KR20020034599A - Lcd for auto selecting of tv input signal - Google Patents

Abstract

PURPOSE: A liquid crystal display automatically selecting a TV input signal is provided to display a steady resolution of image regardless of the type of TV signal by adding a signal selection mode, which automatically selects either NTSC or PAL signal, into an LCD timing controller block. CONSTITUTION: A liquid crystal display automatically selecting a TV input signal includes a video signal processor(300), a synchronous signal detector(310), a counter(320), a MUX(330), and a data and controller signal processor(340). The synchronous signal detector(310) receives a TV signal and divides the signal into vertical and horizontal synchronous signals. The counter(320) counts the TV input signal using the horizontal synchronous signal as a clock signal and using the vertical synchronous signal as a reset signal to output a signal detecting the signal mode of the TV input signal. The MUX(330) automatically selects and outputs a signal suitable for the TV signal mode.

Description

TV input signal automatic selection liquid crystal display {LCD FOR AUTO SELECTING OF TV INPUT SIGNAL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device for automatically selecting a TV input signal. In particular, an NTSC and PAL signal automatic selection mode is added to an LCD timing controller block, and the TV input signal autonomous driving a liquid crystal display device having a constant resolution regardless of the TV signal method is provided. A selective liquid crystal display device.

Conventionally, there is a liquid crystal display device for NTSC (committee organized for selection of US color television standard system) or PAL (color television system developed in West Germany) signal / NTSC signal system separately according to TV signal system. It has been commercialized. In addition, a more advanced liquid crystal display device has been controlling a signal system input through a selection terminal from outside according to a TV signal system.

In general, when the NTSC signal (525 vertical lines) is input, the horizontal display resolution of the liquid crystal display is expressed according to the number of data to be sampled, and the vertical resolution is expressed in a 234 line deinterlacing manner. When the PAL signal (625 vertical lines) is input, the horizontal display resolution of the liquid crystal display is determined according to the number of data to be sampled, and the vertical resolution is 521 lines by removing one line every six vertical lines. It is expressed in the same processing method.

At this time, it is classified into a liquid crystal display device for NTSC signal or a liquid crystal display device for PAL signal according to the TV signal system or an NTSC / PAL combined liquid crystal display device is implemented by using an external switch terminal.

Fig. 1 is a schematic diagram showing the structure of a conventional NTSC / PAL combined liquid crystal display device, which is provided with a TV signal input terminal 2 for inputting a TV signal (NTSC / PAL signal) and the NTSC / PAL signal system. It consists of an NTSC / PAL signal selection terminal (1) which controls switching through the selection terminal from the outside.

The reason why the driving method is limited in the conventional method is that the vertical resolutions of the liquid crystal display devices differ from each other according to the broadcasting method.

In general, when comparing the NTSC method and the PAL method, since the vertical resolution is 525/625 lines and the signal specifications themselves are different from each other, the liquid crystal display devices have been manufactured with different products.

According to the conventional TV signal standard, the horizontal resolution can be used in various modes according to the analog data sampling frequency, but the vertical resolution is generally limited to 234 lines.

In order to realize a PAL TV signal within the limited resolution of such a liquid crystal display, a liquid crystal display is used by dividing NTSC and PAL signals using an external selection terminal as an additional function. That is, the conventional liquid crystal display for TV was used by selecting the TV signal system using an external switch terminal.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to input a TV signal and detect whether it is an NTSC signal system or a PAL signal system and to automatically display a TV signal suitable for the signal system. An object of the present invention is to provide an LCD for automatically selecting an input signal.

TV input signal automatic selection liquid crystal display of the present invention for achieving the above object,

A synchronization signal detecting means for inputting a TV signal and separating and outputting it into a vertical synchronization signal and a horizontal synchronization signal;

A counter means for counting the horizontal synchronizing signal as a clock and using the vertical synchronizing signal as a reset signal to output a signal for detecting a signal system of the TV input signal;

And selecting means for automatically selecting and outputting a signal suitable for the TV signal method inputted by the output signal of the counter means.

According to the TV input signal automatic selection liquid crystal display of the present invention, the counter means generates a control signal for selecting the PAL signal method when the number of counters is 550 or more, and the NTSC signal method when the number of counters is 550 or less. And generating a control signal to select.

According to the TV input signal automatic selection liquid crystal display device of the present invention, the selection means is a multiplexer circuit.

1 is a schematic diagram of a conventional NTSC / PAL combined liquid crystal display device

2 is a schematic diagram of a liquid crystal display for automatic TV input signal selection according to the present invention;

3 is a block diagram of a liquid crystal display for automatic TV input signal selection according to the present invention.

