Voltage control circuit of electrofluid nozzle and method thereof

Abstract

The invention discloses a voltage control circuit of an electrofluid spray head and a method of the voltage control circuit, and relates to the field of electrofluid ink-jet printing. An injection voltage in the voltage group is generated through an injection hole injection voltage generation unit, and a critical voltage in the voltage group is generated through an injection hole critical voltage generation unit; driving signal parameters corresponding to the printing parameters are obtained, a spraying driving signal is generated through a spraying hole spraying voltage control unit so as to switch on or switch off a first MOS tube set, and a critical driving signal is generated through a spraying hole critical voltage control unit so as to switch on or switch off a second MOS tube set; and according to the voltage group and the driving signal parameters, on-off cooperation of the first MOS tube group and the second MOS tube group is controlled, so that the electrofluid ink-jet printer executes printing operation. Two groups of MOS (Metal Oxide Semiconductor) tubes are configured to adapt to various different ink droplets, and adaptive injection voltage and critical voltage are provided for an ink-jet printer so as to complete electrofluid printing operation.

Description

Technical Field

[0001] This application relates to the field of electrohydraulic inkjet printer technology, specifically to a voltage control circuit and method for an electrohydraulic printhead. Background Technology

[0002] Currently, inkjet printing technology, as a contactless, template-free additive manufacturing process, has been widely used in intelligent products based on printed electronics, such as thin-film sensors, flexible displays, and smart labels. Electrohydraulic inkjet printing uses an electric field to drag ink droplets from a meniscus onto a substrate to form patterns. It has a wide viscosity range and the advantage of smaller droplet diameters compared to conventional nozzles, and is currently under extensive research.

[0003] Furthermore, electrohydraulic printing involves the ejection voltage and critical voltage of ink droplets. The ejection voltage is the voltage value that drags the ink droplet from the meniscus of the Taylor cone onto the substrate, executing the printing action; the critical voltage is the voltage value that forms the ink droplet at the meniscus of the Taylor cone, in a standby or quiescent state before the printing action. The critical voltage is generally not zero, which improves the efficiency of the printing process. Both the ejection voltage and the critical voltage are related to the characteristics of the ink droplets.

[0004] Therefore, it is clear that how to configure the jet voltage and critical voltage to enable the electro-hydraulic inkjet printer to perform electro-hydraulic printing operations, based on the different characteristics of ink droplets, is a problem that needs to be solved. Summary of the Invention

[0005] This application provides a voltage control circuit and method for an electric current printhead. By configuring two sets of MOSFETs, the number of MOSFETs in each set can be flexibly selected to adapt to various different ink droplets, providing an appropriate ejection voltage and critical voltage for the inkjet printer, thereby completing the electric current printing operation.

[0006] This application discloses a voltage control circuit for a current-current printhead, which is applied in a current-current inkjet printer. The control circuit includes a control chip, a nozzle ejection voltage generation unit, a nozzle critical voltage generation unit, a nozzle ejection voltage control unit, a nozzle critical voltage control unit, a first MOSFET group, and a second MOSFET group. The source of the first MOSFET group is connected to the nozzle ejection voltage generation unit, and its gate is connected to the nozzle ejection voltage control unit. The nozzle ejection voltage generation unit generates the nozzle ejection voltage, and the nozzle ejection voltage control unit controls the switching on and off of the first MOSFET group. The source of the second MOSFET group is connected to the nozzle critical voltage generation unit, and its gate is connected to the first MOSFET group. The nozzle critical voltage control unit is connected; the nozzle critical voltage generation unit is used to generate the nozzle critical voltage, and the nozzle critical voltage control unit is used to control the on / off state of the second MOS transistor group; the drain of the first MOS transistor group is connected to the drain of the second MOS transistor group, and both the drain of the first MOS transistor group and the drain of the second MOS transistor group are connected to the load; both the first MOS transistor group and the second MOS transistor group include at least two MOS transistors; the control chip controls the nozzle ejection voltage control unit and the nozzle critical voltage control unit through control signals, so that the first MOS transistor group and the second MOS transistor group perform on / off actions, thereby allowing the load to control the ejection action and critical action of the current fluid inkjet standby nozzle.

[0007] In the above scheme, by configuring two sets of MOSFETs, the number of MOSFETs in each set can be flexibly selected to adapt to various ink droplets (different ink droplet characteristics result in different ejection voltages and critical voltages; thus, different voltage requirements are placed on the MOSFETs, and a single MOSFET has a voltage limit, often unable to meet the needs of various ink droplet characteristics), providing an appropriate ejection voltage and critical voltage for the inkjet printer to complete the current-current printing operation. The nozzle ejection voltage generation unit and the nozzle critical voltage generation unit can generate the ejection voltage and critical voltage according to the ink droplet characteristics; the nozzle ejection voltage control unit and the nozzle critical voltage control unit cooperate to generate a PMW signal according to the current printing requirements, thereby adjusting the on / off state of the two sets of MOSFETs. Furthermore, the ejection voltage and critical voltage can be a specific value or a range; for ease of description, this application describes them using specific values.

[0008] In one possible implementation, both the nozzle injection voltage generation unit and the nozzle critical voltage generation unit include a base voltage generation subunit and a voltage amplification subunit; wherein, the base voltage generation subunit is used to generate the base voltage required by the voltage amplification subunit according to the control signal of the control chip; the voltage amplification subunit is used to generate the injection voltage and critical voltage required by the load according to the base voltage.

[0009] The above scheme aims to disclose the circuit composition of the nozzle injection voltage generation unit and the nozzle critical voltage generation unit. Both include a basic voltage generation subunit and a voltage amplification subunit. This application employs a customized design for these two circuits to save costs.

[0010] In one possible implementation, the control chip obtains the voltage group corresponding to the ink droplet to be printed from a first correlation based on the ink droplet characteristics of the ink droplet to be printed in the current current fluid printing; the ink droplet characteristics include ink droplet viscosity, and the voltage group includes the ink droplet ejection voltage and critical voltage; wherein, the first correlation includes the correlation between multiple ink droplet characteristics and multiple voltage groups, one ink droplet characteristic corresponds to one voltage group, and one voltage group corresponds to the number of MOS transistors in one MOS transistor group, and the MOS transistor group is a first MOS transistor group and a second MOS transistor group.

[0011] The above scheme aims to illustrate the selection of voltage groups adapted to the characteristics of ink droplets. In current-current inkjet printing, the types of ink droplets are often limited, and each process involves lengthy adjustments based on droplet characteristics. Associating the adjusted voltage groups with these characteristics facilitates the subsequent setting of corresponding ejection voltages and critical voltages based on droplet characteristics (or droplet type codes, or droplet codes), and also makes it easier to select the number of MOSFETs in the MOSFET group. Higher ejection voltages require a greater number of compatible MOSFETs, and the timing relationships among the various MOSFETs must be carefully considered.

