Liquid ejection device, program, and liquid ejection head

Abstract

This liquid ejection device can operate without reducing a maximum driving frequency even if a delay time occurs when a serial signal transmitted between a driving substrate and a liquid ejection head is converted into a parallel signal. A liquid ejection device 1 is provided with a driving substrate 2 and a liquid ejection head (inkjet head 3) connected to the driving substrate 2 via cables 41 and 42. The liquid ejection device 1 is provided with: a conversion means (de-serializer 31) for converting a signal received via a cable from a serial signal into a parallel signal; a generation means (signal generation section 21, driving signal generation circuit 24) for generating a control signal to drive a prescribed driving means (driving IC 32); a measurement means (signal generation section 21) for measuring a conversion delay time of a signal in the conversion means; and an adjustment means (signal generation section 21) for adjusting a timing at which the control signal is output from the generation means on the basis of the conversion delay time measured by the measurement means.

Description

Technical Field

[0001] The present invention relates to a liquid ejection device, a program, and a liquid ejection head.

Background Art

[0002] Conventionally, there has been a liquid ejection device that ejects ink (liquid) from nozzles to form an image, a structure, or the like on a medium. In such a liquid ejection device, an appropriate amount of ink is ejected at a desired speed by applying a pressure change to the ink in an ink flow path communicating with each nozzle.

[0003] As one method of applying pressure to ink, there is a technique of deforming the wall surface of a pressure chamber in an ink flow path by applying a predetermined drive waveform voltage to an actuator such as a piezoelectric element. Since the actuator deforms at high speed and with high precision with respect to the applied voltage, it is possible to precisely control the ejection timing and the ejection amount.

[0004] In recent years, in accordance with the demands for higher speed and higher precision of liquid ejection devices, the number of nozzles and the corresponding actuators has been increasing. Along with this, the number of drive ICs for selecting actuators corresponding to the nozzles that eject ink also increases. Therefore, since the number of control signals of the drive IC, the number of pins of the connector of the liquid ejection head, and the number of cables increase, it becomes difficult to route the wiring of the printer. There are also problems such as noise malfunctions due to signal crosstalk. In contrast, a countermeasure for reducing the number of pins of the connector of the liquid ejection head can be considered by serially converting and transmitting the control signal. In the invention described in Patent Document 1, a control signal is converted into a serial signal format in a control unit, and the converted control signal is transmitted to a head unit. And the technique of converting a control signal in serial signal format into parallel signal format in the head unit is described.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent No. 6361797 Summary of the Invention Problems to be Solved by the Invention

[0006] By the way, a part of the control signal needs to be input to the drive IC during the steady potential period in which the potential of the drive signal for driving the actuator is kept constant. However, a delay time occurs due to the serial / parallel conversion of the control signal, and there is a possibility that the control signal cannot be input to the drive IC during the steady potential period of the drive signal. On the other hand, in the invention described in Patent Document 1, the steady potential period of the drive signal is set to be long so that the control signal can be input to the head unit during the steady potential period of the drive signal even if the delay time of the control signal changes. Further, when a head with a large pulse width of the drive signal and a short steady potential period is manufactured, or when it is desired to change the drive signal for each head, it is necessary to further lengthen the steady potential time of the drive signal for stable operation. However, if the steady potential period of the drive signal is made longer, there is a problem that the maximum drive frequency becomes smaller accordingly. The above problem is common to signals for which a delay time occurs not only in the signal related to the drive of the actuator but also in signals that are serially / parallel converted between the drive substrate and the liquid ejection head.

[0007] An object of the present invention is to provide a liquid ejection device, a program, and a liquid ejection head that can operate without reducing the maximum drive frequency even when a delay time occurs when converting a serial signal transmitted between a drive substrate and a liquid ejection head into a parallel signal. Means for Solving the Problems

[0008] In order to achieve the above object, the liquid ejection device according to the invention described in claim 1 of the present invention is A liquid ejection device including a drive substrate and a liquid ejection head connected to the drive substrate via a cable, Conversion means for converting a signal received via the cable from a serial signal to a parallel signal; Generation means for generating a control signal for driving a predetermined driving means; Measurement means for measuring the conversion delay time of the signal in the conversion means; Adjustment means for adjusting the timing at which the control signal is output from the generation means based on the conversion delay time measured by the measurement means; It is provided with.

[0009] Further, the invention according to claim 2 is the liquid ejection device according to claim 1, wherein The drive substrate includes the generation means, The generation means generates a drive signal for driving the drive means, The liquid ejection head includes the conversion means, The drive means drives an actuator that ejects liquid from a plurality of nozzles by input of the drive signal received via the cable and the control signal parallel-converted by the conversion means.

[0010] Further, the invention according to claim 3 is the liquid ejection device according to claim 2, wherein The adjustment means adjusts the timings at which the control signal and the drive signal are output from the generation means based on the conversion delay time.

[0011] Further, the invention according to claim 4 is the liquid ejection device according to claim 2 or 3, wherein It has a plurality of liquid ejection heads, The adjustment means determines an adjustment time for adjusting the timing at which the control signal is output based on the maximum conversion delay time among the conversion delay times of the plurality of liquid ejection heads.

