KR19990081201A - Video Signal Gain and Cutoff Level Control Device based on IC Control Method - Google Patents

Abstract

The video signal gain and cutoff level adjusting device according to the disclosed I ² C control method adjusts the gain and the cutoff level of the R, G, and B video signals supplied to the cathode ray tube according to the I ² C data signal. This is to adjust the contrast and brightness of the video signal displayed on the screen of the device.

The video signal gain and cutoff level adjusting device according to the I ² C control method according to the present invention receives the horizontal synchronizing signal and the vertical synchronizing signal output from the video card, outputs a reference oscillation signal, and adjusts the gain adjusting and cutoff level values to I ^2. A microcomputer that outputs in C mode and outputs an I ² C clock signal in synchronization with I ² C data, and receives a reference oscillation signal and a horizontal / vertical synchronization signal from a micro computer and a video card to a high voltage circuit and a deflection circuit. A horizontal and vertical oscillation signal processing unit for supplying a signal, an FBT connected to an output terminal of the horizontal and vertical oscillation signal processing unit to generate a high pressure supplied to a cathode ray tube, a gain control included in I ² C data input from a microcomputer, Detect the cutoff level value and determine the video signal of R, G and B input from the video card according to the detected gain adjustment value. A video preamplifier for outputting a gain control signal with gain adjustment and a cutoff level control signal according to the detected cutoff level value, and R, G and B for adjusting brightness according to the cutoff level control signal output from the video preamplifier. And a cutoff control unit for outputting a cutoff control signal of the video signal to the cathode ray tube, and a video output amplifier for amplifying a video signal of R, G, and B output by adjusting the gain of the video preamplifier and applying it to the cathode ray tube.

Accordingly, the present invention simply adjusts the gain and cutoff levels of each of the R, G, and B video signals in the video preamplifier and outputs them to the cathode ray tube according to the I ² C data signal output from the microcomputer, thereby simplifying the contrast and brightness of the video signal. In addition to reducing the number of input and output terminals of the video preamp, the circuit configuration can be simplified.

Description

Video Signal Gain and Cutoff Level Control Device based on IC Control

The present invention relates to a video signal gain and cutoff level control device according to an IC (Inter-Integrated Circuit; abbreviated as I ² C) control method, and more specifically, to a cathode ray tube according to the I ² C data signal I ² C control method to adjust the contrast and brightness of the video signal displayed on the screen of the video display device by adjusting the gain and cutoff level of the supplied R (red), G (green) and B (blue) video signals And a video signal gain and cutoff level control device.

In general, a video display device such as a monitor is a peripheral device that allows a user to easily monitor and check the operation state of a computer system. The display device is configured to vary the gain of the R, G, and B color signals input from the computer system, thereby adjusting the white balance ( White Balance, and Contrast to make the contrast between the bright and dark sides of the screen clear.

In addition, the cathode ray tube used in the monitor requires a specific range of brightness values, and sets the cutoff voltage of the cathode ray tube according to the bias of the R, G, and B color signals displayed on the cathode ray tube, and adjusts the brightness. By adjusting, a bias voltage based on the set cutoff voltage is generated to change the brightness.

1 is a view for explaining the configuration of the video signal gain and cutoff level adjusting apparatus according to the prior art as described above.

As shown, the microcomputer 10 performs the overall operation of the image display device, and controls the contrast and brightness control signals of the R, G, and B video signals displayed on the cathode ray tube (not shown). Width Modulation) to the video preamplifier 40 to be described later.

The ACL (Automatic Contrast Limit) circuit unit 20 is connected to the contrast control signal output terminal of the microcomputer 10, and is operated when the contrast control signal output from the microcomputer 10 becomes higher than a predetermined voltage to pull down the voltage. Pull Down).

The amplification gain control unit 30 is composed of a plurality of variable resistors VR1 to VR3 to control each of the R, G, and B video signals input from a video card (not shown) in the video preamplifier 40 described later. Determine the amplification factor to adjust the gain.

The video preamplifier 40 receives the contrast and brightness control signals output from the microcomputer 10 and adjusts the contrast and brightness of the R, G and B video signals input from the video card (not shown). The adjusted contrast / brightness signal is output to the cathode ray tube.

In addition, the video preamplifier 40 adjusts the gains of the R, G, and B video signals according to the amplification factor adjusted by the amplification gain control unit 30, and outputs them to the cathode ray tube.

