Liquid ejection head

Abstract

To provide a liquid ejection head capable of performing a non-discharge drive without deteriorating usability.SOLUTION: A liquid ejection head includes: an actuator which varies volumes of a plurality of pressure chambers corresponding to nozzles; a driving circuit which generates a driving signal containing an extension pulse for extending the volumes of the pressure chambers and a contraction pulse for contracting the volumes of the pressure chambers for the actuator; a memory which contains first print data of one line determining a waveform pattern generated on the driving circuit and second print data of a line different from the first print data; and a signal processing circuit 101 which outputs the first print data and the second print data or predetermined third print data different from the first print data. The driving circuit outputs the third print data when the first print data and the second print data accords with a predetermined pattern and, when the first print data and the second print data do not accord with the above-described pattern, makes non-ejection driving possible by outputting the first print data.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a liquid ejection head. [Background technology]

[0002] Conventional methods of providing ejection control signals to liquid ejection heads such as inkjet heads that eject ink include transferring setting data such as drive waveforms to a head drive circuit in advance, and then transferring print image data to the head drive circuit sequentially in accordance with a print synchronization signal.

[0003] As speeds and resolutions increase, effects such as crosstalk occur depending on whether a droplet was ejected immediately before or whether surrounding nozzles have ejected droplets. In particular, when the inter-cycle delay, which is the interval between lines, becomes shorter due to increased speed, the effects of residual vibration and meniscus vibration become a problem.

[0004] For example, when droplets are ejected on the next line, the vibrations that occurred when droplets were ejected on the previous line remain. It is also known that vibrations can be damped by a cancel pulse after an ejection pulse. However, meniscus vibrations dampen more slowly than residual vibrations, and their effects become more pronounced as the speed increases.

[0005] The initial state of the meniscus for each line affects the ejection performance of the droplet ejection volume and ejection speed. As a result, the first line, which is not driven immediately before, tends to have a smaller ejection volume and a faster ejection speed compared to the second and subsequent lines, resulting in reduced print quality.

[0006] Therefore, one method of non-ejection driving a liquid ejection head is to input a non-ejection waveform, such as precursor drive, boost drive, or pre-drive, to a non-drive line. After non-ejection driving, the meniscus changes, improving the print quality of the liquid ejection head. However, non-ejection driving generally increases power consumption because it is driven periodically or for a fixed period of time. For example, one method could be to add non-ejection drive data to the print image, but this would require the user to add data to the print image, reducing usability. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Utility Model Registration No. 3122820 Summary of the Invention [Problem to be solved by the invention]

[0008] According to the present invention, it is possible to provide a liquid ejection head that can be driven in a non-ejecting state without reducing usability. [Means for solving the problem]

[0009] A liquid ejection head according to an embodiment includes an actuator, a drive circuit, a memory, and a signal processing circuit. The actuator varies the volume of a plurality of pressure chambers corresponding to nozzles. The drive circuit generates a drive signal for the actuator, including an expansion pulse for expanding the volume of the pressure chamber and a contraction pulse for contracting the volume of the pressure chamber. The memory stores one line of first print data and a line of second print data different from the first print data, which determine a waveform pattern to be generated by the drive circuit. The signal processing circuit references the memory and outputs the first print data, the second print data, or predetermined third print data different from the first print data. The drive circuit outputs the third print data when the first print data and the second print data match a predetermined pattern, and outputs the first print data when the first print data and the second print data do not match the pattern. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a liquid ejection recording apparatus including a liquid ejection head according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a signal processing circuit of the liquid ejection head according to the embodiment. [Figure 3] FIG. 3 is a block diagram showing an example of the configuration of a head drive circuit of a liquid ejection head according to an embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a truth table for the print data conversion process performed by the control signal processing unit of the signal processing circuit of the liquid ejection head according to the embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing an example of setting data for determining a drive waveform based on print data for the liquid ejection head according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram showing another example of a truth table for the print data conversion process performed by the control signal processing unit of the signal processing circuit of the liquid ejection head according to the embodiment. [Figure 7]FIG. 7 is a block diagram showing an example of the configuration of a head drive circuit of a liquid ejection head according to another embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing an example of setting data for determining a drive waveform based on print data in a head drive circuit of a liquid ejection head according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] A liquid ejection head 100 according to an embodiment and a liquid ejection device 200 using the liquid ejection head 100 will be described below with reference to FIGS. 1 to 6. FIG. 1 is a block diagram showing an example of the configuration of the liquid ejection device 200 including the liquid ejection head 100 according to an embodiment. FIG. 2 is a block diagram showing an example of the configuration of the signal processing circuit 101 of the liquid ejection head 100. FIG. 3 is a block diagram showing an example of the configuration of the head drive circuit 102 of the liquid ejection head 100. FIG. 4 is an explanatory diagram showing an example of a truth table for the print data conversion process performed by the control signal processing unit 108 of the signal processing circuit 101 of the liquid ejection head 100. FIG. 5 is an explanatory diagram showing an example of setting data for determining the drive waveform based on the print data of the liquid ejection head 100. FIG. 6 is an explanatory diagram showing another example of the truth table for the print data conversion process performed by the control signal processing unit 108 of the signal processing circuit 101 of the liquid ejection head 100.

