KR0183736B1 - Method of judging photo sensor arrangement of cathode ray tube picture - Google Patents

Abstract

The present invention relates to a method of determining an alignment state of a photo sensor on a screen with a cathode ray (CRT), the method comprising: applying a predetermined pattern to square up and add a change amount of the photo sensor output on an effective screen; A second step of applying the pattern to square and add a change amount of the optical sensor output on a boundary line; A third step of dividing the sum value of the second step by the sum value of the first step and setting the square root as a reference value; A fourth step of applying the pattern to square and add a change amount of the optical sensor output to be recognized; A fifth step of dividing the sum value of the fourth step by the sum value of the first step and setting the square root as a comparison target value; And a sixth step of determining that if the comparison target value of the fifth step is larger than the reference value of the third step, the optical sensor to be recognized matches the valid screen, and if the comparison target value of the fifth step does not match the valid screen. As a feature, it is possible to confirm whether the optical sensors used in the screen inspection using the optical sensor are matched on the effective screen, thereby increasing the accuracy of the inspection.

Description

How to determine the alignment of cathode ray and light sensor on screen

1 is a schematic diagram of a convergence inspection system applied to an embodiment of the present invention.

2 is a pattern control diagram based on FIG.

3 is an example of a reference light sensor layout for the target screen.

4 shows the number of cases in which the light sensors can be aligned.

FIG. 5 is a graph of the output of the optical sensor aligned at position S5 of FIG.

FIG. 6 is a graph of the output of the photosensors aligned at positions S3, S4 and S6 of FIG.

FIG. 7 is a graph of the output of the optical sensor aligned to the position S1 of FIG.

FIG. 8 is a graph of the output of the optical sensor aligned at position S2 in FIG.

FIG. 9 is a diagram in which FIGS. 5, 6, 7, and 8 overlap.

10 is a flowchart for implementing an embodiment of the present invention with a plurality of reference light sensors.

* Explanation of symbols for main parts of the drawings

1: computer 1a: CPU board

1b: DSP board (Digital Signal Processor board, 1b)

2 ; Pattern Generator

3: Cathode Ray Tube

4: photo-sensor array

5: Data Acquisition board

6: Monitor 6a: Photo-sensor

6b: Black pattern 6c: Valid screen

6d: Backraster area

6e: monitor cabinet

6f: light source S1: position on the effective screen

S2: Position on the boundary between the effective screen and the back raster

S3: Position on the back raster area S4: Position on the monitor cabinet

S5: away from the monitor and close to the light source

S6: away from the monitor and away from the light source

The present invention relates to a method for determining an alignment state of a photo sensor on a screen with a cathode ray (CRT), and in particular, a method for confirming whether the light sensors used for screen inspection using the light sensor are matched on an effective screen. It is about.

Examples of inspecting the cathode ray and the screen using an optical sensor include inspection of convergence, color purity, and geometric characteristic. Especially in factories that produce cathode ray tubes or cathode ray tubes such as computer monitors and color televisions, the convergence of the screens must be adjusted to accurately reproduce the color of the screen. In the past, convergence was adjusted as a visual inspection, but nowadays a convergence inspection system using a camera or a sensor is emerging.

When the cathode ray and the screen are inspected using the optical sensor as described above, conventionally, the process of checking whether the optical sensors used in the screen inspection are matched on the effective screen is not performed. Accordingly, when the optical sensors deviate from the effective screen, the accuracy of the inspection is lowered. For example, in the case of examining dynamic convergence, optical sensors are arranged on the outer side of the effective screen in order to detect a lot of misconvergence. Therefore, the probability that the optical sensors deviate from the effective screen is increased, and the accuracy of the inspection is reduced. In particular, in the case of a calibration that is a standard of convergence measurement, for example, a calibration for obtaining a unit length (mm / pixel) per pixel, the problem can be greatly highlighted.

The present invention was devised to improve the above problems, and an object thereof is to provide a method for confirming whether optical sensors used in screen inspection using an optical sensor are matched on an effective screen.