[0012] Further, the invention according to claim 5 is the liquid ejection device according to claim 2 or 3, wherein It has a plurality of liquid ejection heads, The adjustment means determines, for each liquid ejection head, an adjustment time for adjusting the timing at which the control signal is output.

[0013] Further, the invention according to claim 6 is the liquid ejection apparatus according to any one of claims 2 to 5, The adjustment means adjusts the timing at which a control signal input to the drive means during a period in which the potential of the drive signal is constant among the plurality of control signals is output.

[0014] Further, the invention according to claim 7 is the liquid ejection apparatus according to any one of claims 1 to 6, comprises conversion control means for controlling the conversion means, When the conversion delay time exceeds a predetermined value, the conversion control means repeatedly reconnects the communication of the signal in the conversion means until the conversion delay time falls within the predetermined value.

[0015] Further, the invention according to claim 8 is the liquid ejection apparatus according to any one of claims 2 to 7, The measurement means measures the conversion delay time based on a reference signal received from the drive substrate to the liquid ejection head together with the control signal and converted by the conversion means.

[0016] Further, the invention according to claim 9 is the liquid ejection apparatus according to claim 1, The liquid ejection head includes a sensor for performing predetermined measurement, The drive means is controlled according to a reading signal of the sensor, The drive substrate includes the conversion means, The measurement means measures the conversion delay time of the reading signal in the conversion means, The adjustment means adjusts the timing at which the control signal is output from the generation means based on the conversion delay time of the reading signal.

[0017] Further, the program of the invention according to claim 10 is A liquid ejection device including a drive substrate and a liquid ejection head connected to the drive substrate via a cable, conversion means for converting a signal received via the cable from a serial signal to a parallel signal, generation means for generating a control signal for driving predetermined drive means, A computer of a liquid ejection device including measurement means for measuring a conversion delay time of the signal in the conversion means, adjustment means for adjusting the timing at which the control signal is output from the generation means based on the conversion delay time measured by the measurement means, is made to function as.

[0018] Further, the liquid ejection head according to the invention of claim 11 is a liquid ejection head connected to a drive substrate via a cable and ejecting liquid from a plurality of nozzles based on signals for ejecting liquid from the respective nozzles, conversion means for converting the signal received via the cable from a serial signal to a parallel signal, drive means for driving an actuator that ejects liquid by the input of the signal parallel-converted by the conversion means, signal output means for outputting a signal synchronized with the signal converted in the conversion means to the drive substrate, is provided.

Advantages of the Invention

[0019] According to the present invention, even when a delay time occurs when converting a serial signal transmitted between a drive substrate and a liquid ejection head into a parallel signal, it is possible to operate without reducing the maximum drive frequency.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a block diagram showing the functional configuration of the liquid ejection device 1. The liquid ejection device 1 includes a drive substrate 2 and an inkjet head 3 as a liquid ejection head. Here, only one inkjet head 3 is shown, but when the liquid ejection device 1 is a color printer that ejects a plurality of ink colors, the inkjet heads 3 are provided corresponding to the plurality of ink colors (for example, four colors of yellow, magenta, cyan, and black), respectively. Also, a plurality of inkjet heads 3 related to the ejection of the same color ink may be provided to further increase the number of nozzles. The drive substrate 2 and the inkjet head 3 are connected by cables 41 and 42. As the cables 41 and 42, for example, coaxial cables or STP (Shielded Twisted Pair) are used.

[0023] The drive substrate 2 includes a signal generation unit 21, an input / output interface 22 (I / F), a serializer 23, a drive signal generation circuit 24, a unit control unit 25, a memory (not shown), and the like.

[0024] The signal generation unit 21 performs arithmetic processing based on commands related to image recording, settings, and image data to be recorded received from an external device by the input / output interface 22, and performs various control processes related to the image recording operation in the liquid ejection device 1. Specifically, the signal generation unit 21 generates digital format control signals and drive data signals for ejecting ink from a plurality of nozzles of the inkjet head 3 respectively. The signal generation unit 21 outputs the generated control signals and drive data signals in a parallel signal format. The control signals include pixel data to be described later and signals for controlling the operation availability and operation timing such as the transfer of pixel data and the supply of drive signals. As the signal generation unit 21, for example, an FPGA (Field Programmable Gate Array) is used.

[0025] The input / output interface 22 is an interface for receiving commands related to image recording, settings, and image data to be recorded from an external device, and for outputting status and abnormality occurrence information related to the image recording operation to the external device from the signal generation unit 21. As the input / output interface 22, a network card (LAN card) or the like is used.

[0026] The serializer 23 serially converts various control signals in a parallel signal format output from the signal generation unit 21. The serially converted control signals are output to the deserializer 31 in the inkjet head 3 via the cable 41 connecting the drive substrate 2 and the inkjet head 3.

[0027] The drive signal generation circuit 24 converts the digital format drive data signal output from the signal generation unit 21 into an analog format, amplifies it, and generates a drive signal. The generated drive signal is output to the drive IC 32 in the inkjet head 3 via the cable 42 and is used to drive the actuator 33 in the inkjet head 3. Therefore, the signal generation unit 21 and the drive signal generation circuit 24 function as generation means.

