JP2021154612A - Liquid ejection device - Google Patents

Abstract

To provide a liquid ejection device which comprises a print head with a memory mounted thereon, and can stably operate.SOLUTION: A liquid ejection device is provided, comprising: a print head having a memory stored with prescribed information; a carriage on which the print head is mounted, and which moves along a main scan direction; a determination circuit which sends a lead signal to the memory and receives a response signal to the lead signal, and determines that read abnormality of the memory occurs when the received response signal is not normal; and a cable which is electrically connected to the print head, and slides in association with movement of the carriage. The determination circuit determines that the cause of read abnormality is wiring abnormality of the cable when receiving a normal response signal in a first state that the carriage does not move and the cable does not slide, and receiving an abnormal response signal in a second state that the carriage moves and the cable slides.SELECTED DRAWING: Figure 13

Description

The present invention relates to a liquid discharge device including a print head equipped with a memory.

As an example of a liquid ejection device, an inkjet printer that ejects ink as a liquid to print an image or a document is known. Such an inkjet printer uses, for example, a piezoelectric element such as a piezo element as a driving element, and when the driving element drives, a predetermined amount of ink is ejected from a nozzle to form an image or a document on a print medium.

For example, Patent Document 1 describes an inkjet printer as an example of a liquid ejection device, in which a print head unit (print head) for executing printing includes a memory, and is based on the information stored in the memory. An inkjet printer that can improve print quality by driving a print head is disclosed.

Japanese Unexamined Patent Publication No. 2000-071440

However, Patent Document 1 does not describe the operation of the liquid discharge device when a reading abnormality occurs in reading erroneous information when reading the information stored in the memory mounted on the print head. Therefore, when the reading abnormality occurs, the operation of the liquid discharge device may become unstable. That is, the liquid discharge device described in Patent Document 1 has room for improvement from the viewpoint of stabilizing the operation of the liquid discharge device provided with the print head equipped with the memory.

One aspect of the liquid discharge device according to the present invention is
A print head having a discharge unit for discharging liquid and a memory for storing predetermined information,
A carriage equipped with the print head and moving along the main scanning direction,
A determination circuit that transmits a read signal to the memory, receives a response signal to the read signal, and determines that a read abnormality has occurred in the memory when the received response signal is not normal.
A cable that is electrically connected to the print head and slides as the carriage moves.
With
The determination circuit receives the normal response signal in the first state in which the carriage does not move and the cable does not slide, and the response signal is not normal in the second state in which the carriage moves and the cable slides. Is received, it is determined that the cause of the read abnormality is the wiring abnormality of the cable.

It is a figure which shows the schematic structure of the liquid discharge device. It is a figure which shows the functional structure of the liquid discharge device. It is a figure which shows the schematic structure of the discharge part. It is a figure which shows an example of the circuit structure of the temperature abnormality detection circuit. It is a figure which shows an example of the waveform of the drive signal COM. It is a figure which shows the functional structure of the drive signal selection circuit. It is a figure which shows the electric composition of the selection circuit corresponding to one discharge part. It is a figure which shows an example of the decoding content in a decoder. It is a figure for demonstrating operation of a drive signal selection circuit. It is a figure which shows the state transition of the operation mode of a liquid discharge device. It is a figure for demonstrating the operation of the liquid discharge device in the initial setting mode. It is a figure for demonstrating the operation of the liquid discharge device in the start determination mode. It is a figure for demonstrating the operation of the liquid discharge device in a determination mode. It is a figure for demonstrating the operation of the liquid discharge device in the 1st standby mode. It is a figure for demonstrating operation of a liquid discharge device in a drive mode. It is a figure for demonstrating the operation of the liquid discharge device in the 2nd standby mode. It is a figure for demonstrating operation of a liquid discharge device in a stop mode.

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. 1. Overview 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 a carriage. In the following description, the direction in which the carriage 20 reciprocates 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. Although the X direction, the Y direction, and the Z direction will be described as being orthogonal to each other, the description is not limited to the fact that the various configurations constituting the liquid discharge device 1 are provided orthogonally. Further, as the medium P, any printing target such as printing paper, resin film, or cloth can be used. Here, in the following description, the direction along the Y direction in which the medium P is conveyed is referred to as a transfer direction, which is a direction intersecting the transfer direction in which the medium P is conveyed, and the carriage 20 reciprocates to move the medium. The direction along the X direction in which P is scanned is referred to as the main scanning direction, and the direction intersecting both the carriage direction and the main scanning direction and along the Z direction in which ink is ejected with respect to the medium P is defined as the main scanning direction. Sometimes referred to as the discharge direction.

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 to be ejected 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. Further, as the liquid container 2 in which such ink is stored, an ink cartridge, a bag-shaped ink pack formed 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 be mounted on the carriage 20.

A control signal Ctrl-H for controlling the print head 21 output by the control mechanism 10 and one or a plurality of drive signal COMs for driving the print head 21 are input to the print head 21. Then, the print head 21 ejects the ink supplied from the liquid container 2 along the Z direction, which is the ejection direction, 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 along the X direction. That is, the carriage 20 mounts the print head 21 and moves along the X direction, which is the main scanning 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. As the transfer roller 42 rotates, the medium P is conveyed along the Y direction, which is the transfer direction.

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. , The ink is landed at an arbitrary position on the surface of the medium P to form a desired image on the medium P.

2. Functional configuration of the liquid discharge device FIG. 2 is a diagram showing a functional 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, a linear encoder 90, a notification mechanism 91, an input unit 92, and a cable 190.

The cable 190 electrically connects the control mechanism 10 and the print head 21, and transmits various signals propagating between the control mechanism 10 and the print head 21. Here, as described above, the print head 21 is mounted on the carriage 20 and reciprocates along the X direction. Therefore, the cable 190 electrically connected to the print head 21 slides as the carriage 20 moves. As such a cable 190, a flexible flat cable (FFC: Flexible Flat Cable) or the like in which a plurality of signal lines are provided side by side in substantially parallel with an insulator can be used.

The input unit 92 includes a switch (not shown) for the user to operate the liquid discharge device 1. Then, various commands for the user to operate the liquid discharge device 1 are input to the input unit 92 via the switch. The command input to the input unit 92 is input to the control mechanism 10.

Information indicating the state of the liquid discharge device 1 is input from the control mechanism 10 to the notification mechanism 91. Then, the notification mechanism 91 notifies the user of information indicating the state of the liquid discharge device 1 based on the input information. The notification mechanism 91 may be, for example, a liquid crystal panel or the like, or may be an indicator lamp using an LED, an incandescent lamp or the like. Further, the notification mechanism 91 may be configured to notify the user by voice or vibration. Here, the input unit 92 and the notification mechanism 91 may be integrally formed like a touch panel or the like.

The control mechanism 10 includes a drive circuit 50, a control circuit 100, and a power supply circuit 110. The control circuit 100 includes a processor such as a microcontroller, for example. 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, the input unit 92, and the like.

The operation of the control circuit 100 will be specifically described. The control circuit 100 grasps the scanning position of the print head 21 based on the scanning 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 movement of the print head 21 mounted on the carriage 20, 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 driver circuit (not shown). Similarly, the control signal Ctrl-T may be input to the carriage motor 31 via a driver circuit (not shown). After the signal is converted, the signal may be input to the transfer motor 41.

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

The drive circuit 50 includes a drive signal output circuit 51 and a reference voltage signal output circuit 52. The drive control signal dA is input to the drive signal output circuit 51. The drive signal output circuit 51 generates a drive signal COM by converting the drive control signal dA into a digital / analog signal and then amplifying the converted analog signal in class D. That is, the drive control signal dA is a digital signal that defines the waveform of the drive signal COM, and the drive signal output circuit 51 generates the drive signal COM by amplifying the waveform defined by the drive control signal dA in class D. Output to the print head 21. Therefore, the drive control signal dA may be an analog signal as long as it is a signal capable of defining the waveform of the drive signal COM. Further, the waveform defined by the drive signal output circuit 51 and the drive control signal dA may be amplified, and may be a class A amplifier circuit, a class B amplifier circuit, a class AB amplifier circuit, or the like.

The reference voltage signal output circuit 52 generates a reference voltage signal VBS indicating the reference potential of the drive signal COM and outputs the reference voltage signal to the printhead 21. The reference voltage signal VBS 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 5.5 V, 6 V, or the like.

