KR19980077318A - Head driving device and driving method according to voltage fluctuation - Google Patents

Abstract

The present invention relates to a head driving apparatus and a driving method for preventing head breakage generated at high voltage by checking power fluctuations during head nozzle driving and changing head driving timing.

When the driving voltage Vcc is provided to the inverting stage and the start pulse is applied to the non-inverting stage, the first comparator OP1 outputs the operation signal High to the output stage and the output signal of the first comparator OP1. It is composed of a second comparator (OP1) that receives the head drive voltage to the inverting stage and receives a comparison voltage at the non-inverting stage and outputs the result of comparing the two voltages to the output stage. By setting the time, the cost of the power supply circuit can be reduced.

Description

Head driving device and driving method according to voltage fluctuation

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer, and more particularly, to a head driving apparatus and a driving method for preventing head breakage generated at a high voltage by changing a head driving timing by checking power fluctuations during head nozzle driving. .

Among the peripheral devices of the computer, it is a representative output device displayed on a medium such as paper so that the user can recognize the contents according to the work of the computer.

Among these printers, inkjet printers are typical printers that can be purchased at a low price and have excellent print quality.

First, the configuration and operation principle of a general inkjet printer will be described with reference to FIG. 1.

CPU 10 that reads, analyzes and executes a system program in the EPROM 21 that stores initial setting values required for printer operation and values required for the system, and outputs a control signal according to the contents of the program; A signal transmitted from a computer (not shown) through a ROM 12 having various fonts embedded therein, a RAM 13 used to temporarily store data during system operation, and a printer interface 22. Buffer 23 for receiving and temporarily storing) and most logic circuits necessary for control of the CPU 10 are implemented as an ASIC to provide CPUs for most devices around the CPU 10. ASIC circuit section 20 for performing data transfer with (10), and head drive driver 30 for controlling the drive of ink cartridge 31 in accordance with a control signal from CPU 10 transmitted from said ASIC circuit 20; Wow The carriage motor drive circuit 40 which controls the operation of the ground return drive motor 41 and the line feed motor drive circuit which controls the drive of the line feed motor 51 for feeding and discharging paper using mainly a stepping motor. 50, and a power supply (SMPS) 60 for providing a drive voltage necessary for the overall printer device.

FIG. 2 is a block diagram illustrating the power supply 60 of FIG. 1 in more detail.

A filter circuit 61 for filtering out noise components included in the external power source, a rectifier circuit 62 for rectifying the input AC power source to a DC power source, a transformer T for inducing the rectified power source to a rear end, And a switching element 63 for turning on / off the primary power of the transformer T and a pulse width modulation circuit for outputting a variable duty width for controlling the on / off time of the switching element 63 ( Pulse Width Modulation-IC (PWM-IC) 64, a 5V regulator 65 for providing a power source induced at the secondary side of the transformer T with a constant voltage of 5V to the controller logic section, and the transformer T. 24V output circuit 66 for using different induction voltages as a power source for driving each motor and cartridge, and detecting the overcurrent or overvoltage of the 24V output circuit 66 to provide a control signal to the PWM-IC. OVP (Over Voltage Protection) Circuit And an over current protection (OCP) circuit.

Meanwhile, the head drive driver 30 in FIG. 1 uses a separate constant voltage source or a large capacity constant voltage source for head driving. That is, as shown in Figure 2 is to use a constant voltage of 5V used to drive the control logic unit.

As such, the power circuit is complicated when using a separate constant voltage source, and a large capacity precise constant voltage is required in common use, which has caused a price increase.

In addition, the head may be damaged due to power fluctuations.

The present invention for solving the above problems provides a head drive device and a driving method that enables the head drive even if the head drive timing fluctuates by varying the head drive timing by checking the power fluctuation during the head nozzle drive to change within a certain range. For the purpose.

According to an aspect of the present invention, a first comparator OP1 is provided with a driving voltage Vcc at an inverting stage and outputs an operation signal High to an output terminal when a start pulse is applied to a non-inverting stage. The head driving driver receives the head driving voltage at the inverting stage according to the output signal of the first comparator OP1 and receives the comparison voltage at the non-inverting stage and outputs the result of comparing the two voltages at the output terminal. Characterized in that configured.

1 is a block diagram showing a configuration of a general inkjet printer;

2 is a circuit diagram showing in detail the power supply of FIG.

3 is a circuit diagram of a head driving unit according to the present invention;

4 is a flow chart showing the implementation of the present invention.

Hereinafter, the configuration and operation of the present invention will be described with reference to the accompanying drawings. 3 is a circuit diagram illustrating a head driver according to the present invention. A first comparator OP1 for receiving a start pulse output from the CPU to the non-inverting terminal and outputting a high signal, resistors R1 and R2 for configuring a comparison voltage at the inverting terminal of the first comparator; The second comparator OP2 receiving the output signal of the first comparator to the inverting terminal, and the zener diode ZD and the resistor R3 for configuring the comparison voltage at the non-inverting terminal of the second comparator are shown. A resistor R4 and a capacitor C1 for charging and discharging the head driving voltage are connected to the inverting terminal of the second comparator, and a pull-up resistor R5 is connected to the output terminal.

The head drive drive circuit thus constructed is operated as follows. In the normal state, the start pulse has a low value. Thus, the first comparator is not operated. When the high signal is input to perform the power check, the first comparator OP1 outputs high. Accordingly, the head driving voltage starts charging according to the time constant of the resistor R4 and the capacitor C1.

When the charged voltage is greater than the comparison voltage set by the zener diode ZD, the output of the second comparator OP2 is low. This is to check the potential of any head drive voltage. Using the same time constant, the current drive voltage is measured by measuring the arrival time to a certain potential. In other words, it has a fast charging time in the case of high voltage.

4 is a flowchart illustrating a head driving method according to a voltage change according to the present invention. Receives a print command (step S1) and outputs a start pulse to check the driving voltage (step S2).

A count is performed for timing measurement until the response from the nozzle is delivered (S4 step). (S3 step)

If there is a response from the nozzle of the head, the count t ends (step S5).

The head drive voltage at this time Calculate as (S6 step)

The head driving timing corresponding to the measured voltage is determined (step S7) and the printing operation is performed for the corresponding time (step S8).

As described above, the cost of the power supply circuit can be reduced by setting the time of the head by detecting a voltage change without using a precise constant voltage source.

Claims (4)

A first comparator OP1 for receiving the driving voltage Vcc at the inverting stage and outputting an operation signal High to the output stage when the start pulse is applied to the non-inverting stage, The voltage variation of the second comparator OP1 that receives the head driving voltage to the inverting stage according to the output signal of the first comparator OP1 and receives the comparison voltage to the non-inverting stage and outputs a result of comparing the two voltages to the output terminal. Inkjet printer head drive according to. The method of claim 1, The non-inverting end of the second comparator (OP2) comprises a zener diode (ZD) for confirming the reference voltage, characterized in that the inkjet printer head drive according to the voltage variation. The method of claim 1, The inkjet printer head driving apparatus according to the voltage fluctuation, characterized in that the inverting end of the second comparator (OP2) is composed of a resistor and a capacitor to perform charging by the time constant until a voltage greater than the comparison voltage. Outputting a signal for checking the head drive voltage according to a print command, counting timing until a nozzle recognition pulse is answered, Calculating a head drive voltage according to the count amount; Setting the head drive time according to the calculated result, An inkjet printer head driving method according to voltage fluctuations which proceeds to a process of performing fritting for a set head driving time.