[0028] The unit control unit 25 performs overall control of the entire operation of the liquid ejection device 1.

[0029] A memory (not shown) stores image data of a recording target acquired from an external device and pixel data that determines the ink ejection state from each nozzle generated from the image data. After the pixel data is output from the memory (not shown), it is input to the signal generation unit 21 and output from the signal generation unit 21 in a parallel signal format together with other control signals. Then, the pixel data is serially converted by the serializer 23 together with other control signals.

[0030] The inkjet head 3 includes a deserialzier 31, a drive IC 32, an actuator 33, a nozzle row 34, and the like.

[0031] The deserialzier 31 converts the control signal in serial signal format output from the serializer 23 into a parallel signal format. Here, the deserialzier 31 functions as conversion means. The parallel-converted control signal is output to the drive IC 32. The parallel-converted pixel data among the control signals is output to the drive IC 32 of the inkjet head 3 and used to select the nozzles that eject ink.

[0032] The drive IC 32 inputs the drive signal output from the drive signal generation circuit 24 and the control signal output from the deserialzier 31. Based on the control signal, the drive IC 32 outputs a drive signal for deforming the actuator 33 at an appropriate timing, amplitude, and period to the actuator 33 corresponding to the selected nozzle. Therefore, the drive IC 32 functions as drive means.

[0033] The actuator 33 applies a pressure change to the ink to eject the ink for each channel (ink flow path) that communicates with each nozzle and supplies the ink, or to vibrate the liquid surface (meniscus) without ejecting the ink. Here, a piezoelectric element such as PZT (lead zirconate titanate) is used as the actuator 33, and this piezoelectric element is disposed between each channel as a partition of the one-dimensionally arranged channels. A predetermined voltage is applied to the actuator via electrode films provided on both side surfaces of the actuator (that is, the inner surfaces of the channels), so that the actuator bends and deforms and applies pressure to the internal ink. Note that dummy channels for affecting the bending deformation are provided at both ends of the one-dimensionally arranged channels, and deformation operations are performed without supplying or ejecting ink. Here, a shear mode is used for the deformation of the actuator, but deformation in other modes such as a bend mode may be used.

[0034] The nozzle row 34 has two or more predetermined numbers of nozzles arranged in an appropriate pattern.

[0035] The actuator 33 and the nozzle row 34 are each configured as one block, but may be configured by being divided into a plurality of blocks.

[0036] FIG. 2A is a diagram showing a delay that occurs when a control signal is converted by the serializer 23 and the deserialzier 31. (A) of FIG. 2A is an encoder signal that is a conveyance position detection signal of a conveyance belt (not shown) on which a recording medium on which the inkjet head 3 performs ejection is placed. The encoder signal is input from an external device to the signal generation unit 21 via the input / output interface 22. The signal generation unit 21 controls the timing of outputting various signals based on the encoder signal. The pixel data (B1) in FIG. 2A, the LAT signal (C1) in FIG. 2A, and the GSCLK signal (D1) in FIG. 2A are set times (t for setting the timing output from the signal generation unit 21 based on the encoder signal. 0) is a part of the control signal that is provided and output. These are signals before serial / parallel conversion (Ser / Des conversion) by the serializer 23 and the deserialzier 31. The LAT signal is an update signal for pixel data, and the GSCLK signal is a signal used to control gradation. The LAT signal and the GSCLK signal have a timing constraint that they must be input to the driving IC during a steady potential period in which the potential of the driving signal (E in FIG. 2A) is kept constant, which will be described later. The pixel data (B2) in FIG. 2A, the LAT signal (C2) in FIG. 2A, and the GSCLK signal (D2) in FIG. 2A are signals that are input to the driving IC 32 after serial / parallel conversion. Here, a conversion delay time (t d ) occurs due to the serial / parallel conversion. The driving signal (E) in FIG. 2A is an example of the driving signal input to the driving IC 32. The driving signal has a setup time (t 0 a) provided and output based on the encoder signal to set the output timing from the driving signal generation circuit 24. When the control signal is serially / parallel converted and a delay occurs, as shown in FIG. 2A, the LAT signal (C2) and the GSCLK signal (D2) will be input to the driving IC 32 outside the steady potential period of the driving signal (E), resulting in a timing violation where the timing constraint cannot be satisfied in some cases.

