JPH0281597A - Convergence measuring instrument for color television receiver - Google Patents

Abstract

PURPOSE:To obtain high convergence measuring accuracy by operating a gravity center according to a fluorescent body code with the user of a luminance signal and a chrominance code signal, and measuring the convergence of a color television picture receiver with the help of the relative position of the respective gravity centers of three primary colors. CONSTITUTION:The dots or cross pattern of a color television to be measured is photographed by a television camera 8, the three primary colors are obtained, and the most largest color output in units of a picture element to be picture-processed is color outputted as the phosphor color in the pixel picture element. In addition, the three primary signal outputs of the color television camera 8 are mixed to prepare the luminance signals, and they are A/D-converted by an A/D converter 11. Next, the phosphor code signal and the digital-converted luminance signal are stored into a frame memory 12, the gravity centers are operated according to the phosphor codes by a computer 16, and the convergence is obtained by the relative position of the respective gravity centers of the red, green and blue colors. Thus, the three primary colors can be completely separated, the convergence can be measured, and the highly accurate measurement can be executed in a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a convergence measuring device for a color television receiver that measures misconvergence of a color television using a color television camera.

[Conventional technology]

FIG. 4 shows a camera part of a convergence measurement method using a conventional black-and-white television camera disclosed in, for example, Japanese Unexamined Patent Publication No. 61-257096. In the figure, 1 is a black-and-white television camera, 3 is a three-primary color filter, 2 is is a motor that moves the three primary color filters 3.

Next, the operation will be explained. A three primary color filter 3 is placed between a black and white television camera 1 and a television receiver into which a dot pattern is input. Here motor 2 uses 3 primary color filters 3
, and calculate the center of gravity for each of the images transmitted through the red filter 3R, the green filter 3G, and the blue filter 3B. Convergence is calculated from the relative positions of red, green, and blue centers of gravity.

[Problem to be solved by the invention]

Conventional convergence measuring devices for color television receivers were configured as described above, so in order to measure convergence, it was necessary to replace the color filter in front of the camera and measure each of R, G, and B. First, there are problems in that it requires a long measurement time, and it is difficult to obtain sufficient measurement accuracy due to the interference of other colors due to the transmission characteristics of color filters.

This invention was made in order to solve the above-mentioned problems, and it is a color television receiver that can simultaneously measure the convergence of three colors using a color television camera and eliminate measurement errors peculiar to color television cameras. The purpose is to obtain a convergence measurement device.

[Means to solve the problem]

A convergence measurement device for a color television receiver according to the present invention includes a color television camera placed in front of the color television receiver to be measured, and a circuit that compares three primary color outputs of the color television camera and converts the color code; It is equipped with a circuit that mixes the three primary color outputs of the color television camera and performs A/D conversion, a frame memory for storing images and color codes, and a computer that performs calculations, control, and display.

[Effect]

In this invention, a dot or cross pattern of a color television to be measured is photographed with a color television camera, three primary color signals are obtained, and the largest color output in each pixel for image processing is coded as the phosphor color for that pixel. Output. Further, the three primary color signal outputs of the color television camera mentioned above are mixed to form a luminance signal, which is A/D converted. Next, the phosphor code signal and the digitally converted luminance signal are stored in a frame memory, and a computer calculates the center of gravity for each phosphor code. Since convergence is determined by the relative positions of the centers of gravity of red, green, and blue calculated as described above, convergence can be measured by completely separating the three primary colors, and highly accurate measurement can be performed in a short time.

〔Example〕

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

FIG. 1 shows a color television receiver convergence measuring device according to an embodiment of the present invention, in which 8 is a color television camera, 9 is an RGB mixer, 10 is an RGB comparator, 11 is an A/D converter, and 12 is an RGB mixer. is frame memory, 1
3 is a synchronization circuit that controls the overall timing; 14 is a D/A converter that restores the digitized image; 15 is a display that monitors the processed image; and 16 is calculation and control.

A computer performs display; 17 is a keyboard for issuing processing instructions; and 18 is a display for displaying measurement results.

Further, FIG. 2 is a perspective view showing the positions of the television receiver to be measured and the color television camera of the above embodiment.

Next, the operation and effect will be explained.