Explanation of symbols on the main parts of the drawings

10: liquid crystal display for TV 100: timing controller block

110: NTSC / PAL detection circuit

120: data and control signal generator

200: liquid crystal display panel 300: video signal processing unit

310: synchronization signal detection circuit unit 320: counter circuit unit

330: musbu

340: data and controller signal processor

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In addition, in all the drawings for demonstrating an embodiment, the thing with the same function uses the same code | symbol, and the repeated description is abbreviate | omitted.

FIG. 2 is a schematic diagram of a TV input signal automatic selection liquid crystal display device according to the present invention, comprising: an NTSC and PAL detection circuit unit 110 for inputting a TV signal to detect whether the input signal is an NTSC signal system or a PAL signal system; And a timing controller block (100) including data for generating a signal and control signal suitable for the TV signal input by the output signal of the NTSC and PAL detection circuit unit (110), and a control signal generator (120). .

As shown, in the present invention, since a circuit for selecting a TV broadcast method is built in the timing controller block 100 of the liquid crystal display device, an input signal is automatically detected without a separate external selection terminal to match the signal method. Data and control signals are generated.

3 is a block diagram showing a more detailed configuration of a liquid crystal display for automatic TV input signal selection according to the present invention. The video signal processor 300 outputs NTSC signals and PAL signals, which are TV signals, and inputs the TV signals. The synchronization signal detecting circuit unit 310 which separates and outputs the vertical synchronization signal VSYNC and the horizontal synchronization signal HSYNC, and uses the vertical synchronization signal VSYNC as a clock as a reset signal. A counter circuit unit 320 for outputting a signal that detects whether the TV input signal is an NTSC signal system or a PAL signal system, and an NTSC signal suitable for the TV signal system inputted by the output signal of the counter circuit unit 320. Or a mux unit 330 for selecting and outputting a PAL signal, and a data and controller signal processor 340 for inputting an output signal of the mux unit 330 to process data and a controller signal. The.

Here, the counter circuit unit 320 counts whether the number of counters exceeds 550 by using the horizontal synchronization signal HSYNC as a clock and the vertical synchronization signal VSYNC as a reset signal. In this case, when the counter value exceeds 550, a 'high' signal is output to allow the mux unit 330 to select the PAL signal, and then the data and control signal generator 120 performs the PAL signal processing processor. .

On the other hand, if the value of counting the horizontal synchronizing signal in one vertical synchronizing signal does not exceed 550, a 'low' signal is outputted to the mux unit 330 to select an NTSC signal, and then the subsequent processing is performed by the NTSC signal processing process. Proceed.

The present invention can expand the application range of the liquid crystal display for a TV by integrating different data processing processes caused by different TV broadcasting systems in each country.

In general, the timing control block of the liquid crystal display device is designed to less than 10,000 gates, but the circuit block of the present invention is a circuit that can be designed to a thousand gates or less, there is an advantage that can be implemented without changing the timing control.

The present invention is also applicable to flat panel display devices other than liquid crystal display devices.

The present invention can be applied to all flat panel display devices having a fixed output resolution, in addition to devices that are not relatively limited to horizontal and vertical synchronization signals such as CRT displays.

As described above, the TV input signal automatic selection liquid crystal display device according to the present invention has the effect of developing a separate display device and the switching method broadcast selection due to the fact that the TV signal is composed of different countries. have.

Conventional liquid crystal displays for TVs have been manufactured by dividing them into liquid crystal TV displays for NTSC signals or liquid crystal TV displays for PAL signals. In a more improved manner, a method of selecting an NTSC or PAL method as a switch for a TV signal in one liquid crystal display device has been used.

The TV input signal automatic selection liquid crystal display device of the present invention does not require the development of a separate liquid crystal display device according to the TV signal, and also automatically selects the input signal method without switching according to the TV signal method to select a signal suitable for the liquid crystal display device. It is generated and automatically displayed. In addition, there is an effect that can realize a liquid crystal display device that can cope with all the TV signal system of each country in the state that additional additional material costs in the industry is not added.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, these modifications and changes should be seen as belonging to the following claims. something to do.

Claims (3)

In the liquid crystal display device, A synchronization signal detecting means for inputting a TV signal and separating and outputting it into a vertical synchronization signal and a horizontal synchronization signal; A counter means for counting the horizontal synchronizing signal as a clock and using the vertical synchronizing signal as a reset signal to output a signal for detecting a signal system of the TV input signal; And a selection means for automatically selecting and outputting a signal conforming to the TV signal method inputted by the output signal of the counter means. The method of claim 1, wherein the counter means, If the number of counters is more than 550, control signal for selecting PAL signal method And a control signal for selecting an NTSC signal type when the number of counters is 550 or less. The method of claim 1, wherein the selection means, A TV input signal automatic selection liquid crystal display, characterized in that it is a multiplexer circuit.