[0037] An example of adjusting the output timing from the signal generation unit 21 to input the LAT signal and the GSCLK signal to the driving IC 32 during the steady potential period of the driving signal is shown in FIG. 2B. The encoder signal (A) in FIG. 2B is the same signal as the encoder signal in FIG. 2A, and the driving signal (E) in FIG. 2B has the same waveform as the driving signal in FIG. 2A. The pixel data (B3) in FIG. 2B, the LAT signal (C3) in FIG. 2B, and the GSCLK signal (D3) in FIG. 2B are adjusted times (t 0 ) calculated by subtracting the conversion delay time (t d ) from the setup time (t 1) is provided and output. These are the signals before serial / parallel conversion by the serializer 23 and the deserialzier 31. The pixel data (B4) in FIG. 2B, the LAT signal (C4) in FIG. 2B, and the GSCLK signal (D4) in FIG. 2B are the signals input to the driving IC 32 after serial / parallel conversion. Due to the serial / parallel conversion, a conversion delay time (t d ) occurs. Even when the control signal is serially / parallel converted and a delay occurs, since an adjustment time (t 1 ) is provided, the LAT signal (C4) in FIG. 2B and the GSCLK signal (D4) in FIG. 2B are input to the driving IC 32 during the steady potential period of the driving signal (E) as shown in FIG. 2B, and the control signal and the driving signal are input to the driving IC 32 at appropriate timings.

[0038] The conversion delay time (t d ) of the control signal caused by the conversion in the serializer 23 and the deserialzier 31 varies depending on the individual differences of the serializer 23 and the deserialzier 31, the length of the cable 41, the usage environment, etc. Therefore, in order to provide an appropriate adjustment time (t 1 ), as shown in FIG. 1, a part of the control signal output from the deserialzier 31 is used as the signal S and input to the signal generation unit 21 of the driving substrate 2 via the cable 42. The signal S may be any of the control signals. Here, the circuit from the deserialzier 31 to the connector on the inkjet head 3 to which the cable 42 is connected functions as signal output means. The signal generation unit 21 measures the conversion delay time from the input signal S. Then, based on the conversion delay time, the signal generation unit 21 determines the adjustment time of the control signal and outputs the control signal to the serializer 23 with the adjustment time provided. Here, the signal generation unit 21 functions as measurement means and adjustment means. The control signal with the adjustment time provided is converted by the serializer 23 and the deserialzier 31 and input to the driving IC 32 together with the driving signal. In this case, the LAT signal and the GSCLK signal are input to the driving IC 32 during the steady potential period of the driving signal.

[0039] As described above, by compensating for the conversion delay time in the control signal in serial signal format transmitted from the drive substrate 2 to the inkjet head 3 so as to satisfy the timing constraint between the control signal and the drive signal, there is no need for a memory or a controller for compensating for the conversion delay time inside the inkjet head 3, and the conversion delay time can be compensated with a simple configuration. Further, since there is no memory or controller inside the inkjet head 3, the price of the inkjet head 3, which is a consumable, can be reduced. In addition, since it is not necessary to take a long steady period of the drive signal, the inkjet head can be driven at the maximum drive frequency regardless of the number of inkjet heads mounted in the liquid ejection device 1. Furthermore, it is possible to satisfy the timing constraints of signals such as GSCLK with timing constraints for a multi-waveform drive signal with a steady potential period between waveforms as short as about several hundred nsec.

[0040] The timing for determining the adjustment time of the control signal is acquired when the liquid ejection device 1 is powered on. Or it may be acquired periodically. Also, for example, if the conversion delay time cannot be compensated only by providing an adjustment time to the control signal, that is, when the conversion delay time (t d ) in FIG. 2A is longer than the set time (t 0 ), in addition to providing an adjustment time to the control signal, the signal generation unit 21 may provide another adjustment time to the drive signal and output it. The adjustment time provided to the drive signal is set so that no timing violation occurs between the control signal and the drive signal. By providing another adjustment time to the drive signal, the ejection timing of the inkjet head 3 can be set on the drive substrate 2 side, so that it is possible to correct the deviation of the ink landing position.

[0041] Also, the control signal for which the adjustment time is provided may be one or more of the plurality of control signals. In the signal generation unit 21, by providing the adjustment time only to the signal with strict timing constraints, the configuration of the drive substrate 2 becomes simple. A signal with strict timing constraints is, for example, the LAT signal or the GSCLK signal, and these signals need to be input to the driving IC 32 during the steady potential period of the driving signal. Therefore, only for these signals, even if an adjustment time is provided when a timing violation occurs, the conversion delay time may be compensated. This simplifies the configuration of the driving substrate 2.

[0042] Also, the conversion delay time may change each time signal communication in the serializer 23 and the deserialzer 31 is established. Therefore, when the conversion delay time exceeds a predetermined value, the signal generation unit 21 repeatedly reconnects the communication in the serializer 23 and the deserialzer 31 until the conversion delay time falls within the predetermined value. Here, the signal generation unit 21 functions as conversion control means. When the conversion delay time exceeds the predetermined value, for example, when the conversion delay time cannot be compensated only by providing an adjustment time to the control signal, that is, when the conversion delay time (t d ) in FIG. 2A is longer than the set time (t 0 ) or when a timing violation occurs between the driving signal and the signal. Reconnection of the communication in the serializer 23 and the deserialzer 31 is performed by resetting the communication in the serializer 23 and the deserialzer 31 or by stopping the supply of the clock signal used for the communication.

