KR100321288B1 - Convergence adjustment circuit of a projection tv - Google Patents

Abstract

The technical field to which the invention described in the claims belongs.

It relates to a projection image indicator.

B. Technical problem to be solved

It provides a convergence adjustment circuit that simplifies the hardware circuit configuration in the projection image display.

C. Summary of the Solution

The present invention relates to a convergence adjustment circuit of a projection image display device, comprising: horizontal / vertical convergence adjustment data including horizontal / vertical adjustment signal components for R, G, and B corresponding to the request in response to a convergence adjustment request from the outside. A convergence control unit for generating and outputting the digital / analog conversion unit for converting and outputting horizontal / vertical convergence adjustment data output from the convergence control unit into an analog convergence adjustment signal, and the horizontal / vertical output unit from the digital-analog conversion unit. And a sample / hold circuit unit for separating and outputting the horizontal / vertical adjustment signal components for R, G, and B in the convergence adjustment signal.

D. Significant Uses of the Invention

Used for projection video display.

Description

CONVERGENCE ADJUSTMENT CIRCUIT OF A PROJECTION TV}

The present invention relates to a projection image display device, and more particularly, to an apparatus for separating convergence adjustment data of a projection image display device.

In general, the projection image display has three cathode ray tubes for red (R), green (G), and blue (B), unlike general TVs, and thus, each R, G, B cathode ray tube ( Cathod-ray Tube (CRT) is a device implemented to enable the screen to be enlarged by enlarging the image formed on the large screen through the optical unit consisting of a plurality of reflectors and lenses.

FIG. 1 conceptually illustrates an arrangement of R, G and B cathode ray tubes and a screen provided in the projection image display. As shown in FIG. 1, R, G and B cathode rays are provided separately in a projection image display. The images projected from the tubes 100, 104, 108 are magnified through the lenses 102, 106, 110 and then merged on the screen 112 to be displayed as a single image.

However, as shown in FIG. 1, since the R, G, and B cathode ray tubes 100, 104, and 108 are arranged in a straight line with respect to the screen in the conventional projection image display, the images projected from the cathode ray tubes 100, 104 and 108 are displayed on the screen 112. There was a problem that the sharpness of the screen is lowered because it does not exactly match. Therefore, in order to solve the above problems, the conventional projection image display is essentially provided with a convergence adjustment circuit for adjusting the image projected from each cathode ray tube to be exactly matched on the screen.

2 is a block diagram of a general convergence adjustment circuit provided in a conventional projection image display. Referring to FIG. 2, an operation of a conventional convergence adjustment circuit is described. The convergence control unit 200 generates and outputs convergence adjustment data for each of R, G, and B corresponding to the request according to an external convergence adjustment request. . At this time, the output R, G, B convergence adjustment data (R_out, G_out, B_out) is input to a digital-to-analog converter (DAC) 202, 204, 206, and converted into an analog convergence adjustment signal and then sample / The hold / hold circuits 208, 210, and 212 separate the horizontal and vertical adjustment signal components.

FIG. 3 illustrates a detailed circuit configuration of the sample / hold circuit. In an embodiment of the present invention, a sample / hold circuit 208 for separating a convergence adjustment signal for an analog-converted R image into a horizontal / vertical adjustment signal component 208 is illustrated. ) Is shown as an example. Referring to FIG. 3, the separation operation of the convergence adjustment signal into the horizontal / vertical adjustment signal component is described in detail. First, the convergence adjustment signal for R, which is analog-converted and output from the DAC 202, is basically shown in FIG. As shown in a), the horizontal convergence adjustment signal component R_H and the vertical convergence adjustment signal component R_V are sequentially included, and the convergence adjustment signal R_out for R configured as described above is sample / Through the sample circuit 300 of the hold circuit 208, the horizontal / vertical convergence according to the switching operation according to the horizontal / vertical switch control signals H_hold and V_hold as shown in FIGS. 4B and 4C. It is separated into adjustment signal components (R_H, R_V).

However, in order to obtain a convergence adjustment signal using the conventional convergence adjustment circuit as described above, three DACs for R, G, and B must be separately provided, thereby increasing the hardware volume.

As described above, in order to obtain the convergence adjustment signal using the convergence adjustment circuit provided in the conventional projection image display, three DACs for each of R, G, and B must be separately provided, which increases the hardware volume of the convergence adjustment circuit. There was a problem.

Accordingly, an object of the present invention is to provide a convergence adjustment circuit of a projection image display which reduces the hardware volume by reducing the number of digital / analog converters required for convergence adjustment.

1 is a view showing the arrangement of the R, G, B cathode ray tube and the screen of a conventional projection image display;

2 is a configuration diagram of a convergence adjustment circuit of a conventional projection image display device;

3 is a block diagram of a sample / hold circuit of a conventional convergence adjustment circuit;

4 is a timing diagram for separating horizontal / vertical convergence adjustment signal components in a conventional sample / hold circuit;

5 is a configuration diagram of a convergence adjustment circuit of a projection image display according to an embodiment of the present invention;

6 is a block diagram of a sample / hold circuit of a convergence adjustment circuit according to an embodiment of the present invention;

7 is a timing diagram for separating horizontal / vertical convergence adjustment signal components in a sample / hold circuit according to an exemplary embodiment of the present invention.

