DIG-D is an example of the first diagnostic signal in the first embodiment, and the terminal 353-17 to which the diagnostic signal DIG-D is input is an example of the first terminal in the first embodiment.

The diagnostic signal DIG-E is input to terminals 353-15. Similarly, the abnormal signal XHOT is also input to the terminal 353-15 of the connector 350. That is, terminals 353-15
Also serves as a terminal to which the diagnostic signal DIG-E is input and a terminal to which the abnormal signal XHOT is input.

As described above, in the first embodiment, each of the diagnostic signals DIG-A to DIG-E is common to each of the latch signal LAT, the clock signal SCK, the change signal CH, the print data signal SI1 and the abnormal signal XHOT. It is input to the terminal. Here, an example of a method of inputting each of the diagnostic signals DIG-A to DIG-E and each of the latch signal LAT, the clock signal SCK, the change signal CH, the print data signal SI1 and the abnormal signal XHOT to a common terminal will be described. do.

For example, the control circuit 100 has a diagnostic signal DIG-A and a latch signal LAT, a diagnostic signal DIG-B and a clock signal SCK, and a diagnostic signal DIG-C and a change signal according to the operating states of the liquid discharge device 1 and the printhead 21. The CH, the diagnostic signal DIG-D, and the print data signal SI1 are generated in time divisions. Specifically, when the liquid ejection device 1 is in the printing state of ejecting ink, the control circuit 100 generates a latch signal LAT, a clock signal SCK, a change signal CH, and a print data signal SI1 and outputs them to the print head 21. do. Further, when the print head 21 performs self-diagnosis when the liquid ejection device 1 is not in the printing state of ejecting ink, the control circuit 100 generates diagnostic signals DIG-A to DIG-D and outputs them to the print head 21. .. As a result, each of the latch signal LAT, the clock signal SCK, the change signal CH and the print data signal SI1 and each of the diagnostic signals DIG-A to DIG-D are propagated by common wiring and then input to the print head 21. Will be done. That is, each of the latch signal LAT, the clock signal SCK, the change signal CH, and the print data signal SI1 and each of the diagnostic signals DIG-A to DIG-D are input to a common terminal.

Further, as a method of inputting the diagnostic signal DIG-E and the abnormal signal XHOT to a common terminal, for example, a wiring for outputting the diagnostic signal DIG-E indicating the diagnostic result in the diagnostic circuit 240 and an abnormal signal XHOT are output. The wiring to be connected is wired or connected at the print head 21, and the wired or connected signal is input to a common terminal. Then, it propagates through the terminal with a common wiring. As a result, if at least one of the diagnosis result of whether or not the temperature in the temperature abnormality detection circuit 250 is abnormal and the diagnosis result in the diagnosis circuit 240 are abnormal, normal ejection of ink in the print head 21 is not possible. When an L level signal indicating that the signal is input to the terminal and both the diagnosis of whether or not the temperature in the temperature abnormality detection circuit 250 is abnormal and the diagnosis in the diagnosis circuit 240 are normal, the print head 21 is used. An H-level signal indicating that normal ink ejection is possible is input to the terminal.

A method of inputting each of the above-mentioned diagnostic signals DIG-A to DIG-E and each of the latch signal LAT, the clock signal SCK, the change signal CH, the print data signal SI1 and the abnormal signal XHOT into a common terminal of the connector 350. Is an example, and may be configured such that the signal propagated by the wiring and the signal input to the terminal can be switched by using, for example, a selector or the like.

The print data signal SI, change signal CH, latch signal LAT, clock signal SCK, and abnormal signal XHOT are important signals for controlling the ejection of the print head 21, and are poorly connected to the wiring to which these signals are propagated. If this occurs, the ink ejection accuracy may deteriorate. The wiring through which such an important signal is propagated and the wiring through which the signal for which the printhead 21 performs self-diagnosis are propagated are common wiring, and the terminal to which the signal is input and the signal for which the printhead 21 performs self-diagnosis are used. By using the terminal to which is input as a common terminal, the print data signal SI1, the change signal CH, the latch signal LAT, the clock signal SCK, and the abnormal signal XHOT are normally performed based on the result of the self-diagnosis of the print head 21. It is also possible to diagnose whether or not it has been propagated. Further, since a plurality of signals are propagated by one wiring and a plurality of signals are input to one terminal, the number of wirings to be provided in the cable as a propagation path and the number of terminals provided in the connector 350 are reduced. It is also possible.

As described above, the connector 350 has a terminal 353-17 to which the diagnostic signal DIG-D is input, a terminal 353-23 to which the diagnostic signal DIG-A is input, and a terminal 353-19 to which the diagnostic signal DIG-C is input. , Has a terminal 353-21 to which the diagnostic signal DIG-B is input and a terminal 353-11 to which the drive signal COM1 is input.

The temperature signal TH is input to terminals 353-25. Further, the voltage VHV is input to the terminals 353-13. Further, the ground signal GND is input to each of the terminals 353-14, 353-16, 353-18, 353-20, 353-22, 353-24, 353-26, respectively.

Next, the details of the signal input to the connector 360 will be described with reference to FIG. FIG. 19 is a diagram for explaining the details of the signal input to the connector 360. As shown in FIG. 19, the connector 360 has a terminal to which each of the drive signals COM1 to COM6 is input, a terminal to which each of the reference voltage signals CGND1 to CGND6 is input, and each of the print data signals SI2 to SI6. It includes a terminal to be input, a terminal to which each of the voltages VHV, VDD1 and VDD2 is input, and a plurality of terminals to which a plurality of ground signals GND are input.

Specifically, each of the drive signals COM1 to COM6 is input from terminals 363-12, 363-10, 363-8, 363-6, 363-4, 363-2, respectively. Further, each of the reference voltage signals CGND1 to CGND6 is input from terminals 363-11, 363-9, 363-7, 363-5, 363-3,363-1 respectively.

Each of the print data signals SI2 to SI6 is input from terminals 363-24, 363-22, 363-20, 363-18, 363-16, respectively. Further, the voltage VDD1 is input from the terminal 363-26, and the voltage VDD2 is input from the terminal 363-21.

The ground signal GND is input to each of the terminals 353-13, 353-14, 353-15, 353-17, 353-19, 353-23, 353-25, respectively.

1.8 Wiring formed in the print head Here, an example of wiring in which the diagnostic signals DIG-A to DIG-E input from the connector 350 are propagated on the surface 321 of the substrate 320 will be described with reference to FIG. .. FIG. 20 is a diagram showing an example of wiring formed on the surface 321 of the substrate 320. In FIG. 20, a part of the wiring formed on the substrate 320 is not shown. Further, in FIG. 20, the electrode groups 330a to 330f formed on the surface 322 of the substrate 320 are shown by broken lines.

As shown in FIG. 20, the substrate 320 has wirings 354-a to 354-o.

The terminals 353-23 are electrically connected to the wiring 354-a. The diagnostic signal DIG-A and the latch signal LAT input from the terminals 353-23 are propagated by the wiring 354-a and then input to the integrated circuit 241. That is, the wiring 354-a electrically connects the terminal 353-23 and the integrated circuit 241. The wiring 354-a through which the diagnostic signal DIG-A and the latch signal LAT are propagated is an example of the second wiring of the first embodiment.

