TWI277523B - Driving circuit for inkjet heating chip - Google Patents

Abstract

A driving circuit for an inkjet heating chip of a printhead is disclosed. The driving circuit is connected with a first input terminal, a second input terminal, a third input terminal and a common terminal for avoiding a heater to occur error printing operation. The driving circuit includes: a heater, a selection circuit and a protection circuit. The protection circuit is used to conduct the selection circuit and the common terminal in response to the triggering of a control signal from the first input terminal. When electric leakage or noise is generated at the output terminal of the selection circuit, the protection circuit can eliminate the output voltage generated from the selection circuit so as to prevent the output voltage to trigger the heater resulting in error printing operation or unnecessary energy consumption.

Description

1277523 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to an ink jet driving circuit for heating a wafer, and more particularly to an ink jet driving circuit suitable for heating a wafer of an ink jet head. [Prior Art]

In recent years, with the popularity of personal computers and the rapid development of ___, inkjet printers have become an essential product in personal computer equipment. For the average user, the A's-based basic inkjet printer is sufficient for various documents to be printed. As we all know, the quality of the ink-printing table is very good, such as the composition of the ink, the choice of paper, and the way of ink. In order to pursue a more perfect print quality, the relevant developers have entered the big time and focus on the ink storage and ink supply structure design, in order to meet the simple structure, low production cost, high ink storage capacity and high print quality. Wait for the request. Among them, the mechanism that controls the printhead to discharge ink droplets to the inkjet medium is one of the important factors for designing inks. In general, the manner in which the ink jet head ejects ink droplets mainly includes two types: a thermal bubble type and a micro piezo type. Taking a thermal bubble type ink jet head as an example, the principle of operation is heating by a heater resistor to generate bubbles to eject the ink, and to eject the ink onto the ink jet medium through a plurality of orifices. Please refer to the first figure (a), which is a schematic view of a conventional ink jet head using a thermal bubble type ink droplet 1277523. As shown in the figure, the conventional ink jet head mainly consists of a heating wafer 11 and a The barrier layer 12 and a orifice sheet 13 are formed. The heating wafer 11 includes an ink supply port (110) disposed at the center and a set of heating resistors (not shown) surrounding the ink supply port, and a plurality of ink chambers 121 are formed in the barrier layer 12, and the orifice film is formed. 13 has a plurality of injection holes 131 corresponding to the ink chamber 121, so that when the heating wafer u is assembled with the orifice sheet 13, and is adhered to the inkjet head carrier 15 at the bottom of the ink cartridge body 14 by an adhesive (such as In the first figure (b), the ink stored in the ink cartridge body 14 will sequentially flow into the ink supply port 110 of the heating wafer 11 and the ink chamber 121, and finally heated by a heating resistor to generate bubbles and then ink. The ink is discharged and sprayed onto the ink jet medium through the orifice 131 on the orifice sheet 13. Of course, in order to cope with the different ink color requirements of the color ink jet printer, the ink cartridge can be provided with a multi-array ink jet head to control the ejection of ink of different colors onto the ink jet medium. ' '

Wherein, the heating wafer 11 is internally provided with a multi-array inkjet driving circuit for respectively controlling the operation of the corresponding heating resistor, please refer to the second figure (a)' which is used to control the heating resistor operation in the heating wafer. The schematic diagram of the inkjet driving circuit is as shown in the figure, which includes: a selective transistor (SEL-MOS) 21, an electrostatic protection transistor (ESD_M〇s) 22, a heating resistor (Heater resistor) 23, a driving transistor ( Driver M〇s) 24, pull down resistor 25 and three input terminals a (Address), P (primitive) and SEL, wherein the selection of the transistor 21 is used for the selection of the printer control system The gate end of the ink jet head performing the ink jetting operation is connected to the input terminal sel, and the 1277523 is used for receiving the ink jet head selection circuit (not shown) of the printer control system. The selection signal, so if the inkjet head selected as the inkjet print, the gate terminals of the selection transistors 21 to which all of the heating resistors 23 included are received, a selection signal, that is, an enable signal ( Enable signal), to The other end of the selection transistor 21 is connected to an input terminal A, which receives a control signal transmitted by an inkjet head driving circuit (not shown) of the printer control system, indicating that the printer control system is to be The heating resistor 23 connected to the selection transistor 21 is driven to operate.

