KR0122604Y1 - Power control circuit for an ink-jet printer - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION The invention described in the claims relates to an inkjet printer, and more particularly, to a power supply control circuit for maintaining a printhead of an inkjet printer at all times.

2. The technical problem to be solved by the present invention is to provide a power supply control circuit of an ink jet printer with low power loss and able to cope with a light and simple product trend.

3. Summary of Solution of the Invention: A power supply control circuit for maintaining a printhead of an ink jet printer having a power supply means in a printable state at all times, wherein the switching means is provided at a prescribed level from the power supply means. Different logic level values are output each time the power switch is connected to the input voltage terminal to which voltage is supplied. At this time, the power supply control means outputs a first power supply control signal corresponding to the logic level value output from the switching means to the logic voltage generation means to generate a logic voltage. On the other hand, the control means for controlling the overall operation of the ink jet printer reads the logic level value output from the switching means and outputs a control signal for capping the plant head when the logic level value is a power off signal, and then the power control means. Outputting a second power control signal to the power supply control means for inverting the logic level value of the first power supply control signal outputted from the controller to block the generation of the logic voltage.

4. Significant use of the invention: It can be useful for power supply control circuits for capping the printhead of ink jet printers.

Description

Power supply control circuit of ink jet printer

1 is a schematic block diagram of a typical ink jet printer.

2 is a detailed circuit diagram of a conventional power supply control circuit.

3 is a detailed circuit diagram of a power supply control circuit according to the present invention.

The present invention relates to an ink jet printer, and more particularly to a power supply control circuit for keeping the print head of the ink jet printer in a printable state at all times.

Usually, among the recording methods for recording an image on a recording medium such as paper or overhead project film, a recording method such as a wire dot method, a thermal transfer method, or an ink jet method uses a unique recording head. Doing.

Among these recording methods, the ink jet method is a method of spraying ink directly onto a recording medium. Accordingly, the printer employing the ink jet method has a recording head in which a plurality of nozzles in which fine ejection holes for ejecting ink are formed. The discharge holes formed in these nozzles are filled with ink.If the nozzles are not used for a long time, the discharge holes may be contaminated due to an increase in viscosity due to infiltration of air bubbles or dust particles into the discharge holes or evaporation of the ink solvent. I get stuck. As a result, the image quality is lowered because the optimum ink is not ejected. Accordingly, currently commercially available ink jet printers are designed to cap the recording head while not recording. This is done by covering the nozzle of the recording head with a cap and discharging or aspirating ink in all discharge holes for a predetermined time or for a predetermined time when the carriage in which the recording head is installed is moved to the home position at the end of recording. Clean the discharge hole. At this time, the discharged or sucked ink is stored in a separate waste ink tank.

In the conventional ink jet printer, when the power is turned off after the end of printing or during printing, the controller for controlling the overall operation of the ink jet printer detects a power off signal and generates a control signal for operating the print head to a capping position. In this case, the motor driving unit moves the print head to the capping position in response to a control signal applied from the control unit to perform the capping operation, thereby preventing the discharge hole from being contaminated or blocked. Hereinafter, a process of operating a printhead to a capping position by detecting a power-off signal by a controller of an ink jet printer will be described with reference to FIGS. 1 and 2.

1 shows a schematic block diagram of a general ink jet printer. In FIG. 1, the central processing unit (CPU) 102 executes a program stored in the ROM 104 and uses an ink jet through an input / output interface (hereinafter referred to as an I / O interface) 106. Control each part of the printer. The ROM 104 stores a control program of the CPU 102 and various initial data. The RAM 100 temporarily stores data according to the operation of the CPU 102. The I / O interface 106 interfaces signals input and output between the CPU 102 and input / output devices, that is, the power supply control circuit 108 and the operation panel 110, the motor driver 112, and the head driver 114. . The power supply control circuit 108 inputs a voltage Vin output from a power supply (not shown), and moves the CPU 102 and the motor driver to move the print head to a capping position when the ink jet printer is powered off. 112 to control the power supplied. The operation panel 110 includes a plurality of keys for inputting various commands to the CPU 102 and a display device for displaying various states by the CPU 102. The motor driver 112 drives the carriage transfer motor (hereinafter referred to as CR motor) 116 and the LF (Line Feed) motor 118 under the control of the CPU 102. The CR motor 116 is driven by the motor driver 112 to transfer a head cartridge (not shown) in which the head 120 is installed. The LF motor 118 is driven by the motor driving unit 112 to transfer a recording medium such as paper. The head driver 114 drives the head 120 to eject ink through the nozzles provided in the head 120 to record an image on the recording medium. The head 120 is driven by the head driving unit 114 as a recording head in which a plurality of nozzles in which discharge holes are formed are arranged.