[0012] The liquid ejection head 100 is, for example, a share mode inkjet head that ejects ink as a liquid onto a recording medium such as a paper sheet. A liquid ejection device 200 using the liquid ejection head 100 is a recording device such as an inkjet printer that prints by ejecting ink onto a recording medium such as a paper sheet.

[0013] The liquid ejection device 200 includes a liquid ejection head 100, a processor 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, an operation panel 204, a communication interface (communication IF) 205, a conveying motor 206, a motor drive circuit 207, a pump 208, and a pump drive circuit 209.

[0014] The liquid ejection device 200 also has a bus line 210 such as an address bus and a data bus. The liquid ejection head 100, processor 201, ROM 202, RAM 203, operation panel 204, communication interface 205, motor drive circuit 207, and pump drive circuit 209 are connected to the bus line 210 directly or via an input / output circuit, and can send and receive data between them.

[0015] The liquid ejection head 100 includes a signal processing circuit 101 , a head driving circuit 102 , and an actuator group 103 .

[0016] The signal processing circuit 101 is connected to a processor 201, ROM 202, and RAM 203, which are print control devices, via a bus line 210, for example. The signal processing circuit 101 is a logic circuit capable of processing communication signals, such as a microcontroller, FPGA, or ASIC. For example, the receiver and transmitter of the signal processing circuit 101 may be configured with a single signal line or two LVDS signal lines. The signal processing circuit 101 outputs print data to the head drive circuit 102, which determines the waveform pattern to be generated by the head drive circuit 102. The signal processing circuit 101 may receive and transmit a clock signal in addition to the print data signal to process the communication signal. When the input print data for multiple lines matches a print pattern of a specific algorithm, the signal processing circuit 101 transmits the specific print data for the specific lines to the head drive circuit 102 as a non-ejection drive waveform, which is a print pattern different from the original print pattern—in this embodiment, a precursor waveform.

[0017] As a specific example, the signal processing circuit 101 includes a receiving unit 104, a plurality of print data buffers 105, a control signal processing unit 108, and a transmitting unit 109. The signal processing circuit 101 performs a print data conversion process to convert input print data of a plurality of lines into different print data based on an algorithm.

[0018] The receiving unit 104 receives print data of multiple lines transmitted from the processor 201, ROM 202, RAM 203, etc., which are the print control device. The receiving unit 104 transmits the received print data of multiple lines to the print data buffer 105.

[0019] A plurality of print data buffers 105 are provided. When corresponding print data is input to each print data buffer 105, the buffer outputs the print data to the control signal processing unit 108. When incompatible print data is input, the buffer outputs the print data to another print data buffer 105. For example, the number of print data buffers 105 provided is equal to the number of lines used in the print data conversion process by the signal processing circuit 101 to replace the print data with a non-ejection drive waveform. In this embodiment, two or three print data buffers 105 are provided, and when corresponding one line of print data is input, the buffer outputs print data to the control signal processing unit 108. When incompatible print data is input, the buffer outputs print data for the incompatible line to the print data buffer 105 corresponding to the next line. In the following explanation, the three print data buffers 105 may be described as follows, depending on the order of the multiple lines: the first print data buffer 105 is print data buffer 1051, the second print data buffer 105 is print data buffer 1052, and the third print data buffer 105 is print data buffer 1053. Each print data buffer 105 also functions as a memory, which is a storage means for storing the corresponding one line of print data.