When the gate of the selected transistor 21 receives the selection signal input by the printer control system via the input terminal SEL, the Vin voltage is about 11.6V, and the input terminal A also inputs the control voltage of 11.6V, the transistor 21 is selected. It will be turned on, so that the voltage of the Η node opposite to the input terminal SEL is about 10·5 V (as shown in the second figure (b)), since the voltage of the Η node is high voltage, the control and heating resistor 23 can be controlled. The connected driving transistor 24 is turned on, so that the input terminal 传送 will transmit a voltage to the heating resistor 23, so that the temperature of the heating resistor 23 rises, and the ink is heated to generate bubbles to eject the ink to the inkjet. Printed on the media. As for the electrostatic protection transistor 22, respectively, is disposed between the input terminal 接地 and the ground terminal, and between the input terminal P and the ground terminal, mainly at the input terminal A and the input terminal P to prevent the electrostatic benefit from affecting the selection of the transistor 21, the driving power The crystal 24 and the heating resistor 23 operate. The pull-down resistor 25 is disposed between the input terminal A and the ground terminal and between the Η node and the ground terminal, and is mainly used to stabilize the voltage, so that the selection transistor 21 and the driving transistor 24 can operate stably. 1277523 Please refer to the second figure (b), which is the change of the voltage of the Η node corresponding to the SEL voltage when the circuit operation of the second figure (a) is used, and please refer to the second figure (c). For the enlarged view of the low voltage region (0-1.5V) of the SEL signal in the second graph (b), it can be seen from the second graph (c) that as long as the gate of the transistor 21 is selected, there is abnormally small leakage voltage or noise. When it is generated, the voltage of the Η node is generated, and the rising curve of the voltage is very steep, that is, as long as the gate electrode of the transistor 21 is selected to have some abnormal small leakage voltage or noise, it is easy to make the voltage of the Η node. Exceeding the threshold voltage of the driving transistor 24 ^, that is, the Vt value, and triggering the driving of the transistor 24 to cause the heating resistor 23 to malfunction and unnecessary energy consumption, thereby causing poor printing, the second figure ( a) The disclosed circuit design only has a higher Vt voltage value in the driving transistor 24 to avoid poor dot printing, but increasing the Vt voltage value of the driving transistor 24 also causes unnecessary power consumption. Therefore, the conventional circuit structure shown in the second diagram (a) has the following

Disadvantages · L no noise and leakage voltage protection: only static protection and voltage regulation at the input terminals A, P, can not be removed when the internal circuit generates noise or leakage voltage. 2. The process is limited: when the Vt value of the driving transistor 24 is lowered, and the higher concentration doping is performed, the gate terminal of the selected transistor 21 is also selected as long as there is a small leakage voltage and noise, and the transistor is selected. 21, that is, leakage current is formed, which causes unnecessary malfunction and energy consumption of the heating resistor 23, and relatively causes the driving transistor 24 to adopt a process design with a low Vt value. 1277523 曲3·Non-required power consumption: because the drive transistor 24 process can not do higher wave doping' so when the driving transistor 24 is turned on, there is no extreme (Μη) ^ source terminal (W) resistance is relatively high concentration doping The resistance of the hybrid is large, and the consumption of more unnecessary power is generated. 4. Inappropriate f-spraying: Because there is no protective electric money meter inside, it is easy to cause the driving transistor 24 to have an abnormal function when the noise or the voltage is leaked.

The St heating resistor 23 operates to cause unnecessary ejection points to appear and the operation of the "dissipation" affecting the normal ejection point to form a printing failure. The above-mentioned shortcomings will affect the quality of inkjet printing, 'the need to be improved'. How to develop a protective circuit that can improve the above-mentioned conventional technology and is suitable for inkjet heating wafers, which is urgently needed to be solved. 】

The main purpose of the case is to provide a kind of noise and leakage for the heating of the wafer, and to make the 'further heating'. The positive section and the hobby (4) regrets the quality of the print. Reduce the advantages, such as the value of soil consumption, phase 2 control, non-essential power: upper and lower limit, abnormal spray printing and other shortcomings. ~ The above purpose 'The _ the broader form of the case is to provide a force 1277523