FIG. 3 is an enlarged view of a part of the field of view of the color television camera 8, in which 30R, 30G, and 30B represent the red, green, and blue electron beams hitting the phosphor, respectively, and 31 represents the black matrix. In the figure, if the horizontal period during which the color television camera 8 is scanning is 32, the output waveforms of the color television camera 8 are (R) red, (G) green, (
B) It becomes blue and is output even when the corresponding phosphor color is not used. This is because the filter built into the color television camera is designed to have gentle spectral sensitivity characteristics. However, this uncorresponding primary color output causes a large error in convergence measurement.

Therefore, in the present invention, (C1) in FIG.

As shown in (C2), the three primary color signal outputs of the color television camera are compared, and the largest among them is output as a fluorescent code signal. On the other hand, FIG. 3(Y) is a mixture of the color television camera output signals of FIGS. 3(R), (G), and (B), and is output as a luminance signal. Then, the type and brightness of the phosphor are expressed in units of picture elements subjected to image processing using the phosphor code signal and luminance signal. That is, in FIG. 1, the output of the RGB mixer 9 corresponds to the luminance signal (Y), and the output of the RGB comparator 10 corresponds to the phosphor code signals (CI) and (C2). Both outputs are stored in the frame memory 12, and the center of gravity is calculated for each phosphor code by the computer 16. Convergence can be determined by the relative position of the center of gravity of each phosphor. Then, the result is output to the display 18.

As described above, according to the present embodiment, since forced color identification is performed, the CRT to be measured attached to the color camera 8 is not affected by other primary color outputs of the color TV camera 8.
R, G, and B of an image can be completely separated, and convergence can be measured with high precision.

In the above embodiment, the frame memory 12 for storing the phosphor code signal and the luminance signal is provided, and the center of gravity of the image data is calculated by a computer. You can do it like this.

Further, in the above embodiment, a color television camera 8 with analog RGB output is shown, but this may be a color television camera with a video output together with a color demodulation circuit.

Furthermore, in the above embodiment, the phosphor code signal is encoded into 2 bits in FIG. 3, but the same effect can be obtained even if the R, G, and B color identification signals are used as they are without being encoded. play.

〔Effect of the invention〕

As described above, according to the present invention, the color code signal obtained by comparing the three primary color outputs of the color television camera placed in front of the color television receiver to be measured is mixed with the three primary color outputs,
The A/D converted luminance signal is stored, the center of gravity is calculated for each phosphor code, and the relative position of the center of gravity of each of the three primary colors is determined.
Since the convergence of the color television receiver is measured, R, G, and B of the CRT image to be measured taken by the color television camera can be completely separated, and high convergence measurement accuracy can be obtained. , which has the effect of improving product quality. Furthermore, since the three primary colors RGB are combined and image processed as a Y signal, it is possible to obtain a positional resolution close to that of a black and white television camera. Furthermore, although it is a color process, the A/D converter and frame memory are small in scale, so the device has the effect of being inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a convergence measuring device for a color television receiver according to an embodiment of the present invention, FIG. 2 is a perspective view showing the positions of a television receiver to be measured and a color television camera, and FIG. FIG. 4 is an operational explanatory diagram showing signal processing waveforms of a convergence measuring device for a color television receiver according to an embodiment of the present invention, and FIG. 4 is a perspective view showing three primary color filters and a monochrome television camera of a convergence measuring device according to the prior art. In the figure, 8 is a color television camera, 9 is an RGB mixer, 10 is an RGB comparator, 11 is an A/D converter, 1
2 is a frame memory, 13 is a synchronization circuit that controls the overall timing, and 14 is a D that restores the digitized image.
/A converter, 15 is a display that monitors processed images, 16 is a computer that performs calculation and control 2 display, 17 is a keyboard that gives processing instructions, 18 is a display that displays measurement results, 20 is a television receiver to be measured, 30R is a red electron beam, 30G is a green electron beam,
30B is a blue electron beam, 31 is a plaque matrix,
32 is a horizontal scanning period. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) Compare the color television camera for photographing a color television receiver into which a dot pattern or cross pattern is input and the three primary color signal outputs that are output from the color television camera, and use the largest color output as the color code. a color code output means for outputting a signal; a luminance signal output means for mixing the three primary color signal outputs, A/D converting the signals and outputting a luminance signal; A convergence measurement device for a color television receiver, characterized in that the device comprises a calculation means for calculating the center of gravity for each code and measuring the convergence of the color television receiver based on the relative position of the center of gravity for each of the three primary colors.