[0020] For example, in an example having two print data buffers 105, print data buffer 1051 outputs print data (second print data) for the next line of the drive line to control signal processing unit 108, and print data buffer 1052 outputs print data (first print data) for the drive line to control signal processing unit 108. Here, the drive line is a line that drives an actuator (pressure chamber), or in other words, a line that determines the operation of head drive circuit 102. In an example having three print data buffers 105, for example, print data buffer 1051 outputs print data (second print data) for the next line of the drive line to control signal processing unit 108, print data buffer 1052 outputs print data (first print data) for the drive line to control signal processing unit 108, and print data buffer 1053 outputs print data (second print data) for driving or having driven the line before the drive line to control signal processing unit 108.

[0021] The control signal processing unit 108 functions, for example, as a memory that is a storage means for storing predetermined print patterns. The control signal processing unit 108 also receives each line of print data transmitted from each print data buffer 105 and performs processing to determine whether the data matches the print pattern of a specific algorithm. If the print data for each line transmitted from each print data buffer 105 matches the print pattern of a specific algorithm, the control signal processing unit 108 outputs a precursor waveform (non-ejection waveform), which is an example of print data (third print data) different from the print data for the driven line, as print data to the transmission unit 109. If the print data for each line transmitted from each print data buffer 105 does not match the print pattern of the specific algorithm, the control signal processing unit 108 outputs the same print data as the print data for the driven line to the transmission unit 109.

[0022] The transmission unit 109 outputs the print data input by the control signal processing unit 108 to the head driving circuit 102 .

[0023] The head drive circuit 102 is a circuit that generates a drive signal including an expansion pulse that expands the volume of a plurality of pressure chambers in the actuator group 103 and a contraction pulse that contracts the volume of the pressure chambers. The head drive circuit 102 generates a drive waveform as a drive signal based on print data and drives the actuator group 103 of the liquid ejection head 100. The actuator group 103 expands and contracts the pressure chambers that contain ink, causing ink droplets to be ejected from nozzles that communicate with the pressure chambers. In this way, the liquid ejection head 100 ejects ink onto a recording medium transported by a transport mechanism, and prints an image or the like on the recording medium.

[0024] As shown in FIG. 3, the head drive circuit 102 includes an I / O section 110, a logic section 120, and an analog section 130.

[0025] The I / O unit 110 has a comparator 111 and a serial-to-parallel conversion unit 112. In the drawings, the "serial-to-parallel conversion unit" is abbreviated to "conversion unit."

[0026] A clock signal CLK and a data signal DI of Low Voltage Differential Signaling (LVDS) are input to the comparator 111. The data signal DI includes print data, setting data, etc. The comparator 111 outputs the data of the clock signal CLK and the data of the data signal DI to the serial-to-parallel converter 112.

[0027] The serial-parallel conversion unit 112 converts the serial format data input from the comparator 111 into parallel format data. It acquires the data of the data signal DI at the timing of the rising edge of the clock signal CLK. More specifically, it acquires the values ​​(0 or 1) of the setting data and print data included in the data signal DI at the timing when the clock signal CLK changes from 0 to 1. The serial-parallel conversion unit 112 outputs the data of the parallel format data signal DI to the logic unit 120. The serial-parallel conversion unit 112 also outputs the data of the clock signal CLK to the logic unit 120 and the analog unit.

[0028] The logic unit 120 includes a start byte recognition unit 121, a setting data register 122, a print data register 123, and a waveform pattern generation unit .

[0029] Start byte recognition unit 121 recognizes the start byte of the data in parallel data signal DI input from serial-parallel conversion unit 112, and separates it into setting data and print data. Start byte recognition unit 121 outputs the setting data to setting data register 122 and outputs the print data to print data register 123.

[0030] The setting data register 122 stores the setting data input from the start byte recognition unit 121 .

[0031] The print data register 123 stores the print data input from the start byte recognition unit 121 .

[0032] The waveform pattern generating unit 124 acquires the setting data from the setting data register 122 and the print data from the print data register 123, and generates a waveform pattern as a drive signal based on the setting data and the print data. The waveform pattern generating unit 124 outputs the generated waveform pattern to the analog unit 130.