An inkjet driving circuit is suitable for heating a wafer in one of the inkjet heads, and is connected to a first input terminal, a second input terminal, a third input terminal and a common terminal to avoid a heater An erroneous printing operation and unnecessary energy consumption occur, the inkjet driving circuit includes: a selection circuit connected to the first input end and the second input end for inputting the first input end a control signal and a trigger of a selection signal transmitted by the second input to generate an output voltage to drive the operation of the heater; a protection circuit coupled between the selection circuit and the common terminal And connecting to the output end of the selection circuit and the heater; wherein the protection circuit is caused to be turned on by the control signal of the first input end, and the selection circuit is electrically connected to the common terminal When the output terminal of the circuit generates a drain voltage and/or noise, the output voltage generated by the selection circuit is eliminated through the protection circuit to prevent the output voltage from triggering the heater and causing an error. Indian action. According to the concept of the present invention, the selection circuit is a switch for switching between the control signal input by the first input terminal and the triggering of the selection signal transmitted by the second input terminal. According to the concept of the present invention, the switching circuit of the selection circuit is a metal oxide semiconductor transistor, which includes a gate, a drain and a source, and the gate is connected to the second input terminal for Receiving the selection signal, the drain is connected to the first input terminal for receiving the control signal, and the source is connected to the protection circuit and the heater. According to the concept of the present invention, the protection circuit is a switch for causing the selection of the circuit and the common terminal according to the concept of the present invention in response to the triggering of the control signal at the first input. The metal-oxide-semiconductor transistor has a switching-off relationship of a child-protected circuit, and the gate system and the first wheel system comprise a gate, a drain, and a full mark, and the gate electrode and the selected electric rain The ingress connection is configured to receive the control credit to connect the selection circuit to the output end of the packet and the heater, and the voltage is eliminated to prevent the output from being generated by the voltage and/or noise. Outputting the printing action and unnecessary energy, and triggering the heater to cause an error. According to the concept of the present invention, the first input terminal of the inkjet driving circuit is disposed between the common terminal and the common terminal. Between the end points, there is: a resistor, and an output circuit output end of the selection circuit and the first input two pull-down resistors for stabilizing the selection according to the concept of the present invention, the voltage and a switch, the heating resistance The heater Including a heating resistor switching relationship and the selection of the lightning failure #, and - the third input terminal connection, the heat-cut resistor connection, which is due to the library::: road, the joint terminal and the plus The heating resistor disk is connected to the mountain selection circuit - the output voltage is triggered - the input (four) is transmitted by the voltage; the temperature of the resistor is increased. According to the concept of the present invention, the protection circuit is provided in the two-way system comprising - electrostatic interference. The input voltage of the terminal is not electrostatically dry according to the concept of the present case, The w drive circuit includes an electrostatic 12 1277523 protection circuit disposed between the first input terminal and the common terminal, * for preventing the input voltage of the first input terminal from being disturbed by static electricity. The concept of the present invention, wherein the common terminal is a ground terminal for the lowest voltage end of the inkjet circuit. To achieve the above object, the present invention further provides a heating chip, which is suitable for an inkjet head structure, The heating chip system comprises: a plurality of heaters; a plurality of inkjet driving circuits respectively controlling one of the plurality of heaters to perform a printing operation, and a first input end, a second input end, and a third The input end and a common end point are connected, wherein each inkjet driving circuit comprises: a selection circuit connected to the first input end and the second input end for inputting according to the first input end And triggering a control signal and a selection signal transmitted by the second input to generate an output voltage to drive one of the plurality of heaters to operate; a protection circuit coupled to the selection circuit and the common terminal And connecting to an output end of the selection circuit and the heater; wherein the protection circuit is caused to be electrically connected to the common terminal w by triggering the control signal at the first input end, When the output terminal of the selection circuit generates a drain voltage and/or noise, the output voltage generated by the selection circuit is eliminated through the protection circuit to prevent the output voltage from triggering one of the plurality of heaters. However, an erroneous printing operation and unnecessary energy consumption occur. [Embodiment] Some exemplary embodiments embodying the features and advantages of the present invention will be described in detail in the description of 13 1277523 in the following paragraph. It should be understood that the present invention can be used in different aspects. There are various changes that do not depart from the scope of the present invention, and the descriptions and illustrations therein are used in the nature of the description, rather than limiting the case.