The terminals 353-21 are electrically connected to the wiring 354-b. The diagnostic signal DIG-B and the clock signal SCK input from the terminals 353-21 are propagated by the wiring 354-b and then input to the integrated circuit 241. That is, the wiring 354-b electrically connects the terminal 353-21 and the integrated circuit 241. The wiring 354-b through which the diagnostic signal DIG-B and the clock signal SCK are propagated is an example of the fourth wiring of the first embodiment.

The terminals 353-19 are electrically connected to the wiring 354-c. The diagnostic signal DIG-C and the change signal CH input from the terminals 353-19 are propagated by the wiring 354-c and then input to the integrated circuit 241. That is, the wiring 354-c electrically connects the terminal 353-19 and the integrated circuit 241. The wiring 354-c in which the diagnostic signal DIG-C and the change signal CH are propagated is an example of the third wiring of the first embodiment.

The terminals 353-17 are electrically connected to the wiring 354-d. The diagnostic signal DIG-D and the print data signal SI1 input from the terminals 353-17 are propagated by the wiring 354-d and then input to the integrated circuit 241. That is, the wiring 354-d electrically connects the terminal 353-17 and the integrated circuit 241. The wiring 354-d in which the diagnostic signal DIG-D and the print data signal SI1 are propagated is an example of the first wiring of the first embodiment.

The terminals 353-15 are electrically connected to the wiring 354-e. The diagnostic signal DIG-E and the abnormality signal XHOT output from the integrated circuit 241 are propagated by the wiring 354-e and then input to the terminals 353-15. That is, the wiring 354-e electrically connects the terminal 353-15 and the integrated circuit 241.

Here, it is preferable that vias and the like are not formed in each of the wirings 354-a to 354-d propagating in each of the diagnostic signals DIG-A to DIG-D, and for example, as shown in FIG. It is preferable that the connector 350 and the integrated circuit 241 constituting the diagnostic circuit 240 are provided on the surface 321 which is the same surface of the substrate 320. Each of the diagnostic signals DIG-A to DIG-D is a signal for diagnosing whether or not normal ink ejection is possible in the integrated circuit 241. Therefore, if ambient noise or the like interferes when the diagnostic signals DIG-A to DIG-D are propagated, the integrated circuit 241 cannot perform the diagnosis normally, and as a result, the print head The ejection accuracy of 21 may deteriorate. By not providing vias or the like in the wirings 354-a to 354-d propagating each of the diagnostic signals DIG-A to DIG-D, there is a possibility that noise or the like may interfere with the diagnostic signals DIG-A to DIG-D. It is possible to reduce it.

As described above, when the integrated circuit 241 diagnoses that the print head 21 can normally eject the ink based on the input diagnostic signals DIG-A to DIG-D, the latch signal LAT and the clock are input. The signal SCK and the change signal CH are output to the drive signal selection circuit 200 as the latch signal cLAT, the clock signal cSCK and the change signal cCH. Specifically, the latch signal cLAT, the clock signal cSCK, and the change signal cCH output from a terminal (not shown) of the integrated circuit 241 are propagated by the wirings 354-f to 354-h and input to the drive signal selection circuit 200. To. In FIG. 20, only the wirings 354-f to 354-h in which the latch signal cLAT, the clock signal cSKC, and the change signal cCH input to the drive signal selection circuit 200-1 are propagated are shown, and the drive signal selection circuit is shown. The wiring through which the latch signal cLAT, the clock signal cSCK, and the change signal cCH input to 200-2 to 200-6 are propagated is omitted.

Specifically, the integrated circuit 241 constituting the diagnostic circuit 240 is electrically connected to the wiring 354-f. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-f is connected to the wiring 354-f via the integrated circuit 241.
It is electrically connected to c. As a result, the change signal cCH based on the change signal CH is input to the wiring 354-f. The change signal cCH is input to any of a plurality of electrodes included in the electrode group 330a provided on the surface 322 of the substrate 320 via the wiring 354-f and vias (not shown). The wiring 354-f through which this change signal cCH is propagated is an example of the ninth wiring of the first embodiment. Then, the change signal cCH is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 330a. That is, the wiring 354-f electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, the integrated circuit 241 is electrically connected to the wiring 354-g. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-g is electrically connected to the wiring 354-b via the integrated circuit 241. As a result, the clock signal cSCK based on the clock signal SCK is input to the wiring 354-g. The clock signal cSCK is input to any of a plurality of electrodes included in the electrode group 330a provided on the surface 322 of the substrate 320 via the wiring 354-g and vias (not shown). The wiring 354-g in which the clock signal cSKK is propagated is an example of the eighth wiring of the first embodiment. Then, the clock signal cSCK is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 330a. That is, the wiring 354-g electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, the integrated circuit 241 is electrically connected to the wiring 354-h. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-h is electrically connected to the wiring 354-a via the integrated circuit 241. As a result, the latch signal cLAT based on the latch signal LAT is input to the wiring 354-h. The latch signal cLAT is input to any of a plurality of electrodes included in the electrode group 330a provided on the surface 322 of the substrate 320 via the wiring 354-h and vias (not shown). The wiring 354-h in which the latch signal cLAT is propagated is an example of the seventh wiring of the first embodiment. Then, the latch signal cLAT is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 330a. That is, the wiring 354-h electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, as shown in FIG. 20, the terminals 353-17 are also electrically connected to the wiring 354-i. The print data signal SI1 input from the terminals 353-17 is propagated by the wiring 354-i, and then is included in a plurality of electrode groups 330a provided on the surface 322 of the substrate 320 via vias (not shown) or the like. It is input to one of the electrodes. The wiring 354-i through which the print data signal SI1 is propagated is an example of the fifth wiring of the first embodiment. Then, the print data signal SI1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 330a. That is, the wiring 354-i electrically connects the terminal 353-17 and the drive signal selection circuit 200-1.

The terminal 353-11 to which the drive signal COM1 is input is electrically connected to the wiring 354-j. Then, the drive signal COM1 is propagated by the wiring 354-j and then input to any of a plurality of electrodes included in the electrode group 330a provided on the surface 322 of the substrate 320 via a via (not shown) or the like. To. The wiring 354-j through which the drive signal COM1 is propagated is an example of the sixth wiring of the first embodiment. Then, the drive signal COM1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 330a. That is, the wiring 354-j electrically connects the terminal 353-11 and the drive signal selection circuit 200-1.

Similarly, each of the terminals 353-9, 353-7, 353-5, 353-3, 353-1 to which the drive signals COM2 to COM6 are input is electrically with each of the wirings 354k to 354-o. Be connected. Then, each of the drive signals COM2 to COM6 is wired 354.
After being propagated in −k to 354-o, it is input to any of a plurality of electrodes included in the electrode group 330a provided on the surface 322 of the substrate 320 via vias (not shown) or the like.