[0033] In other words, the analog section 130 is a drive waveform generating section that generates a drive waveform based on a waveform pattern. The analog section 130 includes a level shifter 131, a pre-buffer 132, and a gate driver 133.

[0034] The level shifter 131 converts the waveform pattern input from the waveform pattern generating unit 124 into a high voltage waveform pattern. The level shifter 131 outputs the high voltage waveform pattern to the pre-buffer 132.

[0035] The pre-buffer 132 appropriately amplifies and shapes the waveform pattern input from the level shifter 131. The pre-buffer 132 outputs the appropriately amplified and shaped waveform pattern to the gate driver 133.

[0036] The gate driver 133 outputs a drive waveform for driving the actuator group 103 of the liquid ejection head 100 by controlling the ON / OFF of a plurality of switch elements that the gate driver 133 has based on the waveform pattern input from the pre-buffer 132. In other words, the gate driver 133 is a drive waveform output unit that outputs a drive waveform based on the waveform pattern. For example, the switch element is a MOSFET, and the gate driver 133 controls the ON / OFF of the MOSFET by applying a control signal (gate voltage) to the gate of the MOSFET.

[0037] The actuator group 103 has a plurality of actuators. Each actuator is a driving element that expands and contracts a pressure chamber that contains ink, causing ink droplets to be ejected from a nozzle that communicates with the pressure chamber. For example, each actuator is a piezoelectric driving element made of PZT (lead zirconate titanate). Each actuator of the actuator group 103 is driven in accordance with a driving signal supplied from the head driving circuit 102 to expand and contract the pressure chamber, thereby varying the volume of the pressure chamber and causing droplets to be ejected from the nozzle.

[0038] The processor 201 corresponds to the central part of a computer. The processor 201 controls each part to realize various functions of the liquid ejection device 200 in accordance with an operating system and application programs. The processor 201 is, for example, a CPU (Central Processing Unit).

[0039] The ROM 202 corresponds to the read-only main memory of the computer. The ROM 202 stores the operating system and application programs. The ROM 202 may also store data necessary for the processor 201 to execute processes for controlling each unit.

[0040] The RAM 203 corresponds to the rewritable main memory of the computer. The RAM 203 stores data necessary for the processor 201 to execute processing. The RAM 203 is also used as a work area where information is rewritten as needed by the processor 201. The work area includes an image memory where print data is expanded.

[0041] The operation panel 204 has an operation unit and a display unit. The operation unit has function keys such as a power key, a paper feed key, an error reset key, etc. The display unit can display various states of the liquid ejection device 200.

[0042] The communication interface 205 receives print data from a client terminal connected via a network such as a LAN (Local Area Network). For example, when an error occurs in the liquid ejection device 200, the communication interface 205 transmits a signal notifying the client terminal of the error.

[0043] The motor drive circuit 207 controls the driving of the transport motor 206. The transport motor 206 functions as a drive source for a transport mechanism that transports a recording medium such as printing paper. When the transport motor 206 starts, the transport mechanism begins transporting the recording medium. The transport mechanism transports the recording medium to a printing position using the liquid ejection head 100. After printing, the transport mechanism ejects the recording medium from an outlet (not shown) to the outside of the liquid ejection device 200.

[0044] The pump drive circuit 209 controls the driving of the pump 208. When the pump 208 is driven, ink in an ink tank (not shown) is supplied to the liquid ejection head 100.

[0045] Next, referring to Figures 4 and 5, we will explain an example of a method for generating a drive waveform from two lines of print data (two print data buffers 1051, 1052) in the signal processing circuit 101 and head drive circuit 102 of the liquid ejection head 100 of this embodiment.

[0046] As an example, as shown in FIG. 4, the setting data register 122 stores print data and drive waveforms corresponding to the print data. For example, print data "0" is a non-drive waveform pattern, print data "1" is a 1-drop drive waveform pattern that ejects one drop of liquid, print data "2" is a 1-drop drive waveform pattern that ejects two drops of liquid, print data "3" is a 1-drop drive waveform pattern that ejects three drops of liquid, and print data "4" is a waveform pattern that drives a precursor as a non-ejection waveform. Note that in FIG. 5, "x" is a "Don't Care" symbol that does not matter what the value of the print data is, and is any one of 0 to 3. The values ​​of the print data input to the signal processing circuit 101 are 0 to 3.