Generally, the heating chip disposed inside the inkjet head structure triggers the heating resistor to perform the inkjet printing operation according to the control signal transmitted by the printer control system, so that the capacitor array is required to be heated inside the wafer. The ink driving circuit controls a plurality of heating resistors respectively, and the following description will be made in such a manner that an ink-jet driving circuit controls the operation of the corresponding heating resistor. Please refer to the third figure, which is a schematic diagram of an inkjet driving circuit for controlling the operation of a heating resistor in a heating wafer. As shown in the figure, the inkjet driving circuit of the present invention is composed of a selection circuit 31, a protection circuit 32, and a pull-down resistor. The R1, R2 and the ESD protection circuits 331, 332 are configured, and the inkjet drive circuit is connected to the first input terminal A, the second input terminal SEL, the third input terminal P and a common terminal signal. In addition to the operation of the heater 34 according to the signal transmitted by the printer control system (not shown), the ink jet driving circuit of the present invention can prevent the internal circuit of the selecting circuit 31 from leaking voltage and/or by the protection circuit 32. Or the interference of the noise causes the heater 34 to perform an erroneous printing operation and unnecessary energy consumption. Wherein, the common terminal is a ground 35 and the second input SEL is connected to an inkjet head selection circuit (not shown) of the printer control system for receiving the inkjet head selection. The selection signal transmitted by the circuit, so if the ink cartridge (not shown) is selected as the inkjet printing head (not shown), all the heaters 34 included in the ink cartridge are connected to the circuit 12 1477523 The end point of the connection with the second round of the human-end fox will be connected to a selection signal, and the first-input terminal a is connected to the inkjet head drive circuit (not shown) of the printer control system. A control signal is generated to drive the heater 34 connected to the selection circuit 31 to operate.

The I select circuit 31 is a switch, and in the preferred embodiment of the present invention, a metal oxide semiconductor transistor (hereinafter referred to as MOS transistor) 311 is a preferred embodiment, and the M〇s transistor 3ΐ a gate (Date) and a source (Source), the gate terminal of the MOS transistor 311 is connected to the second input terminal SEL for receiving the printer control = system selection circuit The selection signal is connected to the first input % A for receiving the control signal transmitted by the driving circuit of the printer control system. As for the source terminal, the protection circuit 32, the pull-down resistor R2 and the heater 34 are connected. The connection is made so that the M〇s transistor 311 switches according to the control signal input by the first input terminal A and the selection signal transmitted by the second input terminal SEL. The anti-compliance circuit 32 is a switch, and in the preferred embodiment of the present invention, a metal oxide semiconductor transistor (hereinafter referred to as M〇s transistor) 321 is a preferred embodiment, and the MOS transistor 321 is also included. a gate (Gate), a drain (Drain) and a source (Source), the gate terminal is connected to the first input terminal A for receiving the control signal, and the gate terminal is connected to the M〇s transistor 311. The source, the pull-down resistor R2 and the heater 34 are connected, and the source terminal is connected to the ground terminal 35. The MOS transistor 321 as the protection circuit 32 causes the MOS transistor 321 to be triggered by the control signal of the first input terminal A. The drain between the drain and the source is turned on even if the circuit 15 !277523 is selected.

