JPH06113343A - Method for detecting deviation in horizontal landing for picture display device - Google Patents

Abstract

PURPOSE:To detect a deviation in a horizontal landing of a picture display device. CONSTITUTION:The deviation in the horizontal landing is detected by the detector employing a camera 53 able to measure the brightness of a screen of the picture display device, a device 52 switching red, blue and green filters, an A/D converter 55 A/D-converting a video signal, a detection use signal source 51, and a personal computer 54 data-processing the video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to vertically deflecting each electron beam when a screen displayed on an image display screen is divided into a plurality of sections in the vertical direction. For detecting horizontal landing shifts in a device that displays the scanning lines of the above and displays a television image as a whole.

[0002]

2. Description of the Related Art In recent years, various attempts have been proposed to make a color television picture tube a flat tube structure. Conventionally, a flat type color picture tube of this type has a structure as shown in, for example, Japanese Patent Application Laid-Open No. 57-135590. The configuration will be described below with reference to the drawings.

As shown in FIG. 4, an image display screen 8
Toward the rear, a back electrode 1, a wire cathode 2 for emitting an electron beam, an electron beam extraction electrode 3, an electron beam.
The frame control electrode 4, the focusing electrode 5, the horizontal deflection electrode 6, the vertical deflection electrode 7, and the image display screen 8 are arranged, and the whole is housed in one vacuum container. The line cathode 2 that emits electron beams is stretched in the horizontal direction and emits the electron beams that are linearly distributed in the horizontal direction. Further, a plurality of lines (only 7 lines 2a to 2g are shown in FIG. 4) are provided at intervals in the vertical direction. The above-mentioned line cathode 2 is controlled so as to sequentially emit an electron beam from the upper line cathode 2a to the lower line 2t for a predetermined time. The back electrode 1 not only prevents the generation of electron beams emitted from other line cathodes but also pushes out the electron beams only in the anodic direction. The beam lead-out electrode 3 is taken out through the through-holes 10 which are arranged in a row in the horizontal direction facing the respective line cathodes 2 to 2 at regular intervals. Control electrode 4
Is composed of a vertically long conductive plate 15 having a through hole 14 at a position facing each of the line cathodes 2a to 2t, and a plurality of conductive plates 15 are arranged in parallel in a horizontal direction at a predetermined interval. Here, the control electrode 4 corresponds to the passing amount of each of the electron beams divided in the horizontal direction by the electron beam extraction electrode 3 in correspondence with the picture element of the video signal and is synchronized with the horizontal deflection timing. And is in control. The focusing electrode 5 has a through hole 1 at a position facing each through hole 14 provided in the control electrode 4.
An electron beam is focused by a conductive plate 17 having a number 6.
The horizontal deflection electrode 6 is composed of a plurality of conductive plates 18 and 18 'vertically arranged along both sides of the through hole 16 in the horizontal direction, and a horizontal deflection voltage is applied to each conductive plate. The electronic beam along each picture element is
Each of them is deflected in the horizontal direction, and the R, G, and B phosphors 20 are sequentially irradiated on the surface of the image display screen 8 to emit light. Here, each electron beam is deflected by 2 trio.
The vertical deflection electrode 7 includes a plurality of conductive plates 19, which are arranged in parallel in the horizontal direction at intermediate positions in the vertical direction of the through holes 16.
19 ', vertical deflection voltage is applied, and electronic beam
Is vertically deflected. Here, a pair of electrodes 1
Electron beam emitted from a single line cathode by 9, 19 '
The image is vertically deflected by 8 lines. That is, as shown in FIG. 5, one horizontal section includes two trio of R, G, and B, and one vertical section includes eight horizontal scanning lines. In the image display screen 8, the phosphor 20 is applied to the back surface of the glass plate 21 in a stripe shape, and a metal back and a black stripe carbon are applied. A high voltage is applied to the metal-backed portion of the image display device 8 to form an acceleration electrode.