1.9 Actions / Effects As described above, in the printhead 21 and the liquid discharge device 1 in the present embodiment, common transmission among the wirings through which the diagnostic signals DIG-A to DIG-D for performing self-diagnosis are propagated. The wiring in which the print data signal SI1 and the diagnostic signal DIG-D input to the printhead 21 via the path are propagated on the board 320 is branched at the terminal 353-17, and the wiring is one of the branched wirings 354-. d is input to the integrated circuit 241 constituting the diagnostic circuit 240, and the wiring 354-i, which is the other branched wiring, does not go through the integrated circuit 241 but via the electrodes included in the electrode group 330a, and the drive signal selection circuit 200-1. Is supplied to. As a result, the print data signal SI1 supplied to the drive signal selection circuit 200-1 is supplied to the drive signal selection circuit 200-1 without going through the integrated circuit 241. Therefore, the print data signal SI1 supplied to the drive signal selection circuit 200-1 is less likely to have waveform distortion due to signal delay or the like caused by the operation of the integrated circuit 241. That is, the self-diagnosis function is executed based on the diagnostic signal DIG-D supplied to the integrated circuit 241 via the wiring 354-d, and is supplied to the drive signal selection circuit 200-1 via the wiring 354-i. The printing process can be executed based on the print data signal SI1 without deteriorating the ejection accuracy of the ink. This makes it possible for the print head 21 and the liquid ejection device 1 to both normally execute the self-diagnosis function and execute the printing process without deteriorating the ink ejection accuracy.

2 Second Embodiment Next, the liquid discharge device 1 and the print head 21 of the second embodiment will be described. In explaining the liquid discharge device 1 and the printhead 21 of the second embodiment, the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted or simplified.

FIG. 21 is a block diagram showing an electrical configuration of the liquid discharge device 1 according to the second embodiment. As shown in FIG. 21, the control circuit 100 in the second embodiment has two latch signals LAT1 and LAT2 that define the ejection timing of the printhead 21, and two change signals that define the waveform switching timing of the drive signal COM. It differs from the first embodiment in that CH1 and CH2 and two clock signals SCK1 and SCK2 for defining the timing at which the print data signal SI is input are generated and output to the printhead 21. Further, the control circuit 100 generates diagnostic signals DIG-A to DIG-D and DIG-F to DIG-I for diagnosing whether or not the print head 21 can normally discharge the liquid, and the print head 21 generates the diagnostic signals. It differs from the first embodiment in that it outputs to.

Here, in the liquid discharge device 1 according to the second embodiment, the diagnostic signal DIG-A and the latch signal LAT1, the diagnostic signal DIG-B and the clock signal SCK1, the diagnostic signal DIG-C and the change signal CH1, and the diagnostic signal DIG-D Print data signal SI1, diagnostic signal DIG-F and latch signal LAT2, diagnostic signal DIG-G and clock signal SCK2, diagnostic signal DIG-H and change signal CH2, and diagnostic signal DIG-I and print data signal SIn are common. It is output to the diagnostic circuit 240 included in the printhead 21 via the propagation path.

The diagnostic circuit 240 diagnoses whether or not normal ink ejection is possible based on each of the diagnostic signals DIG-A to DIG-D and the diagnostic signals DIG-F to DIG-I. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21 based on the diagnostic signals DIG-A to DIG-D, the propagation common to the diagnostic signals DIG-A to DIG-C. The latch signal LAT1, the clock signal SCK1 and the change signal CH1 input via the path are combined with the latch signal cLAT1, the clock signal cSCK1 and the change signal cCH.
Output as 1. Further, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21 based on the diagnostic signals DIG-F to DIG-I, it propagates in common with the diagnostic signals DIG-F to DIG-H. The latch signal LAT2, the clock signal SCK2 and the change signal CH2 input via the path are output as the latch signal cLAT2, the clock signal cSCK2 and the change signal cCH2.

Here, among the signals input to the diagnostic circuit 240, the print data signal SI1 input via the propagation path common to the diagnostic signal DIG-D is branched at the print head 21 and then one of the branched signals. Is input to the diagnostic circuit 240, and the other signal is input to the drive signal selection circuit 200-1. Further, among the signals input to the diagnostic circuit 240, the print data signal SIn input via the propagation path common to the diagnostic signal DIG-I is branched at the print head 21 and then one of the branched signals is used. It is input to the diagnostic circuit 240, and the other signal is input to the drive signal selection circuit 200-n.

In the following description, the printhead 21 according to the second embodiment will be described as including 10 drive signal selection circuits 200-1 to 200-10. Therefore, the print head 21 in the second embodiment has 10 print data signals SI1 to SI10 corresponding to each of the 10 drive signal selection circuits 200-1 to 200-10, and 10 drive signals COM1 to. COM10 and 10 reference voltage signals CGND1 to CGND10 are input.

Here, the drive signal selection circuit 200-1 is an example of the first drive signal selection circuit in the second embodiment. The print data signal SI1 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-1 is an example of the first print data signal in the second embodiment, and is output by the drive signal selection circuit 200-1. The plurality of piezoelectric elements 60 driven by the drive signal VOUT1 are an example of the first drive element group in the second embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT1 is the first in the second embodiment. 1 This is an example of a drive element. Similarly, the drive signal selection circuit 200-2 is an example of the second drive signal selection circuit in the second embodiment. The print data signal SI2 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-2 is an example of the second print data signal in the second embodiment, and is output by the drive signal selection circuit 200-2. The plurality of piezoelectric elements 60 driven by the drive signal VOUT2 are an example of the second drive element group in the second embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT2 is the second embodiment. 2 This is an example of a driving element.

Further, the drive signal selection circuit 200-10 is another example of the first drive signal selection circuit in the second embodiment. The print data signal SI10 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-10 is another example of the first print data signal in the second embodiment, and the drive signal selection circuit 200-10 is used. The plurality of piezoelectric elements 60 driven by the output drive signal VOUT10 is another example of the first drive element group in the second embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT10 is the second. It is another example of the 1st drive element in an embodiment. Similarly, the drive signal selection circuit 200-9 is another example of the second drive signal selection circuit in the second embodiment. The print data signal SI9 that defines the waveform selection of the drive signal COM in the drive signal selection circuit 200-9 is another example of the second print data signal in the second embodiment, and the drive signal selection circuit 200-9 is used. The plurality of piezoelectric elements 60 driven by the output drive signal VOUT9 is another example of the second drive element group in the second embodiment, and any one of the plurality of piezoelectric elements 60 driven by the drive signal VOUT9 is the second. It is another example of the 2nd drive element in an embodiment.

FIG. 22 is a perspective view showing the configuration of the print head 21 in the second embodiment. Figure 2
As shown in 2, the print head 21 has a head 310 and a substrate 320. Further, an ink ejection surface 311 on which a plurality of ejection portions 600 are formed is located on the lower surface of the head 310 in the Z direction.

FIG. 23 is a plan view showing the ink ejection surface 311 of the head 310 in the second embodiment. As shown in FIG. 23, on the ink ejection surface 311 in the second embodiment, 10 nozzle plates 632 having a plurality of nozzles 651 formed are provided side by side in the X direction. Further, in each of the nozzle plates 632, nozzle rows L1 to L10 in which nozzles 651 are provided side by side in the X direction are formed. Each of the nozzle rows L1 to L10 is provided corresponding to each of the drive signal selection circuits 200-1 to 200-10. That is, the plurality of piezoelectric elements 60 included in each of the nozzle rows L1 to L10 form a plurality of piezoelectric element groups. Specifically, the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 is an example of the first drive element group in the second embodiment, and the drive signal selection circuit 200-2. The plurality of piezoelectric elements 60 included in the nozzle row L2 corresponding to the above are examples of the second drive element group in the second embodiment. Further, the plurality of piezoelectric elements 60 included in the nozzle row L10 corresponding to the drive signal selection circuit 200-10 is another example of the first drive element group in the second embodiment, and the drive signal selection circuit 200-9 has a plurality of piezoelectric elements 60. The plurality of piezoelectric elements 60 included in the corresponding nozzle row L9 is another example of the second drive element group in the second embodiment.