[0012] In one possible implementation, the control chip obtains the driving signal parameters corresponding to the printing parameters from a second association relationship based on the printing parameters of the current current fluid printing. The driving signal parameters include the high-level time, frequency, and low-level time of the driving signal, and the printing parameters include the printing frequency, single injection time, and single silence time. The second association relationship includes the association relationship between multiple printing parameters and multiple driving signals, with one printing parameter corresponding to one driving signal parameter.

[0013] The above scheme aims to illustrate how to determine drive signal parameters based on current-current printing parameters. These parameters include the current-current printing frequency, single-jet time, and single-silent time. The high-level time, frequency, and low-level time of the drive signal, as well as the amplitude of the high and low levels, can be configured based on these parameters. The drive signal controls the switching of the MOSFET. Simultaneously, the load switches between high and low levels, forming a square wave voltage to control the nozzle. This reduces the manual debugging time of the drive signal. Furthermore, the nozzle jet voltage control unit and nozzle critical voltage control unit can be customized to handle only the square wave voltage, thus reducing costs.

[0014] In one possible implementation, the first MOSFET group includes a first MOSFET and a second MOSFET, and the nozzle injection voltage control unit includes a first branch and a second branch; the first MOSFET corresponds to the first branch of the nozzle injection voltage control unit, and the second MOSFET corresponds to the second branch of the nozzle injection voltage control unit; wherein, the control chip controls the on / off state of the first MOSFET and the second MOSFET with a first timing sequence, the first timing sequence being determined by the time difference between the on / off state of the first MOSFET and the second MOSFET.

[0015] In the above scheme, a two-MOSFET group is used as an example to illustrate that the number of MOSFETs in the MOSFET group is the same as the number of branches in the nozzle injection voltage control unit. That is, one branch controls the on / off state of one MOSFET, and the timing of the two branches of the nozzle injection voltage control unit must be synchronized. Due to the physical differences of MOSFETs, both turning on and off of a MOSFET requires time. The difference between two MOSFETs is generally on the order of microseconds. However, this difference may cause inconsistencies in the on / off times of the two MOSFETs, which will further lead to inaccurate nozzle injection voltage control and affect the accuracy of subsequent current-current printing. Therefore, it is necessary to calibrate and control the timing of each MOSFET in the same MOSFET group.

[0016] In one possible implementation, the second MOSFET group includes a third MOSFET and a fourth MOSFET, and the nozzle critical voltage control unit includes a third branch and a fourth branch; the third MOSFET corresponds to the third branch of the nozzle critical voltage control unit, and the fourth MOSFET corresponds to the fourth branch of the nozzle critical voltage control unit; wherein, the control chip controls the on / off state of the third MOSFET and the fourth MOSFET with a second timing sequence, the second timing sequence being determined by the time difference between the on / off state of the third MOSFET and the fourth MOSFET.

[0017] In the above scheme, the MOSFET group also uses two MOSFETs as an example to illustrate that the number of MOSFETs in the MOSFET group is the same as the number of branches in the nozzle critical voltage control unit. That is, one branch of the nozzle critical voltage control unit corresponds to one MOSFET, and the timing between the two branches must be synchronized. The reason is the same as in the nozzle injection voltage control unit, which also requires calibration and control of the timing of each MOSFET in the MOSFET group corresponding to the nozzle critical voltage control unit.

[0018] In one possible implementation, the nozzle injection voltage control unit includes a first high-level time and a first low-level time, and the nozzle critical voltage control unit includes a second high-level time and a second low-level time; wherein, when the injection voltage is at the first high-level time, the critical voltage is at the second low-level time, and the first high-level time is less than the second low-level time; when the injection voltage is at the first low-level time, the critical voltage is at the second high-level time, and the second high-level time is less than the first low-level time.

[0019] The above scheme aims to illustrate the need to consider the timing relationship between the two sets of MOSFETs. The nozzle injection voltage control unit and the nozzle critical voltage control unit control the conduction and turn-off of the MOSFET groups in opposite directions; it is necessary to avoid simultaneous conduction and turn-off of the two control units. Simultaneous conduction may damage the MOSFETs in both MOSFET groups, while simultaneous turn-off may affect the printing accuracy of the current-current nozzle. Relatively speaking, avoiding simultaneous conduction of the two MOSFET groups is more important. Therefore, this can be achieved by setting the high-level duration to be shorter than the low-level duration. That is, before the high-level of one MOSFET group appears, the other MOSFET group must be in a low-level state; after the high-level of one MOSFET group ends, the other MOSFET group enters a high-level state.

[0020] In one possible implementation, the control chip controls the first MOSFET group to turn on and the second MOSFET group to turn off in a third timing sequence, the third timing sequence being determined by the time difference between the second MOSFET group turning off and the first MOSFET group turning on, so that when the first MOSFET group turns on, the second MOSFET group is already in a turned-off state; the control chip controls the first MOSFET group to turn off and the second MOSFET group to turn on in a fourth timing sequence, the fourth timing sequence being determined by the time difference between the first MOSFET group turning off and the second MOSFET group turning on, so that when the second MOSFET group turns on, the first MOSFET group is already in a turned-off state.

[0021] The above scheme provides a specific timing setting method for the timing relationship between the two groups of MOSFETs. Timing settings are performed for two different states of the two MOSFET groups; furthermore, when setting the timing relationship between the two MOSFET groups, and a MOSFET group contains multiple MOSFETs, the longer on-time or off-time of the multiple MOSFETs is used as the on-time or off-time of that MOSFET. This refined timing setting avoids the simultaneous on and off of the two MOSFET groups, resulting in a smoother transition.

[0022] The second aspect of this application discloses a voltage control method for an electro-hydraulic nozzle, applied in a voltage control circuit of an electro-hydraulic nozzle as described in any of the above claims, the control method comprising: The system acquires the voltage group corresponding to the ink droplet to be printed, and generates the jet voltage in the voltage group through the nozzle jet voltage generation unit and the critical voltage in the voltage group through the nozzle critical voltage generation unit; it acquires the drive signal parameters corresponding to the printing parameters, and generates a jet drive signal through the nozzle jet voltage control unit to turn on or off the first MOS transistor group, and generates a critical drive signal through the nozzle critical voltage control unit to turn on or off the second MOS transistor group. The printing parameters include printing frequency, single jet time, and single silence time. The drive signal parameters include frequency, high level time, and low level time. Based on the voltage group and the drive signal parameters, the system controls the switching of the first MOS transistor group and the second MOS transistor group to enable the electrostatic inkjet printer to perform the printing operation.

[0023] In the above scheme, the voltage group and drive signal parameters corresponding to the ink droplet to be printed are obtained. Then, the voltage control circuit of the current-current printhead generates the corresponding ejection voltage, critical voltage, and drive signal, thereby controlling the on / off state of the two MOSFET groups to achieve current-current printing. This reduces the time required for manual adjustment of the voltage group and drive signal based on the ink droplet characteristics.

