Nozzle driving waveform generating device and ink-jet printer

Abstract

The invention discloses a nozzle driving waveform generation device and an ink-jet printer, and relates to the technical field of ink-jet printing. The device comprises a DAC digital-to-analog conversion module, an OPA amplification module, a power amplification module and a coupling bias module, the DAC digital-to-analog conversion module is electrically connected with the OPA amplification module, the OPA amplification module is electrically connected with the DAC digital-to-analog conversion module and the power amplification module, and the power amplification module is electrically connected with the OPA amplification module and the coupling bias module. According to the nozzle driving waveform generation device and the ink-jet printer provided by the embodiment of the invention, the negative voltage driving waveform or the positive voltage driving waveform can be generated according to the actual application condition, so that the driving requirements of various nozzles including a negative-pressure nozzle, a positive-pressure nozzle and the like are met, and the compatibility is good; a negative pressure power supply does not need to be added to meet the negative voltage requirement of the negative pressure nozzle, the structure is simple, and the printing efficiency and the printing effect can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inkjet printing, and in particular to a nozzle drive waveform generating device and an inkjet printer. Background Art

[0002] With the development of nozzle technology and the improvement of inkjet requirements, nozzles that require negative pressure drive have emerged, such as the Xerox 5501 nozzle. This type of nozzle needs to generate an adjustable negative voltage waveform with a DC bias range of 0 to -20V for driving; since the current nozzle driving circuit is set to output positive voltage for output stability and reduction of driving error, it cannot meet the needs of negative pressure driven nozzles. In order to achieve negative pressure driven nozzles, the existing method is often to set a power supply containing negative voltage for nozzle negative pressure drive, but the driving voltages of nozzles of different brands are also different. If the needs of nozzles of different brands are to be met, multiple negative voltages need to be set for power supply, which will lead to complex circuits and increased costs. At the same time, the long circuit response time affects printing efficiency. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a nozzle driving waveform generating device and an inkjet printer to solve the problem in the prior art that the driving waveform of a negative pressure nozzle is difficult to generate.

[0004] In a first aspect, an embodiment of the present invention provides a nozzle drive waveform generating device, the device comprising: a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module, and a coupling bias module, wherein the DAC digital-to-analog conversion module and the OPA amplification module are electrically connected, the OPA amplification module is electrically connected to the DAC digital-to-analog conversion module and the power amplifier module, and the power amplifier module is electrically connected to the OPA amplification module and the coupling bias module;

[0005] The DAC digital-to-analog conversion module is used to convert a digital first driving waveform input from the inkjet printer control module into an analog second driving waveform and output it to the OPA amplification module;

[0006] The OPA amplification module is used to perform operational amplification on the second driving waveform and then output a third driving waveform;

[0007] The power amplifier module is used to amplify the power of the third driving waveform and then output a fourth driving waveform;

[0008] The coupling bias module is used to convert the fourth driving waveform into a fifth driving waveform, and the fifth driving waveform is used to drive the nozzle to eject ink.

[0009] Preferably, the DAC digital-to-analog conversion module includes a DAC chip and its peripheral circuits, the DAC chip at least including: signal input pins D0 to D9, signal output pins OUT1P and OUT2P, as well as an AVDD pin, an AGND pin, a REFO pin, a DACEN pin, a DVDD pin, a DGND pin, a PD pin, a REN pin, CREF1 and CREF2 pins, a CLK pin, and a CS pin. The peripheral circuits of the DAC chip include: a first inductor having one end electrically connected to the AVDD pin of the DAC chip and the other end for accessing an analog power supply, a second inductor having one end electrically connected to the AVDD pin of the DAC chip and the other end for accessing a power supply, a first capacitor and a second capacitor having one end electrically connected to the AVDD pin of the DAC chip and the other end grounded, a third capacitor having one end electrically connected to the REFO pin of the DAC chip and the other end grounded, a fourth capacitor and a fifth capacitor respectively connected to the DACEN pin and the REN pin of the DAC chip, a sixth capacitor having one end electrically connected to the CREF1 pin of the DAC chip and the other end grounded, and a seventh capacitor having one end electrically connected to the CREF2 pin and the other end grounded.

