KR100196845B1 - Apparatus for interfacing video signals of a computer and a television - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal interface device of a computer and a television configured to convert a video signal from a computer so that it can be viewed on a television. Also, the first and second clocks are generated by horizontal and vertical synchronization signals provided from the computer, and the RGB color signals provided by the computer are converted into digital color signals of predetermined bits by read / write control signals in synchronization with the first clock. The digital color signal of one line amount is converted into an analog signal.

By outputting the RGB color signal converted into an analog signal by the composite synchronization signal that synthesizes the horizontal and vertical synchronization signals of the television, the TV composite video signal can be used to enjoy computer games and stereoscopic images on the TV screen. Provide effect.

Description

Computer and TV, video signal interface device

1 is a block diagram of an interface device according to the present invention.

2 is a waveform diagram for explaining the present invention.

* Explanation of symbols for main parts of the drawings

100: computer 200: interface device

210,220: first and second buffer unit 230: synchronous control unit

240: A / D conversion section 250: line memory section

260: D / A converter 270: adder

280: encoder section

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal interface device of a computer and a television, and more particularly, to a video signal of a computer that can be displayed on a computer monitor and to a video signal that can be displayed on a television. A video signal interface device.

In general, the VGA (Video Graphics Array) mode in a computer typically has a resolution of 640x480 in standard VGA mode and 1024x768 in super VGA mode. In addition, the scanning method in a computer adopts a non-interlaced scanning method that sequentially scans frames constituting one screen in units of lines, and in a standard VGA mode, a horizontal synchronization signal (Horizontal Synchronizing Pulse) ) Is 31.47KHz and the Vertical Synchronizing Pulse has a frequency of 60Hz.

On the other hand, in the television (NTSC method in the present invention), all odd scan lines of the CRT screen are scanned for 1/60 second and all even scan lines are scanned for the next 1/60 second using the interlaced scanning method. The full screen frame is displayed for 1/30 second, with the horizontal sync signal at 15.73KHz and the vertical sync signal at 60Hz.

On the other hand, in the case of various game images, particularly three-dimensional graphics image of the computer, it is advantageous for the user to watch on a TV of a larger screen.

However, as described above, since the video signal of the computer and the television video signal are not compatible, the video signal output of the computer cannot be seen as it is on a television.

Accordingly, it is an object of the present invention to provide a video signal interface device of a computer and a television which is capable of converting a video signal format of a computer into a teleconferencing video signal format.

A video signal interface device of a computer and a television according to the present invention is an interface device capable of converting a computer video signal into a television video signal format, and is capable of converting R, G, and B color signals from the computer without changing a DC level. A first buffer part which is kept constant and outputs; A second buffer unit for temporarily storing and outputting first horizontal and vertical synchronization signals from the computer; A synchronization controller for selectively outputting a first clock signal, a second clock signal, a read / write control signal, and a second horizontal and vertical synchronization signal based on the first horizontal and vertical synchronization signals from the second buffer unit; An A / D converter for sampling the R, G, and A color signals from the first buffer unit based on the first clock signal from the synchronization control unit, converting the R, G, and A color signals into a predetermined bit and outputting the digital color signals; One line amount stored in synchronization with the second clock signal from the A / D converter based on a read / write control signal in synchronization with the first clock signal from the synchronization controller A line memory section for outputting a digital color signal; A D / A converting unit converting the digital color signal from the line memory unit into an analog R, G, B color signal based on the second clock signal and outputting the analog color signal; An adder which synthesizes second horizontal and vertical synchronization signals from the synchronization controller and outputs a composite synchronization signal; And an encoder unit for outputting a television composite video signal based on the analog R, G, and B color signals from the D / A converter and the composite synchronization signal from the adder.

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

1 is a block diagram of a video signal interface device of a computer and a television according to the present invention, and includes a computer 100, first and second buffer units 210 and 220 of the interface device 200, a synchronization controller 230, and A /. A D converter 240, a line memory 250, a D / A converter 260, an adder 270, and an encoder 280 are included.

In the figure, the computer 100 is an analog from a VGA card of a computer (usually, connected to a 15-pin connector monitor as a graphic interface device used in a slot of a computer's mainboard). It outputs the R, G, and B signals, and outputs the horizontal synchronizing signal (H-SYNC1: 31.47 KHz) and the vertical synchronizing signal (V-SYNC1: 60 Hz).