The power supply circuit 110 generates voltages VHV, VDD1, VDD2, and ground signal GND. The voltage VHV is a DC voltage signal having a voltage value of, for example, 42 V. Further, the voltages VDD1 and VDD2 are DC voltage signals having a voltage value of, for example, 3.3 V. The ground signal GND is a signal indicating a reference potential of voltages VHV, VDD1, VDD2, and is, for example, a signal of a ground potential having a voltage value of 0 V. The voltage VHV is used as a voltage for amplification in the drive signal output circuit 51, 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 and output signals having a plurality of voltage values other than the voltages VHV, VDD1, VDD2, and ground signal GND.

Further, the control circuit 100 controls the print head 21 based on various signals such as image data input from the host computer and the scanning position of the print head 21 detected by the linear encoder 90. As H, a print data signal SI, a change signal CH, a latch signal LAT, and a clock signal SCK are generated, and a memory control signal MC for controlling the storage circuit 240 included in the print head 21 is generated. Then, the control circuit 100 outputs the print data signal SI, the change signal CH, the latch signal LAT, the clock signal SCK, and the memory control signal MC to the print head 21.

The print head 21 includes a drive signal selection circuit 200, a temperature detection circuit 220, a storage circuit 240, a temperature abnormality detection circuit 250, and a plurality of discharge units 600.

The storage circuit 240 has a plurality of storage areas. In the plurality of storage areas included in the storage circuit 240, individual information indicating the characteristics of the printhead 21 and a determination for determining whether or not the read process for reading the information stored in the storage circuit 240 has been normally executed. Information and a plurality of information including the information are stored. Then, the storage circuit 240 outputs the individual information and the determination information as the memory information signal MD to the control circuit 100 based on the memory control signal MC input from the control circuit 100. The storage circuit 240 may include a memory controller in order to control a plurality of storage areas based on the input memory control signal MC.

Here, as the individual information stored in the storage circuit 240, information related to manufacturing in the printhead 21 such as the manufacturing lot and manufacturing conditions of the printhead 21, ink ejection characteristics, and the piezoelectric element 60 included in the ejection unit 600 described later will be described. Information on individual variations of the printhead 21 such as the drive characteristics of the print head 21 and temperature threshold information such as variations in the characteristics of the diode 254 in the temperature abnormality detection circuit 250 and variations in the voltage Vref, which will be described later, are included. Then, the storage circuit 240 generates a memory information signal MD including the corresponding individual information based on the memory control signal MC input from the control circuit 100, and outputs the memory information signal MD to the control circuit 100.

The control circuit 100 corrects various signals for controlling the operation of the printhead 21 based on the memory information signal MD including the individual information input from the storage circuit 240, and outputs the correction to the printhead 21. As a result, the ejection characteristics of the ink ejected from the print head 21 can be improved. Further, the control circuit 100 may output various signals for stopping the operation of the print head 21 based on the input memory information signal MD.

Further, the determination information stored in the storage circuit 240 includes unique information corresponding to the memory control signal MC input from the control circuit 100. When the control circuit 100 outputs the memory control signal MC for reading the determination information stored in the storage circuit 240, the control circuit 100 holds the reference information corresponding to the output memory control signal MC. The storage circuit 240 reads out the corresponding determination information based on the memory control signal MC input from the control circuit 100, generates a memory information signal MD including the read determination information, and outputs the memory information signal MD to the control circuit 100. Then, the control circuit 100 compares the determination information included in the memory information signal MD with the held reference information. As a result, the control circuit 100 determines whether or not the read process for reading the information stored in the storage circuit 240 is normally executed. Specifically, the control circuit 100 transmits the memory control signal MC to the storage circuit 240, receives the memory information signal MD for the memory control signal MC, and stores the received memory information signal MD when it is not normal. It is determined that an abnormality in reading the information stored in the circuit 240 has occurred.

Here, the storage circuit 240 included in the print head 21 is an example of the memory, and the determination information stored in the storage circuit 240 is an example of the predetermined information. Further, the memory control signal MC output by the control circuit 100 is an example of a read signal, and the memory information signal MD input to the control circuit 100 is an example of a response signal. Then, the memory control signal MC is transmitted to the storage circuit 240, the memory information signal MD for the memory control signal MC is received, and the information stored in the storage circuit 240 when the received memory information signal MD is not normal. The control circuit 100 for determining that the reading abnormality has occurred is an example of the determination circuit.

The voltage VHV, VDD1, drive signal COM, print data signal SI, clock signal SCK, latch signal LAT, and change signal CH are input to the drive signal selection circuit 200. The voltages VHV and VDD1 function as a power supply voltage and a control voltage of the drive signal selection circuit 200. Then, the drive signal selection circuit 200 selects or does not select the voltage waveform included in the drive signal COM based on the input print data signal SI, clock signal SCK, latch signal LAT, and change signal CH. Then, the drive signal VOUT is generated and the corresponding discharge unit 600 is set.

Here, the configuration of the discharge unit 600 will be described with reference to FIG. FIG. 3 is a diagram showing a schematic configuration of the discharge unit 600 when the print head 21 is cut so as to include the discharge unit 600.

As shown in FIG. 3, the print head 21 includes a discharge unit 600 and a reservoir 641. Ink is introduced into the reservoir 641 from the ink supply port 661. Further, the reservoir 641 is provided for each color of ink.

The discharge unit 600 includes a piezoelectric element 60, a diaphragm 621, a cavity 631, and a nozzle 651. The diaphragm 621 is provided between the cavity 631 and the piezoelectric element 60. Then, the diaphragm 621 is displaced by being driven by the piezoelectric element 60 provided on the upper surface. That is, the diaphragm 621 functions as a diaphragm that expands / reduces the internal volume of the cavity 631 by being displaced. The inside of the cavity 631 is filled with ink. Further, the cavity 631 functions as a pressure chamber whose internal volume changes by driving the piezoelectric element 60. The nozzle 651 is an opening portion provided in the nozzle plate 632 and communicating with 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. The drive signal VOUT output from the drive signal selection circuit 200 is supplied to the electrode 611, and the reference voltage signal VBS output from the reference voltage signal output circuit 52 included in the drive circuit 50 is supplied to the electrode 612. Such a piezoelectric element 60 is driven according to the potential difference between the electrode 611 and the electrode 612. Then, as the piezoelectric element 60 is driven, the electrodes 611 and 612 and the central portion of the diaphragm 621 are displaced in the vertical direction with respect to both end portions, and the internal volume of the cavity 631 changes with the displacement of the diaphragm 621. As a result, the ink filled in the cavity 631 is ejected from the nozzle 651. The configuration of the piezoelectric element 60 is not limited to the configuration shown in the figure, and may be, for example, a longitudinal vibration type.

Returning to FIG. 2, the temperature abnormality detection circuit 250 is provided corresponding to the drive signal selection circuit 200. Then, the temperature abnormality detection circuit 250 diagnoses the presence or absence of a temperature abnormality in the drive signal selection circuit 200, and outputs an abnormality signal XHOT indicating the diagnosis result.

FIG. 4 is a diagram showing an example of the circuit configuration of the temperature abnormality detection circuit 250. As shown in FIG. 4, 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.

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. Then, among the plurality of diodes 254 connected in series, the voltage VDD2 is supplied to the anode terminal of the diode 254 located on the highest potential side 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. The resistor 255 and the plurality of diodes 254 configured as described above supply the negative side input terminal of the comparator 251 with a voltage Vdet which is the sum of the forward voltages of the plurality of diodes 254. The plurality of diodes 254 are 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.

Returning to FIG. 2, the temperature detection circuit 220 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.

3. 3. Configuration of Drive Signal Selection Circuit Here, the configuration and operation of the drive signal selection circuit 200 provided on the printhead 21 and outputting the drive signal VOUT based on the drive signal COM will be described. In explaining the configuration and operation of the drive signal selection circuit 200, an example of the waveform of the drive signal COM input to the drive signal selection circuit 200 will be described with reference to FIG. After that, a specific example of the configuration and operation of the drive signal selection circuit 200 will be described with reference to FIGS. 6 to 9.

FIG. 5 is a diagram showing an example of the waveform of the drive signal COM. In FIG. 5, the period Ta from the rise of the latch signal LAT to the rise of the change signal CH, the period Tb until the next rise of the change signal CH after the period Ta, and the latch signal LAT after the period Tb are shown. The period until it starts up is shown as Tc. Then, the drive signal selection circuit 200 generates a drive signal VOUT by switching the selection or non-selection of the waveform included in the drive signal COM during the periods Ta, Tb, and Tc. The period T consisting of this period Ta, Tb, and Tc corresponds to the printing period for forming new dots on the medium P. That is, the latch signal LAT is a signal that defines the printing cycle in which new dots are formed on the medium P, and the change signal CH is a signal that defines the switching timing of the waveform included in the drive signal COM.