[0010] Preferably, the OPA amplification module includes a first operational amplifier and its peripheral circuit, the first operational amplifier includes at least a first INA- pin, a first INA+ pin and a first OUTA pin, and the peripheral circuit of the first operational amplifier includes: an eighth capacitor and a first resistor whose two ends are electrically connected to the first INA- pin and the first OUTA pin respectively, a second resistor with one end electrically connected to the first INA- pin and the other end grounded, a third resistor electrically connected to the first OUTA pin, and a fourth resistor electrically connected to the first INA+.

[0011] Preferably, the gain of the first operational amplifier is 11 times.

[0012] Preferably, the OPA amplification module also includes a second operational amplifier and its peripheral circuits, a second operational amplifier and its peripheral components, the second operational amplifier includes a second INA+ pin, a second INA- pin, a second OUTA pin, a second positive voltage pin, and a second negative voltage pin. The peripheral circuit of the second operational amplifier 22 includes: a ninth resistor having one end electrically connected to the second INA+ pin and the other end electrically connected to the first OUTA pin of the first operational amplifier, a tenth resistor having one end electrically connected to the second positive voltage pin and the other end grounded, an eleventh resistor having one end electrically connected to the second positive voltage pin and the other end connected to a positive power supply, a twelfth resistor having one end electrically connected to the second INA- pin and the other end grounded, a thirteenth resistor and a tenth capacitor having two ends electrically connected to the second INA- pin and the second OUTA pin, respectively.

[0013] Preferably, the gain of the second operational amplifier is 4.95 times.

[0014] Preferably, the power amplifier module includes a differential input amplification unit, a voltage amplification unit and an output buffer unit. The third driving waveform is first differentially amplified by the differential amplification unit, then voltage amplified by the voltage amplification unit, and finally output by the output buffer unit to obtain the fourth driving waveform.

[0015] Preferably, the coupling bias module includes a coupling unit and a bias unit, wherein the coupling unit is electrically connected to the power amplifier module and the bias unit respectively, the coupling unit is used to perform level conversion on the fourth drive waveform to obtain a sixth drive waveform, and the bias unit is used to perform voltage reduction or voltage increase processing on the sixth drive waveform to obtain the fifth drive waveform.

[0016] Preferably, the coupling unit includes a MOSFET and its peripheral circuit, wherein the MOSFET includes a first pin, a second pin and a third pin, and the peripheral circuit of the MOSFET includes: an eleventh capacitor with one end electrically connected to the first pin and the other end electrically connected to the ground, a first diode with one end electrically connected to the first pin and the other end electrically connected to the thirteenth resistor, a thirteenth resistor with one end electrically connected to the first diode and the other end connected to the power supply, a second diode with two ends electrically connected to the first pin and the second pin respectively, a fourteenth resistor with one end electrically connected to the second pin and the other end grounded, a fifteenth resistor with one end electrically connected to the third pin and the other end electrically connected to the sixteenth resistor, a sixteenth resistor with two ends electrically connected to the first resistor and the fifteenth resistor respectively, and twelfth to twenty-first capacitors in parallel electrically connected to the second pin.

[0017] In a second aspect, an embodiment of the present invention provides an inkjet printer, comprising the nozzle drive waveform generating device as described in any one of the first aspects.

[0018] In summary, the beneficial effects of the present invention are as follows:

[0019] Since the nozzle drive waveform generating device and inkjet printer of the present invention include a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module and a coupling bias module, wherein the DAC digital-to-analog conversion module and the OPA amplification module are electrically connected, the OPA amplification module is electrically connected to the DAC digital-to-analog conversion module and the power amplifier module respectively, and the power amplifier module is electrically connected to the OPA amplification module and the coupling bias module respectively; the DAC digital-to-analog conversion module is used to convert the digital first drive waveform input from the inkjet printer control module into an analog second drive waveform and then output it to the OPA amplification module; the OPA amplification module is used to perform operational amplification on the second drive waveform and then output a third drive waveform; the power amplifier module is used to perform power amplification on the third drive waveform and then output a fourth drive waveform; the coupling bias module is used to convert the fourth drive waveform into a fifth drive waveform, and the fifth drive waveform is used to drive the nozzle to eject ink. The nozzle drive waveform generating device and inkjet printer provided by the embodiments of the present invention can generate a negative voltage drive waveform or a positive voltage drive waveform according to actual application conditions, thereby meeting the driving requirements of various nozzles including negative pressure nozzles and positive pressure nozzles. It has good compatibility and does not require an additional negative pressure power supply to meet the negative voltage requirements of the negative pressure nozzles. It has a simple structure and can improve printing efficiency and printing effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work, and these are all within the scope of protection of the present invention.

[0021] Figure 1 2 is a schematic structural diagram of a nozzle driving waveform generating device according to an embodiment of the present invention.

[0022] Figure 2 This is a circuit design diagram of a DAC digital-to-analog conversion module according to an embodiment of the present invention.

[0023] Figure 3 4 is a circuit design diagram of the OPA amplifier module according to an embodiment of the present invention.

[0024] Figure 4 4 is a circuit design diagram of the OPA amplifier module according to an embodiment of the present invention.

[0025] Figure 5 It is a circuit design diagram of the power amplifier module according to an embodiment of the present invention.

[0026] Figure 6 2 is a schematic structural diagram of a coupling bias module according to an embodiment of the present invention.

[0027] Figure 7 4 is a circuit design diagram of a coupling unit according to an embodiment of the present invention.

[0028] Figure 8 4 is a circuit design diagram of a bias unit according to an embodiment of the present invention.

[0029] Figure 9 FIG. 4 is a schematic diagram of a fifth driving waveform according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present invention by illustrating examples of the present invention.

[0031] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. The embodiments described below are merely illustrative, and the division of the modules or circuits is only a logical function division, and there may be other division methods in actual implementation. In this embodiment and the accompanying drawings, elements not related to the present invention have been omitted and not illustrated, and the size relationship between the elements in the accompanying drawings is only for ease of understanding and is not used to limit the actual proportion.

[0032] Example 1

[0033] See Figure 1An embodiment of the present invention provides a nozzle drive waveform generating device 10, which includes: a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module, and a coupling bias module, wherein the DAC digital-to-analog conversion module and the OPA amplification module are electrically connected, the OPA amplification module is electrically connected to the DAC digital-to-analog conversion module and the power amplifier module respectively, and the power amplifier module is electrically connected to the OPA amplification module and the coupling bias module respectively;

[0034] The DAC digital-to-analog conversion module is used to convert a digital first driving waveform input from the inkjet printer control module into an analog second driving waveform and output it to the OPA amplification module;

[0035] The OPA amplification module is used to perform operational amplification on the second driving waveform and then output a third driving waveform;

[0036] The power amplifier module is used to amplify the power of the third driving waveform and then output a fourth driving waveform;

[0037] The coupling bias module is used to convert the fourth driving waveform into a fifth driving waveform, and the fifth driving waveform is used to drive the nozzle to eject ink.

[0038] Specifically, the nozzle drive waveform generating device 10 of the embodiment of the present invention includes a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module, a coupling bias module and other modules. The electrical connection relationship between the modules is as follows: Figure 1 As shown, the DAC digital-to-analog conversion module is used to convert the digital driving waveform from the inkjet printer control module into an analog positive voltage driving waveform, the OPA amplification module and the power amplifier module are used to perform operational amplification and power amplification on the driving waveform according to requirements, and the coupling bias module converts the positive voltage driving waveform output from the power amplifier module into a negative voltage driving waveform and outputs it to the nozzle through the JCOM interface to drive the negative pressure nozzle. For the positive pressure nozzle, the nozzle driving waveform generating device 10 can also output the required positive voltage by adjusting the connection gear of the MOSFET in the coupling bias module.