31 is turned on via the drain of the MOS transistor 321 and the source and the ground terminal. 'When the gate terminal of the M?s transistor 311 as the selection circuit 31 is abnormally small, voltage and 7 or noise, the MOS transistor The output voltage of the 311 output to the H node (as shown in the second figure) will be abnormally outputted by the drain and source of the MOS transistor 321 and the voltage generated by the M〇s transistor 311 is eliminated, and the voltage is eliminated to avoid the MOS. The output voltage of the transistor 311 due to abnormal leakage voltage and/or noise exceeds the threshold voltage Vt of the heater 34, so that the heater 34 is triggered when the printing operation is not performed, and the malfunction occurs. The necessary energy consumption. In the present embodiment, the heater 34 is composed of a heating resistor R3 and a switch 341. The heating resistor r3 is connected to the third input terminal p, and the switch 341 is a metal oxide semiconductor transistor. Preferably, the system is connected to the selection circuit 31, the protection circuit 32, the ground terminal 35, and the heating resistor R3. The switch 341 is turned on in response to the trigger of the output voltage of the output circuit 31 to the H node, thereby causing the heating resistor R3 to The grounding terminal 35 is electrically connected, so that the voltage transmitted by the third input terminal P can be transmitted to the heating resistor R3, and the temperature of the heating resistor R3 is raised to heat the ink to cause bubbles to spray the ink to the column. Printed on the media. In addition, the inkjet driving circuit of the present invention is provided with a pull-down resistor R1 between the first input terminal A and the ground terminal 35, and a pull-down resistor R2 is disposed between the Η node and the ground terminal 35, mainly for stabilizing the voltage, The selection circuit 31, the protection circuit 32, and the changeover switch 341 can be stably operated. The electrostatic protection circuits 331, 332 respectively disposed between the input terminal Α and the ground terminal 35 and the input terminal 接地 and the ground terminal 35 are mainly used to prevent the electrostatic benefit shadow 1277523 from selecting the circuit 3i, the protection circuit 32 and the heater 34. . When the gate terminal of the MOS transistor 311 as the selection circuit 31 receives the selection circuit of the printer control system (4), and (4) the selection signal input by the second input terminal SEL, the Vin voltage, about U.6V, and the first input When the terminal A is also input with a control voltage of 11.6V, the 'M〇s transistor 311 will be turned on. At this time, the MOS transistor 3U supplies the switch 34 of the heater 34 to the idle terminal voltage of about 10.2V (such as In the fourth figure (a), since the voltage of the Η node is high voltage, the switch 34i connected to the heating resistor R3 can be controlled to be turned on, so that the third input terminal p will transmit a voltage to the heating resistor. R3, so that the temperature of the heating resistor R3 rises, and the ink is heated to generate bubbles and then the ink nozzle to the printing medium ±. ° '

Please refer to the fourth picture (a) and please cooperate with the fourth picture (b). The fourth picture (b) is the enlarged picture of the low voltage region (〇_15v) of the SEL signal in the fourth picture (a). It can be seen in the figure (b) that when the gate terminal of the M〇s transistor 311 has an abnormally small drain voltage and/or noise, the output of the MOS transistor 311 to the Η node (as shown in the third figure) is abnormal. The output voltage will be eliminated by the MOS transistor 321 to prevent the output voltage of the m〇S transistor 311 due to abnormal leakage voltage and/or noise exceeding the threshold voltage Vt of the heater 34, thus making MOS The voltage curve of the n-node of the gate terminal of the switching switch 341 provided by the transistor 311 to the heater 34 is much gentler than the curve shown in the second diagram (c), so that the voltage transmitted to the switching switch 341 does not easily exceed the threshold of the switching switch 341. The voltage Vt value causes the heating resistor R3 of the heater 34 and the changeover switch 341 to not cause the phenomenon of the error 17 1277523' to further avoid the disadvantages of the prior art, and the high potential portion thereof (as shown in the fourth figure (a)) Also meets the requirements of the inkjet driver circuit of the third figure, so The ink jet driving circuit of the present invention can improve the disadvantages of the prior art by providing the protective circuit 32 between the selecting circuit 31 and the grounding terminal 35, and the heating resistor R3 and the switching switch 341 inside the heater 34 can also operate normally. In summary, the ink jet driving circuit of the present invention improves the prior art by the protection circuit 32 disposed between the selection circuit and the ground terminal 35.

The MOS transistor between the selection circuit is extremely unstable due to noise and leakage voltage = the malfunction of the heating resistor, so that the switching switch inside the heater can operate normally, so that a low threshold voltage can be adopted; Reduced consumption, improve the speed of the circuit 2 ==:: will be improved, 'this case has to be familiar with this technology 2 2 1 according to," please. Decoration, iron are not 7 people to apply for the idea and white Not to be protected as intended by the scope of the patent application. 18