[0047] Then, when signal processing circuit 101 receives two lines of print data at receiving unit 104, it inputs the two lines of print data from receiving unit 104 to print data buffer 1051. Print data buffer 1051 outputs the next line of print data as the corresponding line to control signal processing unit 108, and outputs the line of print data to be driven as the uncorresponding line to print data buffer 1052. Print data buffer 1052 outputs the line of print data to be driven as the corresponding line to control signal processing unit 108.

[0048] The control signal processing unit 108 performs print data conversion processing to output print data different from the print data of the line to be driven when the print data input from the print data buffers 1051 and 1052 matches the print pattern of a specific algorithm to the transmission unit 109. For example, in this embodiment, in order to prevent the phenomenon in which the ejection volume decreases when changing from a non-driven state to an ejection state, a case in which a driven line is non-driven and the next line ejects droplets is determined to be a specific algorithm, and print data is output to the transmission unit 109 to drive a precursor waveform that does not eject droplets but is not a non-drive waveform as a non-ejection waveform in the driven line. Specifically, since the setting data in the setting data register 122 is set to a waveform pattern for precursor drive when the print data is "4," the control signal processing unit 108 outputs print data "4" to the transmission unit 109 so that the print data for the drive line corresponds to precursor drive when the print data is "0" for non-drive on the drive line and matches a pattern of any of "1," "2," or "3" that are print data for ejecting droplets on the next line, as shown in the truth table for the print data conversion process in Fig. 5. Also, as shown in Fig. 5, the control signal processing unit 108 outputs the print data for the drive line to the transmission unit 109 when the print data is "0" for non-drive on the drive line and does not match a pattern of any of "1," "2," or "3" that are print data for ejecting droplets on the next line, i.e., when the print data for the drive line is "0" and the print data for the next line is "0," or when the print data for the drive line is "1," "2," or "3."

[0049] Then, when the head driving circuit 102 acquires the print data of the drive lines from the transmission unit 109, the waveform pattern generation unit 124 acquires the setting data from the setting data register 122 and the print data from the print data register 123. The waveform pattern generation unit 124 then generates a waveform pattern as a drive waveform (drive signal) based on the setting data and the print data of the drive lines output from the signal processing circuit 101. In this way, the signal processing circuit 101 and head driving circuit 102 of the liquid ejection head 100 generate a drive waveform from the print data of the drive lines and the print data of the line one line after the drive line as print data of two lines (two print data buffers 1051, 1052).

[0050] Furthermore, by performing such print data conversion processing, the head drive circuit 102, the print data register 1231 that outputs print data for the next line of the drive line to the waveform pattern generation unit 124, the print data register 1232 that outputs print data for the drive line to the waveform pattern generation unit 124, and the waveform pattern generation unit 124 that serves as a signal processing circuit are made up of multiple integrated circuits, for example, two ICs, the signal processing circuit 101 and the head drive circuit 102.

[0051] Next, referring to Figures 4 and 6, we will explain another example of a method for generating a drive waveform from three lines of print data (three print data buffers 1051, 1052, 1053) in the signal processing circuit 101 and head drive circuit 102 of the liquid ejection head 100 of this embodiment.

[0052] When signal processing circuit 101 receives two lines of print data at receiving unit 104, it inputs three lines of print data from receiving unit 104 to print data buffer 1051. Print data buffer 1051 outputs the print data for the next line to control signal processing unit 108 as the corresponding line, and outputs the print data for the line to be driven and the print data for the line immediately preceding the line to be driven as two uncorresponding lines to print data buffer 1052. Print data buffer 1052 outputs the print data for the line to be driven to control signal processing unit 108 as the corresponding line, and outputs the print data for the previous line to print data buffer 1053 as the uncorresponding line. Print data buffer 1053 outputs the print data for the previous line to control signal processing unit 108 as the corresponding line.