2 shows a detailed circuit diagram of a conventional power supply control circuit 108. The power supply control circuit 108 includes a resistor R1, a power switch SW, a resistor R2, a resistor R3, a resistor R5, a resistor R6, a resistor R7, and a resistor R8 between the input voltage terminal Vin and the ground input from the power supply unit, respectively. It is connected in series. A toggle 200 is connected between the resistor R1 and the connection point P of the power switch SW and the non-inverting input terminal of the comparator 202. The connection points of the resistors R2 and R3 and the connection points of the resistors R5 and R6 are respectively connected to the inverting input terminals of the comparator 202 and the comparator 204, and the output terminal of the comparator 202 is connected to the non-inverting input terminal of the comparator 204. The output terminal of the comparator 204 is connected to the base of the transistor Q2 having an emitter connected to the input voltage terminal Vin through a connection point of the resistors R7 and R8. The collector of the transistor Q2 outputs a logic voltage Vcc according to the output logic state of the comparator 204. The resistor R4 and the capacitor C2 are connected between the input voltage terminal Vin and the output terminal of the comparator 202, respectively. The connection point Q between the toggle 200 and the comparator 202 is connected to the non-inverting input terminal of the comparator 206, and the inverting input terminal of the comparator 206 is connected between the resistors R9 and R10 connected in series between the input voltage terminal Vin and ground. It is connected to the connection point. On the other hand, the output terminal of the comparator 206 is connected to the cathode of the LED for indicating the power on / off state of the ink jet printer to the user, the anode of the LED is connected to the logic voltage Vcc through the resistor R11.

The CPU 102 of the ink jet printer reads a power off signal POS (hereinafter referred to as pos) through the connection point Q to recognize the power on / off state of the ink jet printer, and the read toggle ( A power control signal (hereinafter referred to as a PCS) corresponding to the output logic state of the controller 200 is output. The power control signal PCS is applied to the base of transistor Q1 having an emitter connected to logic voltage Vcc through capacitor C1, and the collector of transistor Q1 is connected to the non-inverting input terminal of comparator 204. On the other hand, a resistor R12 is connected between the logic voltage Vcc and the base of the transistor Q1. Hereinafter, a process of blocking the logic voltage Vcc after moving the printhead of the conventional power supply control circuit 108 having the above-described configuration to the capping position will be described.

When the user connects the power cord of the ink jet printer, the power supply Vin outputs the input power Vin. The input voltage Vin causes the output level of the toggle 200 to be in a logic high state, and thus the output level of the comparators 202, 204, and 206 is also in a logic high state. Accordingly, the transistor Q2 connected to the output terminal of the comparator 204 maintains a turn-off state, and the LED connected to the output terminal of the comparator 206 maintains an unlit state. In this case, when the user presses and releases the power switch SW, the output level of the toggle 200 is inverted to a logic low state, and accordingly, the output levels of the comparators 202, 204, and 206 are also inverted to a logic low state. Therefore, the transistor Q2 connected to the output terminal of the comparator 204 is turned on to output the logic voltage Vcc. On the other hand, the LED is connected to the cathode of the comparator 206 is turned on to notify the user of the power-on state of the ink jet printer. Then, when the user presses and releases the power switch SW again, the output level of the toggle 200 is inverted to a logic high state. Accordingly, the output level of the comparator 206 becomes a logic high state to turn off the LED which is lit, and the CPU 102 recognizes that the user turns off the power by reading the logic high state of the power-off signal POS through the connection point Q. . Therefore, the CPU 102 stops the operation that is being performed and outputs a control signal for capping the plant head 120. The CPU 102 then outputs the power control signal PCS in a logic low state to turn off the power being supplied to each part of the ink jet printer. As a result, transistor Q1 is turned on due to a momentary potential change across capacitor C1. Therefore, the output level of the comparator 204 becomes a logic high state, which turns off the transistor Q2, thereby shutting off the output of the logic voltage Vcc. However, the power supply control circuit of the conventional ink jet printer having the above-described configuration has a drawback in that it has a lot of power loss because it is composed of a plurality of elements, and has a problem that is contrary to the recent light and short production trend.

