JPS6016088A - Check device of crt display picture - Google Patents

Abstract

PURPOSE:To improve the check efficiency by using an identical test pattern to plural kinds of check items. CONSTITUTION:The test pattern generated by a test pattern generator 4 is displayed on a CRT display device 1. A controller 5 controls an observed position and an observed visual field to a display pattern of the CRT display device 1 and observes a prescribed pattern while keeping the pattern within the visual field depending on the check items. The observed picture observed individually is stored once in a buffer and measurement and calculation are conducted to each check item. The result of each calculation and the check reference value at a discriminating section is compared to discriminate.

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention solves multiple types of image quality abnormalities such as poor focusing, insufficient amplitude, tilt, bias, non-linearity, and brightness abnormalities in displayed images of CRT (cathode ray tube) display devices. The present invention relates to a CRT display image inspection system that allows automatic inspection using the same test pattern.

ω) Background of the technology CRT display devices display images such as characters on the CRT display screen by scanning an electron beam modulated by image information such as characters to be displayed, and display images that are clear and distortion-free over the entire display surface. Various correction devices or adjustment devices are provided so that an image free of color is displayed.

However, due to incomplete correction or adjustment by these devices, or failure of these devices, the clarity of the displayed image may decrease due to poor focusing of the electron beam, or the amplitude of the electron beam may be insufficient in the main scanning direction or sub-scanning direction. Various image quality abnormalities may occur, such as reduction or bias of the displayed image due to poor installation of the CRT, distortion of the displayed image due to nonlinearity of the electron beam deflection circuit, and brightness abnormalities due to reflection or folding at the end of the scanning line. Therefore, prior to shipping the product, we conduct a thorough inspection for abnormalities in the image quality of the displayed image.

(0) Prior Art and Problems CRT display images were initially inspected visually, but later inspection devices came to be used to automate or quantify the inspection.

However, conventional inspection devices use dedicated test patterns for each of the various inspection items mentioned above, and therefore have the inconvenience of having to select one test pattern for each inspection item. there were.

(D) Purpose of the Invention The purpose of the present invention is to improve the efficiency of C1 inspection by using the same test pattern for a plurality of inspection items.

(G) Structure of the Invention The CRT display screen inspection device according to the present invention includes a CRT display device, a vertical stripe displayed at at least one corner and approximately the middle of the screen of the CR'I'' display device M, and a maximum Generates a test pattern consisting of a wide convergence defect test pattern for brightness measurement, a brightness abnormality test pattern that is displayed with a predetermined width area on at least one of the left and right sides of the screen, and a plurality of straight line patterns for nonlinearity test. an observation device for observing the display surface of the CRT display device on which the test pattern is displayed; and an inspection device for inspecting the observed test pattern obtained by the observation device; A plurality of types of image quality abnormalities are inspected using the one test pattern.

■ Examples of the invention Next, the gist of the present invention will be specifically explained using examples.

FIG. 1 shows a configuration diagram of an embodiment of the present invention, in which 1 is a CRT display device to be inspected, 2 is an observation device for observing the display surface of the CRT display device, and 3 is an observation test obtained by the observation device 2. 4 is a test pattern generator for generating a test pattern as shown in FIG. 2; and 5 is a control device for controlling the observation position and observation field of the observation device 2.

FIG. 2 shows an example of a test pattern generated by the test pattern generator 4, in which A and B are patterns for inspecting poor focusing of a display image, A is a planar pattern, B is a striped pattern, and C is a striped pattern. D is a pattern of a plurality of equally spaced parallel lines for testing non-linearity in the main scanning direction of a display image, D is a pattern of a plurality of equally spaced parallel lines for testing nonlinearity of a display image in the sub-scanning direction, E is a display image This is a pattern to test for insufficient amplitude, slope, and bias.

The focusing defect inspection pattern consisting of the planar pattern A and the striped pattern B is provided so as to be displayed near the four corners and near the center of the display surface, as shown in FIG. This is C
In an RTX display, the focus at other points is intermediate between the focus at the corners and the center.

Parallel line pattern C and parallel line pattern D Yes 4 = Neither is provided in the center of the display surface, this is CR
This is because, in a T display product device, for example, nonlinearity in the sub-scanning direction appears as shown in FIG. 4 1a), but not as shown in fb).

Further, brightness abnormalities are inspected using a pair of planar patterns A sandwiching striped pattern B in the upper left corner and a pair of planar patterns A sandwiching striped pattern B in the upper left corner. This is because brightness abnormalities in CRT display devices occur at the end of the scanning line due to folding or reflection of the scanning line. This is because it does not occur only in some scanning lines.