In addition, the first buffer unit 210 clamps the analog R, G, and B signals from the computer 100 to a predetermined DC level at a predetermined level so as to be input to the input specification of the A / D converter 240 described later. Output in a suitable form.

In addition, the second buffer unit 220 temporarily stores and outputs the horizontal synchronizing signal H-SYNC1 and the vertical synchronizing signal V-SYNC1 from the computer 100.

Meanwhile, the synchronization controller 230 detects a phase difference between a phase locked loop (PLL), that is, an oscillation output of an input signal and a voltage-controlled oscillator (VCO) to adjust an arbitrary frequency and phase of a high resolution. It uses an oscillation circuit that can output a signal having a 25.174MHz and 12.587MHz based on the horizontal and vertical synchronization signals H-SYNC1 and V-SYNC1 of 31.4KHz and 60Hz from the second buffer unit 220. Selectively outputs first and second clock signals 2CLK and CLK, read / write control signals (L-Controls), and horizontal and vertical sync signals H-SYNC2 and V-SYNC2 at 15.73KHz and 60Hz .

The A / D converter 240 samples the R, G, and B color signals from the first buffer unit 210 based on the first clock signal 2CLK from the synchronization controller 230, and then selects a predetermined bit. A digital color signal (for example, 4 bits or 8 bits) is converted and output.

In addition, the line memory 250 is digital from the A / D converter 240 based on the read / write control signal L-Controls in synchronization with the first clock signal 2CLK from the sync controller 230. Stores the color signal by one line amount.

In addition, the line memory unit 250 synchronizes the second clock signal CLK from the synchronization controller 230 to output digital color signals corresponding to the amount of one line stored in accordance with the read / write control signal L-Controls. Output

Meanwhile, the D / A converter 260 converts the digital color signal from the line memory unit 250 into analog R, G, and B color signals based on the second clock signal CLK from the synchronization controller 230. To print.

The adder 270 synthesizes the television horizontal and vertical sync signals H-SYNC2 and V-SYNC2 from the sync controller 230 and outputs the composite sync signal C-SYNC.

In addition, the encoder 280 uses the television composite video signal (C-SYNC) based on the analog R, G, and B color signals from the D / A converter 260 and the composite synchronization signal C-SYNC from the adder 270. Composite Video Signal).

Next, the operation of the video signal interface device of the computer and the television according to the present invention including the above-described configuration will be described in detail with reference to the waveform diagram of FIG.

First, the computer 100 outputs R, G, and B signals, which are color signals, and horizontal and vertical synchronization signals H-SYNC1 and V-SYNC1.

At this time, the R, G, and B signals are output at 640x480 resolution, which is a standard VGA mode, and the horizontal sync signal H-SYNC1 has a frequency of 31.47KHz and the vertical sync signal V-SYNC1 has a frequency of 60Hz.

In addition, although the number of lines is 480 lines, the number of lines actually output is 525 lines, and by using the interlaced frequency method, 525 horizontal lines in one vertical sync signal (V-SYNC1) pulse section as shown in FIG. It has a synchronization signal (H-SYNC1) pulse.

The horizontal and vertical synchronization signals H-SYNC1 and V-SYNC1 from the computer 100 are applied to the second buffer unit 220 and transmitted to the synchronization control unit 230.

Meanwhile, the R, G, and B color signals from the computer 100 are applied to the first buffer unit 210, clamped to a predetermined DC level, and transmitted to the A / D converter 230.

Next, the synchronization controller 230 A / D receives the first clock signal 2CLK having 25.174 MHz based on the horizontal and vertical synchronization signals H-SYNC1 and V-SYNC1 from the second buffer unit 220. It is applied to the defense screw 240 and the line memory 250.

In addition, the second clock signal CLK having the 12.587 MHz is applied to the line memory unit 250 and the D / A converter 260.

Then, the A / D converter 240 uses the R, G, and B color signals from the first buffer unit 210 as the sampling frequency using the first clock signal 2CLK from the synchronization controller 230 as a sampling frequency. Converted to a digital color signal (4 or 8 bits) and output.