Referring to the video signal gain and cutoff level adjusting apparatus according to the prior art configured as described above in detail, the contrast control signal is output to the video preamplifier 40 in the PWM form in the microcomputer 10.

At this time, when the contrast control signal of a predetermined level (for example, a voltage of 2.5V or more) is output from the microcomputer 10, the ACL circuit unit 20 connected to the contrast control output terminal of the microcomputer 10 is operated. The contrast control signal output from the computer 10 is pulled down by the ACL circuit unit 20 and supplied to the video preamplifier 40.

The video preamplifier 40 changes the DC offset of each of the R, G, and B video signals according to the brightness control signal output from the microcomputer 10, and outputs the brightness signal to the cathode ray tube.

In addition, when R, G, and B video signals are input from the video card to the video preamplifier 40, each video signal is adjusted in the video preamplifier 40 according to the amplification factor determined by the amplification gain control unit 30. And output.

In other words, by adjusting the gain of the R, G and B video signals, the brightness of the image is controlled by changing the sharpness of the image and the DC offset of the R, G and B video signals.

On the other hand, recently developed image display apparatuses such as a monitor to digitally process the data and control signals between the integrated circuit elements (for example, a microcomputer and a video preamplifier) used to display an image to improve the circuit configuration. The I ² C control method, which is simple and has the effect of achieving stable operation, is adopted and produced.

Therefore, in order to adjust the contrast and brightness of the video display device, the video signal gain and cutoff level adjusting device according to the I ² C control method, instead of the contrast and brightness adjustment method through the analog video signal gain and cutoff level adjustment as described above. Was needed.

Accordingly, an object of the present invention is to adjust the contrast and brightness of the video signal displayed on the screen of the image display device by adjusting the gain and cutoff level of the R, G and B video signals supplied to the cathode ray tube according to the I ² C data signal. The present invention provides a video signal gain and cutoff level control device according to an I ² C control scheme.

1 is a view for explaining the configuration of the video signal gain and cutoff level adjusting apparatus according to the prior art;

2 is a view for explaining a video signal gain and cutoff level adjusting apparatus according to the IC control method according to the present invention.

Explanation of symbols on the main parts of the drawings

100: microcomputer 110: horizontal and vertical oscillation signal processor

120: FBT 130: video preamp

140: cut-off control unit 150: video output amplifier

160: cathode ray tube

The video signal gain and cutoff level adjusting device according to the I ² C control method according to the present invention for achieving the above object receives a horizontal synchronization signal and a vertical synchronization signal output from the video card and outputs a reference oscillation signal and adjusts gain and A microcomputer that outputs the cutoff level value in I ² C method and outputs an I ² C clock signal in synchronization with I ² C data, and receives a reference oscillation signal and a horizontal / vertical synchronization signal from a micro computer and a video card. Horizontal and vertical oscillation signal processing unit for supplying signals to the high voltage circuit and deflection circuit, FBT connected to the output terminal of the horizontal and vertical oscillation signal processing unit to generate high pressure supplied to the cathode ray tube, and I ² C data input from the microcomputer. Detect gain control and cutoff level values included in the video card and input from the video card according to the detected gain control value. The video preamplifier outputs a gain control signal for adjusting gains of R, G, and B video signals and a cutoff level control signal according to the detected cutoff level value, and brightness according to the cutoff level control signal output from the video preamplifier. The cutoff control unit outputs a cutoff control signal of the R, G, and B video signals to the cathode ray tube, and amplifies the video signals of the R, G, and B outputs by adjusting the gain in the video preamplifier. Characterized in that the video output amplifier is applied.

Hereinafter, a video signal gain and cutoff level adjusting device according to an I ² C control method of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view for explaining a video signal gain and cutoff level control apparatus according to the I ² C control method according to the present invention.

As shown in the drawing, the microcomputer 100 receives a horizontal synchronization signal and a vertical synchronization signal output from a video card (not shown), and outputs a reference oscillation signal, and controls the contrast, brightness, gain, and cutoff levels. the value and outputs the I ² C scheme as well as outputs to the video preamplifier 130 is below the I ² C clock signal to the I ² C data and a sync.

The horizontal and vertical oscillation signal processor 110 receives the reference oscillation signal output from the microcomputer 100 and the horizontal / vertical synchronization signal output from the video card and receives a high voltage circuit (not shown) and a deflection circuit (not shown). Signal).

