KR100288582B1 - Horizontal output TR protection device of display device - Google Patents

Abstract

The present invention relates to a display device, which aims to prevent the horizontal output TR from being damaged due to a surge voltage when a transient occurs.

The horizontal output TR protection device of the display device of the present invention for this purpose, the horizontal oscillation unit for outputting the abnormal input detection signal according to the abnormal synchronization signal input, and receives the PWM control signal from the horizontal size controller of the microcomputer In a horizontal output circuit comprising a PWM-IC for outputting the PWM signal and a horizontal output stage for outputting a unit signal for determining the horizontal size of the image according to the on / off duty of the PWM signal output from the PWM-IC And a PWM-IC controller interposed between the horizontal oscillation stage and the PWM-IC to control the horizontal output TR in the horizontal output unit to output a stable unit signal by changing an on / off duty of the PWM signal. It is done by.

Description

Horizontal output TV protection device of display device

The present invention relates to a display device, and more particularly, to a horizontal output TR protection device of a display device to prevent the horizontal output TR from being damaged due to a surge voltage when a transient occurs.

In general, a display device (monitor) is a device that displays the results of various signal processing for the user to easily understand. Since the development of electric and electronic technology, most of the system devices are applied to the microcomputer, the monitor user adopts the microcomputer to monitor. It makes it possible to manage monitors more efficiently and conveniently.

The configuration of the display device employing the microcomputer as described above will be described with reference to the system block diagram of FIG. 1.

As shown in FIG. 1, the display apparatus 200 presupposes an association with a computer 100 that processes various signals and transmits the processing results to the display apparatus. Accordingly, the computer 100 receives the CPU 110 that processes various signals input through a keyboard (not shown) and outputs signal processing result data, and the signal processing result data output from the CPU 110. A video card 120 for processing and outputting the image signals R, G, and B and outputting a horizontal synchronization signal H-SYNC and a vertical synchronization signal V-SYNC for synchronizing the output image signals; And a user control key unit 130 for transmitting a user selection signal to the display apparatus 200 for controlling an image signal processing operation.

As such, the display apparatus 200 that receives and displays the image signals R, G, and B output from the video card 120 in the computer 100 has the following configuration. That is, the microcomputer 210 which receives the horizontal and vertical synchronization signals H-SYNC and V-SYNC output from the video card 120 and generates a phase adjustment signal and a reference oscillation signal for screen control of the display device; By applying the phase adjustment signal, the reference oscillation signal, and the horizontal / vertical synchronization signal of the video card 120 outputted from the microcomputer 210, deflecting the electron beam generated in the horizontal and vertical deflection operation, that is, the electron gun of the CRT (not shown). A horizontal deflection unit 220 and a vertical deflection unit 230 for performing an operation of sequentially forming an image by deflecting from the upper left end to the lower right end of the CRT through a yoke (Deflection Yoke; DY); and the video card 120. Image signal processing unit 240 for receiving and amplifying the image signal (R, G, B) output from the display, and through the retrace pulse output from the horizontal deflection unit 220 using the principle of switching circuit and high voltage technology Anod of the CRT Each component of the display device 200 such as a high voltage circuit (not shown) for supplying a high voltage to the stage, a microcomputer 210, a horizontal / vertical deflection unit 220, 230, and an image signal processor 240. It is roughly divided into a power supply circuit section 250 for supplying a driving voltage to the circuit.

The deflection circuit (deflection unit) provided in the display device having such a configuration will be described as follows. The deflection circuit refers to a circuit that changes the deflection of the electron beam projected on the fluorescent surface. The deflection circuit can be classified into two types, an electrostatic deflection method using an electric field and an electronic deflection method using a magnetic field. Use

The configuration of the increased horizontal deflection circuit is as follows. As shown in FIG. 1, the horizontal deflection circuit 220 uses a horizontal oscillation stage 221 mainly using a blocking oscillation circuit and a deflection coil (not shown) by using a switching operation of a transistor (horizontal output TR). The horizontal output stage 223, which generates the sawtooth current for determining the horizontal size of the image, and the output pulse of the horizontal oscillation stage 221, are amplified one or multiple stages through the transistor TR or the field effect transistor FET. And a deflection yoke (H-DY) for deflecting the electron beam generated from the electron gun, and a horizontal drive stage 222 for supplying the base stage of the horizontal output TR (Q1) in the 223 and performing waveform correction.

The horizontal output stage 223 provided in the horizontal deflection circuit 220 having such a configuration is connected to the horizontal size adjusting unit adjusting circuit 260, which is output from the horizontal output stage 223. The pulse width of the sawtooth current, which determines the horizontal size of the image, is fixed to keep the horizontal size of the display device constant. As shown in FIG. 1, the horizontal size adjusting circuit 260 is provided in the microcomputer 210 and is applied to the corresponding job when the horizontal size adjusting job selection signal generated by the user control key unit 130 of the computer 100 is input. A horizontal flyback pulse supplied to the horizontal output terminal 223 when the control signal outputted from the horizontal size controller 212 and the horizontal size controller 212 output the control signal according to the following, abbreviated as FBP PWM-IC (Pulse Width Modulation-IC) for generating a pulse width control signal (PWM signal) and PWM current for amplifying the pulse width control signal of the PWM-IC (262) The horizontal output stage by generating the FBP according to the ON Duty / OFF Duty time of the / voltage amplifier stage 264 and the pulse width control signal (PWM signal) amplified by the PWM current / voltage amplifier stage 264. And an H-PWM transformer 266 to be applied to the horizontal output TR (Q1) of 223.