As shown in FIG. 5, the drive signal output circuit 51 generates a drive signal COM in which the trapezoidal waveforms Adp, Bdp, and Cdp are continuous in the period T, and outputs the drive signal COM to the print head 21. Specifically, the drive signal output circuit 51 generates a trapezoidal waveform Adp in the period Ta. When the trapezoidal waveform Adp is supplied to the piezoelectric element 60, a predetermined amount, specifically a medium amount of ink, is ejected from the corresponding ejection unit 600. Further, the drive signal output circuit 51 generates a trapezoidal waveform Bdp during the period Tb. When the trapezoidal waveform Bdp is supplied to the piezoelectric element 60, a small amount of ink smaller than the above-mentioned predetermined amount is ejected from the corresponding ejection unit 600. Further, the drive signal output circuit 51 generates a trapezoidal waveform Cdp in the period Tc. When the trapezoidal waveform Cdp is supplied to the piezoelectric element 60, the piezoelectric element 60 is driven to such an extent that ink is not ejected from the corresponding ejection unit 600. Therefore, when the trapezoidal waveform Cdp is supplied to the piezoelectric element 60, dots are not formed on the medium P. This trapezoidal waveform Cdp is a waveform for preventing the ink in the vicinity of the nozzle opening portion of the ejection portion 600 from slightly vibrating and increasing the viscosity of the ink. In the following description, in order to prevent the viscosity of the ink from increasing, driving the piezoelectric element 60 to such an extent that the ink is not ejected from the ejection unit 600 may be referred to as "micro vibration".

Here, the voltage value at the start timing and the voltage value at the end timing of the trapezoidal waveforms Adp, Bdp, and Cdp are all common to the voltage Vc. That is, the trapezoidal waveforms Adp, Bdp, and Cdp are waveforms in which the voltage value starts at the voltage Vc and ends at the voltage Vc. The waveform of the drive signal COM shown in FIG. 5 is an example, and is not limited to this.

FIG. 6 is a diagram showing a functional configuration of the drive signal selection circuit 200. The drive signal selection circuit 200 supplies the piezoelectric element 60 in the period T by switching whether or not to select the trapezoidal waveforms Adp, Bdp, and Cdp included in the drive signal COM in each of the periods Ta, Tb, and Tc. The drive signal VOUT to be generated is generated and output.

As shown in FIG. 6, the drive signal selection circuit 200 includes a selection control circuit 210 and a plurality of selection circuits 230. A clock signal SCK, a print data signal SI, a latch signal LAT, a change signal CH, and a voltage VHV are supplied to the selection control circuit 210. The selection control circuit 210 is provided with a set of a shift register 212 (S / R), a latch circuit 214, and a decoder 216 corresponding to each of the discharge units 600. That is, the print head 21 is provided with the same number of shift registers 212, latch circuits 214, and decoders 216 as the n discharge units 600 of the print head 21.

The shift register 212 temporarily holds 2-bit print data [SIH, SIL] included in the print data signal SI for each corresponding ejection unit 600. More specifically, the n-stage shift registers 212 corresponding to the ejection unit 600 are connected in cascade to each other, and the serially supplied print data signal SI is sequentially transferred to the subsequent stage according to the clock signal SCK. Then, when the supply of the clock signal SCK is stopped, the 2-bit print data [SIH, SIL] corresponding to each discharge unit 600 is held in each shift register 212. In FIG. 6, in order to distinguish the n shift registers 212, the first, second, ..., And n stages are shown in order from the upstream side to which the print data signal SI is supplied.

Each of the n latch circuits 214 latches the print data [SIH, SIL] held by the corresponding shift register 212 at the rising edge of the latch signal LAT. Each of the n decoders 216 decodes the 2-bit print data [SIH, SIL] latched by the corresponding latch circuit 214 to generate a selection signal S and supplies it to the selection circuit 230.

The selection circuit 230 is provided corresponding to each of the discharge portions 600. That is, the number of selection circuits 230 included in one print head 21 is the same as the number of n discharge units 600 included in the print head 21. Then, the selection circuit 230 controls the supply of the drive signal COM to the piezoelectric element 60 based on the selection signal S supplied from the decoder 216.

FIG. 7 is a diagram showing an electrical configuration of the 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. The transfer gate 234 also includes a transistor 235, which is an NMOS transistor, and a transistor 236, which is a NMOS transistor.

The selection signal S is supplied from the decoder 216 to the gate terminal of the transistor 235. Further, the selection signal S is logically inverted by the inverter 232 and supplied to the gate terminal of the transistor 236. The drain terminal of the transistor 235 and the source terminal of the transistor 236 are connected to the terminal TG-In of the transfer gate 234. A drive signal COM is input to the terminal TG-In of the transfer gate 234. That is, the terminal TG-In of the transfer gate 234 is electrically connected to the drive circuit 50. Then, the transistor 235 and the transistor 236 are controlled to be conductive or non-conducting according to the selection signal S, so that the source terminal of the transistor 235 and the drain terminal of the transistor 236 are commonly connected to the terminal TG of the transfer gate 234. The drive signal VOUT is output from Out. The terminal TG-Out of the transfer gate 234 from which the drive signal VOUT is output is electrically connected to the electrode 611 of the piezoelectric element 60.

Next, the decoding contents of the decoder 216 will be described with reference to FIG. FIG. 8 is a diagram showing an example of the decoding content in the decoder 216. Two-bit print data [SIH, SIL], a latch signal LAT, and a change signal CH are input to the decoder 216. Then, for example, when the print data [SIH, SIL] is [1,0] that defines the "medium dot", the decoder 216 has a selection signal S that becomes H, L, L levels in the periods Ta, Tb, and Tc. Is output. Here, the logic level of the selection signal S is level-shifted to a high-amplitude logic based on the voltage VHV by a level shifter (not shown).

FIG. 9 is a diagram for explaining the operation of the drive signal selection circuit 200. As shown in FIG. 9, the print data [SIH, SIL] included in the print data signal SI is serially supplied to the drive signal selection circuit 200 in synchronization with the clock signal SCK, and the shift register 212 corresponding to the discharge unit 600 is provided. Will be transferred sequentially at. Then, when the supply of the clock signal SCK is stopped, the print data [SIH, SIL] corresponding to the ejection unit 600 is held in each of the shift registers 212. The print data signal SI is supplied in the order corresponding to the final n-stage, ..., 2-stage, and 1-stage ejection units 600 in the shift register 212.

When the latch signal LAT rises, each of the latch circuits 214 latches the print data [SIH, SIL] held in the corresponding shift registers 212 all at once. LT1, LT2, ..., LTn shown in FIG. 9 indicate print data [SIH, SIL] latched by the latch circuit 214 corresponding to the shift register 212 of the first stage, the second stage, ..., N stages.

The decoder 216 outputs a logic level selection signal S according to the content shown in FIG. 8 in each of the periods Ta, Tb, and Tc according to the dot size defined by the latched print data [SIH, SIL]. do.

When the print data [SIH, SIL] is [1,1], the selection circuit 230 selects the trapezoidal waveform Adp in the period Ta, selects the trapezoidal waveform Bdp in the period Tb, and trapezoidal in the period Tc according to the selection signal S. Do not select waveform Cdp. As a result, the drive signal VOUT corresponding to the large dot shown in FIG. 9 is generated. Therefore, a medium amount of ink and a small amount of ink are discharged from the ejection unit 600. Then, the ink is bonded to the medium P to form large dots on the medium P.

When the print data [SIH, SIL] is [1,0], the selection circuit 230 selects the trapezoidal waveform Adp in the period Ta according to the selection signal S, does not select the trapezoidal waveform Bdp in the period Tb, and does not select the trapezoidal waveform Bdp in the period Tb. Do not select the trapezoidal waveform Cdp in Tc. As a result, the drive signal VOUT corresponding to the middle dot shown in FIG. 9 is generated. Therefore, a medium amount of ink is ejected from the ejection unit 600. Therefore, medium dots are formed on the medium P.

When the print data [SIH, SIL] is [0,1], the selection circuit 230 does not select the trapezoidal waveform Adp in the period Ta according to the selection signal S, but selects the trapezoidal waveform Bdp in the period Tb, and the period Tb. Do not select the trapezoidal waveform Cdp in Tc. As a result, the drive signal VOUT corresponding to the small dot shown in FIG. 9 is generated. Therefore, a small amount of ink is ejected from the ejection unit 600. Therefore, small dots are formed on the medium P.

