KR100813725B1 - LCD drive circuit and self-diagnosis method - Google Patents

Abstract

The present invention relates to an LCD driving circuit and a self-diagnostic method capable of self-diagnosis. The self-diagnostic LCD driving circuit according to the present invention includes a microcontroller, a scaler, a D / A converter, and first and second switching units. The microcontroller controls the operation of the LCD driving circuit. The microcontroller outputs a first control signal and a second control signal. The scaler converts and outputs an image signal to match the resolution and format of the LCD panel. Converts the digital image signal transmitted from the micro-controller into an analog image signal, the first switching unit transmits the image signal output from the PC according to the first control signal to the scaler, the second switching unit is The image signal output from the scaler is fed back to the microcontroller according to a second control signal.

According to the present invention, the LCD driving circuit can self-diagnose whether the image signal is properly converted and displayed on the LCD panel.

LCD driving circuit, self diagnostic.

Description

Self-diagnosis LCD drive circuit and self-diagnosis method {SELF-DIAGNOSABLE CIRCUIT FOR DRIVING AN LCD AND METHOD THEREOF}

1 is a block diagram showing a conventional LCD driving circuit.

2 is a block diagram illustrating a self-diagnostic LCD drive circuit in accordance with the present invention.

3 is a flowchart for explaining the operation of the LCD driving circuit of FIG. 3 according to the present invention;

<Description of Major Symbols in Drawing>

110, 210: Microcontroller

120, 220: scaler

270: D / A Converter

280, 290: 3 state buffer

The present invention relates to a driving circuit of an LCD panel, and more particularly, to a self-diagnostic LCD driving circuit capable of self-diagnosing whether R, G, and B image signals inputted to an LCD driving circuit are properly converted. .

1 is a block diagram showing a driving circuit of a conventional LCD panel. Hereinafter, a configuration and operation of a driving circuit of a general LCD monitor will be described with reference to FIG. 1.

The driving circuit of the LCD monitor may control the R, G, B image signals and control signals output from the PC 100 through the scaler 120 and the interface 130 under the control of the microcontroller 110 that is a system controller. The signal is converted into a signal suitable for the LCD panel 140 and then input to the LCD panel 150. Hereinafter, the operation of each component will be described.

First, the scaler 120 is a digital video processor, and converts an image signal transmitted from the PC 100 to the resolution of the LCD panel 140. For example, when the signal input to the scaler has a resolution of 800 * 600, the scale of the input signal is increased to match the resolution of the LCD panel of 1024 * 768.

Next, the interface unit 130 converts the image signal and the control signal output from the scaler 120 into a signal form suitable for the interface method employed in the LCD panel. In general, the LCD panel has a TTL, LVDS, TMDS interface method, and the interface unit 130 processes and outputs the signal according to the interface method employed by the LCD panel 140.

Next, the micro controller 110 is called a system controller or a microcomputer. When the horizontal and vertical synchronization signals are supplied from the PC 100 and the signal equipment, the micro controller 110 determines the operation mode from the configuration of the synchronization signals and the horizontal and vertical frequencies. The microcontroller recognizes the mode data stored in the nonvolatile memory (not shown), and then controls peripheral circuits or ICs to adjust the operation mode data.

On the other hand, the micro-controller 110 checks the mode from the synchronization signal transmitted from the PC, and then controls the power of the inverter unit 160 and the LCD panel 140 through the power switching unit 150.

Since the driving circuit of the general LCD panel as described above has no self-diagnosis circuit which cannot diagnose the driving circuit of the LCD panel by itself, whether the image signal input from the PC 100 is correctly converted and displayed on the LCD panel. It is difficult to check on.

An object of the present invention is to provide an LCD drive circuit and a self-diagnosis method for the LCD drive circuit which can self-diagnose the operation of the drive circuit of the LCD panel.