[0053] The control signal processing unit 108 outputs print data different from the print data of the line to be driven when the print data input from the print data buffers 1051, 1052, and 1053 matches the print pattern of a specific algorithm to the transmission unit 109. For example, in another example of this embodiment, in order to prevent a phenomenon in which the ejection volume decreases when changing from a non-driven state to an ejection state, the control signal processing unit 108 determines, as a specific algorithm, a case in which the previous line and the driven line are non-driven and the next line ejects droplets, and outputs print data to the transmission unit 109 that drives, as a non-ejection waveform in the drive line, a precursor waveform that does not eject droplets but is not a non-drive waveform. Specifically, the setting data in the setting data register 122 is set to the precursor drive waveform pattern when the print data is "4". Therefore, as shown in the truth table of the print data conversion process in Fig. 6, when the print data for both the previous line and the drive line is "0" indicating non-drive and matches a pattern of "1," "2," or "3" which is print data for ejecting droplets on the next line, the control signal processing unit 108 outputs print data "4" to the transmission unit 109 so that the print data for the drive line corresponds to precursor drive. Also, as shown in Fig. 6, when the print data for the drive line is "0" indicating non-drive and does not match a pattern of "1," "2," or "3" which is print data for ejecting droplets on the next line, that is, when the print data for the drive line is "0" and the print data for the next line is "0," or when the print data for the drive line is "1," "2," or "3," the control signal processing unit 108 outputs the print data for the drive line to the transmission unit 109.

[0054] That is, if precursor driving is performed on a drive line when only one of the drive lines is non-driven, i.e., when the print data for the drive line and those before and after it are driven, non-driven, and driven, the print data will be driven, precursor driven, and drive, which may result in a deterioration in print quality. For this reason, in another example of the embodiment, as a countermeasure to deterioration in print quality, precursor driving is performed on a drive line only when the drive line and the line immediately before the drive line are consecutively non-driven, i.e., when the print data for the drive line and those before and after it are non-driven, non-driven, and drive, the control signal processing unit 108 sets the print data for the drive line and those before and after it to be non-driven, precursor driven, and drive, and does not perform conversion processing if the drive line or only one line before and after it is non-driven.

[0055] When the head driving circuit 102 acquires the print data of the drive lines from the transmission unit 109, the waveform pattern generation unit 124 acquires the setting data from the setting data register 122 and the print data from the print data register 123. The waveform pattern generation unit 124 then generates a waveform pattern as a drive waveform (drive signal) based on the setting data and the print data of the drive lines output from the signal processing circuit 101. In this way, the signal processing circuit 101 and head driving circuit 102 of the liquid ejection head 100 generate drive waveforms from the print data of the drive lines, the print data of the line immediately before the drive line, and the print data of the line immediately after the drive line as three lines of print data (three print data buffers 1051, 1052).

[0056] As described above, the liquid ejection head 100 according to the embodiment can drive the drive lines with different print data when the print data for multiple lines matches a specific pattern in the signal processing circuit 101. Therefore, the liquid ejection head 100 can generate a non-ejection waveform based on the print data for multiple lines without reducing usability and while suppressing an increase in power consumption.

[0057] The above-described embodiment is merely illustrative and not limiting. For example, in the above example, the liquid ejection head 100 includes a signal processing circuit 101, and the signal processing circuit 101 performs print data conversion processing to convert input print data of multiple lines into different print data based on an algorithm. However, the present invention is not limited to this. For example, the liquid ejection head 100 may not include the signal processing circuit 101, and the head driving circuit 102 may perform print data conversion processing. As another embodiment, a head driving circuit 102 of a liquid ejection head 100 that does not include a signal processing circuit 101 will be described below using FIGS. 7 and 8. In the head driving circuit 102 of the liquid ejection head 100, instead of the signal processing circuit 101, a waveform pattern generating unit 124 having functions equivalent to the control signal processing unit 108 performs print data conversion processing to convert input print data of multiple lines into different print data based on the input print data.

[0058] The head drive circuit 102 of another embodiment shown in Fig. 7 differs from the head drive circuit 102 of the embodiment shown in Fig. 3 described above in terms of the number of print data registers 123. That is, the head drive circuit 102 shown in Fig. 7 is provided with the same number of print data registers 123 as the number of lines of print data for performing print data conversion processing. For example, in the examples of Figs. 7 and 8, the head drive circuit 102 of the liquid ejection head 100 performs print data conversion processing based on the print data of the drive line and the print data of the line one line after the drive line, and therefore is provided with two print data registers 123.