[0024] In one possible implementation, the number of MOSFETs in the first MOSFET group is determined by the injection voltage, and the number of MOSFETs in the second MOSFET group is determined by a threshold voltage; wherein, the control method further includes: determining the number of MOSFETs in the first MOSFET group based on the injection voltage; and determining the number of MOSFETs in the second MOSFET group based on the threshold voltage.

[0025] The above scheme aims to illustrate the correspondence between the injection voltage in the first MOSFET group and the number of MOSFETs, and the correspondence between the critical voltage in the second MOSFET group and the number of MOSFETs. That is, when the voltage range that the MOSFETs can withstand is determined, these two correspondences are fixed.

[0026] In one possible implementation, the first MOSFET group includes a first MOSFET and a second MOSFET, and the nozzle injection voltage control unit includes a first branch and a second branch; the first MOSFET corresponds to the first branch of the nozzle injection voltage control unit, and the second MOSFET corresponds to the second branch of the nozzle injection voltage control unit; the control method further includes: controlling the on and off of the first MOSFET and the second MOSFET in a first timing sequence, wherein the first timing sequence is determined by the time difference between the on and off of the first MOSFET and the second MOSFET.

[0027] In one possible implementation, the second MOSFET group includes a third MOSFET and a fourth MOSFET, and the nozzle critical voltage control unit includes a third branch and a fourth branch; the third MOSFET corresponds to the third branch of the nozzle critical voltage control unit, and the fourth MOSFET corresponds to the fourth branch of the nozzle critical voltage control unit; the control method further includes: controlling the on / off state of the third MOSFET and the fourth MOSFET with a second timing sequence, wherein the second timing sequence is determined by the time difference between the on / off state of the third MOSFET and the fourth MOSFET.

[0028] In one possible implementation, the nozzle injection voltage control unit includes a first high-level time and a first low-level time, and the nozzle critical voltage control unit includes a second high-level time and a second low-level time; the control method further includes: when the injection voltage is at the first high-level time, controlling the critical voltage to be at the second low-level time, and the first high-level time is less than the second low-level time; when the injection voltage is at the first low-level time, controlling the critical voltage to be at the second high-level time, and the second high-level time is less than the first low-level time.

[0029] In one possible implementation, the control method further includes: controlling the first MOSFET group to turn on and the second MOSFET group to turn off in a third timing sequence, wherein the third timing sequence is determined by the time difference between the second MOSFET group turning off and the first MOSFET group turning on, so that when the first MOSFET group turns on, the second MOSFET group is already in a turned-off state; and controlling the first MOSFET group to turn off and the second MOSFET group to turn on in a fourth timing sequence, wherein the fourth timing sequence is determined by the time difference between the first MOSFET group turning off and the second MOSFET group turning on, so that when the second MOSFET group turns on, the first MOSFET group is already in a turned-off state.

[0030] The beneficial effects of this application include: By configuring two sets of MOSFETs, the number of MOSFETs in each set can be flexibly selected to adapt to various ink droplets (different ink droplet characteristics result in different ejection voltages and critical voltages; thus, different voltage requirements are placed on the MOSFETs, while a single MOSFET has a voltage limit, often insufficient to meet the needs of multiple different ink droplet characteristics), providing the inkjet printer with a suitable ejection voltage and critical voltage to complete the current-current printing operation. The nozzle ejection voltage generation unit and the nozzle critical voltage generation unit can generate the ejection voltage and critical voltage according to the ink droplet characteristics; the nozzle ejection voltage control unit and the nozzle critical voltage control unit cooperate to generate a PMW signal according to the current printing requirements, thereby adjusting the on / off state of the two sets of MOSFETs; In the process of electrohydraulic inkjet printing, the types of ink droplets are often limited. Each time, a long period of adjustment is required based on the characteristics of the ink droplets. The voltage group obtained from the adjustment can be associated with the characteristics of the ink droplets. This makes it easier to set the corresponding jet voltage and critical voltage directly based on the characteristics of the ink droplets (or ink droplet type code, or ink droplet code), and also makes it easier to select the number of MOSFETs in the MOSFET group. The printing parameters include the printing frequency, single ejection time, and single silence time of the current current-current printing. Based on these parameters, the high-level time, frequency, and low-level time of the drive signal, as well as the amplitude of the high and low levels, can be configured to control the on / off state of the MOSFET through the drive signal. At the same time, the load side switches between high and low levels to form a square wave voltage that controls the nozzle. Each branch controls the on / off state of a MOSFET, and the timing of the two branches in the nozzle jet voltage control unit must be synchronized. Due to the physical differences between MOSFETs, both turning on and off require time, typically on the order of microseconds. However, this difference can cause inconsistencies in the on / off times of the two MOSFETs, further leading to inaccurate nozzle jet voltage control and affecting the accuracy of subsequent current-mode printing. Therefore, it is necessary to calibrate and control the timing of each MOSFET in the same MOSFET group. The nozzle injection voltage control unit and the nozzle critical voltage control unit control the conduction and cutoff of the MOSFET groups in opposite directions. It is necessary to avoid both control units being turned on and off simultaneously. Simultaneous conduction may damage the MOSFETs in both groups, while simultaneous cutoff may affect the printing accuracy of the current-current nozzle. Relatively speaking, avoiding simultaneous conduction of both MOSFET groups is more important. Therefore, this can be achieved by setting the high-level duration to be shorter than the low-level duration. Timing was configured for two different states of the two MOSFET groups. Furthermore, when setting the timing relationship between the two MOSFET groups, and when one MOSFET group contains multiple MOSFETs, the longer on or off time among the multiple MOSFETs was used as the on or off time of that MOSFET. This refined timing configuration avoids the two MOSFET groups from being on and off simultaneously, resulting in a smoother transition. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the voltage control circuit structure of an electro-hydraulic nozzle disclosed in this application. Figure 2 This is a schematic diagram of the voltage control circuit structure of another electro-hydraulic nozzle disclosed in this application specification; Figure 3 This is a schematic diagram of a voltage regulating circuit structure for a base voltage disclosed in this application. Figure 4 This is a schematic diagram of a DAC output circuit structure in a base voltage as disclosed in this application specification; Figure 5 This is a schematic diagram illustrating the timing control principle of two MOS transistor groups disclosed in this application. Figure 6 This is a schematic diagram illustrating the timing control principle of a MOS transistor group disclosed in this application. Figure 7 This is a schematic diagram illustrating the timing control principle of another MOS transistor group disclosed in this application specification; Figure 8 This is a schematic diagram of a voltage control method for an electro-hydraulic nozzle disclosed in this application.