[0043] <Modification Example 1> Next, Modification Example 1 of the present invention will be described. In Modification Example 1, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0044] In the above embodiment, in order to provide an appropriate adjustment time, the signal S which is a part of the control signal is input to the signal generation unit 21, but it is not limited to this. In order to measure the conversion delay time, a reference signal 26 different from the control signal as shown in FIG. 3 may be used. The reference signal 26 is output from the signal generation unit 21 in a parallel signal format together with the control signal, and is input to the serializer 23. Next, the reference signal 26 is serially converted together with the control signal in the serializer 23, and is input to the deserialzier 31 via the cable 41. Next, the reference signal 26 is parallel-converted and output together with the control signal in the deserialzier 31. The reference signal 26 output from the deserialzier 31 is input to the signal generation unit 21 via the cable 42. Here, the circuit from the deserialzier 31 to the connector on the inkjet head 3 to which the cable 42 is connected functions as signal output means. Therefore, similar to the control signal, a delay occurs in the reference signal 26 due to the conversion in the serializer 23 and the deserialzier 31. The conversion delay time of the control signal and the conversion delay time of the reference signal 26 are equivalent.

[0045] <Modification Example 2> Next, Modification Example 2 of the present invention will be described. In Modification Example 2, the same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0046] In addition, in this modification example, the liquid ejection device 1 has a configuration including a plurality of inkjet heads 3. FIG. 4 shows a block diagram illustrating the functional configuration of the liquid ejection device 1 including a plurality of inkjet heads 3. In the example shown in FIG. 4, there are two inkjet heads 3, namely an inkjet head 3a and an inkjet head 3b. In this case, the drive substrate 2 and the inkjet head 3a are connected by a cable 41a and a cable 42a. Also, the drive substrate 2 and the inkjet head 3b are connected by a cable 41b and a cable 42b. The drive substrate 2 includes a serializer 23a and a serializer 23b, and a drive signal generation circuit 24a and a drive signal generation circuit 24b. Other configurations are the same as those in the case where there is one inkjet head 3 shown in FIG. 1. In the example shown in FIG. 4, in order to provide an appropriate adjustment time, for the inkjet head 3a, a signal Sa which is a part of the control signal is input to the signal generation unit 21, and for the inkjet head 3b, a signal Sb which is a part of the control signal is input to the signal generation unit 21. In this modified example, the liquid discharge device 1 including a plurality of inkjet heads 3 is assumed to include two inkjet heads 3, but it is not limited thereto. A configuration including three or more inkjet heads 3 may be employed.

[0047] When the liquid discharge device 1 includes a plurality of inkjet heads 3, the adjustment time may be determined for each of the plurality of inkjet heads 3. That is, for the inkjet head 3a, the signal generation unit 21 measures the conversion delay time related to the inkjet head 3a from the input signal Sa. Then, the signal generation unit 21 determines the adjustment time of the control signal output to the inkjet head 3a based on the conversion delay time related to the inkjet head 3a. Similarly, for the inkjet head 3b, the signal generation unit 21 measures the conversion delay time related to the inkjet head 3b from the input signal Sb. Then, the signal generation unit 21 determines the adjustment time of the control signal output to the inkjet head 3b based on the conversion delay time related to the inkjet head 3b. As a result, it is possible to optimize the adjustment time for each inkjet head 3, and thus the inkjet head 3 can be driven at the maximum drive frequency regardless of the number of mounted inkjet heads 3.

[0048] Also, when the liquid discharge device 1 includes a plurality of inkjet heads 3, the adjustment time may be determined by measuring the conversion delay times in the plurality of inkjet heads 3 respectively and based on the maximum conversion delay time. That is, the signal generation unit 21 compares the conversion delay time based on the input signal Sa shown in FIG. 4 with the conversion delay time based on the signal Sb, and determines the adjustment time based on the larger conversion delay time. Thereby, the configuration of the drive substrate 2 can be simplified.

[0049] Further, when the liquid ejection device 1 includes a plurality of inkjet heads 3, among the plurality of inkjet heads 3, only the inkjet head 3 whose measured conversion delay time exceeds a predetermined specified value may have an adjustment time to compensate for the conversion delay time. This simplifies the configuration of the drive substrate 2. The specified value may be any value as long as there is no timing violation between the control signal and the drive signal. Further, the specified value may be a setting time for setting the timing output from the signal generation unit 21 based on the encoder signal.

[0050] <Modification Example 3> Next, Modification Example 3 of the present invention will be described. In Modification Example 3, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0051] FIG. 5 is a block diagram showing the functional configuration of the liquid ejection device 1 according to this modification example. In this modification example, as shown in FIG. 5, the drive substrate 2 includes a deserialzier 27 as conversion means and a heater control signal generation circuit 28 as generation means. Further, the inkjet head 3 includes temperature sensors 35a and 35b as sensors, a serializer 36, and heaters 37a and 37b as drive means. Further, in this modification example, in addition to between the control signal (LAT signal, GSCLK signal, etc.) and the drive signal, the conversion delay time is compensated between the temperature sensor 35a provided in the inkjet head 3 and the heater 37a, and between the temperature sensor 35b and the heater 37b. In this case, the signal generation unit 21 is configured to control the heater 37a based on the read signal Sea output from the temperature sensor 35a and control the heater 37b based on the read signal Seb output from the temperature sensor 35b. Specifically, the signal generation unit 21 as adjustment means outputs heater control data Ha0 and Hb0 based on the read signals Sea and Seb to the heater control signal generation circuit 28. Then, in the heater control signal generation circuit 28, heater control signals Ha and Hb are generated from the heater control data Ha0 and Hb0 and input to the heaters 37a and 37b via the cable 42.