Further, when the print data [SIH, SIL] is [0,0], the selection circuit 230 does not select the trapezoidal waveform Adp in the period Ta and does not select the trapezoidal waveform Bdp in the period Tb according to the selection signal S. The trapezoidal waveform Cdp is selected in the period Tc. As a result, the drive signal VOUT corresponding to the micro-vibration shown in FIG. 9 is generated. Therefore, the ink is not ejected from the ejection unit 600, and slight vibration occurs.

As described above, the drive signal selection circuit 200 generates the drive signal VOUT by selecting or not selecting the trapezoidal waveforms Adp, Bdp, and Cdp included in the drive signal COM under the conditions specified by the print data signal SI. Then, it is output to the corresponding discharge unit 600. That is, the print data signal SI is a signal that defines the waveform selection of the trapezoidal waveforms Adp, Bdp, and Cdp supplied as the drive signal VOUT.

4. Detection of reading abnormality of information held in the storage unit Detection of wiring abnormality occurring in the cable An individual related to the printhead 21 held in the storage circuit 240 of the printhead 21 in the liquid discharge device 1 configured as described above. The information is read out by the control circuit 100. Therefore, the control circuit 100 is supplied to the print data signal SI, the change signal CH, the latch signal LAT, the clock signal SCK, and the print head 21 for controlling the operation of the print head 21 based on the read individual information. The drive control signal dA that defines the waveform of the drive signal COM can be corrected. As a result, the control mechanism 10 can drive the print head 21 under conditions that take into account variations in the characteristics of the print head 21, and can improve the ink ejection characteristics of the liquid ejection device 1.

However, due to the influence of the ambient environment such as the temperature and humidity in which the liquid discharge device 1 is used, the overvoltage and the overcurrent generated by noise and static electricity, and the like, the control circuit 100 reads out the information stored in the storage circuit 240. May occur so-called read error that cannot be executed normally. When a reading abnormality occurs, the operation of the liquid discharge device 1 may become unstable, and the liquid discharge device 1 may malfunction. For such a problem, it is possible to determine whether or not a read abnormality has occurred by determining whether or not the information read from the storage circuit 240 by the control circuit 100 is desired information.

However, in the case of the liquid discharge device 1 as shown in the present embodiment, the control circuit 100 that outputs the memory control signal MC for controlling the storage circuit 240 and the storage circuit 240 that stores individual information, determination information, and the like. Is electrically connected via a cable 190. Therefore, if a read error occurs in which the read process for reading the information stored in the storage circuit 240 cannot be normally executed, is the cause of the read error a read process error caused by the storage circuit 240, or a cable? It was difficult to determine whether the wiring was abnormal due to a disconnection or poor connection of 190. Therefore, when a read abnormality occurs, it becomes difficult to take appropriate measures against the read abnormality, and as a result, the operational stability of the liquid discharge device 1 provided with the print head 21 equipped with the storage circuit 240 deteriorates. There was a risk of

In particular, as shown in the present embodiment, in the so-called serial type liquid discharge device 1, since the cable 190 slides with the movement of the carriage 20, the print head 21 does not move and the cable 190 does not slide, so-called line printing. Compared with the liquid discharge device of the type, there is a high possibility that a wiring abnormality such as a disconnection or a poor connection occurs in the cable 190. Therefore, in the serial type liquid discharge device 1, it is determined whether the cause of the read abnormality is the read processing abnormality caused by the storage circuit 240, or the wiring abnormality caused by the disconnection of the cable 190 or the connection failure. Is required to do.

In response to such a request, the dedicated wiring and detection circuit for propagating a signal for detecting whether or not a wiring abnormality has occurred in the cable 190 and whether or not a read processing abnormality has occurred in the storage circuit 240 are determined. It may be possible to identify the cause of the read abnormality by individually providing the liquid discharge device 1 with a dedicated wiring for propagating a signal for detection and a detection circuit. However, in this case, the configuration of the liquid discharge device 1 becomes complicated, and as a result, there is a concern that the liquid discharge device 1 is unintentionally increased in size and the cost of the liquid discharge device 1 is increased.

That is, in the liquid discharge device 1 in which the control circuit 100 reads out the information stored in the storage circuit 240 mounted on the print head 21 via a sliding cable 190 such as an FFC, the liquid discharge device 1 is configured. The cause of the read abnormality that occurred when reading the information stored in the storage circuit 240 without becoming complicated was the cause of the read processing abnormality in the storage circuit 240, or the cable 190. It is required to determine whether it is caused by a wiring abnormality.

In response to such a request, in the liquid discharge device 1 of the present embodiment, in a state where the carriage 20 does not move and the cable 190 does not slide, the control circuit 100 receives a normal memory information signal MD, and the carriage 20 moves and the cable When the control circuit 100 receives an abnormal memory information signal MD while the 190 is sliding, it is determined that the cause of the read abnormality is a wiring abnormality occurring in the cable 190. The reason why the read process for reading the information stored in the storage circuit 240 was not normally executed can be identified without complicating the configuration, and as a result, the print head 21 equipped with the storage circuit 240 is provided. It is possible to improve the operational stability of the liquid discharge device 1.

Here, a specific example of the operation of the liquid discharge device 1 in the present embodiment capable of identifying the cause of the reading abnormality will be described with reference to FIGS. 10 to 17. FIG. 10 is a diagram showing a state transition of the operation mode of the liquid discharge device 1. As shown in FIG. 10, the liquid discharge device 1 has an initial setting mode M100, a start determination mode M110, a determination mode M120, a first standby mode M130, a drive mode M140, a second standby mode M150, and a stop mode M160.

When the power supply voltage is supplied to the liquid discharge device 1, the liquid discharge device 1 starts operation. Then, when the liquid discharge device 1 starts the operation, as shown in FIG. 10, the operation mode of the liquid discharge device 1 becomes the initial setting mode M100. This initial setting mode M100 is an operation mode for performing the initial setting of the liquid discharge device 1. Then, after the initial setting of the liquid discharge device 1 is completed, the operation mode of the liquid discharge device 1 shifts to the start determination mode M110.

The details of the initial setting mode M100 will be described with reference to FIG. FIG. 11 is a diagram for explaining the operation of the liquid discharge device 1 in the initial setting mode M100. As shown in FIG. 11, when the operation mode of the liquid discharge device 1 shifts to the initial setting mode M100, the control circuit 100 reads the individual information of the printhead 21 stored in the storage circuit 240. Is generated and output to the storage circuit 240. Then, the storage circuit 240 reads the individual information corresponding to the input memory control signal MC, generates a memory information signal MD including the read individual information, and outputs the memory information signal MD to the control circuit 100. That is, when the operation mode of the liquid discharge device 1 shifts to the initial setting mode M100, the control circuit 100 reads out individual information from the storage circuit 240 (step S101).

Then, the control circuit 100 generates a drive control signal dA that defines the waveform of the drive signal COM supplied to the print head 21 based on the read individual information, and outputs the drive control signal dA to the drive circuit 50. As a result, the drive circuit 50 generates a drive signal COM corresponding to the input drive control signal dA and outputs the drive signal COM to the print head 21. Further, the control circuit 100 generates a print data signal SI, a change signal CH, a latch signal LAT, and a clock signal SCK for controlling the operation of the print head 21 based on the read individual information, and outputs the print data signal SI, the change signal CH, the latch signal LAT, and the clock signal SCK to the print head 21. do. That is, the control circuit 100 generates a control signal for controlling the printhead 21 according to the read individual information (step S102).

This completes the initial setting of the print head 21. Then, after the initial setting of the liquid discharge device 1 is completed, the operation mode of the liquid discharge device 1 shifts to the start determination mode M110.

Returning to FIG. 10, the start determination mode M110 is an operation mode for determining whether or not an initial operation abnormality has occurred in the liquid discharge device 1. Then, when it is determined in the start determination mode M110 that the initial operation abnormality has not occurred in the liquid discharge device 1, the operation mode of the liquid discharge device 1 shifts to the determination mode M120. On the other hand, when it is determined in the start determination mode M110 that the liquid discharge device 1 has an initial operation abnormality, the operation mode of the liquid discharge device 1 shifts to the second standby mode M150. Here, the initial operation abnormality of the liquid discharge device 1 means that a normal power supply voltage is supplied to each part constituting the liquid discharge device 1 due to a disconnection of the wiring pattern constituting the liquid discharge device 1 or an erroneous mounting of electronic parts. Operation abnormalities that occur in the initial operation before the liquid discharge device 1 executes the printing process, such as power supply voltage abnormalities caused by not being installed and mounting abnormalities caused by the wrong configuration being attached to the liquid discharge device 1. Is.