[0032] In the above figure: First MOS transistor group 100, Second MOS transistor group 200, Nozzle injection voltage control unit 300, Nozzle critical voltage generation unit 400. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0034] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0035] This specification discloses a voltage control circuit for an electro-hydraulic nozzle, such as... Figure 1 As shown. The control circuit is used in a current-mode inkjet printer, and the control circuit includes a control chip ( Figure 1 (Not shown in the figure) a nozzle injection voltage generation unit, a nozzle critical voltage generation unit, a nozzle injection voltage control unit 300, a nozzle critical voltage control unit 400, and a first MOS transistor group 100 and a second MOS transistor group 200.

[0036] The source of the first MOS transistor group 100 is connected to the nozzle injection voltage generation unit, and its gate is connected to the nozzle injection voltage control unit 300; the nozzle injection voltage generation unit is used to generate the nozzle injection voltage, and the nozzle injection voltage control unit 300 is used to control the on / off state of the first MOS transistor group 100; the source of the second MOS transistor group 200 is connected to the nozzle critical voltage generation unit, and its gate is connected to the nozzle critical voltage control unit 400.

[0037] The nozzle critical voltage generation unit is used to generate the nozzle critical voltage, and the nozzle critical voltage control unit 400 is used to control the on / off state of the second MOS transistor group 200; the drain of the first MOS transistor group 100 is connected to the drain of the second MOS transistor group 200, and both the drain of the first MOS transistor group 100 and the drain of the second MOS transistor group 200 are connected to the load; both the first MOS transistor group 100 and the second MOS transistor group 200 include at least two MOS transistors; the control chip controls the nozzle jetting voltage control unit 300 and the nozzle critical voltage control unit 400 through control signals, so that the first MOS transistor group 100 and the second MOS transistor group 200 perform on / off actions, thereby allowing the load to control the jetting action and critical action of the fluid inkjet standby nozzle.

[0038] At this point, by configuring two sets of MOSFETs, the number of MOSFETs in each set can be flexibly selected to adapt to various different ink droplets (different ink droplet characteristics result in different ejection voltages and critical voltages; thus, different voltage requirements are placed on the MOSFETs, and a single MOSFET has a voltage limit, often unable to meet the needs of multiple different ink droplet characteristics), providing the inkjet printer with a suitable ejection voltage and critical voltage to complete the current-current printing operation. The nozzle ejection voltage generation unit and the nozzle critical voltage generation unit can generate the ejection voltage and critical voltage according to the ink droplet characteristics; the nozzle ejection voltage control unit and the nozzle critical voltage control unit cooperate with each other to generate a PMW signal according to the current printing requirements, thereby adjusting the on / off state of the two sets of MOSFETs.

[0039] Furthermore, the injection voltage and critical voltage can be a specific value or a range; for the sake of convenience, this application describes them in the form of specific values.

[0040] by Figure 2For example, the first MOSFET group 100, the second MOSFET group 200, the nozzle ejection voltage control unit 300, and the nozzle critical voltage control unit 400 are described. Both the first MOSFET group 100 and the second MOSFET group 200 use two MOSFETs as examples, but this specification does not specify a particular number. A single MOSFET has a voltage tolerance range, such as 0~3000V; however, if the required ejection voltage is 8000V based on the characteristics of ink droplets, a single MOSFET obviously cannot meet the requirements.

[0041] The nozzle injection voltage control unit 300, matched with the first MOSFET group 100, has two branches corresponding to the first MOSFET group, which includes two MOSFETs; each branch of the nozzle injection voltage control unit 300 is matched with one MOSFET. Similarly, the nozzle critical voltage control unit 400, matched with the second MOSFET group 200, also has two branches corresponding to the second MOSFET group, which includes two MOSFETs; each branch of the nozzle critical voltage control unit 400 is matched with one MOSFET.

[0042] Figure 2 HV_A is the ejection voltage, generated by the nozzle ejection voltage generation unit; HV_B is the critical voltage, generated by the nozzle critical voltage generation unit. GYKZ1 and GYKZ2 are input to two branches of the nozzle ejection voltage control unit 300, respectively, and control the on / off state of MOSFETs Q1 and Q2; GYKZ3 and GYKZ4 are input to two branches of the nozzle critical voltage control unit 400, respectively, and control the on / off state of MOSFETs Q3 and Q4. When Q1 and Q2 are on and Q3 and Q4 are off, HV_A is connected to the load, controlling the ink droplets in the nozzle to eject ink droplets (in the ejection state); conversely, when Q3 and Q4 are on and Q1 and Q2 are off, HV_B is connected to the load, controlling the ink droplets in the nozzle to be in the critical state. The load is... Figure 2 In the middle, it is HV_OUT.

[0043] The instruction manual is required for the following: In industrial printing equipment, for ElectrohydroDynamics (EHD) type printheads, corresponding voltage (ejection voltage and critical voltage) signals must be matched according to the droplet characteristics (e.g., viscosity, density, material, etc.). Under the combined action of gravity, surface tension, and electric field force, the droplet forms an initial pendant at the nozzle. As the voltage difference between the droplet and the substrate increases, the initial pendant gradually forms a meniscus at the nozzle (at which point the voltage equals HV_B). When the voltage increases to the critical value (at which point the voltage equals HV_A), the force balance is broken, and the droplet is ejected from the tip of the Taylor cone, forming a jet. This ensures that during the entire electrohydrodynamic printing process, the next frame is ready as soon as one frame is printed; this method increases the printing frequency and ensures consistent droplet morphology.

[0044] right Figure 2 The electronic components are described below. Isolation gate driver chips U1, U2, U3, and U4 ensure isolation between the high-voltage drive signal at the back end and the low-voltage drive signal at the front end, and also ensure rapid switching of the high-voltage drive signal at the back end. Capacitors C1 and C2, C4 and C5, C8 and C10, and C12 and C13 are used to filter the power supply across the isolation gate driver chips U1, U2, U3, and U4, respectively, ensuring stable operation of the isolation gate chips. Resistors R1 and R4, R2 and R3, R6 and R9, R7 and R8, R12 and R13, R11 and R14, R17 and R18, and R16 and R19 are connected in series at the input and output terminals of the isolation gate driver chips U1, U2, U3, and U4, respectively, to adjust the input and output waveforms of the isolation gate driver chips U1, U2, U3, and U4, ensuring that the waveform requirements of current fluid inkjet printing are met. Capacitors C7 and C9, along with resistor R10, form an RC oscillation circuit to filter out output noise in the HV_OUT circuit, thus stabilizing the high-voltage output circuit voltage. D2, D4, D3, and D5 are Zener diodes used to protect the high-voltage MOSFETs Q1, Q2, Q3, and Q4 from breakdown. C3, C6, C11, and C14 filter out noise between the gate and source of the high-voltage MOSFETs, protecting them. R5 and R15 are current-limiting resistors, and D1 is a unidirectional diode that limits the current in the high-voltage circuit, protecting the high-voltage MOSFETs.

