KR100206820B1 - The automatic white balance regulating device of projection tv - Google Patents

Abstract

The present invention relates to an automatic white balance adjustment device of a projection TV, and in the related art, the gain through the amplifier of the cathode ray tube driver may change over time. In the case of the projection cathode ray tube, the shadow mask is a monochromatic cathode ray tube. Because it has to output excessive luminance signal in a small area, it may cause discoloration of the phosphor when used for a long time, and the surface of the mirror used to reduce the volume of the TV system uses a mirror coated with aluminum, silver, etc. In use, there is a problem of chemical change and the possibility of discoloration by the installation environment, and the intermediate structure called coupler combining the cathode ray tube and the lens fills the coolant in the structure, and the coolant has a medium similar to the glass refractive index. Time to cool the cathode ray tube surface With this, there is a problem that the coolant discolors due to chemical reaction of the frame, leakage of the black painter applied to the coupler surface, and the like. Accordingly, the present invention provides a white pattern generator 101 which generates and generates a 100% white pattern; A first switch 102 for selecting and outputting any one of a white signal generated from the white generator 101 and an input luminance signal; A second switch 103 for selecting and outputting any one of a white signal generated from the white generator 101 and an input color signal; A VCD processing unit 105 for performing video, chroma, and deflection signal processing on the signals input through the first switch 102 and the second switch 103; An RGB sensor 106 that detects the RGB light leaving the optical path formed on the screen and converts the detected amount of light into an electrical signal and outputs the electrical signal; A microcomputer (107) for calculating the ratio of color signals using the electrical signal input from the RGB sensor (106) and outputting a correction value according to the calculated ratio; In accordance with the correction value of the microcomputer 107 through the voltage control amplifier to adjust the RGB signal to adjust the RGB signal to match the driving voltage input to the cathode ray tube to configure the RGB cathode ray tube driver (108-110) always the same white It automatically adjusts to balance to bring uniformity of product quality.

Description

Projection TV's Automatic White Balance Adjuster

The present invention relates to an automatic white balance adjustment device of a projection TV, and more particularly, to an automatic white balance adjustment device of a projection TV that enables to automatically adjust the white balance to always maintain the quality of the product.

The cathode ray tube and lens configuration of a conventional projection TV includes an RGB cathode ray tube (4) (5) (6) for converting and displaying an electrical signal into an optical image by the action of a small beam, as shown in FIG. An RGB signal driver (1) (2) (3) for supplying an electrical signal to the RGB cathode ray tube for operation; An RGB lens (10) (11) (13) positioned in front of the RGB cathode ray tube (4) (5) (6) to enlarge an image signal provided therefrom; An RGB coupler (7) (8) (9) positioned in front of the RGB cathode ray tube (4) (5) (6) to allow the lens to be coupled; It is composed of a screen 13 positioned at a distance of focus of the lens to enlarge and project the image.

Looking at the prior art configured as described above is as follows.

Referring to the process of expanding and projecting the R signal on the screen 13, the R signal driver 1 applies an electric signal for driving the R cathode ray tube 4, and the R cathode ray tube 4 receives the received electricity. The signal is converted into an optical image by the action of a beam and displayed.

Then, the R lens 10 enlarges and outputs the signal displayed on the R cathode ray tube 4 through the R coupler 7 in front of the R cathode ray tube 4.

The signal thus output is magnified and projected onto the screen 13 at the focused distance of the R lens 10.

In this way, the G signal and the B signal are also enlarged and projected on the screen 13.

However, when configured as shown in FIG. 2, the distance to the screen from the lens is far from the lens, thereby increasing the volume of the TV system.

Therefore, it is common to reduce the volume of the TV system by preparing a mirror on the optical path as shown in FIG. 1, which is the principle of projection TV.

That is, when the driving signal is applied from the cathode ray tube driving units 1, 2, 3 to the cathode ray tubes 4, 5, 6, and displays an image, the image is the coupler 7, 8, 9 and the lens 10, 11 It is magnified through 12 to generate the mirror 14.

