JPH0470188A - Misconvergence measurement method - Google Patents

Abstract

PURPOSE:To highly precisely measure misconvergence without being affected by means of the fluctuation of deflecting power by providing a means storing luminous position data of single raster, a means storing a luminous distribution, a means separating the luminous distribution of measured patterns by colors and a means operating misconvergence. CONSTITUTION:CPU 9 refers to the content of one of single raster luminous position data memories 7a-7c and extracts only luminous data on the luminous position of a color to be referred to in a measured pattern data memory 7d. Then, the center of the luminous distribution of respective colors is operated based on luminous distribution information of the measured patterns which are color-separated, the relative dislocation quantity of the center of the luminous distribution in respective colors is obtained, and it is displayed in a display part 10 as a misconvergence quantity. Consequently, the measured patterns are set to a luminous state for all the colors and measurement can be executed by one picture reading. Thus, the luminous distribution by respective colors can be obtained by the same timing. Thus, misconvergence can highly precisely be measured without being affected by the fluctuation of deflecting power.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for measuring isth convergence of color plaques/tubes.

[Conventional technology]

A conventional misconvergence measuring method is, for example, one described in Japanese Patent Application Laid-Open No. 41-257096. In this method, the measurement pattern is displayed in a state where all colors are emitted. This is detected using a black and white camera, but three primary color filters are installed on the front of the camera, and these are switched to #1 and #1.
4L, find the center of the luminance distribution for each color, and calculate the misconvergence from that M.

As another method, as described in Japanese Patent Application Laid-open No. 1-204595, the measurement pattern of the full-color luminous pattern 1 is color-separated into layers using a color camera, and the center of the luminance distribution for each color is determined.
There is a method to calculate the amount of misconvergence.

[A4J that the invention attempts to solve A method using an optical filter in the above-mentioned conventional technology.

It takes time to switch filters, and it is also necessary to carry out total reading for each color, making it unsuitable for high-speed meters. Furthermore, since images are captured using separate ties/groups for each color, it is conceivable that measurement accuracy may be reduced due to variations in the center position of the brightness distribution due to fluctuations in the deflection power source.

On the other hand, in the method using a color camera, it is difficult to satisfy measurement accuracy with a color camera (single-panel type) used on a boat because its resolution is considerably lower than that of a black and white camera.

If an expensive color camera (three-chip type) were used, it would be possible to obtain a resolution comparable to that of a black and white camera, but since it would cost about ten times as much as a black and white camera, it would be difficult to adopt it due to cost.

An object of the present invention is to provide a misconvergence measuring method that can measure misconvergence with high precision without being affected by fluctuations in the deflection power source.

Another object of the present invention is to provide a misconvergence measurement method that eliminates the need for an expensive color camera as a measurement camera and performs high-speed measurement without using three primary color filters.

[Means to solve the problem]

In order to achieve the above object, the present invention projects a monochromatic raster on a color cathode ray tube surface, images it with a black and white camera, and acquires light emitting position data of the monochromatic raster within the field of view of the camera on the color cathode ray tube surface. means for displaying the measurement pattern on the surface of the color cathode ray tube in all colors (red, green, and previous light emission), capturing an image of this with the black and white camera, and storing the luminescence distribution; means for separating the luminescence distribution of the measurement pattern of the all-color luminescence state by color based on the monochromatic raster luminescence position l data;
Means was provided for determining the centers of the two luminescence distributions based on the luminescence distribution for each color and calculating the misconvergence from the mutual deviation of the center positions.

[Effect]

Misconvergence measurement can be performed by capturing a measurement pattern on the surface of a color cathode ray tube to be inspected in a state where all colors are emitted in a single image capture. Therefore, since the luminescence distribution for each color can be obtained at the same timing, it is possible to prevent deterioration of measurement accuracy due to variations in the center of the luminescence distribution due to fluctuations in the deflection power supply or the like. Furthermore, since a monochromatic raster is projected, the monochromatic raster light emitting position data is stored in memory for each color, and the measurement pattern is color-separated based on this data, there is no need for an expensive color camera or the use of three primary color filters. Since it can be detected with a black and white camera, measurement speed can be increased.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an overall block diagram of the present invention. first.

The functions and operations of each part will be explained. Signal generator 1
supplies a video signal to the color television 3 for displaying a monochromatic (red, green, blue) raster or measurement pattern on the screen of the color cathode ray tube 2. The monochrome camera 4 is equipped with a positioning means (not shown) and an imaging optical system so as to be able to image a predetermined area of the measurement pattern displayed on the color cathode ray tube 2. N image information of a predetermined area is.

The image processing section 5 binarizes or digitizes into 256N tones, and the memory selection section 6 stores images in the memory 78 for each type of image displayed on the screen of the color cathode ray tube 2.
~7d. Memories 7a, 7b, and 7e are red, green, and blue monochrome raster light emitting position data memories, respectively.
It has a frame memory configuration of 2x512x2 bits. On the other hand, a memory 7 for storing the luminance distribution of the measurement pattern
d has a 512x512x 8-bit frame memory configuration. When the CPU 9 reads the contents of the measurement pattern data memory 7d, the color separation unit 8 extracts the measurement pattern by comparing the contents of any one of the monochrome raster light emission position data memories 7a, 7b, and 7e. It functions to extract only the luminance data of the light emitting position of the color to be compared in the data memory 7d. Therefore, the brightness values of parts other than the light emitting parts of this color are read into the CPU 9 as O (the brighter the brightness, the larger the brightness value).
U9 calculates the center of the brightness distribution of each color based on the brightness distribution information of the measurement pattern separated by one color by the method described above, based on the algorithm described later, and calculates the amount of relative positional shift of the center of brightness distribution of each color. This is displayed on the display section 10 as a misconvergence amount.