According to an aspect of the present invention, an LCD driving circuit operable in a self-diagnosis mode or a normal operation mode includes a microcontroller, a scaler, a D / A converter, and first and second switching units.

In the LCD driving circuit according to the present invention, the microcontroller is to control the operation of the LCD driving circuit, and outputs a first control signal and a second control signal, the scaler to match the image signal to the resolution and format of the LCD panel. And converts and outputs the digital video signal transmitted from the microcontroller to an analog video signal, and the first switching unit converts the video signal output from the PC according to the first control signal. And a second switching unit feeds back an image signal output from the scaler to the microcontroller according to the second control signal.

In the self-diagnosis mode, the microcontroller outputs an analog image signal for a test pattern to the D / A converter, and the digital image signal output from the D / A converter is the scaler and the second. The micro controller is fed back to the micro controller via a switching unit, and the micro controller compares the feedback signal with the output test pattern.

At this time, in the self-diagnosis mode, it is preferable to disable the first control signal and enable the second control signal, and in the normal operation mode, to enable the first control signal and to disable the second control signal. .

Meanwhile, the first and second switching units may be three state buffers.

According to another aspect of the present invention, there is provided a self-diagnostic method of an LCD driving circuit, the method comprising: outputting an image signal of a test pattern from a microcontroller, and converting the image signal of the output test pattern according to the resolution and format of the LCD panel; And feeding back the converted image signal to the microcontroller, and comparing the image signal for the output pattern test pattern with the feedback image signal from the microcontroller and performing self-diagnosis.

Hereinafter, a preferred embodiment of a LCD driving circuit capable of self-diagnosis according to the present invention will be described in detail with reference to the accompanying drawings.                     

2 is a block diagram illustrating a LCD driving circuit capable of self-diagnosis according to the present invention.

Referring to FIG. 2, the LCD driving circuit capable of self-diagnosis according to the present invention includes a microcontroller 210, a scaler 220, an interface unit 230, a D / A converter 270, and a first switching unit 280. And a second switching unit 290. Hereinafter, each component is demonstrated concretely.

First, the microcontroller 210 controls the operation of the LCD driving circuit, and outputs first and second control signals. In the self-diagnosis mode, the microcontroller 210 converts a digital image signal of a test pattern into a D / A converter ( 270).

The D / A converter 270 is connected between the microcontroller 210 and the scaler 220 to convert a digital image signal of the test pattern transmitted from the microcontroller into an analog image signal and transmit the analog signal. Let's do it.

The scaler 220 converts an image signal input from the PC 200 or the D / A converter 270 according to the resolution and format of the LCD panel and outputs the converted video signal.

The first switching unit 280 is connected between the PC 200 and the scaler 220, the operation is controlled according to the first control signal output from the microcontroller. Therefore, when the first control signal is at a high level, the first switching unit is enabled, and an image signal output from the PC is transmitted to the scaler. When the first control signal is at a low level, the first switching unit is disabled. The video signal output from the D / A converter is transmitted to the scaler.                     

The second switching unit 290 is connected between the scaler 220 and the microcontroller 210, the operation is controlled according to the second control signal output from the microcontroller. Therefore, when the second control signal is high level, the second switching unit is enabled to feed back the image signal output from the scaler to the microcontroller. When the second control signal is low level, the second switching unit is disabled to enable the scaler. The image signal output from the controller is not fed back to the microcontroller.

It is preferable that the first and second switching units according to the present invention use a three state buffer.

3 is a flowchart illustrating a process in which the LCD driving circuit according to the present invention controls the first and second control signals in accordance with an operation mode.

Hereinafter, an operation process of each operation mode will be described according to the control signal shown in FIG. 3.

First, the process of operating the LCD driving circuit according to the present invention in the self-diagnosis mode will be described.

First, when the LCD driving circuit is in the self-diagnosis mode, the microcontroller transmits a digital image signal for a test pattern to the D / A converter, and a low level first control signal and a high level second control signal. Are output to the first switching unit and the second switching unit, respectively.