Returning to FIG. 22, the substrate 320 has a surface 321 and a surface 322 facing the surface 321, and has a side 323, a side 324 facing the side 323 in the X direction, a side 325, and a side 325. On the other hand, it has a substantially rectangular shape formed by the sides 326 facing in the Y direction.

The configuration of the substrate 320 in the second embodiment will be described with reference to FIGS. 24 and 25. FIG. 24 is a plan view of the substrate 320 in the second embodiment as viewed from the surface 322. Further, FIG. 25 is a plan view of the substrate 320 in the second embodiment as viewed from the surface 321.

As shown in FIGS. 24 and 25, electrode groups 430a to 430j are provided on the surface 322 of the substrate 320. Each of the electrode groups 430a to 430j has a plurality of electrodes arranged side by side in the Y direction. The electrode groups 430a to 430j are located in the order of the electrode groups 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, 430i, 430j from the side 323 side to the side 324 side.

Further, the substrate 320 is formed with ink supply path insertion holes 431a to 431j and FPC insertion holes 432a to 432e, which are through holes penetrating the surfaces 321 and 322 of the substrate 320.

The FPC insertion hole 432a is located between the electrode group 430a and the electrode group 430b in the X direction, and the FPC electrically connected to the electrode group 430a and the FPC electrically connected to the electrode group 430b are inserted. Will be done. The FPC insertion hole 432b is located between the electrode group 430c and the electrode group 430d in the X direction, and the FPC electrically connected to the electrode group 430c and the FPC electrically connected to the electrode group 430d are inserted. Will be done. The FPC insertion hole 432c is located between the electrode group 430e and the electrode group 430f in the X direction, and the FPC electrically connected to the electrode group 430e and the FPC electrically connected to the electrode group 430f are inserted. Will be done. The FPC insertion hole 432d is located between the electrode group 430g and the electrode group 430h in the X direction, and the FPC electrically connected to the electrode group 430g and the FPC electrically connected to the electrode group 430h are inserted. Will be done. The FPC insertion hole 432e is located between the electrode group 430i and the electrode group 430j in the X direction, and the FPC electrically connected to the electrode group 430i and the FPC electrically connected to the electrode group 430j are inserted. Will be done.

The ink supply path insertion hole 431a is located on the side 323 side of the electrode group 430a in the X direction. The ink supply path insertion holes 431b and 431c are located between the electrode group 430b and the electrode group 430c in the X direction, the ink supply path insertion hole 431b is on the side 325 side, and the ink supply path insertion hole 431c is on the side 326 side. It is located side by side. The ink supply path insertion holes 431d and 431e are located between the electrode group 430d and the electrode group 430e in the X direction, the ink supply path insertion hole 431d is on the side 325 side, and the ink supply path insertion hole 431e is on the side 326 side. It is located side by side. The ink supply path insertion holes 431f and 431g are located between the electrode group 430f and the electrode group 430g in the X direction, the ink supply path insertion hole 431f is on the side 325 side, and the ink supply path insertion hole 431g is on the side 326 side. It is located side by side. The ink supply path insertion holes 431h and 431i are located between the electrode group 430h and the electrode group 430i in the X direction, and the ink supply path insertion hole 431h is on the side 325 side and the ink supply path insertion hole 431i is on the side 326 side. It is located side by side. The ink supply path insertion hole 431j is located on the side 324 side of the electrode group 430j in the X direction. Then, in each of the ink supply path insertion holes 431a to 431j, an ink supply path (not shown) for supplying ink to the ink supply port 661 for introducing ink into the ejection unit 600 corresponding to each of the nozzle rows L1 to L10. A part is inserted.

As shown in FIG. 25, an integrated circuit 241 constituting the diagnostic circuit 240 is provided on the surface 321 of the substrate 320. The integrated circuit 241 is provided on the surface 321 side of the substrate 320 between the fixed portion 347 and the fixed portion 349 and on the side 326 side of the FPC insertion holes 432a to 432e. Then, the integrated circuit 241 constituting the diagnostic circuit 240 diagnoses whether or not the ink can be normally ejected from the nozzle 651 based on the diagnostic signals DIG-A to DIG-D and DIG-F to DIG-I. .. Although FIG. 25 shows one integrated circuit 241 as the diagnostic circuit 240, it may be composed of two or more integrated circuits. Specifically, it is based on the integrated circuit 241 that diagnoses whether or not the ink can be normally ejected from the nozzle 651 based on the diagnostic signals DIG-A to DIG-D, and the diagnostic signals DIG-F to DIG-I. Further, an integrated circuit 241 for diagnosing whether or not the ink can be normally ejected from the nozzle 651 may be provided.

Further, as shown in FIGS. 24 and 25, the substrate 320 is provided with connectors 350, 360, 370, and 380. The connector 350 is on the surface 321 side of the substrate 320 and is provided along the side 323. Further, the connector 360 is provided on the surface 322 side of the substrate 320 along the side 323. Here, the connectors 350 and 360 in the second embodiment are different from the first embodiment only in that the number of the plurality of terminals included is 20, and the other configurations are the same as those shown in FIG. Therefore, detailed description of the connectors 350 and 360 in the second embodiment will be omitted. It should be noted that the 20 terminals 353 arranged side by side on the connector 350 in the second embodiment are arranged in order from the side 325 side to the side 326 side in the direction along the side 323, terminals 353-1,353-2. ..., Called 353-20. Similarly, the 20 terminals 363 juxtaposed to the connector 360 in the second embodiment are arranged in order from the side 325 side to the side 326 side in the direction along the side 323, terminals 363-1,363-2. , ..., referred to as 363-20.

The connector 370 is on the surface 321 side of the substrate 320 and is provided along the side 324. Further, the connector 380 is provided on the surface 322 side of the substrate 320 along the side 324. The configuration of the connectors 370 and 380 will be described with reference to FIG. 26. FIG. 26 is a diagram showing the configuration of the connectors 370 and 380 in the second embodiment.

The connector 370 has a housing 371, a cable mounting portion 372 formed in the housing 371, and a plurality of terminals 373. The plurality of terminals 373 are arranged side by side along the side 324. Specifically, 20 terminals 373 are arranged side by side along the side 324. Here, the 20 terminals 373 are referred to as terminals 373-1,373-2, ..., 373-20 in order from the side 325 side to the side 326 side in the direction along the side 324. The cable mounting portion 372 is located on the substrate 320 of the plurality of terminals 373 in the Z direction. A propagation path such as a flexible flat cable is attached to the cable attachment portion 372.

The connector 380 has a housing 381, a cable mounting portion 382 formed in the housing 381, and a plurality of terminals 383. The plurality of terminals 383 are arranged side by side along the side 324. Specifically, 20 terminals 383 are arranged side by side along the side 324. Here, the 20 terminals 383 are referred to as terminals 383-1,383-2, ..., 383-20 in order from the side 325 side to the side 326 side in the direction along the side 324. The cable mounting portion 382 is located on the substrate 320 of the plurality of terminals 383 in the Z direction. A propagation path such as a flexible flat cable is attached to the cable attachment portion 382.

FIG. 27 is a cross-sectional view of the print head 21 according to the second embodiment when viewed from the Y direction. As shown in FIG. 27, the plurality of nozzle rows L1 to L10 are provided side by side in the direction along the X direction. Specifically, the plurality of nozzle rows L1 to L10 have nozzle rows L1, L2, L3, L4 from the side 323 side where the connector 350 of the substrate 320 is provided toward the side 324 side where the connector 370 is provided. , L5, L6, L7, L8, L9, L10 are provided in this order.

