JPS6083080A - Frame detection for crt screen quality inspection - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (,11) Technical Field of the Invention The present invention provides a method for displaying a display screen of a CRT (cathode ray display tube) in a correct positional relationship relative to a display frame of a display device, and without distortion (display). CR7 automatically checks whether
CRTii! relates to a screen quality inspection method, and in particular makes it possible to detect the display frame, which serves as a reference for the double-sided quality inspection, without being affected by unevenness or shadows in the illumination system. The present invention relates to a frame detection method for one-sided quality inspection.

(b) Prior art and problems In the display devices used in various data processing devices using CRTs, including word processing sensors, the screen displayed on the CRT does not have the correct positional relationship relative to the display frame of the display device. When it is not displayed, the quality of the screen is significantly degraded.

For example, in a display device 1 for an information processing device as shown in FIG. It may be shifted one step lower or to the left or right with respect to display frame 4,
It is necessary that the screen 3 is not tilted or distorted. In home televisions, slight shifts or distortions on the screen may cause the user to notice a drop in quality, but it may cause some discomfort.
- In a u-processing display device, screen shifts, edges, and distortions deform displayed graphs, characters, and symbols, resulting in a significant deterioration of screen quality. This kind of screen shift,
Inspection of tilt and distortion is carried out after the CRT 2 is mounted on the display device 1. Conventionally, the above inspection was carried out only by inspectors or by visual observation.
l! ! ! It has been proposed that the one-sided quality inspection method be used to automatically perform the inspection without manual intervention. The outline of this CRT screen quality inspection method is as shown in Figure 1.
Since the dimensions of the screen 3 are determined, the display screen is observed with an observation device such as a television camera, and various determination amounts determined relative to the dimensions of the frame 4 and both sides 3 are measured, and the model of the display device 1 is determined. Accordingly, the quality of the display screen is determined based on a uniquely defined reference amount for each determination amount. The purpose of using the determination amount and the reference amount is to avoid being influenced by the distance, distance, etc. between the display device 1 and the observation device. In order to measure this determination amount, it is important to detect frame 4 as a reference, and in Japanese Patent Application No. 57-113566, the CRT 2 can be used without displaying anything and without projecting illumination light onto the screen of the CRT 2. It is proposed to use lighting that does not illuminate the area 4 and observe the area in the ζ frame. This is the housing part 5 of the display device 1.
This is because it is necessary to observe the straight line portion 6 with contrast in paint color, etc., and measure its dimensions. The tube surface and frame 4 of the CRT 2 are usually of a dark color, the housing portion 5 is a bright color, and the straight line portion 6 indicating the boundary between the frame 4 and the housing portion 5 is configured to be easy to detect. However, in reality, the view of this frame part δ (11) is often not always consistent and stable.Depending on the unevenness of the illumination and the direction of the illumination, shadows may be formed or reflections of the illumination may occur from the surface of the CRT 2. This is because a bright color is displayed on the observation line for measuring the determination amount in frame 4.

FIG. 2 is a diagram illustrating detection of frame 4. The frame 4 and the casing portion 5 are located on the line indicated by A-A' of the display device 1 in FIG.
When detecting the boundary line 6 with
6, it is explained that a gray level signal as shown in the same figure (C1) is obtained. In this case, the boundary position between the frame 4 and the housing part 5 is determined from the gray signal waveform indicating the boundary between the frame 4 and the housing part 5. 4
R and 4L can be detected clearly in U (ffl). Therefore, the frame size can be detected by measuring the range indicated by In reality, due to various reasons as mentioned above, the same figure (as shown in bl)
It is difficult to detect the waveform indicating the boundary between the frame 4 and the housing part 5)
A waveform of f′ appears. In particular, if there is a brightly colored symbol such as 7 in the frame 4, a waveform such as 7'' will appear, resulting in an error in detecting the boundary between the frame 4 and the housing portion 5.

(C) Purpose of the Invention The purpose of the present invention is to eliminate the above-mentioned drawbacks by providing a frame 4 and a housing portion 5.
Measure a certain range of the straight line part 6 representing the boundary between the straight line part 6 and
The object of the present invention is to provide a frame detection method for screen quality inspection in which the frame 4 can be detected stably by adding the grayscale values of the image for a plurality of pixels in a direction parallel to the CRi.