The signal generated by the mirror 14 is thus reflected and displayed on the screen 13.

At this time, when the image is displayed on the screen 13, the camera 15 installed in the front center of the screen 13 detects color coordinates and applies a 100% white signal to the TV system.

In this case, as shown in FIG. 4, the white balance adjustment is performed by tuning the composite video signal through the tuner 21 and outputting a video signal processed by the intermediate frequency processor 22 to obtain a luminance obtained by filtering the comb filter 23. The signal Y and the color signal C are provided to the VCD processing unit 24.

The VCD processing unit 24 carries out RGB signal line driving units 25-27 for color signals RGB obtained by processing video signals, chroma signals, and deflection signals with respect to the input luminance signal Y and the color signal C, respectively. Will output

The R.G cathode ray tube driver 25, 26 then adjusts the gain through its internal amplifier to maintain the white balance of the desired color coordinates.

The gain through the B cathode ray tube drive 27 for ease of adjustment and for limiting the total beam current is fixed.

However, in the conventional technology as described above, the gain through the amplifier of the cathode ray tube driver may change over time, and in the case of the projection TV cathode ray tube, the monochromatic cathode ray tube does not have a shadow mask, so that a large area is excessively large. The luminance signal must be emitted, so the phosphor may discolor when used for a long time, and the surface of the mirror used to reduce the volume of the TV system uses a mirror coated with a material such as aluminum or silver. And there is a problem that may be discolored by the installation environment.

In addition, as shown in FIG. 3, an intermediate structure called a coupler, which combines the cathode ray tube and the lens, fills the cooling liquid in the structure, which is made of a medium similar to the refractive index of glass and serves to cool the surface of the cathode ray tube. With this, there is a problem that the coolant discolors due to chemical reaction of the frame, leakage of the black painter applied to the coupler surface, and the like.

Accordingly, an object of the present invention for solving the conventional problems as described above is to provide an automatic white balance adjustment device of the projection TV to maintain the same white balance in any situation to always maintain the quality of the product.

1 is a TV receiver of a conventional projection TV

2 is a configuration diagram of a cathode ray tube and a lens in FIG.

3 is a diagram illustrating a coupling structure of a CRT and a lens in FIG. 1.

4 is a circuit diagram of a white balance adjusting device of a conventional projection TV.

5 is a circuit diagram of the automatic white balance adjustment device of the projection TV of the present invention.

6 is a diagram illustrating an internal structure of a TV receiver to which an RGB sensor is attached.

* Explanation of symbols for main parts of the drawings

101: white pattern generator 102: first switch

103: second switch 104: comb filter

105: VCD processing unit 106: RGB sensor

107: microcomputer 107a: RGB ratio calculator

107b: R.G output data value calculator 107c: digital / analog converter

108-110: cathode ray tube driving unit

The automatic white balance adjustment device circuit configuration of the projection TV of the present invention for achieving the above object, as shown in Figure 5, the white pattern generating unit 101 is generated by generating a 100% white pattern; A first switch 102 for selecting and outputting any one of a white signal generated from the white generator 101 and an input luminance signal; A second switch 103 for selecting and outputting any one of a white signal generated from the white generator 101 and an input color signal; A VCD processing unit 105 for performing video, chroma, and deflection signal processing on the signals input through the first switch 102 and the second switch 103; An RGB sensor 106 that detects the RGB light leaving the optical path formed on the screen and converts the detected amount of light into an electrical signal and outputs the electrical signal; A microcomputer (107) for calculating the ratio of color signals using the electrical signal input from the RGB sensor (106) and outputting a correction value according to the calculated ratio; In accordance with the correction value of the microcomputer 107 is configured by the RGB cathode ray tube driver 108-110 to adjust the gain by the voltage control amplifier to match the driving voltage input to the cathode ray tube.

The microcomputer 107 includes: an RGB ratio calculator 107a for comparing and calculating a value output from the RGB sensor 106 with a reference value; An R.G output data value calculator (107a) for determining an output value of the R.G signal according to the ratio obtained through the RGB ratio calculator (107a); A digital / analog converter 107c converts the output data value of the R.G output data value calculator 107b into an analog value and outputs the converted analog data.