That is, the shortest distance between the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 and the connector 350 is a plurality of plurality included in the nozzle row L2 corresponding to the drive signal selection circuit 200-2. It is shorter than the shortest distance between the piezoelectric element 60 and the connector 350. Further, in this case, there are other nozzle rows L2 to L10 and nozzle rows L2 to L10 between the plurality of piezoelectric elements 60 included in the nozzle row L1 corresponding to the drive signal selection circuit 200-1 and the connector 350. The piezoelectric element 60 included in each is not located. In other words, the nozzle row L1 is located closest to the connector 350 side of the nozzle rows L1 to L10 formed on the ink ejection surface 311.

Similarly, the shortest distance between the plurality of piezoelectric elements 60 included in the nozzle row L10 corresponding to the drive signal selection circuit 200-10 and the connector 370 is a plurality included in the nozzle row L9 corresponding to the drive signal selection circuit 200-9. It is shorter than the shortest distance between the piezoelectric element 60 and the connector 370. Further, in this case, there are other nozzle rows L1 to L9 and nozzle rows L1 to L9 between the plurality of piezoelectric elements 60 included in the nozzle row L10 corresponding to the drive signal selection circuit 200-10 and the connector 370. The piezoelectric element 60 included in each is not located. In other words, the nozzle row L10 is located on the connector 360 side of the nozzle rows L1 to L10 formed on the ink ejection surface 311.

Next, the details of the signals input to the connectors 350, 360, 370, and 380 will be described with reference to FIGS. 28 to 31.

FIG. 28 is a diagram for explaining the details of the signal input to the connector 350 in the second embodiment. As shown in FIG. 28, the connector 350 has a terminal to which each of the drive signals COM1 to COM5 is input, a terminal to which each of the reference voltage signals CGND1 to CGND5 is input, a temperature signal TH, a latch signal LAT1, and a clock signal. A terminal to which each of the SCK1, the change signal CH1 and the print data signal SI1 is input, a terminal to which each of the diagnostic signals DIG-A to DIG-D is input, and a plurality of terminals to which a plurality of ground signals GND are input. including.

Specifically, each of the drive signals COM1 to COM5 is input to each of the terminals 353-9, 353-7, 353-5, 353-3, 353-2. Here, the drive signal CO
The terminal 353-9 to which M1 is input is an example of the fifth terminal in the second embodiment. Further, each of the reference voltage signals CGND1 to CGND5 is input to terminals 353-10, 353-8, 353-6, 353-4, 353-2, respectively.

Both the diagnostic signal DIG-A and the latch signal LAT1 are input to terminals 353-17. That is, the terminals 353-17 also serve as a terminal to which the diagnostic signal DIG-A is input and a terminal to which the latch signal LAT1 is input. The diagnostic signal DIG-A is an example of the second diagnostic signal in the second embodiment, and the terminal 353-17 to which the diagnostic signal DIG-A is input is an example of the second terminal in the second embodiment.

Both the diagnostic signal DIG-B and the clock signal SCK1 are input to terminals 353-15. That is, the terminals 353-15 also serve as a terminal to which the diagnostic signal DIG-B is input and a terminal to which the clock signal SCK1 is input. The diagnostic signal DIG-B is an example of the fourth diagnostic signal in the second embodiment, and the terminal 353-15 to which the diagnostic signal DIG-B is input is an example of the fourth terminal in the second embodiment.

Both the diagnostic signal DIG-C and the change signal CH1 are input to terminals 353-13. That is, the terminals 353-13 also serve as a terminal to which the diagnostic signal DIG-C is input and a terminal to which the change signal CH1 is input. The diagnostic signal DIG-C is an example of the third diagnostic signal in the second embodiment, and the terminal 353-13 to which the diagnostic signal DIG-C is input is an example of the third terminal in the second embodiment.

Both the diagnostic signal DIG-D and the print data signal SI1 are input to the terminals 353-11. That is, the terminals 353-11 also serve as a terminal to which the diagnostic signal DIG-D is input and a terminal to which the print data signal SI1 is input. The diagnostic signal DIG-D is an example of the first diagnostic signal in the second embodiment, and the terminal 353-11 to which the diagnostic signal DIG-D is input is an example of the first terminal in the second embodiment.

As described above, the connector 350 has a terminal 353-11 to which the diagnostic signal DIG-D is input, a terminal 353-17 to which the diagnostic signal DIG-A is input, and a terminal 353-13 to which the diagnostic signal DIG-C is input. , Has a terminal 353-15 to which the diagnostic signal DIG-B is input and a terminal 353-9 to which the drive signal COM1 is input.

The temperature signal TH is input to terminals 353-19 of the connector 350. Further, the ground signal GND is input to each of the terminals 353-12, 353-14, 353-16, 353-18, and 353-20.

FIG. 29 is a diagram for explaining the details of the signal input to the connector 360 in the second embodiment. As shown in FIG. 29, the connector 360 has a terminal to which each of the drive signals COM1 to COM5 is input, a terminal to which each of the reference voltage signals CGND1 to CGND5 is input, and each of the print data signals SI2 to SI5. A terminal to be input, a terminal to which the voltage VDD1 is input, and a plurality of terminals to which a plurality of ground signals GND are input are included.

Specifically, each of the drive signals COM1 to COM5 is input to each of the terminals 363-10, 363-8, 363-6, 363-4, 363-2. Further, each of the reference voltage signals CGND1 to CGND5 is input to each of the terminals 363-9, 363-7, 363-5, 363-3,363-1.

The print data signals SI2 to SI5 are terminals 363-18, 363-16, 36, respectively.
It is input to each of 3-14 and 363-12. Further, the voltage VDD1 is input to the terminals 363-20. Further, the ground signal GND is input to each of the terminals 353-11, 353-13, 353-15, 353-17, and 353-19.

FIG. 30 is a diagram for explaining the details of the signal input to the connector 370 in the second embodiment. As shown in FIG. 30, the connector 370 has a terminal to which each of the drive signals COM6 to COM10 is input, a terminal to which each of the reference voltage signals CGND6 to CGND10 is input, an abnormal signal XHOT, a latch signal LAT2, and a clock signal. A terminal to which each of the SCK2, the change signal CH2, and the print data signal SI10 is input, a terminal to which each of the diagnostic signals DIG-E to DIG-I is input, and a plurality of terminals to which a plurality of ground signals GND are input. including.

Specifically, each of the drive signals COM6 to COM10 is input to each of the terminals 373-2, 373-4, 373-6, 373-8, 373-10. Here, the terminal 373-10 to which the drive signal COM10 is input is another example of the fifth terminal in the second embodiment. Further, each of the reference voltage signals CGND6 to CGND10 is input to terminals 373-1,373-3,373-5,373-7,373-9, respectively.

Both the diagnostic signal DIG-E and the abnormal signal XHOT are input to terminals 353-12.

Both the diagnostic signal DIG-F and the latch signal LAT2 are input to terminals 373-14. That is, the terminals 353-14 also serve as a terminal to which the diagnostic signal DIG-F is input and a terminal to which the latch signal LAT2 is input. This diagnostic signal DIG-F is another example of the second diagnostic signal in the second embodiment, and the terminal 373-14 to which the diagnostic signal DIG-F is input is another example of the second terminal in the second embodiment. be.