[0039] The following is a detailed description of the circuit design diagrams of the DAC digital-to-analog conversion module, OPA amplification module, power amplifier module, and coupling bias module.

[0040] In one embodiment, Figure 2The following is a detailed circuit design diagram of the DAC digital-to-analog conversion module. The DAC digital-to-analog conversion module includes a DAC chip and its peripheral circuitry. In this embodiment, the DAC chip model is MAX5185BEEI. The DAC chip includes the following pins: signal input pins D0-D9, signal output pins OUT1P and OUT2P, as well as AVDD, AGND, REFO, DACEN, DVDD, DGND, PD, REN, CREF1 and CREF2, CLK, and CS. The abbreviations AVDD, AGND, and CLK are commonly used in the semiconductor and embedded systems industries, representing their respective functions. For example, AVDD is the pin that connects to the positive terminal of the analog voltage, AGND is the ground pin, and CLK is the pin that receives the clock signal. These abbreviations will not be elaborated on here.

[0041] It is worth noting that the signal input pins D0, D1, D2, D3, D4, D5, D6, D7, D8, and D9 are used to connect to corresponding digital signal output pins in the inkjet printer control module. In one embodiment, the inkjet printer control module is an FPGA, and the FPGA signal output pins include F_WD0, F_WD1, F_WD2, F_WD3, F_WD4, F_WD5, F_WD6, F_WD7, F_WD8, and F_WD9. Accordingly, the D0 pin of the DAC chip is electrically connected to the F_WD0 pin, the D1 pin is electrically connected to the F_WD1 pin, and the D9 pin is electrically connected to the F_WD9 pin. In addition, the CS pin and CLK pin of the DAC chip are electrically connected to the F_CS pin and F_CLK pin of the FPGA, respectively, for receiving chip select signals and clock signals from the FPGA. The DAC chip includes two output pins, OUT1P and OUT2P, which can output two analog signals. In another embodiment, when the nozzle requires multiple sets of analog driving waveform signals to drive, the number of DAC chips can be appropriately increased accordingly.

[0042] The other pins of the DAC chip are electrically connected to its peripheral components to form the DCA digital-to-analog conversion module, such as Figure 2As shown, one end of the first inductor FB2 and one end of the second inductor FB3 are electrically connected to the AVDD pin. The other end of the first inductor FB2 is connected to the AVCC analog power supply, and the other end of the second inductor FB3 is connected to the 3.3V VCC power supply. In addition, one end of the first capacitor C94 and the second capacitor C95 are also electrically connected to the AVDD pin, and the other ends of the first capacitor C94 and the second capacitor C95 are both grounded. The AGND pin of the DAC chip is directly grounded; the REFO pin is grounded through the third capacitor C96. The peripheral circuit composed of these components is used to connect the DCA chip to a stable analog power supply. In addition, one end of the fourth capacitor C100 and the fifth capacitor C101 are connected to the DACEN pin and the REN pin, where the DACEN pin is connected to the VCC power supply and the REN pin is grounded, to connect to a stable digital power supply. One end of the sixth capacitor C103 is connected to the CREF1 pin and the other end is grounded. One end of the seventh capacitor C107 is connected to the CREF2 pin and the other end is grounded. The DCA chip also includes the NC pin, the REFR pin, and floating pins such as OUT1N and OUT2N.

[0043] The DAC digital-to-analog conversion module converts the digital first driving waveform input from the inkjet printer control module into an analog second driving waveform, and then inputs the second driving waveform into the OPA amplification module for operational amplification.