When described in detail with respect to the operation and effect of the present invention configured as described above. When the user turns on the white balance adjustment, the first switch 102 and the second switch 103 select the output signal of the white pattern generator 101 that generates the 101% white pattern, thereby processing the VCD processing unit 105. To provide.

When the white balance is not adjusted, the luminance signal Y and the color signal C of the comb filter 104 for filtering the video signal are selected and provided to the white pattern generator 101.

Then, the VCD processing unit 105 outputs the color signal RGB obtained by performing the video, chroma, and deflection signal processing of the TV to the RGB cathode ray tube driver 108-1010, respectively.

The gain is adjusted by the gain set in the voltage control amplifiers VCA1 and VCA2 of the RG cathode ray tube driving units 108 and 109 and the amplifier AMP of the B cathode ray tube driving unit 100, and the gain-adjusted signal is adjusted to each cathode ray tube. Is displayed via.

This displayed signal is magnified through the coupler 114, 115, 116 and the lenses 117, 118, 119 and transmitted to the mirror 120 as in FIG. 6.

The signal transmitted to the mirror 120 is reflected and magnified and projected on the screen 121.

At this time, the RGB sensor 106 installed in the overscan portion of the TV receiver 122 analyzes the spectrum of RGB light and converts the respective amounts into electrical signals and inputs them to the microcomputer 700.

Then, the RGB ratio calculating unit 107a of the microcomputer 700 calculates the ratio of RGB input from the RGB sensor 106, and the RGB output data value calculating unit 700b transmits the RGB ratio transmitted from the RGB ratio calculating unit 107a. Is compared with the RGB ratio of the white balance color temperature which is set in advance, and an error amount thereof is obtained, and the calculated RG error amount is output.

Accordingly, the digital / analog converter 700c converts the R.G errors output from the RGB output data value calculator 700b into digital values and outputs the digital values to the R.G cathode ray tube drivers 108 and 109, respectively.

The R.G cathode ray tube driving units 108 and 109 are inputted to the voltage control amplifiers ACV1 and ACV2 to adjust and output gains for errors.

At this time, the gain of the B cathode ray tube driving unit 110 is fixed.

By adjusting the gain in this way, you can maintain white balance under any circumstances.

As described above, the RGB sensor is installed in the overscan area of the TV receiver of the present invention to calculate the ratio of the overscanned RGB signal and compare the result with a preset ratio to obtain an error amount, and according to the error amount, the cathode ray The gain of the tube drive is automatically adjusted so that the same white balance is always achieved so that uniformity of product quality can be obtained.

Claims (3)

White pattern generating means generated by making a 100% white pattern; Switching means for selecting and outputting one of a white signal and a TV signal of the white generating means; VCD processing means for outputting a color signal subjected to video, chroma and deflection signal processing on the signal input from the switching means; An RGB sensor that detects RGB light that leaves the optical path formed on the screen and converts the detected amount of light into an electrical signal and outputs the electrical signal; A microcomputer that calculates a ratio of color signals using an electrical signal input from the RGB sensor and outputs a correction value according to the calculated ratio; And a cathode ray tube driving means for adjusting the gain through the voltage controlling amplifier according to the correction value of the microcomputer to adjust and output the color signal of the VCD processing means to match the driving voltage input to the cathode ray tube. Automatic white balance adjuster. The apparatus of claim 1, further comprising: an RGB ratio calculating means for calculating a ratio of RGB input from an RGB sensor; R.G output data value calculating means for comparing the ratio of RGB obtained through the RGB ratio calculating means with the RGB ratio of a preset white balance color temperature and outputting an error of the R.G ratio according thereto; And digital / analog converting means for converting an error of the digital value obtained through the R.G output data value calculating means into an analog value and outputting the analog value. The apparatus of claim 1, wherein the RGB sensor is installed in an overscan portion of the TV receiver.