(d) Structure of the Invention The structure of the present invention includes a CRT display device, a test pattern generating means for generating a test pattern on the CRT display device, and a standard for determining screen quality that is installed in the CRT display device. a reference member forming a line; an observation means for observing both the test pattern I:〆(βi'!++ +A and outputting data of the reference line and the test pattern image;
A means for calculating a determination amount based on the relative interval l(i,,% ratio) on the reference line from the data of the reference line and the Nast pattern image, and a quality determination method for determining the presence or absence of screen quality defects from these determination amounts. In the CR1 screen quality inspection method having a determination means, means is provided for calibrating the frame size which is a reference when calculating the determination amount.

(e) Embodiment of the invention FIG. 3 is a diagram for explaining the invention in detail. In order to measure the position of the straight line 9° indicating the boundary between the frame 4 and the housing portion 5 included in the rectangular area shown in FIG. , before determining the position of straight line 9' from the change in density of each pixel, check the reflections from parts other than straight line 9' (for example, f81% as shown in 7 in Figure 2).
9', avoid the influence of 9'. To do this, first scan the rectangular area 9 in a direction parallel to the straight line 9°, and then line up the sum of the gray values of the respective pixels in the direction orthogonal to the straight line 9°. The island pattern shown (called the projection pattern) is (given).

This projection pattern is not a shading value of only one line in the direction orthogonal to the straight line 9 as explained in Fig. 2, but
Multiple iI from to Y2! Since it is the sum of the shading values of the lil element, the influence of partial reflection is suppressed, and a continuous straight line 9'' appears as a clear change in shading as shown in Figure 3d.However, from this projection pattern, Since it is difficult to determine the exact frame position if the frame part of the object to be measured is tilted, this position is set as a temporary frame W3:.Then, after that, the second As explained in the figure, by scanning in the direction perpendicular to the straight line 9゛,
We will determine the position of the straight line 9゛, but at that time,
As shown in the figure, when several positions (positions as shown by 7') that are candidates for the frame appear, the position that falls between the tentative frame positions is determined as the true frame position. Although only the position determination of the straight line 9° of the rectangular portion 9 has been described, the same applies to the straight line portions 8', IO', and II' of the rectangular portions 8, 10, and 11.

Then, from the straight lines 8'' and 9'', the width X is 10'' and 11'', so the width Y is 1ui.

FIG. 4 is a block diagram of a circuit showing one embodiment of the present invention. First, a frame/screen observation switching instruction signal is sent from the control section 20, the illumination section 50 illuminates the frame part of the display device 1 so that it can be detected, and an observation position instruction signal is sent to the observation section 21, as shown in FIG. Observe the rectangular area shown. The control section 20 sends out a temporary scanning/actual scanning switching signal to change the image signal to the J switching section 22.
Then, the measured waveform of the rectangular area is stored in the frame area storage buffer 23. The projection pattern creation circuit 24 reads measurement waveforms from the frame area storage buffer 23, and generates a plurality of image waveforms between Y) and Y2 for rectangular areas 8 and 9 in FIG. 3, and X1 to X1 for rectangular areas 10 and 11. Add multiple image waveforms between X2.

In this case, even if there is a brightly colored symbol as shown by 7, the reflected waveform 7' will appear to be in the upper range and will not be noticeable. Therefore, rI! of the waveform 1 shown in FIG. 3 ft11! An II image signal is obtained. The edge detection circuit 25 detects the X and Y dimensions in FIG. 3 from the image discharge and determines a temporary frame position. The temporary frame position is the temporary frame position information storage section 2G! This is stored. The control unit 20 switches the image signal switching unit 22 and changes the observation position of the observation unit 21 according to the observation position instruction signal,
Image signals for one line each at the horizontal center and the vertical center of the first drawing surface 3 are stored in the line buffer 27. The edge detection circuit 28 reads an image signal as shown in ff52 (fb) from the line buffer 27, detects the frame size, and detects the frame /ii! +i-plane switching section All 29 side-cuts are stored in the edge information storage section 30. The frame information detection unit 32 refers to the output of the temporary frame position information storage unit 2G and detects the 1ζ frame edge information storage unit 30.
If an incorrect frame size is detected by the waveform shown by 7゛, it is corrected and the true frame size is adjusted to the screen position (i-displacement detection unit 34 and iI!ji plane) force detection t++: 35
Send to.