Next, the line memory 250 divides the digital image from the A / D converter 240 based on the first clock signal 2CLK from the sync controller 230 and the read / write control signal L-Controls. Store and output signals line by line.

In detail, as illustrated in the waveform diagram of FIG. 2, the R, G, and B color signals applied from the computer 100 are divided into one vertical synchronization signal V-SYNC1 with 525 lines of R, G, and B colors. The signal is present in the horizontal sync signal H-SYNC1 section.

Therefore, in order to convert to a television system (NTSC system in the present invention), two vertical synchronization devices are configured such that one vertical synchronization signal V-SYNC2 has 265.5 lines, that is, 265.5 pulses of horizontal synchronization signal H-SYNC2. One screen should be made with the signal (V-SYNC2) section.

Therefore, in the first vertical synchronization signal section of the R, G, and B color signals from the computer 100, the odd-numbered line signals (LINE MEM IN: 1, 3, 5, ..., 523, 525) are used as the second vertical signal. In the synchronization signal section, the even-numbered line signals (LINE MEM IN: 2, 4, 6, ..., 522, 524) are sequentially stored and output in line units in the line memory unit 250.

On the other hand, the digital color signal output from the line memory section 250 is doubled in the time domain based on the second clock signal CLK divided by two divisions of the first clock signal 2CLK from the synchronization controller 230. It is outputted as shown in the waveform LINE MEM OUT of FIG.

Next, the digital color signals read out from the line memory unit 250 are analog R, G, and B colors based on the second clock signal CLK from the synchronization controller 230 in the D / A converter 260. The signal is converted and output.

On the other hand, the synchronization controller 230 outputs vertical and horizontal synchronization signals H-SYNC2 and V-SYNC2 having 60 Hz and 31.47 KHz, respectively, from the second buffer unit 220, and an adder that receives these signals. In operation 170, the vertical and horizontal synchronization signals H-SYNC2 and V-SYNC2 are synthesized to apply the composite image signal C-SYNC to the encoder 280.

Then, the encoder unit 280 synthesizes the analog R, G, and B color signals from the D / A converter 260 and the composite synchronization signal C-SYNC from the adder 270 to composite the NTSC format. The video signal is converted and output.

Then, the video signal of the computer can be viewed through the interface device 200 with a display device such as a general television.

As described above, according to the present invention, by converting the video signal of the VGA format that can be displayed on a computer monitor to a television video signal (NTSC system in the present invention) format and outputting the video signal, the computer game and stereoscopic image can be displayed on a large television or the like. There is an effect that can be seen with the device.

Claims (2)

An interface device 200 capable of converting a video signal of a computer 100 into a television video signal format, wherein the R, G, B color signals from the computer 100 are kept constant without a change in a DC level and output. A first buffer unit 210; A second buffer unit 220 for temporarily storing and outputting first horizontal and vertical synchronization signals from the computer 100; The first clock signal 2CLK, the second clock signal CLK, the read / write control signal L-Controls, and the second based on the first horizontal and vertical synchronization signals from the second buffer unit 220. A synchronization controller 230 for selectively outputting horizontal and vertical synchronization signals; An A / D converter configured to sample R, G, and B color signals from the first buffer unit 210 based on the first clock signal from the synchronization controller 230, and convert the R, G, and B color signals into a predetermined bit of digital color signals 240; The digital color signal from the A / D converter 240 is stored by one line amount in synchronization with the first clock signal 2CLK from the synchronization controller 230 based on a read / write control signal. A line memory section 25 for synchronizing with the second clock signal CLK from the synchronization control section 230 and outputting digital color Sanhor d as much as one line amount stored based on the read / write control signal; A D / A converting unit (260) for converting the digital color signal from the line memory unit (250) into an anaroll R, G, and B color signal based on the second clock signal (CLK); An adder 270 for synthesizing the second horizontal and vertical sync signals from the sync controller 130 and outputting a composite sync signal; A computer comprising an encoder unit 280 for outputting a television composite video signal based on the analog R, G, B color signals from the D / A converter 260 and the composite synchronization signal from the adder 270. And video signal interface device of TV. 2. The computer and television video signal interface device according to claim 1, wherein the second clock signal (CLK) of the control unit (230) divides the first clock signal (2CLK) into two divided outputs.