The details of the activation determination mode M110 will be described with reference to FIG. FIG. 12 is a diagram for explaining the operation of the liquid discharge device 1 in the start determination mode M110.

As shown in FIG. 12, when the operation mode of the liquid discharge device 1 transitions to the start determination mode M110, the control circuit 100 generates a memory control signal MC for reading the determination information stored in the storage circuit 240. Output to the storage circuit 240. Then, the storage circuit 240 reads the determination information corresponding to the input memory control signal MC, generates a memory information signal MD including the read determination information, and outputs the memory information signal MD to the control circuit 100. That is, when the operation mode of the liquid discharge device 1 shifts to the start determination mode M110, the control circuit 100 reads the determination information from the storage circuit 240 (step S111).

Then, the control circuit 100 compares the determination information read from the storage circuit 240 with the above-mentioned reference information stored in the control circuit 100. As a result, the control circuit 100 determines the reading abnormality based on whether the determination information read from the storage circuit 240 is the information corresponding to the output memory control signal MC. That is, the control circuit 100 executes a determination as to whether the determination information read from the storage circuit 240 is information corresponding to the reference information (step S112).

When the control circuit 100 determines that the determination information read from the storage circuit 240 is information corresponding to the reference information (Y in step S112), the operation mode of the liquid discharge device 1 shifts to the determination mode M120. On the other hand, when the control circuit 100 determines that the determination information read from the storage circuit 240 does not correspond to the reference information (N in step S112), the control circuit 100 causes an initial operation abnormality in the notification mechanism 91. (Step S113). Then, after the notification mechanism 91 notifies that the liquid discharge device 1 has an initial operation abnormality, the operation mode of the liquid discharge device 1 shifts to the second standby mode M150.

As described above, in the liquid discharge device 1 of the present embodiment, when the control circuit 100 receives the memory information signal MD which is not normal in the start determination mode M110, the cause of the read abnormality is the initial operation abnormality of the liquid discharge device 1. Is determined to be.

As described above, as the initial operation abnormality of the liquid discharge device 1, for example, a power supply abnormality in which a normal power supply voltage is not supplied to each part constituting the liquid discharge device 1 or an incorrect configuration is attached to the liquid discharge device 1. There are mounting abnormalities caused by the above. If a power supply abnormality occurs in the liquid discharge device 1 as an initial operation abnormality, the storage circuit 240 does not operate because the power supply voltage is not supplied. Therefore, even when the control circuit 100 generates the memory control signal MC for reading the determination information stored in the storage circuit 240 and outputs the memory control signal MC to the storage circuit 240, the storage circuit 240 keeps the input memory. The determination information corresponding to the control signal MC cannot be read out, and therefore, the memory information signal MD including the determination information is not generated. Therefore, the memory information signal MD including the determination information corresponding to the memory control signal MC is not input to the control circuit 100.

Further, if a mounting abnormality occurs in which the print head 21 attached to the liquid discharge device 1 is erroneously attached, it is stored in the storage circuit 240 because the print head 21 attached to the liquid discharge device 1 is different. Judgment information is also different. Therefore, even when the control circuit 100 generates the memory control signal MC for reading the determination information stored in the storage circuit 240 and outputs it to the storage circuit 240, the output memory is output to the control circuit 100. The memory information signal MD including the determination information corresponding to the control signal MC is not input.

As described above, when the operation mode of the liquid discharge device 1 is the start determination mode M110, the control circuit 100 determines whether or not there is a read abnormality based on whether or not the received memory information signal MD is normal. This makes it possible to determine whether or not an initial operation abnormality has occurred in the liquid discharge device 1. That is, the initial operation abnormality of the liquid discharge device 1 provided with the print head 21 equipped with the storage circuit 240 is detected based on one piece of information as to whether or not the memory information signal MD received by the control circuit 100 is normal. This makes it possible to improve the operational stability of the liquid discharge device 1.

Here, the start determination mode M110 is an example of a start mode after the power supply voltage is supplied to the liquid discharge device 1 and before the carriage 20 starts moving. Further, considering that the initial setting mode M100 is also an operation mode after the power supply voltage is supplied to the liquid discharge device 1 and before the carriage 20 starts moving, the initial setting mode M100 and the start determination mode M110 are used. It can be said that the operation mode including the above is an example of the start mode in a broad sense.

Returning to FIG. 10, the determination mode M120 is an operation mode for determining whether or not a read abnormality has occurred, and a cause of the read abnormality occurs in the storage circuit 240 based on the timing at which the read abnormality occurs. This is an operation mode for determining whether the reading process is abnormal or the wiring is abnormal in the cable 190 electrically connected to the storage circuit 240. Then, in the determination mode M120, when it is determined that there is no read abnormality in which the information stored in the storage circuit 240 cannot be read normally, the operation mode of the liquid discharge device 1 shifts to the first standby mode M130. Then, in the determination mode M120, when it is determined that a read abnormality has occurred in which the information stored in the storage circuit 240 cannot be read normally, the operation mode of the liquid discharge device 1 shifts to the second standby mode M150. do.

The details of the determination mode M120 will be described with reference to FIG. FIG. 13 is a diagram for explaining the operation of the liquid discharge device 1 in the determination mode M120. As shown in FIG. 13, when the operation mode of the liquid discharge device 1 shifts to the determination mode M120, the control circuit 100 generates and stores the memory control signal MC for reading the determination information stored in the storage circuit 240. Output to circuit 240. Then, the storage circuit 240 reads the determination information corresponding to the input memory control signal MC, generates a memory information signal MD including the read determination information, and outputs the memory information signal MD to the control circuit 100. That is, when the operation mode of the liquid discharge device 1 shifts to the determination mode M120, the control circuit 100 reads the determination information from the storage circuit 240 (step S121).

Then, the control circuit 100 compares the determination information read from the storage circuit 240 with the above-mentioned reference information stored in the control circuit 100. As a result, the control circuit 100 determines whether the determination information read from the storage circuit 240 is information corresponding to the output memory control signal MC. That is, the control circuit 100 executes a determination as to whether the determination information read from the storage circuit 240 is information corresponding to the reference information (step S122).

When the control circuit 100 determines that the determination information read from the storage circuit 240 does not correspond to the reference information (N in step S122), the control circuit 100 tells the notification mechanism 91 that the cause of the read abnormality is the storage circuit 240. It is notified that the reading process is abnormal in (step S128). Then, after the notification mechanism 91 notifies that the liquid discharge device 1 has an abnormality in the reading process, the operation mode of the liquid discharge device 1 shifts to the second standby mode M150.

On the other hand, when the control circuit 100 determines that the determination information read from the storage circuit 240 is information corresponding to the reference information (Y in step S122), the control circuit 100 is the carriage 20 on which the printhead 21 is mounted. A control signal Ctrl-C for starting the reciprocating movement is generated and output to the carriage motor 31. As a result, the carriage 20 starts reciprocating movement along the main scanning direction (step S123).

Then, the control circuit 100 reads out the determination information from the storage circuit 240 in a state where the carriage 20 continues the reciprocating movement in the main scanning direction (step S124). Then, the control circuit 100 compares the determination information read from the storage circuit 240 with the above-mentioned reference information stored in the control circuit 100. As a result, the control circuit 100 determines whether the determination information read from the storage circuit 240 is information corresponding to the output memory control signal MC. That is, the control circuit 100 executes a determination as to whether the determination information read from the storage circuit 240 is information corresponding to the reference information (step S125).

When the control circuit 100 determines that the determination information read from the storage circuit 240 does not correspond to the reference information (N in step S125), the control circuit 100 tells the notification mechanism 91 that the cause of the read abnormality is the cable 190. Notify that the wiring abnormality has occurred (step S129). Then, after the notification mechanism 91 notifies that the liquid discharge device 1 has a wiring abnormality, the operation mode of the liquid discharge device 1 shifts to the second standby mode M150.

On the other hand, when the control circuit 100 determines that the determination information read from the storage circuit 240 is the information corresponding to the reference information (Y in step S125), the control circuit 100 is the carriage 20 on which the printhead 21 is mounted. A control signal Ctrl-C for stopping the reciprocating movement is generated and output to the carriage motor 31. As a result, the carriage 20 stops reciprocating along the main scanning direction (step S126). After that, the operation mode of the liquid discharge device 1 shifts to the first standby mode M130.