Next, a misconvergence measurement method according to the present invention will be described in detail. To measure, first, color cathode ray tube 2
Monochromatic rasters of red, green, and blue are sequentially projected on the screen to create monochromatic raster light emitting position data for each color. Figure 2 shows the image projected on the color cathode ray tube 2 taken by the black-and-white camera 4. When a white (all-color luminous It) raster is projected on the color cathode ray tube 3, which shows a part of the image within the visual field of a predetermined area, the result will be as shown in Fig. 2(a), and a red monochromatic raster will be projected. When released, it will look like Figure 2 (b).Similarly, the light emission position data corresponding to each color will look like Figure 2 (c) and (d) for green and blue, respectively. ,
Taking red as an example, in the same way as shown in FIG. 2(b), logic "1" is written in the memory address of the memory 7a corresponding to the red light emitting part and logic "0" is written in the other parts. The creation of each sub-emission position data of the color cathode ray tube 2 within the field of view of the camera 4 is completed when the values are 0 or more, which is also performed for green and blue.

Next, a grid pattern, which is a measurement pattern shown in FIG. 3(a), is projected onto the color cathode ray tube 2.

FIG. 3(b) shows an in-field image of a predetermined area captured by the monochrome camera 4. FIG. Misconvergence is defined as the amount of relative positional deviation of the center coordinates of the brightness distribution for each color of the grid points of the grid pattern 11. Therefore, as shown in FIG. 3(b), a vertical line measurement window 12 is provided for determining the center of luminance distribution for each color in the horizontal (x) direction. On the other hand, a horizontal line measurement window 13 is provided for determining the center of luminance distribution for each color in the vertical (y) direction.

First, a method for measuring the center of luminance distribution by color in the horizontal direction will be explained using red as an example. FIG. 4(a) shows an image of the vertical line measurement window 12 before color separation, and FIG. 4(b) shows an image after color separation. First, the vertical brightness sum Mvitx+ of the window inner surface 912a after five color separation is calculated. demand.

1st! The result is shown in (C). Using Mvln+, the center X of the luminance distribution in the horizontal direction of red is calculated using equation (1).

xl=ΣMvx+x+・X/ΣMvm+-+
(1) In the same way, find the horizontal luminance distribution centers X, , X, of green and blue.

Next, we will discuss how to measure the center of luminance distribution by color in the vertical direction.

This will be explained using red as an example. Part 5 (a) shows the image of the horizontal line measurement window 13 before color separation, and (b) shows the image after color separation.First, the image inside the window 13a after one color separation.
Find the horizontal brightness sum MHmtv+. Using s Mit+i+y+, the result of which is shown in FIG. 5(C), the vertical brightness distribution center Y of red color is calculated by equation (2).

Y, = ΣMlll(Yl ・Y/ΣMI, xtv+
-(2) Similarly, find the vertical luminance distribution center y(!, Y,) of green and blue.

From the center of the brightness distribution obtained in this way, the relative positional deviation amount of red and blue with respect to green is Xa Xi, Xa-Xs,
Y(l YIL, YOYm is calculated and the result is displayed on the display section 1.
Display at 0.

Note that if you are re-measuring without moving the black and white camera 4, you do not need to create monochrome raster light emitting position data from now on, but if you have moved it, you must create monochrome raster light emitting position data before starting measurement. It is necessary to perform the measurement after that.

〔Effect of the invention〕

According to the present invention, the measurement pattern is made to emit light in all colors,
-Measurement is possible by capturing images twice.

Therefore, since the color-specific light emission distribution can be obtained at the same timing, misconvergence can be measured with high precision without being affected by fluctuations in the deflection power source.

Furthermore, before measurement, a monochrome raster is projected in advance.

Since monochrome raster light emitting position data is stored in memory for each color, there is no need for an expensive color camera as a measurement sensor or the need for three primary color filters.
Measurement speed can be increased.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the overall configuration of the present invention, Figure 2 is an explanatory diagram of the relationship between an image projected on a color cathode ray tube in a full-color light emitting state and an image in monochrome raster light emission, and 3rd rM is a color diagram. An explanatory diagram of the relationship between an image projected on a cathode ray tube and a predetermined small area for measurement, and FIGS. 4 and 5 are explanatory diagrams of a method for determining the center of luminance distribution for each color of a measurement pattern. 2...Color cathode ray tube, 4...Black and white camera, Figure 5...Image processing section, 7a. 7b. 7c... Monochrome raster light emission position data memory, 7d... Measurement pattern data memory, 8... Color separation unit, 9... CPU. 2M Figure 5 Figure 5 (ω Figure 4 (b) Color separation style (α) Color division salmon diarrhea (b) Self-bun string (c) Bright cliff bunte (C) I-taka 5'1 乎

Claims (1)

[Claims] 1. Means for projecting a monochrome raster on a color cathode ray tube surface and capturing the image with a black and white camera, and storing data on the light emitting position of the monochrome raster within the field of view of the monochrome camera on the color cathode ray tube surface; A means for projecting all colors in a light emitting state on a cathode ray tube surface, capturing an image of this with the black and white camera, and storing the light emitting brightness distribution; A method for measuring misconvergence, comprising means for separating by color, determining the brightness center of the luminance distribution for each color, and calculating a relative positional shift amount of the center position to determine misconvergence.