According to an aspect of the present invention, a convergence adjustment circuit of a projection image display includes horizontal / vertical adjustment signal components for R, G, and B corresponding to the request in response to a convergence adjustment request from the outside. A convergence control unit for generating and outputting horizontal and vertical convergence adjustment data, a digital-analog conversion unit for converting and outputting horizontal and vertical convergence adjustment data output from the convergence control unit into an analog convergence adjustment signal, and the digital-analog conversion unit And a sample / hold circuit unit for separating and outputting the horizontal / vertical adjustment signal components for R, G, and B in the horizontal / vertical convergence adjustment signal output from the control unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Many specific details are set forth in the following description and in the accompanying drawings, in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

5 is a block diagram of a convergence adjustment circuit of a projection image display according to an exemplary embodiment of the present invention. Referring to FIG. 5, the operation of the convergence adjustment circuit according to the embodiment of the present invention will be described in detail. First, the convergence control unit 500 performs convergence adjustment data for each of R, G, and B when there is a convergence adjustment request from the outside. Unlike the conventional convergence control unit 200 for outputting, the horizontal convergence adjustment data H_out including the horizontal adjustment signal components for each of R, G, and B, and the vertical adjustment signal components for each of R, G, and B are included. Generates and outputs the vertical convergence adjustment data V_out. Subsequently, the horizontal / vertical convergence adjustment data H_out and V_out output from the convergence control unit 500 are input to the digital-analog converter 502, and the first and second digital-converters in the digital-to-analog converter 502 are provided. After converting the analog-convergence adjustment signal from the analog-to-analog converter (DAC) 504,506, R, G through the first and second sample / hold circuits 510, 512 in the sample / hold circuit unit 508 It is separated into the horizontal adjustment signal components (R_H, G_H, B_H) and the vertical adjustment signal components (R_V, G_V, B_V) for B, respectively, to adjust the convergence of the R, G, B cathode ray tubes (100, 104, 108).

FIG. 6 illustrates a detailed circuit configuration of the sample / hold circuit unit 508 according to an embodiment of the present invention. In FIG. 6, the horizontal adjustment signal components of the analog converted horizontal convergence adjustment signals for R, G, and B are respectively shown. The first sample / hold circuit 510 separated by (R_H, G_H, B_H) is shown as an example. Referring to FIG. 6, the separation operation of the horizontal convergence adjustment signal H_out into the horizontal adjustment signal components R_H, G_H, and B_H for each of R, G, and B according to an embodiment of the present invention will be described in detail. The horizontal convergence adjustment signal H_out, which is analog-converted and output from the first digital-analog converter 504 in the digital-analog converter 502, is R, G as shown in FIG. , And sequentially include horizontal adjustment signal components (R_H, G_H, B_H) for each B. The horizontal convergence adjustment signal configured as described above is input to the sample circuit 600 in the first sample / hold circuit 510. do. At this time, the sample circuit 600 according to the embodiment of the present invention is sequentially switched in accordance with the R, G, B switching control signal to extract the horizontal adjustment signal components for each of the R, G, B from the horizontal convergence adjustment signal R, G, and B each of which are composed of four switches and whose timing is adjusted at the time when the corresponding horizontal adjustment signal components R_H, G_H, and B_H are input, as shown in (b), (c), and (d) of FIG. The switching operation is performed by the switching control signals R_hold, G_hold, and B_hold to separate the corresponding horizontal adjustment signal components. That is, the horizontal / vertical convergence adjustment signal output from the convergence control unit 500 is separated into horizontal / vertical adjustment signal components for each of R, G, and B through the sample / hold circuit unit 508, and then R, G, and B cathode rays. The horizontal / vertical convergence of the tubes 100, 104 and 108 will be adjusted.

Accordingly, in the convergence adjustment circuit according to the embodiment of the present invention, the processing for each of the R, G, and B convergence adjustment signals is converted into the processing for the horizontal / vertical convergence adjustment signals, thereby implementing the necessary adjustment in the conventional convergence adjustment circuit. The number of digital-to-analog converters can be reduced, and the circuit can be simplified further by reducing the switching control signal used in the sample / hold circuit part to one switching control signal for separating each signal component.

As described above, the present invention converts the processing of the R, G, and B convergence adjustment signals into the processing of the horizontal / vertical convergence adjustment signals, thereby reducing the number of digital-to-analog converters required for the conventional convergence adjustment circuit. There is an advantage in that the volume of the web can be reduced, and the circuit can be simplified by reducing the two switching control signals used in the sample / hold circuit part to one switching control signal to separate each signal component. .

Claims (3)

In the convergence adjustment circuit of the projection image display, Convergence control unit for generating and outputting horizontal / vertical convergence adjustment data including horizontal / vertical adjustment signal components for R. G. ratios (R, G, B) corresponding to the request in response to an external convergence adjustment request. Wow, A first digital-to-analog converter for converting the horizontal / vertical convergence adjustment data output from the convergence control unit into an analog convergence adjustment signal and outputting the analog convergence adjustment signal; and a vertical convergence adjustment data for analog convergence. A digital-to-analog converter comprising a second digital-to-analog converter for converting a control signal; And a sample / hold circuit for separating and outputting the horizontal / vertical adjustment signal components for each of the R / G ratios from the horizontal / vertical convergence adjustment signal output from the digital-analog converter. Convergence control circuit. Claim 2 has been deleted. The method of claim 1, wherein the sample / hold circuit, A R / G non-switching control signal is switched to sequentially remove the R / N non-horizontal adjustment signal components from the horizontal convergence adjustment signal, and the R / N non-vertical sequentially from the vertical convergence adjustment signal. A convergence adjustment circuit of a projected image display, characterized by consisting of first and second sample / hold circuits for separating adjustment signal components.