FBT 120 is connected to the output terminal of the horizontal and vertical oscillation signal processor 110 to generate a high pressure to supply to the cathode ray tube 160.

The video preamplifier 130 detects contrast, brightness, gain, and cutoff level values included in the I ² C data input from the microcomputer 100, and is input from the video card according to the detected gain adjustment value. A gain control signal in which the gains of the R, G, and B video signals are adjusted is output to the video output amplifier 150, and a cutoff level control signal according to the detected cutoff level value is output to the cutoff controller 140.

The cutoff control unit 140 outputs a cutoff control signal of R, G, and B video signals for adjusting brightness according to the cutoff level control signal output from the video preamplifier 130 to the cathode ray tube 160.

The video output amplifier 150 amplifies the video signals of the R, G, and B outputs by adjusting the gain of the video preamplifier 130 and applies them to the cathode ray tube 160 as a final video signal.

Next, the operation of the video signal gain and cutoff level adjusting device according to the I ² C control method according to the present invention configured as described above will be described in detail.

First, I ² C data included in the gain control and cut-off level value from the microcomputer 100 is output to the video preamplifier 130, a video pre-amplifier 130, in the I ² C input from the microcomputer 100 The gain adjustment and cutoff level values contained in the data are detected.

When the gain adjustment and the cutoff level value output from the microcomputer 100 are detected through the video preamplifier 130, the video preamplifier 130 cuts the cutoff control signal according to the detected cutoff level value. The output signal is adjusted to the video preamplifier 150 by adjusting the gains of the R, G, and B video signals input from the video card according to the detected gain control signal.

Accordingly, the cutoff control unit 140 adjusts the cutoff level of the R, G, and B video signals for adjusting the brightness according to the cutoff control signal input from the video preamplifier 130, and outputs the cutoff level to the cathode ray tube 160.

In addition, the video output amplifier 150 amplifies a video signal whose gain, which is input from the video preamplifier 130, is amplified and applied to the cathode ray tube 160 as a final video signal.

The reason why the video signals of R, G, and B are amplified again in the video output amplifier 150 is to generate an image output signal having a size sufficient to display an image on the screen of the cathode ray tube 160.

That is, the video preamplifier 130 adjusts the gain of the R, G, and B video signals according to the gain adjustment and the cutoff level value included in the I ² C data input from the microcomputer 100 to improve the sharpness of the image. In addition, the cutoff control unit 140 adjusts the brightness of the image by changing the cutoff levels of the R, G, and B video signals according to the control signal of the video preamplifier 130.

As described above, according to the video signal gain and cutoff level adjusting device according to the I ² C control method of the present invention, the R, G, and B video signals of the video preamplifier are output according to the I ² C data signal output from the microcomputer. By adjusting the gain and cutoff level and outputting them to the cathode ray tube, it is possible to simply adjust the contrast and brightness of the video signal.

In addition, the number of input and output terminals of the video preamplifier can be reduced, thereby simplifying the circuit configuration.

Claims (1)

Receiving the horizontal synchronizing signal and a vertical synchronizing signal outputted from the video card, and outputs a reference oscillation signal, gain control, and I ² C clock signal, the cut-off level value to hereinafter as well as I ² C data and a sync output to the I ² C scheme A microcomputer to output the; Horizontal and vertical oscillation signal processing units for receiving a reference oscillation signal and a horizontal / vertical synchronization signal from the microcomputer and a video card and supplying a signal to a high voltage circuit and a deflection circuit; An FBT connected to an output terminal of the horizontal and vertical oscillation signal processor to generate a high pressure supplied to a cathode ray tube; Gain control that detects a gain adjustment and a cutoff level value included in the I ² C data input from the microcomputer, and adjusts the gain of R, G, and B video signals input from the video card according to the detected gain adjustment value. A video preamplifier for outputting a signal and a cutoff level control signal according to the detected cutoff level value; A cutoff controller for outputting a cutoff control signal of R, G, and B video signals for adjusting brightness according to a cutoff level control signal output from the video preamplifier to a cathode ray tube; And Adjusting the video signal gain and cutoff level according to the I ² C control method characterized in that the video preamp is configured with a video output amplifier to amplify the video signal of the R, G and B output by adjusting the gain applied to the cathode ray tube Device.