[0045] At this point, GYKZ1, GYKZ, GYKZ3, and GYKZ4 are generated by the FAGA inside the drive signal unit (not shown in the figure). By controlling their high and low levels, the high-voltage MOSFETs Q1, Q2, Q3, and Q4 are controlled to turn on and off. By adjusting the frequency of the signal waveforms of GYKZ1, GYKZ, GYKZ3, and GYKZ4, as well as the proportion of their respective signals (high and low levels), the duty cycle and frequency of the high-voltage waveform are adjusted, thereby outputting the drive signal required by the downstream nozzle.

[0046] Furthermore, HV_A and HV_B are generated by the DC-DC voltage amplifier subunit; VOUT1 and VOUT2 generated by the drive signal unit are used to adjust the output values ​​of the DC-DC voltage amplifier subunit, with outputs being HV_A and HV_B, respectively. The amplification factor of the voltage amplifier subunit can be set as needed, for example: amplification of 1000 times, VOUT1 input of 1V, and HV_A output of 1000V.

[0047] The base voltages obtained by the base voltage generation subunit described below are VOUT1 and VOUT2. This specification uses... Figure 3 For example, the circuit of the base voltage VOUT1 is shown. The circuit of VOUT2 is similar to that of VOUT1, so a separate branch example will not be shown.

[0048] Figure 3 The drive signal voltage regulation circuit is shown. C15 is a bootstrap capacitor to ensure stable operation of U5; D6 is a freewheeling diode to protect the U5 chip; L1 is a power inductor with an appropriate value to ensure stable output voltage; C19, C20, and C21 are input voltage filter capacitors to provide a clean voltage to the DC-DC BUCK chip; C16, C17, and C18 are output voltage filter capacitors to provide a clean power supply to the downstream DC-DC boost circuit. R20 and R24 divide the +24V voltage, and through resistor value configuration, adjust the EN pin level to the required range. R22 is connected in series with the RT / CLK pin; different resistance values ​​control the frequency of the U1 BUCK chip. R25 is connected in series with C23 to form an RC circuit, which provides feedback compensation for the output voltage and stabilizes it. C22 filters pin noise from the U5 chip. R21, R23, R26, and the voltage VFB at the FB pin are adjusted using the voltage superposition principle, thereby regulating the output voltage VOUT1. The output voltage range is DC (0-15V). The internal drive signal unit of this circuit has two paths, outputting VOUT1 and VOUT2 respectively. Figure 2 In the middle, they are used to adjust the amplitudes of HV_A and HV_B, respectively. Figure 3 In this circuit, the input voltage of DACOUTA is 0~5V.

[0049] DACOUTA is generated by the drive signal unit through controlling the DAC chip U7, such as... Figure 4 The DAC output circuit shown is shown.

[0050] Figure 4In the process, the IIC bus isolation chip U7 communicates with the FPGA inside the drive signal unit using the IIC protocol. The isolation chip U7 performs level conversion and isolation. C26 and C27 are filter capacitors at the power input of U7, ensuring stable operation of the bus isolation chip U7. R29 and R30 are pull-up resistors at the input IIC communication, providing a fixed level to ensure stable IIC communication. R27 and R28 are pull-up resistors at the output of U7, providing a fixed level to ensure stable operation of the IIC output. C24 and C25 are power supply filter capacitors, ensuring stable +5V ADC level and filtering noise. The FPGA chip inside the drive signal unit, through the IIC isolation chip U7, controls the DAC chip U6 to generate two DC 0~5V voltages, DACVOUTA and DACOUTB. These two voltages are used for... Figure 3 The drive signal is internally DC-DC regulated. SDA1 is the data line for IIC communication, and SCL1 is the clock line for IIC communication.

[0051] Figure 3 and Figure 4 All the circuits described herein are example circuits of the basic voltage generation subunit. Figure 4 It generates two DC 0~5V voltages, DACVOUTA and DACOUTB; where DACVOUTA supplies... Figure 3 As input, DACOUTB is the same case and no example is given; Figure 3 The output voltage range is DC (0-15V) as the base voltage. After the base voltage is amplified by the circuit amplification subunit, the injection voltage and the critical voltage are formed.

[0052] In one example, both the nozzle injection voltage generation unit and the nozzle critical voltage generation unit include a base voltage generation subunit and a voltage amplification subunit; wherein, the base voltage generation subunit is used to generate the base voltage required by the voltage amplification subunit according to the control signal of the control chip; the voltage amplification subunit is used to generate the injection voltage and critical voltage required by the load according to the base voltage.

[0053] At this point, both the nozzle injection voltage generation unit and the nozzle critical voltage generation unit include a basic voltage generation subunit and a voltage amplification subunit. This specification allows for customized designs for these two circuits (e.g., such as...). Figure 3 and Figure 4 As shown below, the existing voltage amplifier and the drive signal generator are not used; existing equipment can handle multiple waveforms or multiple voltage amplification factors at the same time, while the scenario in this specification is current fluid printing. Using square waves and fixed amplification factors can make the printing more precise. That is, this specification only needs to process square waves; after customization, costs can be saved.

[0054] In one example, the control chip obtains the voltage group corresponding to the ink droplet to be printed from a first correlation based on the ink droplet characteristics of the ink droplet to be printed in the current current fluid printing; the ink droplet characteristics include ink droplet viscosity, and the voltage group includes the ink droplet ejection voltage and critical voltage; wherein, the first correlation includes the correlation between multiple ink droplet characteristics and multiple voltage groups, one ink droplet characteristic corresponds to one voltage group, and one voltage group corresponds to the number of MOS transistors in one MOS transistor group, and the MOS transistor group is the first MOS transistor group and the second MOS transistor group.

[0055] At this point, this manual discloses that a voltage group adapted to the droplet characteristics can be selected based on the droplet characteristics. In current fluid inkjet printing, the types of droplets are often limited, and each process involves lengthy adjustments (days or even weeks) based on droplet characteristics. The voltage group obtained from these adjustments can be linked to the droplet characteristics; this facilitates the subsequent direct setting of the corresponding ejection voltage and critical voltage based on the droplet characteristics (or droplet type code, or droplet code), and also facilitates the selection of the number of MOSFETs in the MOSFET group. The higher the ejection voltage, the more MOSFETs need to be adapted, and the timing relationships among the various MOSFETs should also be carefully considered.

[0056] In a voltage group corresponding to a droplet characteristic, both the ejection voltage and the critical voltage can be a voltage range. The voltage range is related to the volume of the printed droplets, the printing frequency, etc., but mainly to the characteristics of the droplets themselves. By establishing this correspondence through extensive manual adjustments, the adjustment time can be reduced significantly.

[0057] In one example, the control chip obtains the driving signal parameters corresponding to the printing parameters from the second association relationship based on the printing parameters of the current current fluid printing. The driving signal parameters include the high-level time, frequency, and low-level time of the driving signal. The printing parameters include the printing frequency, single injection time, and single silence time. The second association relationship includes the association relationship between multiple printing parameters and multiple driving signals, with one printing parameter corresponding to one driving signal parameter.