FIG. 6 shows a detailed configuration diagram of the inspection device 3 shown in FIG. 1,
6 is a buffer for storing the observation test pattern obtained by the observation device 2; 7-1, 7-2, 7-3, 7-4, 7-5, 7-6, and 7-7 are buffers for storing the observation test pattern obtained by the observation device 2; It is used for inspection, and 7-1 is a brightness measurement unit that measures the maximum brightness of the planar pattern A excluding the scanning line terminal side (the rightmost end in FIG. 2) in the observed test pattern; 7-2
7-3 is a brightness measuring unit that measures the lowest brightness of the planar pattern A; 7-3 is a brightness measuring unit that measures the highest brightness of the striped pattern; and 7-4 is a brightness measuring unit that measures the lowest brightness of the striped pattern. , 7-5 is a subtraction unit that calculates the difference between the luminance obtained by the luminance measurement unit 7-1 and the luminance obtained by the luminance measurement unit 7-2, and 7-6 is a luminance measurement unit 7-3.
A subtraction unit 7-7 calculates the difference between the luminance obtained by the luminance measurement unit 7-4 and the luminance obtained by the luminance measurement unit 7-4.
A division section 8-1, 8-2, 8-3, and 8-4 calculates the ratio between the brightness difference obtained by 5 and the brightness difference obtained by subtraction section 7-6, and 8-1, 8-2, 8-3, and 8-4 calculate the amplitude deficiency and slope of the displayed image. 8-1 is a frame size measuring unit for measuring the outer frame size of the display surface of a CRT display device;
-2 is an image dimension measurement unit that measures the relative external dimensions of the displayed image with respect to the outer frame of the display surface according to pattern E in the observation test pattern; 8-3 is an actual dimension calculation unit that measures the actual external dimensions of the displayed image; 8-4 is a tilt/bias calculation unit that calculates the tilt and bias of a displayed image; 9-1, 9-2, 9-3, and 9;
-4 and 9-5 are used to test the non-linearity of the displayed image, and 9-1 is used to test the left parallel line pattern C or the upper parallel line pattern D in the observation test pattern. 9-2 is a spacing measuring section that measures the spacing; 9-2 is a spacing measuring section that measures the spacing between each line of the right parallel line pattern D or the lower parallel line pattern D in the observation test pattern; 9-3 is a spacing measuring section; 9-4 is an average value calculation unit that calculates the average value of the plurality of values obtained by the interval measurement unit 9-2; A calculation unit 9-5 represents the average value obtained by the average value calculation unit 9-3 and the average value calculation unit 9-4.
a division unit that calculates the ratio with the average value obtained by 10;
-1, 10-2, and 10-3 are used to inspect the brightness abnormality of the displayed image, and 10-1 is the planar pattern to the left of the striped pattern B at the upper left corner or the upper right corner in the observation test pattern. a brightness measurement unit that measures the brightness at A;
10-2 is a brightness measurement unit that measures the brightness in the planar pattern A on the right side of the striped pattern B at the upper left corner or the upper right corner in the observation test pattern;
0-3 is a division unit that calculates the ratio between the brightness obtained by the brightness measurement unit 10-1 and the brightness obtained by the brightness measurement unit 10-2; A memory that stores inspection reference values for brightness abnormalities;
Reference numeral 12 denotes a determination unit that determines whether or not there is an abnormality in image quality of the displayed image.

With the above configuration, the test pattern generator 4
A test pattern such as that shown in FIG. 2 in which the following occurs is displayed on the CRT display device 1. The control device 5 controls the observation position and observation field of the observation device 2 with respect to the display surface of the CRT display device 1, and observes a required pattern in the field of view according to the inspection item.

In other words, when inspecting for poor focusing,
As illustrated in b) or fc), the planar pattern A
and striped pattern B are enlarged and observed. Similarly, in the inspection of brightness abnormalities, the planar pattern A and the striped pattern B are enlarged and observed as illustrated in FIG. The entire test pattern is observed along with the outer frame of the display image 8- of the CRT display device 1, and the entire test pattern is observed when inspecting nonlinearity and brightness abnormalities.

The observation images observed in each case are stored in the -tan buffer 6, and the above-mentioned measurements and calculations are performed for each inspection item.The judgment unit 12 compares each calculation result with the inspection previously stored in the memory 11. A pass/fail judgment is made by comparing with a reference value.

(f) As described in detail, according to the present invention, it is possible to test for multiple types of image quality abnormalities in images displayed on a CRT display device using the same test pattern, thereby improving the efficiency of the test. Can be done.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of the present invention, Fig. 2 is a test pattern used in an embodiment of the present invention, Figs. 3, 4, and 5 are explanatory diagrams of how abnormal image quality appears. FIG. 6 shows a detailed configuration diagram of the inspection device, and FIG. 7 shows an example of a partially enlarged observation image of a test pattern. In the figure, 1 is a CRT display device, 2 is an observation device, 3 is an inspection device, and 4 is a test pattern generator. 11-Jo I Zuka 2 Figure 7 (a> (A) 515- (C)

Claims (1)

[Claims] A CRT display device, a vertical stripe displayed in at least one corner and approximately the center of the screen of the CRT display device, a wide focusing defect inspection pattern for measuring maximum brightness, and a predetermined width area on at least one of the left and right sides of the screen. A pattern generator that generates a test pattern consisting of a displayed brightness abnormality test pattern and a plurality of linear patterns for nonlinearity test, and observation that observes the display surface of a CRT display device on which the test pattern is displayed. and an inspection device for inspecting an observation test pattern obtained by the observation device, and the device is characterized in that a plurality of types of image quality abnormalities of the CRT display device are inspected using the one test pattern. An inspection device for CRT display images.