[0052] Also, in this modification example, the reading signal Sea output from the temperature sensor 35a and the reading signal Seb output from the temperature sensor 35b are input to the serializer 36 and serially converted. Then, via the cable 41, they are input to the deserialzier 27, parallel-converted, and input to the signal generation unit 21. Therefore, conversion delay times are generated in the reading signals Sea and Seb due to the conversion by the serializer 36 and the deserialzier 27. In order to measure the conversion delay times generated in the reading signals Sea and Seb, a reference signal Sc as shown in FIG. 5 is used. The reference signal Sc is output from the signal generation unit 21 and input to the serializer 36 via the cable 42. Next, the reference signal Sc is serially converted together with the reading signals Sea and Seb in the serializer 36 and output. The reference signal Sc output from the serializer 36 is input to the deserialzier 27 via the cable 41. Next, the reference signal Sc is parallel-converted in the deserialzier 27 and input to the signal generation unit 21. Therefore, a delay occurs in the reference signal Sc due to the conversion by the serializer 36 and the deserialzier 27, similar to the reading signals Sea and Seb. The conversion delay times of the reading signals Sea and Seb are equal to the conversion delay time of the reference signal Sc. The signal generation unit 21 as the measuring means measures the conversion delay times of the reading signals Sea and Seb from the input reference signal Sc. Then, based on the conversion delay times of the reading signals Sea and Seb, the signal generation unit 21 adjusts the timing for outputting the heater control data Ha0 and Hb0 to the heater control signal generation circuit 28. In the above, the conversion delay times are compensated between the temperature sensor 35a and the heater 37a and between the temperature sensor 35b and the heater 37b, but it is not limited to this. The conversion delay time may be compensated between a predetermined sensor (for example, an optical sensor or an acceleration sensor) provided in the inkjet head 3 and a motor of the liquid ejecting device 1, etc.

[0053] <Modification Example 4> Next, a fourth modification of the present invention will be described. In the fourth modification, the same reference numerals are given to the same configurations as those in the above-described embodiment, and the description thereof will be omitted.

[0054] In the configuration of this modification, as shown in FIG. 6, the drive substrate 2 does not have a drive signal generation circuit 24, and the inkjet head 3 includes a drive signal generation circuit 38. In this modification, the signal generation unit 21 generates a digital control signal and drive data 29 for generating a drive signal based on an instruction related to image recording, settings, and image data of a recording target from an external device received by the input / output interface 22. Next, the control signal and the drive data 29 are output from the signal generation unit 21 in a parallel signal format and input to the serializer 23. Next, in the serializer 23, the control signal and the drive data 29 are serially converted and input to the deserialzier 31 via the cable 41. Next, the control signal and the drive data 29 are parallel-converted and output in the deserialzier 31. The control signal output from the deserialzier 31 is input to the drive IC 32. Also, a part of the control signal output from the deserialzier 31 is input as a signal S to the signal generation unit 21 of the drive substrate 2 via the cable 41. Also, the drive data 29 output from the deserialzier 31 is input to the drive signal generation circuit 38. The drive signal generation circuit 38 converts the drive data 29 output from the deserialzier 31 into a digital signal or an analog signal, amplifies it, and generates a drive signal. The generated drive signal is output to the drive IC 32 in the inkjet head 3 and is used to drive the actuator 33 in the inkjet head 3.

[0055] In this modification example, in addition to the control signal, the drive data 29 is also serially / parallelly converted, so a conversion delay time associated with the serial / parallel conversion also occurs in the drive data 29. Therefore, an adjustment time is provided for the drive data 29 as well as for the control signal. That is, the signal generation unit 21 measures the conversion delay time from the input signal S. Then, the signal generation unit 21 determines the respective adjustment times by subtracting the conversion delay time from the respective set times of the control signal and the drive data 29, and provides the respective adjustment times and outputs the control signal and the drive data 29 to the serializer 23. Thereby, even if the delay time changes with each communication, the deviation of the landing position of the ink can be corrected. Also, when the conversion delay time exceeds a predetermined value, the reconnection of communication in the serializer 23 and the deserializers 31 is repeated until the conversion delay time falls within the predetermined value. Here, the signal generation unit 21 functions as conversion control means. If the predetermined value is, for example, 100 nsec, the deviation of the ejection position can be suppressed within 1% even during high-speed printing. Or, when the conversion delay time exceeds the predetermined value means that the conversion delay time cannot be compensated only by providing an adjustment time for the control signal, that is, when the conversion delay time (t d ) in FIG. 2A is longer than the set time (t 0 ).