[0059] 7, in a head drive circuit 102 of another embodiment, the waveform pattern generation unit 124 determines the drive waveform by referencing not only the print data for one line to be driven, but also the print data for the line immediately following the drive line. As a specific example, the print data register 123 includes a print data register 1231 that refers to the print data for the drive line, and a print data register 1232 that refers to the print data for the line immediately following the drive line.

[0060] The control signal processing unit 108 of the signal processing circuit 101, which references the above-mentioned multiple print data, is a circuit included in the waveform pattern generating unit 124. Therefore, the head driving circuit 102, the print data register 1231 that outputs print data for the next line of the drive line to the waveform pattern generating unit 124, the print data register 1232 that outputs print data for the drive line to the waveform pattern generating unit 124, and the waveform pattern generating unit 124, which serves as a signal processing circuit, are all configured on the same integrated circuit. For example, the print data register 1231 outputs print data for the next line of the drive line to the waveform pattern generating unit 124, and outputs the print data for the drive line to the print data register 1232. The print data register 1232 outputs the print data for the drive line to the waveform pattern generating unit 124. 8, the waveform pattern generating unit 124 acquires setting data from the setting data register 122, acquires print data from the print data registers 1231 and 1232, and generates a waveform pattern as a drive signal based on the predetermined setting data and print data. Each print data register 123 also functions as a memory, which is a storage means for storing print data for one corresponding line.

[0061] A liquid ejection head using the head drive circuit 102 of this other embodiment can drive the drive lines with different print data when the print data for multiple lines matches a specific pattern. Therefore, the liquid ejection head 100 can generate a non-ejection waveform based on the print data for multiple lines without reducing usability and while suppressing an increase in power consumption.

[0062] According to at least one embodiment of the liquid ejection head described above, when the print data of multiple lines matches a specific pattern, the print data of the drive line is driven with different print data, thereby making it possible to generate a non-ejection waveform based on the print data of multiple lines without reducing usability and while suppressing an increase in power consumption.

[0063] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0064] 100...liquid ejection head, 101...signal processing circuit, 102...head drive circuit (drive circuit), 103...actuator group, 104...receiving unit, 105...print data buffer, 108...control signal processing unit, 109...transmitting unit, 110...I / O unit, 111...comparator, 112...serial-to-parallel conversion unit, 120...logic unit, 121...start byte recognition unit, 122...setting data register, 123...print data register, 124...waveform pattern generation unit, 130...analog unit, 131...level shifter, 132...print Buffer, 133...gate driver, 200...liquid ejection device, 201...processor, 202...ROM, 203...RAM, 204...operation panel, 205...communication interface (communication IF), 205...communication interface, 206...conveying motor, 207...motor driving circuit, 208...pump, 209...pump driving circuit, 210...bus line, 1051...printing data buffer, 1052...printing data buffer, 1053...printing data buffer, 1231...printing data register, 1232...printing data register.

Claims

1. an actuator that varies the volume of a plurality of pressure chambers corresponding to the nozzles; a drive circuit that generates a drive signal including an expansion pulse that causes the actuator to expand the volume of the pressure chamber and a contraction pulse that causes the actuator to contract the volume of the pressure chamber; a memory containing first print data of one line and second print data of a line different from the first print data, which determines a waveform pattern to be generated by the drive circuit; a signal processing circuit that refers to the memory and outputs the first print data, the second print data, or predetermined third print data different from the first print data; Equipped with A liquid ejection head, wherein the drive circuit outputs the third print data when the first print data and the second print data match a predetermined pattern, and outputs the first print data when the first print data and the second print data do not match the pattern.

2. 2. The liquid ejection head according to claim 1, wherein the second print data is print data for one line after a line that determines the operation of the drive circuit.

3. 2. The liquid ejection head according to claim 1, wherein the second print data is print data for a line immediately preceding a line that determines the operation of the drive circuit.

4. The liquid ejection head according to claim 1 , wherein the drive circuit, the memory, and the signal processing circuit are configured by a plurality of integrated circuits.

5. The liquid ejection head according to claim 1 , further comprising an integrated circuit having the drive circuit, the memory, and the signal processing circuit.

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