In order to achieve the above object, a method of determining an alignment state of an optical sensor on a cathode ray tube screen according to the present invention includes: a first step of applying a predetermined pattern to square the amount of change of the optical sensor output on an effective screen; A second step of applying the pattern to square and add a change amount of the optical sensor output on a boundary line; A third step of dividing the sum value of the second step by the sum value of the first step and setting the square root as a reference value; A fourth step of applying the pattern to square and add a change amount of the optical sensor output to be recognized; A fifth step of dividing the sum value of the fourth step by the sum value of the first step and setting the square root as a comparison target value; And a sixth step of determining that the optical sensor, which is the recognition target, matches the valid screen when the comparison target value of the fraud fifth step is larger than the reference value of the third stage, and does not match the valid screen when the comparison target value is small. It is characterized by.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present embodiment relates to a method of determining the alignment state of an optical sensor on a cathode ray tube screen during a convergence test.

1 is a schematic diagram of a convergence inspection system applied to an embodiment of the present invention. As shown, the convergence test system is basically a computer (1) with a CPU board (1a) and a DSP (Digital Signal Processor board, 1b), a pattern generator (2), a photo-sensor array 4) and Data Acquisition board (5). The CPU board 1a manages and controls the whole system by the built-in program. The pattern generator 2 serves to apply a predetermined pattern signal to the target CRT 3 according to a control command from the CPU board 1a. The optical sensor array 4 reads out video information from the target CRT 3, that is, a luminance value, in accordance with a control command from the CPU board 1a. The data acquisition board 5 converts the analog signal from the photosensor array 4 into a digital value and then transfers the maximum value and the integral value to the DSP board 1b. The DSP board 1b processes the maximum value and the integral value and transmits a value corresponding to the relative phase difference between the red (R), green (G), and blue (B) beams to the CPU board 1a. do.

In the convergence checking system operating with the above functions, the following functions should be added to implement one embodiment according to the present invention. That is, a program based on the embodiment to be described below should be added to the program embedded in the CPU board 1a so as to check whether the light sensor matches the effective screen and inform the operator of the information. The pattern generator 2 also allows the black pattern and the white pattern to be generated alternately for a predetermined number of times. 2 is a pattern control diagram based on FIG. As shown, the CPU board 1a and the pattern generator 2 perform RS232C communication, and black and white patterns are alternately generated according to a control signal from the CPU board 1a, thereby providing an image input terminal of the cathode ray tube. Is applied to. Reference numeral 2a denotes an RS232C interface board in the pattern generator 2. Three optical sensors 6a are adjusted on the effective screen and black pattern 6b is applied to the target monitor 6 in FIG.

By applying the convergence inspection system as described above, the method of determining the alignment state of the light sensor on the cathode ray and the screen can be implemented by the following process.

First, the reference light sensor must be precisely matched on the effective screen with the reference cathode ray. 3 is an example of a reference light sensor layout for the target screen. In FIG. 3, although 25 reference optical sensors 6a are set, they can be adjusted arbitrarily. The nine central optical sensors are for calibration, and the number can be arbitrarily adjusted. 4 shows the number of cases in which the light sensors can be aligned. A symbol S1 is a position on the valid screen 6c, a symbol S2 is a position on the boundary line between the valid screen 6c and the backraster area 6d, and a symbol S3 is out of the target monitor 6 and close to the light source 6f. The position and S6 deviate from the target monitor 6 and indicate a position far from the light source 6f. As can be seen from FIG. 4, it is not possible to determine whether or not the light sensors are aligned on the effective screen 6c based on the cut-off value. For example, the output of the optical sensor aligned with S5 is likely to be above the cutoff value.