[0044] In one embodiment, Figure 3As shown, the OPA amplification module includes a first operational amplifier 21 and its peripheral circuits. In this embodiment, the first operational amplifier 21 is model SGM80582. The first operational amplifier 21 includes a first INA- pin (negative input pin), a first INA+ pin (positive input pin), a first OUTA pin (input pin), a first positive voltage pin, and a first negative voltage pin, wherein the first positive voltage pin is connected to the 5V VDD power supply and the first negative voltage pin is grounded. The peripheral circuit of the first operational amplifier 21 includes: an eighth capacitor C111 and a first resistor R93, each of which is electrically connected to the first INA- pin and the first OUTA pin respectively; a second resistor R95, one end of which is electrically connected to the first INA- pin and the other end of which is grounded; a third resistor R96 electrically connected to the first OUTA pin; and a fourth resistor R98 electrically connected to the first INA+ pin. The second drive waveform from the DAC digital-to-analog conversion module is input to the first INA+ pin of the first operational amplifier 21 via the fourth resistor R98. After voltage amplification by the first operational amplifier 21, the third drive waveform is obtained and output from the first OUTA pin. Due to factors such as the actual power supply range, the second drive waveform converted by the DAC digital-to-analog conversion module generally has a lower voltage. However, in actual use, the nozzle requires a higher voltage value for its drive waveform, such as a maximum voltage of 50V and a minimum of no less than -50V. Therefore, the low-power second drive waveform generated by the DAC digital-to-analog conversion module needs to be amplified by the OPA amplifier module to achieve the actual voltage amplitude. Preferably, the gain of the first operational amplifier is set to 11 times, so that the voltage gain of the drive waveform passing through the OPA amplifier module is 11 times.

[0045] In one embodiment, in order to further improve the voltage gain, a second operational amplifier 22 can be added after the first operational amplifier 21 to form a two-stage operational amplifier. The OPA amplification module includes a first operational amplifier 21 and a second operational amplifier 22, wherein the first operational amplifier 21 and its peripheral circuits are as described above. Figure 3 As shown, the second operational amplifier 22 and its peripheral circuits are as follows Figure 4As shown, the second operational amplifier 22 is model TLE2142 and includes a second INA+ pin (positive input pin), a second INA- pin (negative input pin), a second OUTA pin (output pin), a second positive voltage pin, and a second negative voltage pin. The peripheral circuit of the second operational amplifier 22 includes: a ninth resistor R674 having one end electrically connected to the second INA+ pin and the other end electrically connected to the first OUTA pin of the first operational amplifier; a tenth resistor R669 having one end electrically connected to the second positive voltage pin and the other end grounded; an eleventh resistor R670 having one end electrically connected to the second positive voltage pin and the other end connected to a positive power supply; a twelfth resistor R673 having one end electrically connected to the second INA- pin and the other end grounded; a thirteenth resistor R672 having two ends electrically connected to the second INA- pin and the second OUTA pin, respectively; and a tenth capacitor C623. The first OUTA pin of the first operational amplifier 21 is electrically connected to the second INA+ pin of the second operational amplifier 22, thereby inputting the output waveform from the first operational amplifier 21 into the second operational amplifier 22 for second-stage operational amplification. Preferably, the gain of the second operational amplifier 22 is set at 4.95 times. It is worth noting that the gains of the first operational amplifier 21 and the second operational amplifier can be set according to actual application conditions and are not limited to the above-mentioned gain multiples.

[0046] The power amplifier module, electrically connected to the OPA amplifier module, is used to further amplify the third drive waveform output from the OPA amplifier module. The power amplifier module can amplify the voltage and power of the drive waveform. Since the OPA amplifier module performs operational amplification on the drive waveform, and operational amplifiers generally only amplify voltage but can only provide very small current, they do not have load capacity in practical applications. Therefore, the drive waveform after OPA amplification only meets the requirements in terms of shape and voltage amplitude, but the power is relatively low. Therefore, it is necessary to power amplify the drive waveform to ensure that it has a certain load output capacity.

[0047] In one embodiment, Figure 5 The figure shows a circuit diagram of the power amplifier module. The power amplifier module is composed of multiple transistors and MOSFETs, including a differential input amplifier unit 51, a voltage amplifier unit 52 and an output buffer unit 53. The third drive waveform is first differentially amplified by the first-stage differential amplifier unit 51 and then voltage-amplified by the second-stage voltage amplifier unit 52. Finally, it is output by the third-stage output buffer unit to obtain the fourth drive waveform.