[0058] At this point, this specification discloses that the drive signal parameters can be determined based on the current fluid printing parameters. The printing parameters include the current fluid printing frequency, single ejection time, and single silence time, etc.; the high-level time, frequency, and low-level time of the drive signal, as well as the amplitude of the high and low levels, can be configured based on these parameters, and the switching of the MOSFET can be controlled by the drive signal; simultaneously, the load switches between high and low levels, forming a square wave voltage to control the nozzle.

[0059] Furthermore, it can reduce the manual debugging time of the drive signal; and the nozzle injection voltage control unit and nozzle critical voltage control unit can be customized to handle only square wave voltage, which can reduce costs.

[0060] In one example, the first MOSFET group includes a first MOSFET and a second MOSFET, and the nozzle injection voltage control unit includes a first branch and a second branch; the first MOSFET corresponds to the first branch of the nozzle injection voltage control unit, and the second MOSFET corresponds to the second branch of the nozzle injection voltage control unit; wherein, the control chip controls the on / off state of the first MOSFET and the second MOSFET with a first timing sequence, the first timing sequence being determined by the time difference between the on / off state of the first MOSFET and the second MOSFET.

[0061] At this point, the first MOSFET group uses two MOSFETs as an example to illustrate that the number of MOSFETs in the MOSFET group is the same as the number of branches in the nozzle jet voltage control unit. That is, one branch controls the on / off state of one MOSFET, and the two branches of the nozzle jet voltage control unit must be synchronized in timing. Due to the physical differences of MOSFETs, both turning on and off of a MOSFET requires time. The difference between two MOSFETs is generally on the order of microseconds. However, this difference may cause inconsistencies in the on / off times of the two MOSFETs, which will further lead to inaccurate nozzle jet voltage control and affect the accuracy of subsequent current-mode printing.

[0062] Therefore, it is necessary to calibrate and control the timing of each MOSFET in the same MOSFET group. For example... Figure 6 As shown, Figure 6 GYKZ1 and GYKZ2 correspond to the two drive signals of the first MOSFET group, which can be referred to... Figure 2 The example illustrates a square wave. Since the on / off states of the first MOSFET group need to be consistent, the waveforms of GYKZ1 and GYKZ2 are also identical. GYKZ1 corresponds to the first MOSFET, and GYKZ2 corresponds to the second MOSFET; the on-times of these two MOSFETs differ by microseconds. Figure 6 The diagram shows the time difference Δt1 between the two MOSFETs. Based on this time difference, GYKZ1 is turned on Δt1 ahead of GYKZ2, thus synchronizing the turn-on times of the two MOSFETs.

[0063] also, Figure 6 Only the turn-on time difference has been explained; similarly, the turn-off time difference is the same. Generally, MOSFETs turn on relatively quickly and turn off relatively quickly; in this way, the two MOSFETs in the first MOSFET group are turned on or off synchronously to ensure the accurate output or stop of HV_A.

[0064] and, Figure 6Only the drive signals for two MOSFETs are shown. When there are multiple MOSFETs in the first MOSFET group, the turn-on or turn-off time of a certain MOSFET can be set as the reference, and the other MOSFETs are equivalent to its turn-on or turn-off time difference. The corresponding drive signals can be configured to be advanced or delayed, thereby ensuring that the first MOSFET group performs turn-on or turn-off operations synchronously.

[0065] In one example, the second MOSFET group includes a third MOSFET and a fourth MOSFET, and the nozzle critical voltage control unit includes a third branch and a fourth branch; the third MOSFET corresponds to the third branch of the nozzle critical voltage control unit, and the fourth MOSFET corresponds to the fourth branch of the nozzle critical voltage control unit; wherein, the control chip controls the on / off state of the third MOSFET and the fourth MOSFET with a second timing sequence, the second timing sequence being determined by the time difference between the on / off state of the third MOSFET and the fourth MOSFET.

[0066] At this point, using two MOSFETs as an example, we can illustrate that the number of MOSFETs in the MOSFET group is the same as the number of branches in the nozzle critical voltage control unit. That is, one branch of the nozzle critical voltage control unit corresponds to one MOSFET, and the timing between the two branches must be synchronized. The reason is the same as in the nozzle injection voltage control unit; the timing of each MOSFET in the MOSFET group corresponding to the nozzle critical voltage control unit also needs to be calibrated and controlled.

[0067] like Figure 7 As shown, Figure 7 GYKZ3 and GYKZ4 correspond to the two drive signals of the second MOSFET group, which can be referred to... Figure 2 The example illustrates a square wave. Since the turn-on and turn-off of the second MOSFET group need to be consistent, the waveforms of GYKZ3 and GYKZ4 are also identical. GYKZ3 can correspond to the third MOSFET, and GYKZ4 can correspond to the fourth MOSFET; the turn-on times of these two MOSFETs differ by microseconds. Figure 7 The time difference Δt2 between the two MOSFETs is shown in the figure. Based on this time difference, GYKZ3 is turned on Δt2 earlier than GYKZ4, so that the turn-on time of the two MOSFETs is synchronized.

[0068] also, Figure 7 Only the turn-off time difference has been explained; similarly, the turn-on time difference is the same. Generally, MOSFETs turn off relatively slowly and turn on relatively slowly as well; in this way, the two MOSFETs in the second MOSFET group are turned on or off synchronously to ensure the accurate output or stop of HV_B.

[0069] and, Figure 7Only the drive signals for two MOSFETs are shown. When there are multiple MOSFETs in the second MOSFET group, the turn-on or turn-off time of a certain MOSFET can be set as the reference, and the other MOSFETs are equivalent to its turn-on or turn-off time difference. The corresponding drive signals can be advanced or delayed to ensure that the second MOSFET group performs turn-on or turn-off operations synchronously.

[0070] In one example, the nozzle injection voltage control unit includes a first high-level time and a first low-level time, and the nozzle critical voltage control unit includes a second high-level time and a second low-level time; wherein, when the injection voltage is at the first high-level time, the critical voltage is at the second low-level time, and the first high-level time is less than the second low-level time; when the injection voltage is at the first low-level time, the critical voltage is at the second high-level time, and the second high-level time is less than the first low-level time.

[0071] At this point, the timing relationship between the two sets of MOSFETs needs to be considered. The nozzle jet voltage control unit and the nozzle critical voltage control unit control the conduction and shutdown of the MOSFET groups in opposite ways; it is necessary to avoid the two control units from conducting and shutting down simultaneously. If they conduct simultaneously, it may damage the MOSFETs in the two MOSFET groups, and if they shut down simultaneously, it may affect the printing accuracy of the current-current nozzle.

[0072] Relatively speaking, it is more important to avoid two MOSFETs conducting simultaneously. Therefore, this can be prevented by setting the high-level duration to be shorter than the low-level duration. In other words, before the high-level of one MOSFET appears, the other MOSFET must be in a low-level state; and after the high-level of one MOSFET ends, the other MOSFET enters a high-level state.