1277523 [Simple description of the diagram] (10) The structure of the ink is shown in Fig. 2 (a): It is a schematic diagram of the inkjet _f path used to control the addition in the heating wafer. Operation of the resistor: Fig. (b) is a diagram showing the change of the voltage corresponding to the SEL and voltage when the circuit of the second diagram (a) operates. P.,····················································· Fig. 3 is a schematic view showing the circuit configuration of the ink jet driving circuit of the preferred embodiment of the present invention. Fig. 4(a) is a graph showing changes in the voltage at the h-node corresponding to the SEL voltage when the circuit shown in the third figure operates. Fig. 4(b) is an enlarged schematic view of the low voltage region of the SEL signal of the fourth figure (a). 19 1277523 Main component symbol description 1: ink jet head 11: heating wafer 110: ink supply port 12: barrier layer 121: ink chamber 13: orifice sheet 131: nozzle hole 14: ink cartridge body 15: ink cartridge holder 21: Selecting the transistor 22: Electrostatic protection transistor 23: Heating resistor 24: Driving transistor 25: Pull-down resistor 31: Selection circuit 311: MOS transistor 32: Protection circuit 321: MOS transistor 331, 332: Electrostatic protection circuit 34 : Heater 341 : Diverter switch Rl, R2 : Pull-down resistor R3 : Heating resistor 35 : Ground terminal A : First input terminal P : Third input terminal SEL : Second input terminal

Claims (1)

1277523 % % X. Patent application scope ·································································· The three-input terminal and a common terminal are connected to prevent a heater from performing an erroneous printing operation, and the ink-jet driving circuit includes a heater; a gate selection circuit and the first input terminal; The second input terminal is connected to the port, and a voltage is generated by a control signal input from the first input end of the first input terminal and a trigger signal selected by the second input terminal to drive the operation of the heater, and ^ a protection circuit connected to the output terminal of the selection circuit and the U selection circuit of the common terminal and the heater; wherein the protection circuit is triggered by the first input of the control signal The output of the selection circuit (4) II two-phase conduction is used to generate a drain voltage and / / (4) at the output terminal of the selection circuit. The protection circuit generates the electricity generated by the selection circuit [nuclear to avoid the output Electric (Iv) action and unnecessary energy consumption. Μ (4) Error column 2 Patent application scope; The ink-jet driving circuit described in the item is a switching switch for selecting the eighth control signal and the input of the private input %. Switching is performed as a result. Triggering of the • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 The open pole is connected to the second input end, and the gate is connected to the first input terminal for receiving the air source domain 'the source system and the protection circuit 4 · as claimed Scope] Jg cake, +, + + ... transport circuit m motor drive circuit, (4) anti-switch is a switch, which is used to select the circuit first: 控制:: control signal trigger Selecting the circuit and the inkjet driving circuit of the second:::# door-to-door, and the second-order oxide semiconductor transistor, wherein the system includes a -pole, a connection: a source The pole is connected to the first input of the selection circuit. (4) The control signal 'the drain is connected to the output of the selection circuit and the heater for the selection circuit due to the drain voltage and/or the noise The output power generated (4) in addition to the second heater, the error printing action and unnecessary: touch • The inkjet (four) circuit described in the fifth patent, the ink-driven (four) circuit of the ink drive circuit, the first input terminal and the common terminal of the ink drive circuit are provided with “-, the pull resistance is two (4) the output end of the circuit and the common connection There are two between the end points: electric: blocking the inkjet driving circuit for stabilizing the output of the selection circuit and the first input terminal r, wherein the heating resistor and the switch are added. The heating resistor is connected to the input end of the circuit, and the connection circuit is connected to the circuit, the common terminal and the heating resistor, and the circuit is connected to the 22 1277523 i I circuit. The output voltage is triggered to connect the heating resistor to the common terminal, so that the voltage transmitted by the third input is transmitted to the heating resistor to raise the temperature of the heating resistor. 8. The inkjet driving circuit of claim 7, wherein the inkjet driving circuit comprises an electrostatic protection circuit disposed between the third input end and the common end point for The third input is prevented from being disturbed by static electricity. 9. The inkjet driving circuit of claim 1, wherein the inkjet driving circuit comprises an electrostatic protection circuit disposed between the first input terminal and the common terminal end. To prevent the first input from being disturbed by static electricity. 10. The inkjet driving circuit of claim 1, wherein the common terminal is a ground terminal for the lowest voltage terminal of the inkjet circuit. 23 1277523 1277523 SEL # §月|曰修(3⁄4正换页 Figure 4 (a)