The FBP applied to the horizontal output TR (Q1) is compared with the pulse applied to the base terminal of the horizontal output TR (Q1) via the horizontal drive stage 222, and the pulse generated as a result of the comparison is the horizontal output TR (Q1). The horizontal size of the image is determined by being outputted to the collector end of and transmitted to the horizontal yoke H-DY.

Conventionally, the user can operate the key as a self-resistance measure to prevent the horizontal output TR (Q1) from being damaged as a transient occurs while using such a display device and a surge voltage is output to the collector terminal of the horizontal output TR. A method of causing a surge voltage blocking command to be issued to the microcomputer 210 has been used. In other words, when the user operates the control key 130 to input the related selection signal H-SIZE to the horizontal size controller 212, the horizontal size controller 212 uses the PWM-IC 262 to control the signal H. Change the FBP signal to reduce the Vp-p of the signal waveform output from the collector stage of the horizontal output TR (Q1).

However, when using such a method, the response speed is delayed in the process of transmitting a signal between the user control key unit 130, the microcomputer 210, and the horizontal size control circuit 260, so that the surge voltage is rapidly lost before the horizontal output TR is damaged. There is a problem that is very difficult to remove.

The present invention has been made to solve the problems described above, the purpose is to adjust the on / off duty time of the PWM signal via the PWM-IC surge control through the horizontal output TR through the PWM-IC even if there is no user's instruction in the event of transient It is to provide a horizontal output TR protection device of a display device that can protect the horizontal output TR by preventing a voltage from being output.

The horizontal output TR protection device of the display device of the present invention devised to achieve the above object includes a horizontal oscillation stage for outputting an abnormal input detection signal according to the abnormal synchronization signal, and PWM from the horizontal size controller of the microcomputer. And a horizontal output terminal for outputting a unit signal for determining a horizontal size of the image according to the on / off duty of the PWM signal output from the PWM-IC. In a horizontal output circuit, the horizontal output TR in the horizontal output stage outputs a stable unit signal by transferring the horizontal oscillation stage and the on / off duty control terminal of the PWM-IC to change the on / off duty of the PWM signal. It further comprises a PWM-IC control unit for controlling.

1 is a system block diagram showing a configuration of a general display device;

2 is a system block diagram showing a configuration of a display apparatus according to the present invention.

3 is a view showing a specific circuit configuration of the horizontal output TR protection unit of FIG.

4 is a diagram showing an output waveform of the horizontal output TR and an output waveform of the H-LOCK signal.

Explanation of symbols on the main parts of the drawings

100: computer 200: display device

210: microcomputer 220: horizontal deflection circuit

221, 225: horizontal oscillation stage 223: horizontal output stage

230: vertical deflection circuit 240: video signal processing unit

250: power supply circuit portion 260: horizontal size control circuit

262,320: PWM-IC 300: PWM-IC control

Q1: Horizontal Output TR

Hereinafter, a horizontal output TR protection device of a display device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a system block diagram showing a configuration of a display device to which a PWM-IC controller is added according to the present invention, and FIG. 3 is a diagram illustrating a specific circuit configuration of the PWM-IC controller.

As shown in FIG. 2, the PWM-IC controller 300 of the present invention is interposed between the PWM-IC 320 and the horizontal oscillation stage 225 to output an output signal of the horizontal oscillation stage 225 to the PWM-IC ( To 320). That is, when an abnormal horizontal / vertical synchronization signal is inputted to the horizontal oscillator 225 due to a transient phenomenon, the H-LOCK signal is converted to PWM- when the H-LOCK signal, which is a specific signal, is output from the horizontal oscillator 225. The on / off duty control terminal (CTR) of the IC 320 is applied to adjust the on / off duty time of the PWM signal so that the surge voltage is automatically cut off without a user's instruction.