Both the diagnostic signal DIG-G and the clock signal SCK2 are input to terminals 373-16. That is, the terminals 373-16 also serve as a terminal to which the diagnostic signal DIG-G is input and a terminal to which the clock signal SCK2 is input. This diagnostic signal DIG-G is another example of the fourth diagnostic signal in the second embodiment, and the terminal 373-16 to which the diagnostic signal DIG-G is input is another example of the fourth terminal in the second embodiment. be.

Both the diagnostic signal DIG-H and the change signal CH2 are input to the terminals 373-18. That is, the terminals 373-8 also serve as a terminal to which the diagnostic signal DIG-H is input and a terminal to which the change signal CH2 is input. This diagnostic signal DIG-H is another example of the third diagnostic signal in the second embodiment, and the terminal 373-18 to which the diagnostic signal DIG-C is input is another example of the third terminal in the second embodiment. be.

Both the diagnostic signal DIG-I and the print data signal SI10 are input to terminals 373-20. That is, the terminals 373-20 also serve as a terminal to which the diagnostic signal DIG-I is input and a terminal to which the print data signal SI10 is input. This diagnostic signal DIG-I is another example of the first diagnostic signal in the second embodiment, and the terminal 373-20 to which the diagnostic signal DIG-I is input is another example of the first terminal in the second embodiment. be.

As described above, the connector 370 has a terminal 373-20 to which the diagnostic signal DIG-I is input, a terminal 373-14 to which the diagnostic signal DIG-F is input, and a terminal 373-18 to which the diagnostic signal DIG-H is input. , Has a terminal 373-16 to which the diagnostic signal DIG-G is input and a terminal 373-10 to which the drive signal COM10 is input.

The ground signal GND is terminal 373-11, 373-13, 373-15, 373-
It is input to each of 17,373-19.

FIG. 31 is a diagram for explaining the details of the signal input to the connector 380 in the second embodiment. As shown in FIG. 31, the connector 380 has a terminal to which each of the drive signals COM6 to COM10 is input, a terminal to which each of the reference voltage signals CGND6 to CGND10 is input, and each of the print data signals SI6 to DI9. It includes a terminal to be input, a terminal to which each of the voltages VHV and VDD2 is input, and a plurality of terminals to which a plurality of ground signals GND are input.

Specifically, each of the drive signals COM6 to COM10 is input to terminals 383-1,373-3,373-5,373-7,373-9, respectively. Further, each of the reference voltage signals CGND6 to CGND10 is input to terminals 383-2,383-4,383-6,383-8,383-10, respectively.

Each of the print data signals SI6 to SI9 is input to terminals 383-13, 383-15, 383-17, and 383-19, respectively. Further, the voltage VHV is input to the terminals 383-11. Further, the voltage VDD2 is input to the terminals 383-16.

The ground signal GND is input to each of the terminals 383-12, 383-14, 383-18, and 383-20.

Here, using FIG. 32, the diagnostic signals DIG-A to DIG-D input from the connector 350 and the diagnostic signals DIG-E to DIG-I input from the connector 370 are propagated on the surface 321 of the substrate 320. An example of wiring will be described. FIG. 32 is a diagram showing an example of wiring formed on the surface 321 of the substrate 320 in the second embodiment. In FIG. 32, a part of the wiring formed on the substrate 320 is not shown. Further, in FIG. 32, the electrode groups 430a to 430j formed on the surface 322 of the substrate 320 are shown by broken lines.

As shown in FIG. 32, the substrate 320 has wirings 354-a to 354-d, 354-f to 354-n, and wirings 374-a to 374-n.

The terminals 353-17 are electrically connected to the wiring 354-a. The diagnostic signal DIG-A and the latch signal LAT1 input from the terminals 353-17 are propagated by the wiring 354-a and then input to the integrated circuit 241. That is, the wiring 354-a electrically connects the terminal 353-17 and the integrated circuit 241. The wiring 354-a through which the diagnostic signal DIG-A and the latch signal LAT1 are propagated is an example of the second wiring of the second embodiment.

The terminals 353-15 are electrically connected to the wiring 354-b. The diagnostic signal DIG-B and the clock signal SCK1 input from the terminals 353-15 are propagated by the wiring 354-b and then input to the integrated circuit 241. That is, the wiring 354-b electrically connects the terminal 353-15 and the integrated circuit 241. The wiring 354-b through which the diagnostic signal DIG-B and the clock signal SCK1 are propagated is an example of the fourth wiring of the second embodiment.

The terminals 353-13 are electrically connected to the wiring 354-c. The diagnostic signal DIG-C and the change signal CH1 input from the terminals 353-13 are propagated by the wiring 354-c and then input to the integrated circuit 241. That is, the wiring 354-c electrically connects the terminal 353-13 and the integrated circuit 241. The wiring 354-c in which the diagnostic signal DIG-C and the change signal CH1 are propagated is an example of the third wiring of the second embodiment.

The terminals 353-11 are electrically connected to the wiring 354-d. The diagnostic signal DIG-D and the print data signal SI1 input from the terminals 353-11 are propagated by the wiring 354-d and then input to the integrated circuit 241. That is, the wiring 354-d electrically connects the terminal 353-17 and the integrated circuit 241. The wiring 354-d in which the diagnostic signal DIG-D and the print data signal SI1 are propagated is an example of the first wiring of the second embodiment.

As described above, when the integrated circuit 241 diagnoses that the ink can be normally ejected from the printhead 21 based on the input diagnostic signals DIG-A to DIG-D, the latch signal LAT1 and the clock are input. The signal SCK1 and the change signal CH1 are output to the drive signal selection circuit 200 as the latch signal cLAT1, the clock signal cSCK1 and the change signal cCH1. Specifically, the latch signal cLAT1, the clock signal cSCK1 and the change signal cCH1 output from a terminal (not shown) of the integrated circuit 241 are propagated by the wirings 354-f to 354-h and input to the drive signal selection circuit 200. To.

Specifically, the integrated circuit 241 constituting the diagnostic circuit 240 is electrically connected to the wiring 354-f. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-f is electrically connected to the wiring 354-c via the integrated circuit 241. As a result, the change signal cCH1 based on the change signal CH1 is input to the wiring 354-f. The change signal cCH1 is input to any of a plurality of electrodes included in the electrode group 430a provided on the surface 322 of the substrate 320 via the wiring 354-f and vias (not shown). The wiring 354-f through which the change signal cCH1 is propagated is an example of the ninth wiring of the second embodiment. Then, the change signal cCH1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 430a. That is, the wiring 354-f electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, the integrated circuit 241 is electrically connected to the wiring 354-g. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-g is electrically connected to the wiring 354-b via the integrated circuit 241. As a result, the clock signal cSCK1 based on the clock signal SCK1 is input to the wiring 354-g. The clock signal cSCK1 is input to any of a plurality of electrodes included in the electrode group 430a provided on the surface 322 of the substrate 320 via the wiring 354-g and vias (not shown). The wiring 354-g in which the clock signal cSCK1 is propagated is an example of the eighth wiring of the second embodiment. Then, the clock signal cSCK1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 430a. That is, the wiring 354-g electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, the integrated circuit 241 is electrically connected to the wiring 354-h. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 354-h is electrically connected to the wiring 354-a via the integrated circuit 241. As a result, the latch signal cLAT1 based on the latch signal LAT1 is input to the wiring 354-h. The latch signal cLAT1 is input to any of a plurality of electrodes included in the electrode group 430a provided on the surface 322 of the substrate 320 via the wiring 354-h and vias (not shown). The wiring 354-h in which the latch signal cLAT1 is propagated is an example of the seventh wiring of the second embodiment. Then, the latch signal cLAT1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 430a. That is, the wiring 354-h electrically connects the integrated circuit 241 and the drive signal selection circuit 200-1.