[0048] The fourth driving waveform will be sent to the coupling bias module for voltage conversion and biasing, thereby forming a negative pressure driving waveform that can meet the needs of the negative pressure nozzle or a positive pressure driving waveform required by the positive pressure nozzle according to actual application conditions.

[0049] In one embodiment, Figure 6 As shown, the coupling bias module includes a coupling unit and a bias unit, wherein one end of the coupling unit is electrically connected to the power amplifier module, and the other end is electrically connected to the bias unit, and is used to convert the fourth driving waveform input into the coupling unit to obtain a sixth driving waveform and output it to the bias unit. The bias unit steps down or boosts the sixth driving waveform according to the actual application situation to obtain a fifth driving waveform that ultimately meets the requirements of the nozzle.

[0050] In one embodiment, Figure 7 , which is a circuit design diagram of a coupling unit. The coupling unit includes a MOSFET and its peripheral circuit, wherein the MOSFET model is NTD20P06L, including a first pin, a second pin, and a third pin, and the peripheral circuit of the MOSFET includes: the MOSFET includes a first pin, a second pin, and a third pin, and the peripheral circuit of the MOSFET includes: an eleventh capacitor C170 with one end electrically connected to the first pin and the other end grounded, a first diode D20 with one end electrically connected to the first pin and the other end electrically connected to a thirteenth resistor R155, and a a thirteenth resistor R155, a second diode D19 having two ends electrically connected to the first pin and the second pin respectively, a fourteenth resistor R152 having one end electrically connected to the second pin and the other end grounded, a fifteenth resistor R153 having one end electrically connected to the third pin and the other end electrically connected to the sixteenth resistor R156, a sixteenth resistor R156 having two ends electrically connected to the fourteenth resistor R155 and the fifteenth resistor R153 respectively, and twelfth to twenty-first capacitors C160 to C169 in parallel having the other ends electrically connected to the second pin and connected to the JCOM interface. The parallel capacitors can improve the stability of the driving waveform.

[0051] In one embodiment, Figure 8 As shown in the figure, it is a circuit design diagram of the bias unit. The coupling unit includes a DCDC power conversion chip and its peripheral circuits. The model of the DCDC power conversion chip is SCT2650. The DCDC power conversion chip includes a VIN pin, an EN pin, a COMP pin, a RT / CLK pin, a PWRPD pin, a BOOT pin, a SW pin, a FB pin and a GND pin. Among them, the English abbreviations such as AVIN and EN are commonly used pin names in the semiconductor and embedded fields, which represent the corresponding functions of the pins. For example, AVIN is an analog input pin, EN is an enable pin, etc., which will not be elaborated here. For the specific circuit diagram of the DCDC power conversion chip and its peripheral components, please refer to Figure 8 , which will not be introduced in detail here.

[0052] In one example, if Figure 9As shown, the fourth drive waveform output by the power amplifier module is a positive power waveform, including a fourth sub-drive waveform A and a fourth sub-drive waveform B. After passing through the coupling unit of the bias module, a sixth drive waveform including a sixth sub-drive waveform C and a sixth sub-drive waveform D is obtained. After passing through the bias unit, fifth sub-drive waveforms E and F are obtained. Finally, the bias module outputs a fifth drive waveform including a negative voltage, which can be used to drive a negative pressure nozzle. When the inkjet printer nozzle is a positive pressure nozzle and requires a positive power waveform, a positive voltage drive waveform meeting the requirements of the positive pressure nozzle can be output simply by adjusting the connection position of the MOSFET in the coupling unit. Therefore, the nozzle drive waveform generation device provided in this embodiment of the present invention can generate either a negative voltage drive waveform or a positive voltage drive waveform according to actual application conditions, thereby meeting the driving requirements of various nozzles, including negative and positive pressure nozzles. It has good compatibility, eliminates the need for an additional negative voltage power supply to meet the negative voltage requirements of the negative pressure nozzle, and has a simple structure. In addition, the coupling unit in the coupling bias module includes a feedback circuit, which can monitor voltage changes in real time to improve response time, increase printing efficiency and improve printing effects.