As described above, when the control circuit 100 receives the memory information signal MD which is not normal in the state where the carriage 20 does not move and the cable 190 does not slide as in steps S121 and S122 shown in the determination mode M120, the control circuit 100 Determines that the cause of the read abnormality is the read processing abnormality of the storage circuit 240, and the control circuit is in a state where the carriage 20 does not move and the cable 190 does not slide as in steps S121 to S126 shown in the determination mode M120. When 100 receives a normal memory information signal MD, the carriage 20 moves, and the cable 190 slides, and the control circuit 100 receives an abnormal memory information signal MD, the control circuit 100 reads abnormally. It is determined that the cause of is a wiring abnormality of the cable 190.

Here, in the cable 190 in which the FFC or the like is used, since a plurality of wirings are provided side by side and the plurality of wirings are held by an insulator or the like, the cable 190 has a wiring abnormality such as a disconnection or a poor connection. Even if the above occurs, if the carriage 20 does not move and the cable 190 does not slide, one end and the other end of the broken cable 190 come into contact with each other, and as a result, the cable 190 becomes conductive. That is, even if the cable 190 has a wiring abnormality such as a disconnection or a poor connection, if the carriage 20 does not move and the cable 190 does not slide, the control circuit 100 and the storage circuit 240 , Electrically connected via cable 190. Therefore, when the control circuit 100 receives an abnormal memory information signal MD in a state where the carriage 20 does not move and the cable 190 does not slide, the control circuit 100 is electrically connected because the cable 190 is electrically connected. , It can be determined that the cause of the read abnormality is the read processing abnormality of the storage circuit 240.

Then, when a wiring abnormality such as a disconnection or a poor connection occurs in the cable 190, the carriage 20 moves and the cable 190 slides, thereby deforming the cable 190, and as a result, one end of the disconnected cable 190. And the other end are separated. That is, the cable 190 is in a non-conducting state. Therefore, one end and the other end of the broken cable 190 are not electrically connected. Therefore, in a state where the carriage 20 does not move and the cable 190 does not slide, the control circuit 100 receives a normal memory information signal MD, and when the carriage 20 moves and the cable 190 slides, the control circuit 100 When the memory information signal MD that is not normal is received, the control circuit 100 can determine that the cause of the read abnormality is the wiring abnormality of the cable 190 because the read processing abnormality of the storage circuit 240 has not occurred.

As described above, in the determination mode M120, the memory received by the control circuit 100 in the state where the carriage 20 does not move and the cable 190 does not slide and the state where the carriage 20 moves and the cable 190 slides. By determining whether or not there is a read abnormality in the storage circuit 240 based on whether or not the information signal MD is normal, whether the cause of the read abnormality is a read processing abnormality in the storage circuit 240 or the wiring of the cable 190. It is possible to determine whether it is abnormal.

Here, steps S121 and S122 shown in FIG. 13 are examples of the first state in which the carriage 20 does not move and therefore the cable 190 does not slide. Steps S123 to S126 shown in FIG. 13 move the carriage 20. However, this is an example of the second state in which the cable 190 slides.

Note that FIG. 13 shows that the step for determining whether the cable 190 has a wiring abnormality shown in steps S123 to S126 of the determination mode M120 is executed only once, but steps S123 to S126 are performed a plurality of times. It may be executed repeatedly. Further, in the reciprocating movement of the carriage 20 shown in steps S123 to S126 of the determination mode M120, the carriage 20 may move so as to repeat at least one of acceleration and deceleration. That is, in steps S123 to S126 of the determination mode M120, the reciprocating movement of the carriage 20 may be controlled so that the movement speed changes. As a result, the cable 190 is deformed into various states, and as a result, the accuracy of detecting wiring abnormalities occurring in the cable 190 in steps S123 to S126 of the determination mode M120 can be improved.

Returning to FIG. 10, the first standby mode M130 is an operation mode for the liquid discharge device 1 to stand by for a period until a request for printing processing from the user and a request for transition to the determination mode M120 from the user are generated. Is. Then, in the first standby mode M130, when the user requests execution of the printing process, the operation mode of the liquid discharge device 1 transitions to the drive mode M140, and the user requests a transition to the determination mode M120. If so, the operation mode of the liquid discharge device 1 shifts to the determination mode M120. Here, the execution request of the print process and the transition request to the determination mode M120 from the user are input via the input unit 92 or the host computer.

The details of the first standby mode M130 will be described with reference to FIG. FIG. 14 is a diagram for explaining the operation of the liquid discharge device 1 in the first standby mode M130. As shown in FIG. 14, when the operation mode of the liquid discharge device 1 shifts to the first standby mode M130, the control circuit 100 determines whether or not the power supply voltage is supplied to the liquid discharge device 1 (step S131). ). Specifically, the control circuit 100 detects whether or not the voltage value of the power supply voltage supplied to the liquid discharge device 1 is equal to or higher than a predetermined value. When the control circuit 100 determines that the voltage value of the power supply voltage supplied to the liquid discharge device 1 is less than a predetermined value, the control circuit 100 does not supply the power supply voltage to the liquid discharge device 1. (N in step S131). In this case, the operation mode of the liquid discharge device 1 shifts to the stop mode M160.

On the other hand, when the control circuit 100 determines that the voltage value of the power supply voltage supplied to the liquid discharge device 1 is equal to or higher than a predetermined value, the control circuit 100 supplies the power supply voltage to the liquid discharge device 1. (Y in step S131). In this case, the control circuit 100 determines whether there is a print request from the user via the input unit 92 or the host computer (step S132). Then, when the control circuit 100 determines that there is a print request from the user (Y in step S132), the operation mode of the liquid discharge device 1 shifts to the drive mode M140.

On the other hand, when the control circuit 100 determines that there is no print request from the user (N in step S132), the control circuit 100 requests a transition from the user to the determination mode M120 via the input unit 92 or the host computer. It is determined whether or not there is (step S133). Then, when the control circuit 100 determines that there is a transition request from the user to the determination mode M120 (Y in step S133), the operation mode of the liquid discharge device 1 transitions to the determination mode M120. On the other hand, when the control circuit 100 determines that there is no transition request from the user to the determination mode M120 (N in step S133), the control circuit 100 determines whether or not the power supply voltage is supplied to the liquid discharge device 1. The determination is made (step S131).

As described above, in the first standby mode M130, the liquid discharge device 1 waits until a print request and a transition request to the determination mode M120 are generated from the user via the input unit 92 or the host computer.

Returning to FIG. 10, the drive mode M140 is an operation mode in which ink is ejected from the ejection unit 600 included in the print head 21 to the medium P. In other words, the liquid ejection device 1 ejects a desired image on the medium P. This is an operation mode for executing the printing process for forming the image. Then, when the printing process of the liquid discharge device 1 is completed in the drive mode M140, the operation mode of the liquid discharge device 1 shifts to the first standby mode M130. Further, in the drive mode M140, when the control circuit 100 determines that the memory information signal MD input from the storage circuit 240 is not normal, the operation mode of the liquid discharge device 1 shifts to the determination mode M120. That is, in the liquid discharge device 1 of the present embodiment, when the control circuit 100 receives the memory information signal MD that is not normal in the drive mode M140, the process transitions to the determination mode M120.

The details of the drive mode M140 will be described with reference to FIG. FIG. 15 is a diagram for explaining the operation of the liquid discharge device 1 in the drive mode M140. As shown in FIG.
When the operation mode of the liquid discharge device 1 shifts to the drive mode M140, the control circuit 100 starts the printing process (step S141). Here, the print process is a process for ejecting ink to the medium P. Specifically, the control circuit 100 has a print data signal SI based on image information input from a host computer or the like. The clock signal SCK, the latch signal LAT, and the change signal CH are output to the print head 21, and the drive circuit 50 outputs the drive signal COM to the print head 21 based on the drive control signal dA input from the control circuit 100. .. Then, the print head 21 drives the piezoelectric element 60 by selecting or not selecting the drive signal COM based on the input print data signal SI, clock signal SCK, latch signal LAT, and change signal CH. This is a process of ejecting ink from the ejection unit 600 to the medium P by generating a drive signal VOUT and supplying it to the corresponding piezoelectric element 60.

With the start of the printing process, the control circuit 100 generates a control signal Ctrl-C for starting the reciprocating movement of the carriage 20 on which the print head 21 is mounted, and outputs the control signal Ctrl-C to the carriage motor 31. As a result, the carriage 20 starts reciprocating movement along the main scanning direction (step S142).