The first switching unit is disabled and the second switching unit is enabled according to the first and second control signals from the microcontroller.

The D / A converter converts a digital image signal of a test pattern into an analog signal and transmits the signal to a scaler. The scaler converts the input video signal to a resolution and a format of the LCD panel and outputs the converted video signal.

The video signal output from the scaler is fed back to the microcontroller through a second switching unit, and the microcontroller compares the video signal for the test pattern output from the microcontroller and the fed back video signal to each other to determine whether the video signal is properly converted. Diagnose

Hereinafter, a process of operating the LCD driving circuit in the normal operation mode will be described in detail.

The microcontroller outputs a high level first control signal and a low level second control signal to the first switching unit and the second switching unit, respectively. As a result, according to the first and second control signals output from the microcontroller, the first switching unit is enabled and the second switching unit is disabled.

Next, an image signal input from the PC is transmitted to the scaler via the first switching unit, and the image signal properly converted in the scaler is displayed on the LCD panel via the interface unit 230.

According to the present invention, it is possible to self-diagnose whether the image signal input to the LCD driving circuit is properly converted and displayed on the LCD panel.

Claims (8)

In the LCD driving circuit having a micro-controller for controlling the operation of the LCD driving circuit and a scaler for converting and outputting the input image signal to match the resolution and format of the LCD panel, A D / A converter for converting a digital video signal transmitted from the microcontroller into an analog video signal; A first switching unit which transmits an image signal output from a PC to the scaler, and A second switching unit for feeding back an image signal output from the scaler to the micro-controller, The micro controller outputs an image signal in a digital form for a test pattern to the D / A converter, and the image signal in analog form from the D / A converter is connected to the micro via the scaler and the second switching unit. Fed back to a controller, wherein the microcontroller compares the fed back image signal with the image signal for the original test pattern. The LCD driving circuit of claim 1, wherein the LCD driving circuit includes a self-diagnosis mode and a normal operation mode, wherein the first switching unit is disabled and the second switching unit is enabled in the self-diagnosis mode. And the first switching unit is enabled and the second switching unit is disabled. The self-diagnostic LCD driving circuit according to claim 2, wherein the microcontroller outputs a first control signal for controlling the operation of the first switching unit and a second control signal for controlling the operation of the second switching unit. . The self-diagnostic LCD driving circuit according to claim 1, wherein the first and second switching units are three state buffers. In the LCD driving circuit operable in the self-diagnosis mode or normal operation mode, A microcontroller for controlling the operation of the LCD driving circuit, which outputs a first control signal and a second control signal, Scaler that converts the input video signal to match the resolution and format of the LCD panel and outputs A D / A converter for converting a digital video signal transmitted from the microcontroller into an analog video signal; A first switching unit which transmits an image signal output from a PC to the scaler according to the first control signal; A second switching unit for feeding back an image signal output from the scaler to the microcontroller according to the second control signal, In the self-diagnosis mode, the microcontroller outputs a digital image signal for a test pattern to the D / A converter, and the analog image signal output from the D / A converter is the scaler and the second. Fed back to the microcontroller via a switching unit, wherein the microcontroller compares the fed back image signal with the image signal for the original test pattern. The method of claim 5, wherein in the self-diagnosis mode, the first control signal is disabled and the second control signal is disabled, and in the normal operation mode, the first control signal is disabled and the second control signal is disabled. Self-diagnostic LCD drive circuit, characterized in that. The self-diagnostic LCD driving circuit according to claim 5, wherein the first and second switching units are three state buffers. In the self-diagnosis method of the LCD drive circuit capable of self-diagnosis, Outputting a video signal for the test pattern by the microcontroller; Converting the image signal for the test pattern according to the resolution and format of the LCD panel and feeding back the converted signal to the microcontroller; And comparing the feedback image signal with the image signal of the original test pattern.

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