The operation of the image display device configured as described above will be described below. The electron beam emitted from the line cathode 2 is controlled by a video signal applied to the control electrode 4. The video signal applied to the control electrode 4 is pulse-width modulated for each of the three color signals R, G, B corresponding to each picture element of the video signal. Since it is described in the public information of Kaisho 57-135590, it is omitted here. The electron beam controlled for each picture element is deflected by the deflection voltage applied to the horizontal deflection electrode 6 and the vertical deflection electrode 7, and the phosphor 20 of the image display screen 8 is illuminated to form an image. It is projected.
A high voltage is applied to the metal-backed acceleration electrode on the back surface of the phosphor 20.

In the horizontal landing of the image display apparatus described above, it is necessary to judge pass / fail because a deviation occurs due to a mechanical assembly error. In the past, the judgment criteria varied depending on the individual because the judgment was made blindly.

[0006]

In the image display device as described above, it is necessary to judge whether the image display device is good or bad because a horizontal landing shift occurs due to a mechanical assembling error. In the past, since the judgment was made blindly, the judgment criteria varied depending on the individual, resulting in poor accuracy and poor work efficiency. The present invention is to solve the above-mentioned problems, in which a screen of an image display device displaying a certain single color is captured by a camera through a filter having the same color as the color, and the image data of the screen is displayed in a grid pattern by a personal computer. A horizontal landing deviation detection method that determines the quality of horizontal landing by detecting the horizontal landing deviation of each block by dividing into blocks and calculating the total luminance of each block and the fact that the total luminance is proportional to the amount of color deviation Is to provide.

[0007]

In order to solve the above problems, the present invention provides a camera capable of measuring the brightness of the screen of an image display device, and a device capable of switching a filter between three colors of red, blue and green. A / D converter for A / D converting a video signal, a signal source for detection, a part for performing data processing of the video signal
It is composed of a sonal computer.

[0008]

According to the present invention, it is possible to accurately set the criteria for determining the quality of horizontal landing and to easily determine the criteria.

[0009]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the image display device 50 having the above-mentioned structure.
This is a device necessary to judge the quality of the horizontal landing. The screen of the image display device 50 in which a certain color is displayed by the detection signal source 51 is displayed on the screen of the filter switching device 52.
(It can be controlled by the personal computer 54), and the image is subjected to A / D conversion by the A / D converter 55, and the image data obtained by A / D conversion of the screen is captured by the personal computer 54. Is divided into grid-like blocks by and the total brightness of each block is calculated.

Next, a method for detecting the horizontal landing shift of each block by utilizing the fact that the sum of luminance and the amount of color shift are proportional will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram in which the screen of the image display device 50 is divided into a grid pattern. For example, the grid section in the shaded area is the A zone, and the others are the B zone. FIG. 3 shows that the total luminance and the amount of color shift are proportional. That is, if the color shift amount Z is set within the allowable range, it can be determined that the product is good when the total luminance is K or less. Further, by setting the color shift amount Z within this allowable range for each zone, it becomes possible to judge the quality of the horizontal landing for each block.

By repeating the above operation for red, blue, and green by controlling the filter switching device 52 with the personal computer 54, it is possible to judge whether the horizontal landing is good or bad.

[0014]

As described above, according to the present invention, it is possible to accurately set the criteria for determining the quality of horizontal landing and to easily determine the criteria.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus used in a horizontal landing detection method for an image display apparatus according to an embodiment of the present invention.

[Fig. 2] Diagram of the screen divided into grids

[Fig. 3] Relationship between color shift amount and total luminance

FIG. 4 is an exploded perspective view of main parts of a flat color picture tube.

FIG. 5 is a view showing a part of a screen of a flat type color picture tube.

[Explanation of symbols]

50 image display device 51 detection signal source 52 device capable of switching filters to three colors of red, blue and green 53 camera 54 personal computer 55 A / D converter

Claims (1)

[Claims] 1. A screen of an image display device displaying a certain monochromatic color is captured by a camera through a filter of the same color as the color, the image data of the screen is divided into grid-like blocks, and the total luminance of each block is summed up. The horizontal landing shift detection method for an image display device is characterized in that the horizontal landing shift of each block is automatically detected and the quality is judged by proportionally calculating the total luminance and the amount of color shift.