The control circuit 100 reads the determination information from the storage circuit 240 in a state where the carriage 20 continues to move back and forth in the main scanning direction (step S143). Then, the control circuit 100 compares the determination information read from the storage circuit 240 with the above-mentioned reference information stored in the control circuit 100. As a result, the control circuit 100 determines whether the determination information read from the storage circuit 240 is information corresponding to the output memory control signal MC. That is, the control circuit 100 executes a determination as to whether the determination information read from the storage circuit 240 is information corresponding to the reference information (step S144).

Then, when the control circuit 100 determines that the determination information read from the storage circuit 240 does not correspond to the reference information (N in step S144), the control circuit 100 is the carriage 20 on which the printhead 21 is mounted. A control signal Ctrl-C for stopping the reciprocating movement is generated and output to the carriage motor 31. As a result, the carriage 20 stops reciprocating along the main scanning direction (step S148). After that, the control circuit 100 ends the printing process (step S149), and the operation mode of the liquid discharge device 1 shifts to the determination mode M120.

On the other hand, when the control circuit 100 determines that the determination information read from the storage circuit 240 is information corresponding to the reference information (Y in step S144), the control circuit 100 is the image information input from the host computer or the like. It is determined whether or not the formation of the image based on the above is completed. That is, the control circuit 100 determines whether the printing process is completed (step S145). Then, when the control circuit 100 determines that the printing process has not been completed (N in step S145), the control circuit 100 has the storage circuit 240 in a state where the carriage 20 continues to reciprocate in the main scanning direction. The determination information is read from (step S143). That is, the control circuit 100 continuously executes the determination as to whether or not the information stored in the storage circuit 240 can be read normally even during the period during which the printing process is being executed.

On the other hand, when the control circuit 100 determines that the printing process is completed (Y in step S145), the control circuit 100 sends a control signal Ctrl-C for stopping the reciprocating movement of the carriage 20 on which the print head 21 is mounted. Generate and output to the carriage motor 31. As a result, the carriage 20 stops reciprocating along the main scanning direction (step S146), and then the control circuit 100 ends the printing process (step S147). Then, the operation mode of the liquid discharge device 1 shifts to the first standby mode M130.

Here, the maximum moving speed when the carriage 20 moves along the main scanning direction in the drive mode M140 is faster than the maximum moving speed when the carriage 20 moves along the main scanning direction in the determination mode M120. preferable. By increasing the moving speed of the carriage 20 in the drive mode M140, it is possible to shorten the printing time for the liquid discharge device 1 to form a desired image on the medium P. That is, the productivity of the liquid discharge device 1 can be improved by increasing the moving speed of the carriage 20 in the drive mode M140. On the other hand, the movement of the carriage 20 in the determination mode M120 is to deform the cable 190 by sliding the cable 190 and detect whether or not the cable 190 has a disconnection or a poor connection. Therefore, it is preferable to move the carriage 20 at a speed at which the deformation of the cable 190 appears remarkably, instead of moving the carriage 20 at a high speed. As a result, it is possible to achieve both high speed of the printing process and improvement of the detection accuracy of the wiring abnormality of the cable 190.

Returning to FIG. 10, the second standby mode M150 is an operation mode in which the liquid discharge device 1 stands by after a read abnormality occurs until an abnormality release request for canceling the read abnormality occurs. Here, the abnormality release request may be a request that is automatically generated when the user executes an operation for removing the cause of the read abnormality, or is executed via the input unit 92 or the host computer. It may be a request generated by the operation of the user.

The details of the second standby mode M150 will be described with reference to FIG. FIG. 16 is a diagram for explaining the operation of the liquid discharge device 1 in the second standby mode M150. As shown in FIG. 16, when the operation mode of the liquid discharge device 1 shifts to the second standby mode M150, the control circuit 100 determines whether or not the power supply voltage is supplied to the liquid discharge device 1 (step S151). ). Specifically, the control circuit 100 determines whether or not the voltage value of the power supply voltage supplied to the liquid discharge device 1 is equal to or higher than a predetermined value. Then, when the control circuit 100 determines that the power supply voltage is not supplied to the liquid discharge device 1 (N in step S151), the operation mode of the liquid discharge device 1 shifts to the stop mode M160.

On the other hand, when the control circuit 100 determines that the power supply voltage is supplied to the liquid discharge device 1 (Y in step S151), the control circuit 100 determines whether there is an abnormality release request for canceling the read abnormality. (Step S152). Then, when the control circuit 100 determines that there is no abnormality release request for canceling the read abnormality (N in step S152), the control circuit 100 determines whether or not the power supply voltage is supplied to the liquid discharge device 1. The determination is made (step S151). On the other hand, when the control circuit 100 determines that there is an abnormality release request for canceling the read abnormality (Y in step S152), the operation mode of the liquid discharge device 1 shifts to the start determination mode M110.

Returning to FIG. 10, the stop mode M160 is an operation mode for executing a stop process for stopping the operation of the liquid discharge device 1. Then, after the stop processing of the liquid discharge device 1 is completed, the liquid discharge device 1 stops the operation.

The details of the stop mode M160 will be described with reference to FIG. FIG. 17 is a diagram for explaining the operation of the liquid discharge device 1 in the stop mode M160. As shown in FIG. 17, when the operation mode of the liquid discharge device 1 shifts to the stop mode M160, the control circuit 100 sets the control circuit 100.
The stop process of the liquid discharge device 1 is executed (step S161). Here, the stop processing of the liquid discharge device 1 includes, for example, a storage process of storing data such as drive information of the liquid discharge device 1 and corresponding values in a predetermined register, and ink stored in the print head 21. A capping process or the like of attaching a cap to the nozzle 651 to reduce drying is included. Then, after the stop processing of the liquid discharge device 1 is completed, the liquid discharge device 1 stops the operation.

In the liquid discharge device 1 that operates as described above, since the presence or absence of the initial operation abnormality is determined in the start determination mode M110, the determination mode M120 may be changed after the transition to the drive mode M140. As shown in FIG. 10, it is preferable to make a transition between the activation determination mode M110 and the drive mode M140.

In the determination of the presence or absence of the initial operation abnormality performed in the activation determination mode M110, the carriage 20 does not move and the cable 190 does not slide. Therefore, even if a wiring abnormality occurs in the cable 190, it may not be sufficiently detected by the determination of the initial operation abnormality in the activation determination mode M110. In response to this problem, even between the start determination mode M110 and the drive mode M140, the operation mode of the liquid discharge device 1 shifts to the determination mode M120 before the liquid discharge device 1 executes the printing process. It is possible to detect whether or not a wiring abnormality has occurred in the cable 190. As a result, the stability of operation of the liquid discharge device 1 in the drive mode M140 is improved.

Further, even during the period in which the liquid discharge device 1 stays in each of the operation modes shown in FIGS. 10 to 17, it can be used by the signal input from the input unit 92 or the signal input from the host computer. When a person requests a transition to the determination mode M120, the operation mode of the liquid discharge device 1 may transition to the determination mode M120.

This makes it possible to confirm whether or not a reading abnormality has occurred when reading the information stored in the storage circuit 240 at an arbitrary timing of the user, which is convenient for the user who uses the liquid discharge device 1. Can be improved.

5. Action effect As described above, in the liquid discharge device 1 of the present embodiment, the memory control signal MC is transmitted to the storage circuit 240, the memory information signal MD for the memory control signal MC is received, and the received memory information signal is received. The control circuit 100, which determines that a read abnormality has occurred in the storage circuit 240 when the MD is not normal, does not determine that a read abnormality has occurred in a state where the carriage 20 does not move and the cable 190 does not slide. When it is determined that a read abnormality has occurred while the carriage 20 is moving and the cable 190 is sliding, the control circuit 100 determines that the cause of the read abnormality is a wiring abnormality of the cable 190. That is, the control circuit 100 is stored in the storage circuit 240 based on the memory control signal MC for controlling the storage circuit 240 and the memory information signal MD output by the storage circuit 240 with respect to the memory control signal MC. In addition to detecting that an information reading abnormality has occurred, it is possible to detect a wiring abnormality of the cable 190 that electrically connects the control circuit 100 and the print head 21 provided with the storage circuit 240. As a result, it is possible to identify the cause of the reading process for reading the information stored in the storage circuit 240 not being executed normally without complicating the configuration of the liquid discharge device 1, and to deal with the cause of the reading abnormality. It will be possible to take appropriate measures. Therefore, the operational stability of the liquid discharge device 1 provided with the print head 21 equipped with the storage circuit 240 can be improved.

Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments, and can be implemented in various modes 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. The present invention also includes a configuration that exhibits the same effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

The following contents are derived from the above-described embodiments and modifications.

One aspect of the liquid discharge device is
A print head having a discharge unit for discharging liquid and a memory for storing predetermined information,
A carriage equipped with the print head and moving along the main scanning direction,
A determination circuit that transmits a read signal to the memory, receives a response signal to the read signal, and determines that a read abnormality has occurred in the memory when the received response signal is not normal.
A cable that is electrically connected to the print head and slides as the carriage moves.
With
The determination circuit receives the normal response signal in the first state in which the carriage does not move and the cable does not slide, and the response signal is not normal in the second state in which the carriage moves and the cable slides. Is received, it is determined that the cause of the read abnormality is the wiring abnormality of the cable.

According to this liquid discharge device, a read signal is transmitted to the memory, a response signal to the read signal is received, and if the received response signal is not normal, it is determined that a memory read abnormality has occurred. Receives a normal response signal in the first state where the carriage does not move and the cable does not slide, and receives an abnormal response signal in the second state where the carriage moves and the cable slides. It is determined that the cause is an abnormality in the wiring of the cable. That is, the determination circuit determines whether or not a memory read abnormality has occurred by using a pair of read signals and a response signal, and the read abnormality occurs according to the timing when the memory read abnormality occurs. Factors can be determined. This makes it possible to determine the cause of the read abnormality that occurred when reading the information stored in the memory without complicating the configuration of the liquid discharge device, and it is possible to take appropriate measures against the read abnormality. It becomes. Therefore, it is possible to reduce the possibility that the operation stability of the liquid discharge device provided with the print head equipped with the memory is deteriorated.

In one aspect of the liquid discharge device,
When the determination circuit receives the response signal that is not normal in the first state, it may determine that the cause of the read abnormality is the read processing abnormality of the memory.

According to this liquid discharge device, when the timing at which the memory read abnormality detected using the pair of read signals and the response signal occurs is the first state, the determination circuit determines that the cause of the read abnormality is the memory. By determining that the read processing is abnormal, it is possible to determine the cause of the read abnormality that occurred when reading the information stored in the memory in more detail, and it is possible to take more appropriate measures against the read abnormality. Become. As a result, it is possible to further reduce the possibility that the operational stability of the liquid discharge device including the print head equipped with the memory is lowered.

In one aspect of the liquid discharge device,
The start mode after the power supply voltage is supplied and before the carriage starts moving,
A drive mode for discharging liquid from the discharge unit and
A determination mode for determining whether or not the reading abnormality has occurred, and a determination mode.
Have,
The determination circuit
In the determination mode, when the normal response signal is received in the first state and the response signal is not normal in the second state, it is determined that the cause of the read abnormality is the wiring abnormality. ,
When the response signal that is not normal in the first state is received in the determination mode, it may be determined that the cause of the read abnormality is the read processing abnormality.

According to this liquid discharge device, depending on the timing at which the memory read abnormality detected using the pair of read signals and the response signal occurs, whether the cause of the read abnormality is a cable wiring abnormality or the memory It is possible to determine whether or not the reading process is abnormal, and as a result, it is possible to take more appropriate measures against the reading abnormality. Therefore, it is possible to reduce the possibility that the operation stability of the liquid discharge device including the print head equipped with the memory is deteriorated.

In one aspect of the liquid discharge device,
When the determination circuit receives the response signal that is not normal in the activation mode, it may determine that the cause of the read abnormality is the initial operation abnormality.

According to this liquid discharge device, the determination circuit uses a pair of read signals and a response signal to determine whether or not a memory read abnormality has occurred, and also detects an initial operation abnormality of the liquid discharge device. Therefore, it is possible to take appropriate measures against the initial operation abnormality. Therefore, it is possible to further reduce the possibility that the operational stability of the liquid discharge device including the print head equipped with the memory is lowered.

In one aspect of the liquid discharge device,
When the determination circuit receives the response signal that is not normal in the drive mode, it may transition to the determination mode.

In one aspect of the liquid discharge device,
The determination mode may also transition between the activation mode and the drive mode.

In one aspect of the liquid discharge device,
The maximum moving speed at which the carriage moves along the main scanning direction in the drive mode is
In the determination mode, the carriage may be faster than the maximum moving speed at which the carriage moves along the main scanning direction.

In one aspect of the liquid discharge device,
In the determination mode, the carriage may repeatedly move at least one of acceleration and deceleration.

According to this liquid discharge device, in the determination mode, the carriage repeatedly manually operates at least one of acceleration and deceleration, so that the detection accuracy of whether or not a wiring abnormality has occurred in the cable is improved.

In one aspect of the liquid discharge device,
Equipped with an input section
The determination mode may be entered according to the signal input from the input unit.

1 ... Liquid discharge device, 2 ... Liquid container, 10 ... Control mechanism, 20 ... Carriage, 21 ... Print head, 30 ... Moving mechanism, 31 ... Carriage motor, 32 ... Endless belt, 40 ... Transfer mechanism, 41 ... Transfer motor, 42 ... Conveyor roller, 50 ... Drive circuit, 51 ... Drive signal output circuit, 52 ... Reference voltage signal output circuit, 60 ... Piezoelectric element, 90 ... Linear encoder, 91 ... Notification mechanism, 92 ... Input unit, 100 ... Control circuit, 110 ... power supply circuit, 190 ... cable, 200 ... drive signal selection circuit, 210 ... selection control circuit, 212 ... shift register, 214 ... latch circuit, 216 ... decoder, 220 ... temperature detection circuit, 230 ... selection circuit, 232 ... inverter , 234 ... Transfer gate, 235, 236 ... Transistor, 240 ... Storage circuit, 250 ... Temperature abnormality detection circuit, 251 ... Comparator, 252 ... Reference voltage generation circuit, 253 ... Transistor, 254 ... Diode, 255, 256 ... Resistance, 600 ... Discharge section, 601 ... Piezoelectric body, 611, 612 ... Electrode, 621 ... Vibration plate, 631 ... Cavity, 632 ... Nozzle plate, 641 ... Reservoir, 651 ... Nozzle, 661 ... Supply port, P ... Medium

Claims (9)

A print head having a discharge unit for discharging liquid and a memory for storing predetermined information,
A carriage equipped with the print head and moving along the main scanning direction,
A determination circuit that transmits a read signal to the memory, receives a response signal to the read signal, and determines that a read abnormality has occurred in the memory when the received response signal is not normal.
A cable that is electrically connected to the print head and slides as the carriage moves.
With
The determination circuit receives the normal response signal in the first state in which the carriage does not move and the cable does not slide, and the response signal is not normal in the second state in which the carriage moves and the cable slides. Is received, it is determined that the cause of the read abnormality is the wiring abnormality of the cable.
A liquid discharge device characterized by the fact that. When the determination circuit receives the response signal that is not normal in the first state, it determines that the cause of the read abnormality is the read processing abnormality of the memory.
The liquid discharge device according to claim 1. The start mode after the power supply voltage is supplied and before the carriage starts moving,
A drive mode for discharging liquid from the discharge unit and
A determination mode for determining whether or not the reading abnormality has occurred, and a determination mode.
Have,
The determination circuit
In the determination mode, when the normal response signal is received in the first state and the response signal is not normal in the second state, it is determined that the cause of the read abnormality is the wiring abnormality. ,
When the response signal that is not normal in the first state is received in the determination mode, it is determined that the cause of the read abnormality is the read processing abnormality.
The liquid discharge device according to claim 2. When the determination circuit receives the response signal that is not normal in the activation mode, the determination circuit determines that the cause of the read abnormality is an initial operation abnormality.
The liquid discharge device according to claim 3. When the determination circuit receives the response signal that is not normal in the drive mode, it transitions to the determination mode.
The liquid discharge device according to claim 3 or 4. The determination mode also transitions between the activation mode and the drive mode.
The liquid discharge device according to any one of claims 3 to 5, wherein the liquid discharge device is characterized. The maximum moving speed at which the carriage moves along the main scanning direction in the drive mode is
In the determination mode, the carriage is faster than the maximum moving speed of moving along the main scanning direction.
The liquid discharge device according to any one of claims 3 to 6, wherein the liquid discharge device is characterized. In the determination mode, the carriage repeatedly moves at least one of acceleration and deceleration.
The liquid discharge device according to any one of claims 3 to 7, wherein the liquid discharge device is characterized. Equipped with an input section
The mode shifts to the determination mode according to the signal input from the input unit.
The liquid discharge device according to any one of claims 3 to 8.

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