Next, a predetermined black pattern and a white pattern are alternately applied to the reference cathode ray tube by the number of cases, and the output of the corresponding optical sensor is recorded. FIG. 5 is a graph of the output of the optical sensor aligned at position S5 of FIG. After aligning the optical sensor in the position S5 of FIG. 4, the black pattern and the white pattern were alternately applied to the reference cathode ray tube, and the output of the corresponding optical sensor was recorded. As a result, the black pattern or the white pattern was recorded. Irrespective of this, the maximum value Ymax of the predetermined luminance was turned. The reason is that the light energy due to the ambient light source (6f in FIG. 4) greatly acts on the optical sensor. FIG. 6 is a graph of the output of the photosensors aligned at positions S3, S4 and S6 of FIG. After aligning the optical sensor at the positions S3, S4 and S6 of FIG. 4, the black pattern and the white pattern were alternately applied to the reference cathode ray tube, and the output of the corresponding optical sensor was recorded. As a result, the minimum value Ymin of predetermined luminance was turned regardless of the black pattern or the white pattern. The reason for this is that the light sensor is aligned in an area deviating from the effective screen (6c in FIG. 4) and is not affected by light energy due to the surrounding light source (6f in FIG. 4). FIG. 7 is a graph of the output of the optical sensor aligned to the position S1 of FIG. After aligning the optical sensor at the position S1 of FIG. 4, the black pattern and the white pattern were alternately applied to the reference cathode ray tube, and the output of the corresponding optical sensor was recorded. As a result, when the black pattern was applied, the minimum value Ymin was rotated, and when the white pattern was applied, the maximum value Ymax was rotated. This is a normal result as the light sensor is aligned on the effective screen. FIG. 8 is a graph of the output of the optical sensor aligned at position S2 in FIG. After aligning the optical sensor at the position S2 of FIG. 4, the black pattern and the white pattern were alternately applied to the reference cathode ray tube, and the output of the corresponding optical sensor was recorded. As a result, when the black pattern was applied, the minimum value Ymin was rotated, and when the white pattern was applied, the intermediate value Ymid of the predetermined luminance was turned. This is the result of the light sensor being aligned on the boundary line between the effective screen and the back raster area.

FIG. 9 is a diagram in which FIGS. 5, 6, 7, and 8 overlap. As shown, the output function of the optical sensor aligned on the effective screen is Fref, and the output function of the optical sensor aligned on the boundary line between the effective screen and the back raster area is Fmid, The output function of the sensor is set to Fdc1 and the output function of the light sensor arranged in the bright area while leaving the effective screen is set to Fdc2. The Fdc1 and Fdc2 can be seen as a constant function, Fref and Fmid is a trigonometric function. After all, Fdc1 and Fdc2 can be ignored in the process of setting an algorithm using the output variation of the optical sensor because its derivative is close to 'zero'.

As described above, the reference optical sensor is precisely matched on the effective screen with the reference cathode ray, and then the black pattern and the white pattern are alternately applied to the reference cathode ray tube to record the output of the corresponding optical sensor. The same result can be achieved. Next, the change amount of the reference output recorded as shown in FIG. 7 is obtained. If this is expressed as an expression, F ' _{ref (t)} = F _{ref (t + 1)} -F _{ref (t)} . Here, F ' _{ref (t)} represents the amount of change in the reference output at time t. Based on the above formula, the change amount of the reference output has a sign of (+) or (-) indicating increase or decrease. Therefore, the change in each reference output is squared and summed. If you express it as a formula, Becomes Where N is the number of measurements.

Next, precisely match the reference light sensor on the effective screen with the reference cathode ray and the boundary line of the back raster area, and then apply the black pattern and the white pattern to the reference cathode ray tube alternately, and record the output of the corresponding light sensor. This results in the same result as in FIG. Next, the change amount of the reference output recorded as shown in FIG. 8 is obtained. Expressed as an expression, F ' _{mid (t)} = F _{mid (t + 1)} -F _{mid (t)} . Where F ' _{mid (t)} represents the amount of change in the reference output at time t. Based on the above formula, the change amount of the reference output has a sign of (+) or (-) indicating increase or decrease. Therefore, the change in each reference output is squared and summed. If you express it as a formula, Becomes Where N is the number of measurements.

Next, after dividing the Tot _Mid value by the Tot _Ref value, the square root is set to the reference value Cut _RefRate . If you express it as a formula Becomes

Next, while applying the black pattern and the white pattern alternately to the inspection cathode ray tube, the output variation of the optical sensor to be recognized is squared and summed. If you express it as a formula, Becomes Where k is the number of the optical sensor to be recognized and N is the number of measurements.

Next, after dividing the value of Tot (k) by the value of Tot _Ref , the square root is set to the comparison target value Com _value . If you express it as a formula, Becomes

As a result, when the comparison target value Com _value is larger than the reference value Cut _RefRate , it may be determined that the optical sensor that is the recognition target matches the valid screen, and when the comparison target value Com _value does not match the valid screen. That is, if the _value Cut Com _RefRate + α it is determined that the light sensor corresponds to an effective screen and Com _value ≤Cut _RefRate + α can be determined that the optical sensor is not matched to the effective screen. Α is set by experiment as a value reflecting the characteristics of the optical sensor. It is also possible to determine the relative position from the center of the effective screen while adjusting the actual α value.