[0056] As described above, the liquid ejection device 1 of the present embodiment is a liquid ejection device 1 including a drive substrate 2 and a liquid ejection head (inkjet head 3) connected to the drive substrate 2 via cables 41 and 42, and includes conversion means (deserializers 31, 27) for converting a signal received via the cables 41 and 42 from a serial signal to a parallel signal, generation means (signal generation unit 21, drive signal generation circuit 24) for generating a control signal for driving predetermined drive means (drive IC 32, heaters 37a, 37b), measurement means (signal generation unit 21) for measuring the conversion delay time of the signal in the conversion means, and adjustment means (signal generation unit 21) for adjusting the timing at which the control signal is output from the generation means based on the conversion delay time measured by the measurement means. Accordingly, it is possible to provide a liquid ejection device, a program, and a liquid ejection head that can operate without reducing the maximum driving frequency even if a delay time occurs when converting a serial signal transmitted between a driving substrate and the liquid ejection head into a parallel signal.

[0057] Further, in the liquid ejection device 1 of the present embodiment, the driving substrate 2 includes a generation means, the generation means generates a driving signal for driving a driving means (driving IC 32), the liquid ejection head includes a conversion means, and the driving means drives an actuator 33 that ejects liquid from a plurality of nozzles by inputting the driving signal received via the cables 41 and 42 and the control signal parallel-converted by the conversion means. Accordingly, it is possible to provide a liquid ejection device, a program, and a liquid ejection head that eject liquid without reducing the maximum driving frequency even if a delay time occurs in a control signal in a serial signal format transmitted from the driving substrate to the inkjet head.

[0058] Further, in the liquid ejection device 1 of the present embodiment, the adjustment means adjusts the timings at which the control signal and the driving signal are output from the generation means, respectively, based on the conversion delay time. Accordingly, since the ejection timing of the inkjet head 3 can be set on the driving substrate 2 side, it is possible to correct the deviation of the landing position of the ink.

[0059] Further, the liquid ejection device 1 of the present embodiment has a plurality of liquid ejection heads, and the adjustment means determines an adjustment time for adjusting the timing at which the control signal is output based on the maximum conversion delay time among the conversion delay times of the plurality of liquid ejection heads. Accordingly, the configuration of the driving substrate 2 can be simplified.

[0060] Further, the liquid ejection device 1 of the present embodiment has a plurality of liquid ejection heads, and the adjustment means determines an adjustment time for adjusting the timing at which the control signal is output for each liquid ejection head. As a result, it is possible to optimize the adjustment time for each inkjet head 3, so that the inkjet head 3 can be driven at the maximum drive frequency regardless of the number of inkjet heads 3 mounted.

[0061] Further, in the liquid ejection device 1 of the present embodiment, the adjustment means adjusts the timing at which a control signal input to the drive means (drive IC 32) is output during a period in which the potential of the drive signal is constant among a plurality of control signals. As a result, the configuration of the drive substrate 2 becomes simpler than when adjusting the timing at which all control signals are output.

[0062] Further, the liquid ejection device 1 of the present embodiment includes conversion control means for controlling the conversion means, and when the conversion delay time exceeds a predetermined value, the conversion control means repeats reconnecting the communication of the signal in the conversion means until the conversion delay time falls within the predetermined value. As a result, even when the conversion delay time exceeds a predetermined value, the conversion delay time can be compensated.

[0063] Further, in the liquid ejection device 1 of the present embodiment, the measurement means measures the conversion delay time based on a reference signal 26 received from the drive substrate 2 together with a control signal and converted by the conversion means. As a result, a memory and a controller for compensating the conversion delay time are not required inside the inkjet head 3, and it is possible to compensate the conversion delay time with a simple configuration based on the reference signal 26.

[0064] Further, in the liquid ejection device 1 of the present embodiment, the liquid ejection head includes sensors (temperature sensors 35a, 35b) for performing predetermined measurements, the drive means (heaters 37a, 37b) is controlled in response to the reading signals of the sensors, the drive substrate 2 includes conversion means (deserializer 27), the measurement means measures the conversion delay time of the reading signals in the conversion means, and the adjustment means adjusts the timing at which control signals (heater control signals Ha, Hb) are output from the generation means based on the conversion delay time of the reading signals. As a result, even for signals other than the control signals for ejecting ink from the plurality of nozzles of the inkjet head 3, the conversion delay time can be compensated for.

[0065] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, in the above-described embodiments and modified examples, although the signal generation unit 21 determines the adjustment time based on the conversion delay time, the present invention is not limited to this. An external device such as a computer connected via the input / output interface 22 may determine the adjustment time. In this case, information related to the conversion delay time is output to the external device via the signal generation unit 21 and the input / output interface 22 and is used to determine the adjustment time. Therefore, in this case, the external device is also included in the liquid ejection device 1.

[0066] Also, in the above-described embodiments and modified examples, although the signal generation unit 21 performs arithmetic processing, performs various control processes related to the image recording operation in the liquid ejection device 1, and determines the adjustment time based on the conversion delay time, the present invention is not limited to this. It may be configured such that the FPGA as the signal generation unit 21 has a CPU (Central Processing Unit), the FPGA and the CPU perform arithmetic processing, perform various control processes related to the image recording operation in the liquid ejection device 1, and determine the adjustment time based on the conversion delay time. Also, it may be configured such that the CPU functions as an adjustment means by executing a program.