Next, the illumination 50 is turned off and a test pattern is displayed on the CRT 2 of the display device 1. The view 71111 part 21 is located between the center and α of the screen 3 in the horizontal direction in order to obtain the judgment amount from the test pattern.
The line buffer 27, edge detection circuit 28, frame/screen switching unit 29
Then, the grid position for each line is stored in the grid edge information storage unit 3]. The lattice information detection section 33 determines the spacing between the lattices and sends it to the lattice spacing detection section 36. Screen position shift detection unit 34
The judgment amount obtained by scanning the test pattern is sent to the plasterer 1537, the center is+', ss, and the right part 39, and is held/extracted. The screen position deviation determination unit 46 determines the deviation of the center positions of both sides and the aspect of screen inclination, and causes the establishment display unit 49 to display the sending determination result. Screen size detection section 3
5, similarly, each determination amount is sent to the left portion 40, center portion 41, and right portion 42 and held therein. Image 1f+iN method distortion determination unit 4
7 indicates the presence or absence of vertical amplitude distortion and horizontal pincushion by 41+1
The output of 49 people is sent to the judgment display section at a constant rate, and the judgment results are displayed. The grid spacing detection section 36 sends the average value of each grid spacing to a second section 43, a center section 44, and a lower section 45, where it is held.
I'm selling. The linear distortion determination section 48 determines the mode of vertical linear distortion from these average values and sends it to the determination table board 49 to display the determination results.

Next, the observation unit 2j vertically scans the center and one line of the left and right hooks at a position close to m11 of the screen; In this case, left parts 37 and 40, right parts 39 and 4
2. The upper part 43 and the lower part 45 are indicated by the names in parentheses.

As explained above, the present invention detects the frame dimensions that serve as a reference when performing CRi' dual quality inspection automatically. Since this can be performed reliably by eliminating the effects of reflections from bright colors such as design figures and reflections from the lighting system, more reliable quality inspection can be performed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a display device, FIG. 2 is a diagram explaining frame detection, FIG. 3 is a diagram explaining details of the present invention, and FIG.
The figure is a block diagram showing one embodiment of the present invention. 2 is a display device, 2 is a CRi'', 3 is a screen, 4 is a frame, 5 is a housing part, 21 is an observation part, 22 is an image signal switching part, 23
24 is a frame area storage buffer, 24 is a projection pattern creation circuit,
25 is an edge detection circuit, 26 is a temporary frame position information storage unit, 2
7 is a line buffer, 28 is an edge detection circuit, 29 is a frame/screen switching section, 30 is a frame edge information storage section, 31 is a lattice edge information storage section, 32 is a frame information detection section, 33 is a lattice information detection section, 34 35 is a screen size detection unit, 36 is a grid spacing detection unit, 37 and 40 are on the left, 3
8.41.44 is the center part, 39.42 is the right part, 43 is the upper part, 45 is the lower part, 46 is the screen position deviation determination part, 47 is the screen dimension distortion determination HUB, 48 is the linear distortion determination part, 49 is the determination part The display section and 50 are lighting. Kaya 1 Dosun 3 Garden

Claims (1)

[Claims] c R'r display device, test pattern generating means for generating a test pattern on the CRT display device, and the CRT display device;
a reference member that is installed in the RT display device and forms a reference line for determining whether the screen quality is good or bad; an observation means that observes the test pattern and the reference member and outputs data of the reference line and the Nast pattern image; CRTi8 includes means for calculating a determination amount based on the relative interval ratio of the reference line from the data of the reference line and the test pattern image, and a quality determination means for determining the presence or absence of screen quality defects from these determination amounts.
! ! In the i-side quality inspection method, a CRTllIj 1-side product 5! is characterized in that it is provided with means for calibrating frame dimensions that serve as a reference when calculating the determination amount. lj inspection frame detection method.