[0053] Example 2

[0054] The present invention further discloses an inkjet printer comprising a nozzle and a nozzle drive waveform generating device for improving the printing performance of the inkjet printer. The nozzle drive waveform generating device is the nozzle drive waveform generating device described in any of the above embodiments. Since the nozzle drive waveform generating device described in this embodiment has the same circuit structure as the nozzle drive waveform generating device described in any of the above embodiments and thus has the same technical effects, its structure is not further described here.

[0055] In summary, the nozzle drive waveform generating device and the inkjet printer of the present invention include a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module and a coupling bias module, wherein the DAC digital-to-analog conversion module and the OPA amplification module are electrically connected, the OPA amplification module is electrically connected to the DAC digital-to-analog conversion module and the power amplifier module respectively, and the power amplifier module is electrically connected to the OPA amplification module and the coupling bias module respectively; the DAC digital-to-analog conversion module is used to convert the digital first drive waveform input from the inkjet printer control module into an analog second drive waveform and then output it to the OPA amplification module; the OPA amplification module is used to perform operational amplification on the second drive waveform and then output a third drive waveform; the power amplifier module is used to perform power amplification on the third drive waveform and then output a fourth drive waveform; the coupling bias module is used to convert the fourth drive waveform into a fifth drive waveform, and the fifth drive waveform is used to drive the nozzle to eject ink. The nozzle drive waveform generation device and inkjet printer provided by embodiments of the present invention can generate negative or positive voltage drive waveforms based on actual application conditions, thereby meeting the drive requirements of various nozzles, including negative and positive pressure nozzles. The device exhibits excellent compatibility, eliminates the need for an additional negative voltage power supply to meet the negative voltage requirements of negative pressure nozzles, and exhibits a simple structure. Furthermore, the coupling unit in the coupling bias module includes a feedback circuit that monitors voltage changes in real time, improving response time, and enhancing printing efficiency and results.

[0056] The nozzle drive waveform generating device and inkjet printer provided by the present invention are described in detail above. Those skilled in the art will further understand that the various illustrative logic blocks, modules, circuits and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been generally described above in terms of functionality. Whether the functionality is implemented as hardware or software depends on the specific use and the design constraints imposed on the entire system. Those skilled in the art can implement the described functionality in different ways for each specific use. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present invention. It should not be understood as a limitation of the present invention.

Claims

1. A nozzle drive waveform generating device, characterized in that: The device includes: a DAC digital-to-analog conversion module, an OPA amplification module, a power amplifier module and a coupling bias module, wherein the DAC digital-to-analog conversion module and the OPA amplification module are electrically connected, the OPA amplification module is electrically connected to the DAC digital-to-analog conversion module and the power amplifier module respectively, and the power amplifier module is electrically connected to the OPA amplification module and the coupling bias module respectively; The DAC digital-to-analog conversion module is used to convert a digital first driving waveform input from the inkjet printer control module into an analog second driving waveform and then output it to the OPA amplification module; The OPA amplification module is used to perform operational amplification on the second driving waveform and then output a third driving waveform; The power amplifier module is used to amplify the power of the third driving waveform and then output a fourth driving waveform; The coupling bias module is used to convert the fourth driving waveform into a fifth driving waveform, and the fifth driving waveform is used to drive the nozzle to eject ink.

2. The nozzle driving waveform generating device according to claim 1, characterized in that: The DAC digital-to-analog conversion module includes a DAC chip and its peripheral circuits. The DAC chip includes at least: signal input pins D0 to D9, signal output pins OUT1P and OUT2P, as well as an AVDD pin, an AGND pin, a REFO pin, a DACEN pin, a DVDD pin, a DGND pin, a PD pin, a REN pin, CREF1 and CREF2 pins, a CLK pin, and a CS pin. The peripheral circuits of the DAC chip include: a first inductor having one end electrically connected to the AVDD pin of the DAC chip and the other end for connecting to an analog power supply, a second inductor having one end electrically connected to the AVDD pin of the DAC chip and the other end for connecting to a power supply, a first capacitor and a second capacitor having one end electrically connected to the AVDD pin of the DAC chip and the other end grounded, a third capacitor having one end electrically connected to the REFO pin of the DAC chip and the other end grounded, a fourth capacitor and a fifth capacitor respectively connected to the DACEN pin and the REN pin of the DAC chip, a sixth capacitor having one end electrically connected to the CREF1 pin of the DAC chip and the other end grounded, and a seventh capacitor having one end electrically connected to the CREF2 pin and the other end grounded.