Accordingly, an object of the present invention is to provide a power supply control circuit for controlling a print head of an ink jet printer which can reduce the power loss and respond to a light and simple trend of productization.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Also in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the subject innovation, such as specific circuit configurations and components. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

3 is a detailed circuit diagram of the power supply control circuit 108 according to the present invention, the power supply control circuit 108 is largely the power switch unit 300, the power control unit 400, the logic voltage generator ( 500). The power switch unit 300 is connected to a resistor R20 connected to a power input terminal Vin input from a power supply unit, a power switch SW1 connected between the resistor R20 and ground, and a connection point between the resistor R20 and the power switch SW1. Configured toggle 201. The toggle 210 applies the output level of the logic state according to the switching of the power switch SW1 to the clear terminal CLR of the D-flop flop 220. On the other hand, the power control unit 400 is a D-flip flop 220 is connected to the toggle (210) terminal of the power switch unit 300 and the input terminal (D) is connected to the power input terminal Vin, and It consists of a resistor R22 and a capacitor C3 connected in series between the input voltage terminal Vin and ground. The connection point of the resistor R22 and the capacitor C3 is connected to the preset PR terminal of the D-flop flop 220, and the power control signal PCS of the CPU 102 is the clock terminal CK of the D-flop flop 220. Is applied to. The resistor R22 and the capacitor C3 are delay circuits for presetting the D flip-flop 220. The logic voltage generator 500 includes a transistor Q3 having a base and an emitter connected to an output terminal Q and a power input terminal Vin of the D-flop flop 220, respectively. At this time, the collector of the transistor Q3 outputs the logic voltage Vcc according to the output logic state of the D-flop flop 302. The CPU 102 of the ink jet printer also leads the power off signal POS through the connection point Y between the toggle 210 and the clear terminal CLR of the D-flop flop 220. At this time, the CPU 102 applies the power control signal PCS corresponding to the logic state of the power-off signal POS to the clock terminal CK of the D-flip flop 302. Meanwhile, the connection point Y is connected to the cathode of the LED so that the anode of the LED is connected to the logic voltage terminal Vcc through the resistor R11. Hereinafter, an operation example of the power supply control circuit 108 according to the present invention will be described in detail with reference to FIG. 3.

First, when the user of the ink jet printer connects the power cord of the ink jet printer, the voltage supply output from the power supply unit is applied to the power supply control circuit 108. In this case, the initial state is assumed, and the output level of the toggle 210 in the initial state is assumed to be logic high. Then, when the user presses and releases the power switch SW1 to operate the ink jet printer, the output level of the toggle 210 which was initially outputting the logic high level is inverted to the logic low state and output. As the logic low signal inverted and output from the toggle 210 clears the D-flip flop 220, an output signal of a logic low level is output at the output terminal Q of the D-flip flop 220. Is applied to. As a result, the transistor Q3 is turned on to output the logic voltage Vcc. Therefore, the CPU 102, which operates normally at the logic voltage Vcc, controls each unit of the ink jet printer, so that the ink jet printer operates normally. On the other hand, the logic voltage Vcc turns on the LED through the resistor R24 to indicate the user that the power of the ink jet printer is on. Then, if the user presses and releases the power switch SW1 again to turn off the ink jet printer, the output level of the toggle 210 is inverted to a logic high state. At this time, the CPU 102 reads the logic high level output signal output from the toggle 210 to the power-off signal POS through the connection point Y. The CPU 102 then goes through a series of steps for capping the printhead 120 and then clocks the clock stage CK of the D-flip-flop 220 to the logic high level of the power control signal PCS for controlling the logic voltage Vcc. To apply. As a result, the output signal Q inverted to the logic high state is applied to the base of the transistor Q3 at the output terminal Q of the D-flip-flop 220 so that the transistor Q3 is turned off. Therefore, the output of logic voltage Vcc is cut off and the lit LED turns off to indicate to user that the ink jet printer is powered off.

As described above, the present invention achieves the same effect by using fewer component elements compared to the conventional power supply control circuit, thereby reducing production cost and greatly reducing power loss, and can meet the tendency of light and simple productization. have.

Claims (3)

A power supply control circuit for maintaining a print header of an ink jet printer having a power supply means in a printable state, the power switch being connected to an input voltage terminal supplied with a voltage of a predetermined level from the power supply means. Switching means for outputting different logic level values each time of switching, power control means for generating a first power control signal corresponding to the logic level value input from the switching means and applying it to the logic voltage generating means, and the power control A logic voltage generating means for generating a logic voltage in response to a logic level value of the first power control signal input from the means, and controlling the overall operation of the ink jet printer and reading the noli level value output from the switching water means; And output from the power supply control means according to the read logic level value. First power supply control circuit according to claim 2 characterized in that the configuration of the power supply control signal to the control means which outputs to said power source control means for inverting the logic level of the power supply control signal. According to claim 1, wherein the power supply control means is a resistor and capacitor connected in series between the input voltage terminal and the ground, a preset terminal is connected to the connection point of the resistor and the capacitor, respectively, an input terminal to the output terminal of the input terminal and the switching means And a clear terminal connected to the power supply control circuit, characterized in that the flip-flop receives the second power control signal output from the control means as a clock pulse. The power supply according to claim 1, wherein the control means outputs a second power control signal after outputting a control signal for capping the print head when the logic level value output from the switching means is a power off signal. Control circuit.