[0073] like Figure 5 As shown, the time difference between t2 and t3 is smaller than the time difference between t1 and t4. At this time, the time difference between t1 and t2 ensures that GYKZ3 and GYKZ4 are already in the off state (i.e., low level) at time t2. Simultaneously, the time difference between t3 and t4 ensures that GYKZ1 and GYKZ2 are already in the off state (i.e., low level) at time t4. Similarly, the time difference between t4 and t5 is smaller than the time difference between t3 and t6, which will not be elaborated further.

[0074] In one example, the control chip controls the first MOSFET group to turn on and the second MOSFET group to turn off in a third timing sequence, the third timing sequence being determined by the time difference between the second MOSFET group turning off and the first MOSFET group turning on, so that when the first MOSFET group turns on, the second MOSFET group is already in a turned-off state; the control chip controls the first MOSFET group to turn off and the second MOSFET group to turn on in a fourth timing sequence, the fourth timing sequence being determined by the time difference between the first MOSFET group turning off and the second MOSFET group turning on, so that when the second MOSFET group turns on, the first MOSFET group is already in a turned-off state.

[0075] At this point, this application provides another specific timing setting method for the timing relationship between the two groups of MOSFETs. Timing settings are performed for two different states of the two MOSFET groups; furthermore, when setting the timing relationship between the two MOSFET groups, and a MOSFET group contains multiple MOSFETs, the longer on-time or off-time of the multiple MOSFETs is used as the on-time or off-time of that MOSFET. This refined timing setting can prevent the two MOSFET groups from being simultaneously turned on and off, resulting in a smoother transition.

[0076] like Figure 5 As shown, Figure 5 The example provided only illustrates the timing between two MOSFET groups; it does not provide examples of timing between two MOSFETs within a single MOSFET group. The timing between two MOSFETs within a single MOSFET group is provided through... Figure 6 and Figure 7 Examples are provided to facilitate description.

[0077] Figure 5 In this context, the time difference between time t1 and time t2 is the time difference between the first MOSFET group and the second MOSFET group; specifically, it is the time difference between the second MOSFET group being turned off (GYKZ3 and GYKZ4 are at low levels) and the first MOSFET group being turned on (GYKZ1 and GYKZ2), which is generally on the order of microseconds. Similarly, the time difference between time t3 and time t4 is the time difference between the first MOSFET group being turned off and the second MOSFET group being turned on.

[0078] Furthermore, when there are multiple MOSFETs in a MOSFET group, the MOSFET with the longer on or off time is used as the on or off time of the MOSFET group. For example... Figure 5 and Figure 6 If the on-time of the MOSFET corresponding to GYKZ1 is longer than that of the MOSFET corresponding to GYKZ2, then the on-time of the first MOSFET group is taken as the on-time of the first MOSFET group. The turn-off time is similar and will not be elaborated here.

[0079] This specification also provides a voltage control method for an electro-hydraulic nozzle, applied in the voltage control circuit of an electro-hydraulic nozzle as described above. The control method includes steps S801-S803.

[0080] S801. Obtain the voltage group corresponding to the ink droplet to be printed, and generate the jet voltage in the voltage group through the nozzle jet voltage generation unit and generate the critical voltage in the voltage group through the nozzle critical voltage generation unit.

[0081] S802. Obtain the drive signal parameters corresponding to the printing parameters, and generate a jet drive signal through the nozzle jet voltage control unit to turn on or off the first MOS transistor group, and generate a critical drive signal through the nozzle critical voltage control unit to turn on or off the second MOS transistor group. The printing parameters include printing frequency, single jet time and single silence time, and the drive signal parameters include frequency, high level time and low level time.

[0082] S803. Based on the voltage group and the drive signal parameters, control the switching of the first MOS transistor group and the second MOS transistor group to enable the electrostatic inkjet printer to perform a printing operation.

[0083] At this point, the voltage group and drive signal parameters corresponding to the ink droplet to be printed are acquired. Then, the voltage control circuit of the current-current printhead generates the corresponding ejection voltage, critical voltage, and drive signal, thereby controlling the on / off state of the two MOSFET groups to achieve current-current printing. This reduces the time required for manual adjustment of the voltage group and drive signal based on the ink droplet characteristics.

[0084] In one example, the number of MOSFETs in the first MOSFET group is determined by the injection voltage, and the number of MOSFETs in the second MOSFET group is determined by a threshold voltage; wherein, the control method further includes: determining the number of MOSFETs in the first MOSFET group based on the injection voltage; and determining the number of MOSFETs in the second MOSFET group based on the threshold voltage.

[0085] The above scheme aims to illustrate the correspondence between the injection voltage in the first MOSFET group and the number of MOSFETs, and the correspondence between the critical voltage in the second MOSFET group and the number of MOSFETs. That is, when the voltage range that the MOSFETs can withstand is determined, these two correspondences are fixed.

[0086] In one example, the first MOSFET group includes a first MOSFET and a second MOSFET, and the nozzle injection voltage control unit includes a first branch and a second branch; the first MOSFET corresponds to the first branch of the nozzle injection voltage control unit, and the second MOSFET corresponds to the second branch of the nozzle injection voltage control unit; the control method further includes: controlling the on and off of the first MOSFET and the second MOSFET in a first timing sequence, wherein the first timing sequence is determined by the time difference between the on and off of the first MOSFET and the second MOSFET.

[0087] In one example, the second MOSFET group includes a third MOSFET and a fourth MOSFET, and the nozzle critical voltage control unit includes a third branch and a fourth branch; the third MOSFET corresponds to the third branch of the nozzle critical voltage control unit, and the fourth MOSFET corresponds to the fourth branch of the nozzle critical voltage control unit; the control method further includes: controlling the on / off state of the third MOSFET and the fourth MOSFET with a second timing sequence, wherein the second timing sequence is determined by the time difference between the on / off state of the third MOSFET and the fourth MOSFET.

[0088] In one example, the nozzle injection voltage control unit includes a first high-level time and a first low-level time, and the nozzle critical voltage control unit includes a second high-level time and a second low-level time; the control method further includes: when the injection voltage is at the first high-level time, controlling the critical voltage to be at the second low-level time, and the first high-level time is less than the second low-level time; when the injection voltage is at the first low-level time, controlling the critical voltage to be at the second high-level time, and the second high-level time is less than the first low-level time.

[0089] In one example, the control method further includes: controlling the first MOSFET group to turn on and the second MOSFET group to turn off in a third timing sequence, the third timing sequence being determined by the time difference between the second MOSFET group turning off and the first MOSFET group turning on, so that when the first MOSFET group turns on, the second MOSFET group is already in a turned-off state; and controlling the first MOSFET group to turn off and the second MOSFET group to turn on in a fourth timing sequence, the fourth timing sequence being determined by the time difference between the first MOSFET group turning off and the second MOSFET group turning on, so that when the second MOSFET group turns on, the first MOSFET group is already in a turned-off state.