Further, as shown in FIG. 32, the terminals 353-11 are also electrically connected to the wiring 354-i. The print data signal SI1 input from the terminals 353-11 is propagated by the wiring 354-i, and then the electrode group 43 provided on the surface 322 of the substrate 320 via a via (not shown) or the like.
It is input to any of a plurality of electrodes included in 0a. The wiring 354-i through which the print data signal SI1 is propagated is an example of the fifth wiring of the second embodiment. Then, the print data signal SI1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 430a. That is, the wiring 354-i electrically connects the terminal 353-11 and the drive signal selection circuit 200-1.

The terminal 353-9 to which the drive signal COM1 is input is electrically connected to the wiring 354-j. Then, the drive signal COM1 is propagated by the wiring 354-j and then input to any of a plurality of electrodes included in the electrode group 430a provided on the surface 322 of the substrate 320 via a via (not shown) or the like. To. The wiring 354-j through which the drive signal COM1 is propagated is an example of the sixth wiring of the second embodiment. Then, the drive signal COM1 is input to the drive signal selection circuit 200-1 via the FPC connected to the electrode group 430a. That is, the wiring 354-j electrically connects the terminal 353-9 and the drive signal selection circuit 200-1.

Similarly, each of the terminals 353-7, 353-5, 353-3, 353-1 to which the drive signals COM2 to COM5 are input is electrically connected to each of the wirings 354-k to 354-n. Then, each of the drive signals COM2 to COM5 is propagated by the wirings 354k to 354m, and then is included in the electrode group 430a provided on the surface 322 of the substrate 320 via vias (not shown) or the like. Is input to one of the electrodes of.

The terminals 373-20 are electrically connected to the wiring 374-a. The diagnostic signal DIG-I and the print data signal SI10 input from the terminals 373-20 are propagated by the wiring 374-a and then input to the integrated circuit 241. That is, the wiring 374-d electrically connects the terminal 373-20 and the integrated circuit 241. The wiring 374-d through which the diagnostic signal DIG-I and the print data signal SI10 are propagated is another example of the first wiring of the second embodiment.

The terminals 373-18 are electrically connected to the wiring 374-b. The diagnostic signal DIG-H and the change signal CH2 input from the terminals 373-18 are propagated by the wiring 374-b and then input to the integrated circuit 241. That is, the wiring 374-b electrically connects the terminal 373-18 and the integrated circuit 241. The wiring 374-b through which the diagnostic signal DIG-H and the change signal CH2 are propagated is another example of the third wiring of the second embodiment.

The terminals 373-16 are electrically connected to the wiring 374-c. The diagnostic signal DIG-G and the clock signal SCK2 input from the terminals 373-16 are propagated by the wiring 374-c and then input to the integrated circuit 241. That is, the wiring 374-c electrically connects the terminal 373-16 and the integrated circuit 241. The wiring 374-c in which the diagnostic signal DIG-B and the clock signal SCK2 are propagated is another example of the fourth wiring of the second embodiment.

The terminals 373-14 are electrically connected to the wiring 374-d. The diagnostic signal DIG-F and the latch signal LAT2 input from the terminals 373-14 are propagated by the wiring 374-d and then input to the integrated circuit 241. That is, the wiring 374-d electrically connects the terminal 373-14 and the integrated circuit 241. The wiring 374-d through which the diagnostic signal DIG-F and the latch signal LAT2 are propagated is another example of the second wiring of the second embodiment.

When the integrated circuit 241 diagnoses that normal ejection of ink in the printhead 21 is possible based on the input diagnostic signals DIG-F to DIG-I, the input latch signal LAT2, clock signal SCK2 and change The signal CH2 is output to the drive signal selection circuit 200 as a latch signal cLAT2, a clock signal cSCK2, and a change signal cCH2. Specifically, the latch signal cLAT2, the clock signal cSCK2, and the change signal cCH2 output from a terminal (not shown) of the integrated circuit 241 are propagated by the wirings 374f to 374h and input to the drive signal selection circuit 200. To.

Specifically, the integrated circuit 241 constituting the diagnostic circuit 240 is electrically connected to the wiring 374-f. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 374-f is electrically connected to the wiring 374-d via the integrated circuit 241. As a result, the latch signal cLAT2 based on the latch signal LAT2 is input to the wiring 374-f. The latch signal cLAT2 is input to any of a plurality of electrodes included in the electrode group 430j provided on the surface 322 of the substrate 320 via the wiring 374-f and vias (not shown). The wiring 374-f through which the latch signal cLAT2 is propagated is another example of the ninth wiring of the second embodiment. Then, the latch signal cLAT2 is input to the drive signal selection circuit 200-10 via the FPC connected to the electrode group 430j. That is, the wiring 374-f electrically connects the integrated circuit 241 and the drive signal selection circuit 200-10.

Further, the integrated circuit 241 is electrically connected to the wiring 374-g. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 374-g is electrically connected to the wiring 374-c via the integrated circuit 241. As a result, the clock signal cSCK2 based on the clock signal SCK2 is input to the wiring 374-g. The clock signal cSCK2 is input to any of a plurality of electrodes included in the electrode group 430j provided on the surface 322 of the substrate 320 via the wiring 374-g and vias (not shown). The wiring 374-g through which the clock signal cSCK2 is propagated is another example of the eighth wiring of the second embodiment. Then, the clock signal cSCK2 is input to the drive signal selection circuit 200-10 via the FPC connected to the electrode group 430j. That is, the wiring 374-g electrically connects the integrated circuit 241 and the drive signal selection circuit 200-10.

Further, the integrated circuit 241 is electrically connected to the wiring 374-h. Then, when the diagnostic circuit 240 diagnoses that the ink can be normally ejected from the print head 21, the wiring 374-h is electrically connected to the wiring 374-b via the integrated circuit 241. As a result, the latch signal cLAT2 based on the change signal CH2 is input to the wiring 374-h. The change signal cCH2 is input to any of a plurality of electrodes included in the electrode group 430j provided on the surface 322 of the substrate 320 via the wiring 374h and vias (not shown). The wiring 374-h through which the change signal cCH2 is propagated is another example of the seventh wiring of the second embodiment. Then, the change signal cCH2 is input to the drive signal selection circuit 200-10 via the FPC connected to the electrode group 430j. That is, the wiring 374-h electrically connects the integrated circuit 241 and the drive signal selection circuit 200-10.

Further, as shown in FIG. 32, the terminals 373-14 are also electrically connected to the wiring 374-i. The print data signal SI10 input from the terminals 373-14 is propagated by the wiring 374-i, and then is included in a plurality of electrode groups 430j provided on the surface 322 of the substrate 320 via vias (not shown) or the like. It is input to one of the electrodes. The wiring 374-i through which the print data signal SI10 is propagated is another example of the fifth wiring of the second embodiment. Then, the print data signal SI10 is input to the drive signal selection circuit 200-10 via the FPC connected to the electrode group 430j. That is, the wiring 374-i electrically connects the terminal 373-14 and the drive signal selection circuit 200-1.