3. The nozzle driving waveform generating device according to claim 1, characterized in that: The OPA amplification module includes a first operational amplifier and its peripheral circuit, the first operational amplifier includes at least a first INA- pin, a first INA+ pin and a first OUTA pin, and the peripheral circuit of the first operational amplifier includes: an eighth capacitor and a first resistor with both ends electrically connected to the first INA- pin and the first OUTA pin respectively, a second resistor with one end electrically connected to the first INA- pin and the other end grounded, a third resistor electrically connected to the first OUTA pin, and a fourth resistor electrically connected to the first INA+.

4. The nozzle driving waveform generating device according to claim 3, characterized in that: The gain of the first operational amplifier is 11 times.

5. The nozzle driving waveform generating device according to claim 3, characterized in that: The OPA amplification module also includes a second operational amplifier and its peripheral circuits and components. The second operational amplifier includes a second INA+ pin, a second INA- pin, a second OUTA pin, a second positive voltage pin, and a second negative voltage pin. The peripheral circuits of the second operational amplifier 22 include: a ninth resistor with one end electrically connected to the second INA+ pin and the other end electrically connected to the first OUTA pin of the first operational amplifier; a tenth resistor with one end electrically connected to the second positive voltage pin and the other end grounded; an eleventh resistor with one end electrically connected to the second positive voltage pin and the other end connected to a positive power supply; a twelfth resistor with one end electrically connected to the second INA- pin and the other end grounded; a thirteenth resistor and a tenth capacitor with two ends electrically connected to the second INA- pin and the second OUTA pin, respectively.

6. The nozzle driving waveform generating device according to claim 5, characterized in that: The gain of the second operational amplifier is 4.95 times.

7. The nozzle driving waveform generating device according to claim 4, characterized in that: The power amplifier module includes a differential input amplification unit, a voltage amplification unit and an output buffer unit. The third driving waveform is first differentially amplified by the differential amplification unit, then voltage amplified by the voltage amplification unit, and finally output by the output buffer unit to obtain the fourth driving waveform.

8. The nozzle driving waveform generating device according to claim 1, characterized in that: The coupling bias module includes a coupling unit and a bias unit, wherein the coupling unit is electrically connected to the power amplifier module and the bias unit respectively, the coupling unit is used to perform level conversion on the fourth drive waveform to obtain a sixth drive waveform, and the bias unit is used to perform voltage reduction or voltage increase processing on the sixth drive waveform to obtain the fifth drive waveform.

9. The nozzle driving waveform generating device according to claim 8, characterized in that: The coupling unit includes a MOSFET and a peripheral circuit thereof, wherein the MOSFET includes a first pin, a second pin, and a third pin, and the peripheral circuit of the MOSFET includes: an eleventh capacitor with one end electrically connected to the first pin and the other end electrically connected to the ground, a first diode with one end electrically connected to the first pin and the other end electrically connected to the thirteenth resistor, a thirteenth resistor with one end electrically connected to the first diode and the other end connected to a power supply, a second diode with two ends electrically connected to the first pin and the second pin respectively, a fourteenth resistor with one end electrically connected to the second pin and the other end grounded, a fifteenth resistor with one end electrically connected to the third pin and the other end electrically connected to the sixteenth resistor, a sixteenth resistor with two ends electrically connected to the first resistor and the fifteenth resistor respectively, and twelfth to twenty-first capacitors in parallel electrically connected to the second pin.

10. An inkjet printer, characterized in that: The device comprises the nozzle drive waveform generating device according to any one of claims 1 to 9.

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