[0090] It should be noted that the above embodiments of the apparatus are only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0091] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0092] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0093] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A voltage control circuit for an electro-hydraulic nozzle, characterized in that, The control circuit is used in a current-current inkjet printer. The control circuit includes a control chip, a nozzle ejection voltage generation unit, a nozzle critical voltage generation unit, a nozzle ejection voltage control unit, a nozzle critical voltage control unit, and a first MOSFET group and a second MOSFET group; wherein... The source of the first MOS transistor group is connected to the nozzle injection voltage generation unit, and its gate is connected to the nozzle injection voltage control unit; the nozzle injection voltage generation unit is used to generate the nozzle injection voltage, and the nozzle injection voltage control unit is used to control the on / off state of the first MOS transistor group. The source of the second MOS transistor group is connected to the nozzle critical voltage generation unit, and its gate is connected to the nozzle critical voltage control unit; the nozzle critical voltage generation unit is used to generate the nozzle critical voltage, and the nozzle critical voltage control unit is used to control the on / off state of the second MOS transistor group. The drain of the first MOSFET group is connected to the drain of the second MOSFET group, and both the drain of the first MOSFET group and the drain of the second MOSFET group are connected to the load; both the first MOSFET group and the second MOSFET group include at least two MOSFETs. The control chip controls the nozzle ejection voltage control unit and the nozzle critical voltage control unit through control signals, so that the first MOS transistor group and the second MOS transistor group perform on and off actions, thereby enabling the load control current current fluid inkjet standby nozzle to eject and critically operate.

2. The control circuit according to claim 1, characterized in that, Both the nozzle injection voltage generation unit and the nozzle critical voltage generation unit include a basic voltage generation subunit and a voltage amplification subunit; wherein... The base voltage generation subunit is used to generate the base voltage required by the voltage amplification subunit according to the control signal of the control chip. The voltage amplification subunit is used to generate the injection voltage and critical voltage required by the load based on the base voltage.

3. The control circuit according to claim 1 or 2, characterized in that, The control chip obtains the voltage group corresponding to the ink droplet to be printed from the first correlation relationship based on the characteristics of the ink droplet to be printed in the current current fluid printing. The ink droplet characteristics include ink droplet viscosity, and the voltage group includes the ink droplet ejection voltage and critical voltage. The first correlation relationship includes the correlation relationship between multiple ink droplet characteristics and multiple voltage groups. One ink droplet characteristic corresponds to one voltage group, and one voltage group corresponds to the number of MOS transistors in one MOS transistor group. The MOS transistor group is the first MOS transistor group and the second MOS transistor group. The control chip controls the nozzle ejection voltage generation unit to generate the ejection voltage corresponding to the ink droplet to be printed, and controls the nozzle critical voltage generation unit to generate the critical voltage corresponding to the ink droplet to be printed.

4. The control circuit according to claim 1 or 2, characterized in that, The control chip obtains the corresponding drive signal parameters from the second association relationship based on the printing parameters of the current current fluid printing. The drive signal parameters include the high level time, frequency, and low level time of the drive signal. The printing parameters include the printing frequency, single injection time, and single silence time. The second association relationship includes the association relationship between multiple printing parameters and multiple drive signals, with one printing parameter corresponding to one drive signal parameter. The nozzle injection voltage control unit and the nozzle critical voltage control unit control the first MOS transistor group and the second MOS transistor group to perform conduction and shutdown actions through the drive signal parameters.

5. The control circuit according to claim 1, characterized in that, The first MOSFET group includes a first MOSFET and a second MOSFET, and the nozzle injection voltage control unit includes a first branch and a second branch; the first MOSFET corresponds to the first branch of the nozzle injection voltage control unit, and the second MOSFET corresponds to the second branch of the nozzle injection voltage control unit; wherein... The control chip controls the on / off state of the first MOSFET and the second MOSFET according to a first timing sequence, which is determined by the time difference between the on / off state of the first MOSFET and the second MOSFET.

6. The control circuit according to claim 1 or 5, characterized in that, The second MOSFET group includes a third MOSFET and a fourth MOSFET, and the nozzle critical voltage control unit includes a third branch and a fourth branch; the third MOSFET corresponds to the third branch of the nozzle critical voltage control unit, and the fourth MOSFET corresponds to the fourth branch of the nozzle critical voltage control unit; wherein, The control chip controls the on / off state of the third MOS transistor and the fourth MOS transistor according to a second timing sequence, which is determined by the time difference between the on / off state of the third MOS transistor and the fourth MOS transistor.

7. The control circuit according to claim 1, characterized in that, The nozzle injection voltage control unit includes a first high-level time and a first low-level time, and the nozzle critical voltage control unit includes a second high-level time and a second low-level time; wherein... When the injection voltage is at the first high level time, the critical voltage is at the second low level time, and the first high level time is less than the second low level time; When the injection voltage is at the first low level time, the critical voltage is at the second high level time, and the second high level time is less than the first low level time.

8. The control circuit according to claim 1 or 7, characterized in that, The control chip controls the first MOS transistor group to turn on and the second MOS transistor group to turn off in a third timing sequence. The third timing sequence is determined by the time difference between the second MOS transistor group turning off and the first MOS transistor group turning on, so that when the first MOS transistor group turns on, the second MOS transistor group is already in the off state. The control chip controls the first MOS transistor group to turn off and the second MOS transistor group to turn on in a fourth timing sequence. The fourth timing sequence is determined by the time difference between the first MOS transistor group turning off and the second MOS transistor group turning on, so that when the second MOS transistor group turns on, the first MOS transistor group is already in the off state.

9. A voltage control method for an electro-hydraulic nozzle, characterized in that, The control method, applied in the voltage control circuit of a current-current nozzle as described in any one of claims 1-8, comprises: Obtain the voltage group corresponding to the ink droplet to be printed, and generate the jet voltage in the voltage group through the nozzle jet voltage generation unit and generate the critical voltage in the voltage group through the nozzle critical voltage generation unit; The system acquires the drive signal parameters corresponding to the printing parameters, and generates a jet drive signal through the nozzle jet voltage control unit to turn on or off the first MOS transistor group, and generates a critical drive signal through the nozzle critical voltage control unit to turn on or off the second MOS transistor group. The printing parameters include printing frequency, single jet time and single silence time, and the drive signal parameters include frequency, high level time and low level time. Based on the voltage group and the drive signal parameters, the switching of the first MOS transistor group and the second MOS transistor group is controlled to enable the electrostatic inkjet printer to perform printing operations.

10. The control method according to claim 9, characterized in that, The number of MOSFETs in the first MOSFET group is determined by the injection voltage, and the number of MOSFETs in the second MOSFET group is determined by the threshold voltage; wherein, the control method further includes: The number of MOS transistors in the first MOS transistor group is determined based on the injection voltage; The number of MOS transistors in the second MOS transistor group is determined based on the critical voltage.

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