The present invention is not limited to the above embodiment. For example, in order to improve the accuracy of the determination, a plurality of reference light sensors may be used in the process of obtaining the reference value. In this case, the Tot _Mid value and the Tot _Ref value are obtained by the number of reference optical sensors to be applied, and the precision of the determination can be improved by selecting the maximum value among them. 10 is a flowchart for implementing an embodiment of the present invention as a plurality of reference light sensors. As shown in the drawing, first, a plurality of reference light sensors are aligned on an effective screen of a reference cathode ray tube, and then an amount of change in output of each reference light sensor is obtained by alternately applying a white pattern and a black pattern. Next, the output variation is squared and summed, and a maximum value Tot _RefMax is selected from the sum values. In this case, a step of setting and comparing a predetermined default value may be added to cope with an unexpected error. For example, when the Tot _RefMax value is 60% or less of the default value, the default value may be replaced with the Tot _RefMax value. Next, after aligning the plurality of reference light sensors on the effective screen boundary line with the reference cathode ray, the process is repeated to _divide the Tot _MidMax value by the Tot _RefMax value and set the square root to the reference value Cut _refRate .

Next, the above process is performed on the optical sensor to be recognized, and the value of Tot (k) is obtained. Next, the Tot (k) value is divided by the Tot _RefMax value, and the square root thereof is set as the comparison target value Com _value . As a result, when the comparison target value Com _value is larger than the reference value Cut _RefRate , it may be determined that the optical sensor that is the recognition target matches the valid screen, and when the comparison target value Com _value does not match the valid screen. In other words it can be determined that the determination if the _value Cut Com _RefRate + α the photosensor corresponds to an effective screen, and if the _value Com ≤Cut _RefRate + α that the optical sensor is not matched to the effective screen. Α is set by experiment as a value reflecting the characteristics of the optical sensor. It is also possible to determine the relative position from the center of the effective screen while adjusting the actual α value. The result determined as described above is output and displayed on the monitor.

As described above, according to the method for determining the alignment state of the optical sensor according to the present invention, it is possible to confirm whether the optical sensors used in the screen inspection using the optical sensor are matched on the effective screen. ) Can be raised.

Claims (8)

A first step of applying a predetermined pattern to square and add a change amount of the optical sensor output on the effective screen; A second step of applying the pattern to square and add a change amount of the optical sensor output on a boundary line; A third step of dividing the sum value of the second step by the sum value of the first step and setting the square root as a reference value; A fourth step of applying the pattern to square and add a change amount of the optical sensor output to be recognized; A fifth step of dividing the sum value of the fourth step by the sum value of the first step and setting the square root as a comparison target value; And a sixth step of determining that if the comparison target value of the fifth step is larger than the reference value of the third step, the optical sensor to be recognized matches the valid screen, and if the comparison target value of the fifth step does not match the valid screen. Method for determining the alignment state of the optical sensor on the cathode ray tube screen characterized in that. The method of claim 1, wherein the pattern is output from a pattern generator of a convergence inspection system. The method according to claim 1, wherein the black pattern and the white pattern are alternated. The method of claim 1, wherein the effective screen boundary is a boundary line between the effective screen and the back raster area. A first step of applying a predetermined pattern to square the sums of the change amounts of the outputs with respect to the plurality of optical sensors on the effective screen, and then selecting a maximum value from the summed values; A second step of applying the pattern to the optical sensors on the effective screen boundary by summing squared variations of the respective outputs and selecting a maximum value from the summed values; A third step of dividing the maximum value of the second step by the maximum value of the first step and setting the square root as a reference value; A fourth step of applying the pattern to square and add a change amount of the optical sensor output to be recognized; A fifth step of dividing the sum value of the fourth step by the maximum value of the first step and setting the square root as a comparison target value; And a sixth step of determining that if the comparison target value of the fifth step is larger than the reference value of the third step, the optical sensor to be recognized matches the valid screen, and if the comparison target value of the fifth step does not match the valid screen. Method for determining the alignment state of the optical sensor on the cathode ray tube screen characterized in that. The method according to claim 5, wherein the pattern is output from a pattern generator of a convergence inspection system. The method of claim 5, wherein the pattern is a black pattern and a white pattern are alternating. 6. The method of claim 5, wherein the effective screen boundary is a boundary between the effective screen and the back raster area.