The terminal 373-10 to which the drive signal COM10 is input is electrically connected to the wiring 374-j. Then, the drive signal COM10 is propagated by the wiring 374j and then input to any of a plurality of electrodes included in the electrode group 430j provided on the surface 322 of the substrate 320 via vias (not shown) or the like. To. The wiring 374-j through which the drive signal COM10 is propagated is another example of the sixth wiring of the second embodiment. Then, the drive signal COM10 is input to the drive signal selection circuit 200-10 via the FPC connected to the electrode group 430j. That is, the wiring 374-j electrically connects the terminal 373-10 and the drive signal selection circuit 200-10.

Similarly, each of the terminals 373-7, 373-6, 373-4, 373-2 to which the drive signals COM6 to COM9 are input is electrically connected to each of the wirings 374-k to 374-n. Then, each of the drive signals COM6 to COM9 is propagated by the wirings 374k to 374m, and then is included in the electrode group 430j provided on the surface 322 of the substrate 320 via vias (not shown) or the like. Is input to one of the electrodes of.

As described above, even when two sets of diagnostic signals DIG-A to DIG-D and diagnostic signals DIG-F to DIG-I are input from each of the two connectors 350 and 360, the first Similar to the embodiment, it is possible to achieve both the normal execution of the self-diagnosis function and the execution of the printing process without deteriorating the ink ejection accuracy.

Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments, and can be implemented in various embodiments without departing from the gist thereof. For example, the above embodiments can be combined as appropriate.

The present invention includes a configuration substantially the same as the configuration described in the embodiment (for example, a configuration having the same function, method and result, or a configuration having the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the present invention includes a configuration having the same action and effect as the configuration described in the embodiment or a configuration capable of achieving the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 ... liquid discharge device, 2 ... liquid container, 10 ... control mechanism, 20 ... carriage, 21 ... printhead, 30 ... moving mechanism, 31 ... carriage motor, 32 ... endless belt, 40 ... transport mechanism, 41 ... transport motor, 42 ... Conveyor roller, 50 ... Drive signal generation circuit, 50a ... Drive circuit, 60 ... Piezoelectric element, 90 ... Linear encoder, 100 ... Control circuit, 110 ... Power supply circuit, 200 ... Drive signal selection circuit, 210 ... Temperature detection circuit, 220 ... Selective control circuit, 222 ... Shift register, 224 ... Latch circuit, 226 ... Decoder, 230 ... Selective circuit, 232 ... Inverter, 234 ... Transfer gate, 240 ... Diagnostic circuit, 241 ... Integrated circuit, 250 ... Temperature abnormality detection circuit , 251 ... comparator, 252 ... reference voltage generation circuit, 253 ... transistor, 254 ... diode, 255, 256 ... resistor, 310 ... head, 311 ... ink ejection surface, 320 ... substrate, 321, 322 ... surface, 323, 324 , 325,326 ... Side, 330a, 330b, 330c, 330d, 330e, 330f ... Electrode group, 331a, 331b, 331c, 331d, 331e, 331f ... Ink supply path insertion hole, 332a, 332b, 332c ... FPC insertion hole, 346, 347, 348, 349 ... Fixed part, 350 ... Connector, 351 ... Housing, 352 ... Cable mounting part, 353 ... Terminal, 354-a, 354-b, 354-c, 354-d, 354-e, 354 -F, 354-g, 354-h, 354-i, 354-j, 354-k ... Wiring, 360 ... Connector, 361 ... Housing, 362 ... Cable mounting part, 363 ... Terminal, 370 ... Connector, 371 ... Housing , 372 ... Cable mounting part, 373 ... Terminal, 374-a, 374-b, 374-c, 374-d, 374-f, 374-g, 374-h, 374-j, 374-k ... Wiring, 380. ... Connector, 381 ... Housing, 382 ... Cable mounting part, 383 ... Terminal, 430a, 430b, 430c, 430d, 430e, 430f, 430g, 430h, 430i, 430j ... Electrode group, 431a, 431b, 431c, 431d, 431e, 431f, 431g, 431h, 431i, 431j ... Ink supply path insertion hole, 432a, 432b, 432c, 432d, 432e ... FPC insertion hole, 600 ... Discharge section,
601 ... Piezoelectric material, 611, 612 ... Electrode, 621 ... Diaphragm, 631 ... Cavity, 632 ... Nozzle plate, 641 ... Reservoir, 651 ... Nozzle, 661 ... Ink supply port, P ... Medium

Claims (8)

The first drive element that discharges the liquid from the nozzle by driving based on the drive signal,
A diagnostic circuit that diagnoses whether or not normal liquid discharge is possible based on the first diagnostic signal, the second diagnostic signal, the third diagnostic signal, and the fourth diagnostic signal.
The first terminal to which the first diagnostic signal is input, the second terminal to which the second diagnostic signal is input, the third terminal to which the third diagnostic signal is input, and the fourth terminal to which the fourth diagnostic signal is input. A connector having a terminal and a fifth terminal into which the drive signal is input,
The board on which the connector is provided and
A first drive signal selection circuit that selects the waveform of the drive signal and supplies it to the first drive element.
Equipped with
The first terminal also serves as a terminal to which a first print data signal defining the waveform selection of the drive signal in the first drive signal selection circuit is input.
The board has a first wiring, a second wiring, a third wiring, a fourth wiring, a fifth wiring, a sixth wiring, a seventh wiring, an eighth wiring, and a ninth wiring.
The first wiring electrically connects the first terminal and the diagnostic circuit.
The second wiring electrically connects the second terminal and the diagnostic circuit.
The third wiring electrically connects the third terminal and the diagnostic circuit.
The fourth wiring electrically connects the fourth terminal and the diagnostic circuit.
The fifth wiring electrically connects the first terminal and the first drive signal selection circuit.
The sixth wiring electrically connects the fifth terminal and the first drive signal selection circuit.
The seventh wiring is electrically connected to the second wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.
The eighth wiring is electrically connected to the third wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.
The ninth wiring is electrically connected to the fourth wiring via the diagnostic circuit, and the diagnostic circuit and the first drive signal selection circuit are electrically connected to each other.
A print head that features that. The first drive element group including the first drive element and
A second drive element that discharges liquid from the nozzle by driving based on the drive signal, and
A second drive signal selection circuit that selects the waveform of the drive signal based on the second print data signal and supplies it to the second drive element.
The second drive element group including the second drive element and
Equipped with
The shortest distance between the first drive element group and the connector is
It is shorter than the shortest distance between the second drive element group and the connector.
The print head according to claim 1. It has a plurality of drive element groups including the first drive element group and the second drive element group.
No other drive element group is located between the first drive element group and the connector.
The print head according to claim 2. The connector and the diagnostic circuit are provided on the same surface of the substrate.
The print head according to any one of claims 1 to 3. The second terminal also serves as a terminal to which a signal defining the discharge timing of the liquid is input.
The print head according to any one of claims 1 to 4. The third terminal also serves as a terminal to which a signal defining the waveform switching timing of the drive signal is input.
The print head according to any one of claims 1 to 5. The fourth terminal also serves as a terminal to which a clock signal is input.
The print head according to any one of claims 1 to 6. The print head according to any one of claims 1 to 7.
The drive signal generation circuit that generates the drive signal and
To prepare
A liquid discharge device characterized by the fact that.

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