The circuit configuration of the PWM-IC controller 300 will be described in detail with reference to FIG. 3. First, when the TDA9105 chip is used as the horizontal oscillation stage 225 and the KA3842 chip is used as the PWM-IC 320 as the preferred embodiment of the present invention, the horizontal generator outputs an H-LOCK signal when an abnormal signal is input. The transistor Q2 is interposed between the H-LOCK terminal of the diagnosis 225 and the on / off duty control terminal of the PWM-IC 320 (pin 2; CTR terminal hereinafter). The transistor driving power supply 12V and the pull-up resistor R1 are connected between the H-LOCK terminal and the base terminal B of the transistor Q2, and in the normal state, the transistor passes through the pull-up resistor R1 and the base terminal resistor R2. A voltage of a predetermined magnitude is applied to the base terminal B of Q2. A diode D1 for interrupting the output current of the collector terminal C is connected to the collector terminal C of the transistor Q2, and the emitter terminal E of the transistor Q2 is grounded. At this time, a collector power supply 12V and a resistor R3 for supplying current to the collector terminal C are connected between the collector terminal C and the diode D2 of the transistor Q2. In addition, by connecting the resistor (R4) and the capacitor (C1) in parallel between the diode (D1) and the control terminal (CTR), the current passing through the diode (D1) is stably controlled without the unnecessary noise of the PWM-IC (320) To be input to terminal CTR. Meanwhile, the PWM-IC 320 may be driven by the control signal H-SIZE input from the horizontal size controller 212 via the resistor R5.

A detailed circuit operation of the PWM-IC controller 300 having such a configuration will be described below. First, when a normal horizontal / vertical synchronization signal is input to the horizontal oscillation stage 225, the TDA9105 chip is turned off by itself, so that the base stage B of the transistor Q2 is sufficient from the transistor driving power supply 12V. A current is applied to turn transistor Q2 ON. Therefore, the collector terminal C and the emitter terminal E of the transistor Q2 are conducted so that the current supply power supply 12V is grounded, so that the control terminal CTR of the PWM-IC 320 is horizontal when there is a user's key input. No signal is input except the control signal H-SIZE applied from the size controller 212.

However, when the frequency of the horizontal / vertical synchronization signal input to the horizontal oscillation stage 225 suddenly changes due to a transient phenomenon (for example, 80 KHz to 60 KHz), the H-LOCK terminal of the horizontal oscillation stage 225 is shown in FIG. 4. As shown in (b) of the figure, an H-LOCK signal of low level (dotted line portion) is output. In other words, the signal waveform (a) of Figure 4 shows the output signal of the conventional horizontal output TR (Q1) under the influence of the surge voltage (dotted line) when a transient occurs, the signal waveform (c) is a horizontal according to the present invention The output signal of the stabilized horizontal output TR (Q1) is shown through the output TR protection device.

Therefore, when the H-LOCK signal having the waveform as shown in FIG. 4B is applied to the point a, the transistor driving power supply 12V is momentarily depressurized when the potential drops rapidly. Since a sufficient current is not applied to the base terminal B of the transistor Q2, the transistor Q2 is turned off. As transistor Q2 is turned off, current passes through resistor R3 from current supply 12V connected to collector terminal C of transistor Q2 via resistor R3 and passes diode D1 through point a2. As such, the pulse flow component of the current passing through the diode D1 is removed through the capacitor C1, and the current from which the pulse flow (noise) component is removed is passed through the resistor R4 through the point a3 and the PWM-IC 320 Is input to the control terminal CTR.

As such, when a current is input to the control terminal CTR of the PWM-IC 320, the PWM-IC 320 adjusts the on / off duty time of the PWM signal, and the horizontal output terminal 223 according to the adjusted duty time. The converted FBP is applied to the horizontal output TR (Q1). Therefore, the signal output from the collector terminal C of the horizontal output TR (Q1) is stabilized as shown in the signal waveform (c) of FIG. 4, so that the horizontal output TR (Q1) can be protected from the surge voltage even when a transient occurs. .

As described above, when the transient output is detected by the horizontal output TR protection device of the display device of the present invention, the output waveform of the horizontal output TR is adjusted by adjusting the on / off duty time of the PWM signal even if there is no user's instruction. This stabilizes the horizontal output TR from being damaged by surge voltage.

Claims (3)

When an abnormal synchronization signal is input, a horizontal oscillation stage for outputting an abnormal input detection signal, a PWM-IC receiving a PWM control signal from a horizontal size controller of a microcomputer, and outputting a PWM signal accordingly, and the PWM-IC In the horizontal output circuit including a horizontal output stage for outputting a unit signal for determining the horizontal size of the image in accordance with the on / off duty of the PWM signal output from Interposed between the horizontal oscillation 돤 and the PWM-IC, transferring an abnormal input detection signal of the horizontal oscillation stage to an on / off duty control terminal of the PWM-IC to change the on / off duty of the PWM signal; And a PWM-IC control unit for controlling the horizontal output TR in the horizontal output stage to output a stable unit signal. The method of claim 1, wherein the PWM-IC control unit The PWM-IC controller is configured to interpose a transistor between an abnormal input detection signal output terminal of the horizontal oscillation terminal and an on / off duty control terminal of the PWM-IC, and a transistor supply power to a base terminal of the transistor. The collector stage is configured by connecting a current supply power selectively grounded according to whether the transistor is on or off, When the low potential signal is output from the sensing signal output terminal, the transistor is turned off so that the signal generated from the current supply power connected to the transistor collector terminal is input to the on / off duty control terminal of the PWM-IC. Horizontal output TR protection of the display device. The horizontal output TR protection device of a display device according to claim 2, wherein a current blocking diode is interposed between the collector terminal of the transistor and the on / off duty control terminal of the PWM-IC.