[0067] Also, in the above-described embodiments and modified examples, although the signal S and the reference signal 26 output from the deserialization unit 31 are input to the signal generation unit 21 via the cable 42, the present invention is not limited to this. The signal S and the reference signal 26 output from the deserialization unit 31 may be input to the signal generation unit 21 via the cable 41.

[0068] In addition, the signal S and the reference signal 26 may be transmitted as differential signals to suppress the influence of noise. Also, the cables 41 and 42 may be either UTP (Unshielded Twisted Pair) cables or FPC (Flexible Printed Circuits).

[0069] In addition, specific details such as the configurations, circuit layouts, and operation procedures shown in the above embodiments can be appropriately changed without departing from the spirit of the present invention.

Industrial Applicability

[0070] This invention can be used in a liquid ejection device, a program for controlling the liquid ejection device, and an inkjet head driven in the liquid ejection device.

Explanation of Reference Numerals

[0071] 1 Liquid ejection device 2 Drive substrate 21 Signal generation unit (generation means, measurement means, adjustment means) 22 Input / output interface 23, 23a, 23b Serializer 24, 24a, 24b Drive signal generation circuit (generation means) 25 Unit control unit 26 Reference signal 27 Deserializer (conversion means) 28 Heater control signal generation circuit (generation means) 29 Drive data 3 Inkjet head (liquid ejection head) 31, 31a, 31b Deserializer (conversion means) 32, 32a, 32b Drive IC (drive means) 33, 33a, 33b Actuator 34, 34a, 34b Nozzle row 35a, 35b Temperature sensor (sensor) 36 Serializer 37a, 37b Heater (drive means) 38 Drive signal generation circuit 41, 42, 41a, 42a, 41b, 42b Cables

Claims

1. A liquid ejection device comprising a drive substrate and a liquid ejection head connected to the drive substrate via a cable, conversion means for converting a signal received via the cable from a serial signal into a parallel signal, generation means for generating a control signal for driving predetermined drive means, measurement means for measuring the conversion delay time of the signal in the conversion means, adjustment means for adjusting the timing at which the control signal is output from the generation means based on the conversion delay time measured by the measurement means, A liquid ejection device comprising the above.

2. The drive substrate comprises the generation means, The generation means generates a drive signal for driving the drive means, The liquid ejection head comprises the conversion means, The drive means drives an actuator that ejects liquid from a plurality of nozzles by input of the drive signal received via the cable and the control signal parallel-converted by the conversion means. The liquid ejection device according to Claim 1.

3. The adjustment means adjusts the timings at which the control signal and the drive signal are output from the generation means respectively based on the conversion delay time. The liquid ejection device according to Claim 2.

4. Having a plurality of liquid ejection heads, The adjustment means determines an adjustment time for adjusting the timing at which the control signal is output based on the maximum conversion delay time among the conversion delay times of the plurality of liquid ejection heads. The liquid ejection device according to Claim 2 or 3.

5. Having a plurality of liquid ejection heads, The adjustment means determines an adjustment time for adjusting the timing at which the control signal is output for each liquid ejection head. The liquid ejection device according to Claim 2 or 3.

6. Among the plurality of control signals, the adjustment means adjusts the timing at which the control signal input to the drive means during a period when the potential of the drive signal is constant is output. The liquid ejection device according to any one of Claims 2 to 5.

7. Comprising conversion control means for controlling the conversion means, When the conversion delay time exceeds a predetermined value, the conversion control means repeatedly reconnects the communication of the signal in the conversion means until the conversion delay time falls within the predetermined value. The liquid ejection device according to any one of Claims 1 to 6.

8. The liquid ejection device according to any one of claims 2 to 7, wherein the measurement means measures the conversion delay time based on a reference signal received from the drive substrate to the liquid ejection head together with the control signal and converted by the conversion means.

9. The liquid ejection head includes a sensor for performing predetermined measurement, The driving means is controlled according to a reading signal of the sensor, The drive substrate includes the conversion means, The measurement means measures a conversion delay time of the reading signal in the conversion means, The adjustment means adjusts a timing for outputting the control signal from the generation means based on the conversion delay time of the reading signal. The liquid ejection device according to claim 1.

10. A liquid ejection device including a drive substrate and a liquid ejection head connected to the drive substrate via a cable, Conversion means for converting a signal received via the cable from a serial signal to a parallel signal, Generation means for generating a control signal for driving predetermined driving means, A computer of a liquid ejection device including Measurement means for measuring a conversion delay time of the signal in the conversion means, Adjustment means for adjusting a timing at which the control signal is output from the generation means based on the conversion delay time measured by the measurement means, A program for functioning as

11. A liquid ejection head connected to a drive substrate via a cable and ejecting liquid from a plurality of nozzles based on signals for ejecting liquid from each nozzle, Conversion means for converting the signal received via the cable from a serial signal to a parallel signal, Driving means for driving an actuator for ejecting liquid by an input of the signal parallel-converted by the conversion means, Signal output means for outputting a signal synchronized with the signal converted by the conversion means to the drive substrate, A liquid ejection head comprising.

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