KR100210427B1 - Inspection apparatus for video graphic signal - Google Patents

Abstract

The present invention relates to an apparatus for inspecting a video graphic signal, which enables fast and accurate inspection of one pixel, that is, a pixel unit, which is a minimum unit of a screen without looking at a screen displayed on a monitor.

The present invention scans the color signals (R, G, B signals) to the monitor according to the graphic data generated in the test pattern, separates the color signals scanned by the monitor and compares the separated color data with the reference voltage, respectively. After detecting the color signal, the detected color signal is counted for one horizontal section, and color loss and saturation are examined as a result value. The extracted red, green, and blue signals are logically calculated and the result value is one horizontal level. Counting during the interval to check the color bleeding due to the phase change as a result value.

Description

Video Graphics Signal Inspector

1 is a waveform diagram of a general color signal (R, G, B) and a horizontal synchronization signal.

2 is a block diagram of a conventional video graphics signal inspection apparatus.

3 is a block diagram of a video graphic signal inspection apparatus according to the present invention.

4 is a waveform diagram of each part of FIG.

5 is a phase difference detection waveform diagram of R, G, and B signals in the comparison unit of FIG. 3, and (a) to (e) are detection waveform diagrams of R, G, and B signals when there is no phase difference. , (f) to (j) are detection waveform diagrams for R, G, and B signals when a phase difference exists.

* Explanation of symbols for main parts of the drawings

101: VGA card 103-105: first to third color signal extraction unit

106-108: First to third video graphics signal inspection unit

109: phase comparison unit 1 10: video graphics signal determination unit

The present invention relates to the inspection of R, G, B (red, green, blue) and horizontal and vertical signals, which are video graphic signals scanned by a monitor. The present invention relates to an apparatus for inspecting video graphics signals that enables fast and accurate pixel-by-pixel inspection.

In general, R, G, B (red, green, blue) signals, which are video graphic signals scanned by a monitor, are represented by the waveform shown in FIG.

Here, the number of color data appearing in the horizontal synchronizing signal is converted according to the graphic mode. In the graphic mode of 1024 * 768, 1024 color data appear after one horizontal synchronizing signal.

The voltage levels of the R, G, and B signals represent the saturation of the color.

That is, when the color is expressed in white on the monitor screen, the color data of R, G, and B are all at the high level, and when the color is represented in black, the R, G, and B are all at the low level. .

By adjusting and mixing the levels of these R, G and B, color combinations such as 16 colors and 256 colors can be made.

The most common method for inspecting the defects of the R, G, and B signals described above is a method of detecting defects such as cracking of the screen and color bleeding while the monitor is visually observed. The device is used to examine the R, G and B signals, which are video graphics signals.

That is, first, the test pattern generator 1 generates graphic data for inspecting a video graphic signal, and the generated graphic data causes red, green, and blue colors on the screen of the monitor 3 in the VGA card 2. Scan the combined video graphics signal.

At this time, the test pattern generator 1 stores the data value of the test pattern in the first memory 4 in advance.

In addition, when the R, G, B signals are output from the VGA card 2, the analog switch 5 sequentially switches the R, G, B signals at a predetermined period and transfers them to the analog / digital converter 6, and the analog / The digital converter 6 converts the transmitted analog R, G and B signals into corresponding digital R, G and B signals and stores the same in the second memory 7.

Thereafter, the comparison unit 8 compares the R, G, B signal data values, which are the test patterns stored in the first memory 4, with the detected R, G, B signal data values stored in the second memory 7, If it is the same value, it is determined that it is good, and if it is different from each other, it is determined as bad.

However, the first inspection method of the conventional video graphics signal inspection method is to visually check the display state of the screen and determine the quality / defect, which is the easiest inspection method or one pixel for inspecting screen cracks and color bleeding. It is difficult to determine whether or not the pixel is defective, and it is more difficult to determine the degree of saturation (saturation) of the color.

The second test method accurately reads the levels of red, green, and blue to determine the color, so the accuracy is very high. However, all color data must be converted into an analog / digital converter without any missing, so a very high-speed analog / digital converter and a large amount of memory In addition, there is a disadvantage in that it is necessary, and in addition, there is a disadvantage in that it is insufficient to cope with the speed of the graphic signal.

Accordingly, the present invention has been proposed to solve the above-mentioned problems occurring during the inspection of the conventional video graphic signal, and an object of the present invention is to display one pixel that is the minimum unit of the screen without looking at the screen displayed on the monitor. In other words, the present invention provides a video graphics signal inspection apparatus that enables fast and accurate pixel-by-pixel inspection.

Technical means for achieving the object of the present invention comprises: a VGA card for scanning color signals (R, G, B signals) to a monitor corresponding to graphic data generated in a test pattern; First to third color signal extractors for high-pass filtering the color signals scanned by the monitor and comparing the filtered color data with reference voltages, respectively, and outputting the resultant signals as detected color signals; Logically compute the red, green, and blue signals and the phase-inverted horizontal registration signals extracted by the first to third color signal extractors, respectively, and counter the result for one horizontal period, and convert the result value into each color data check value. A first to third video graphic signal inspecting unit for outputting; A phase comparison unit for performing a logical operation on the red, green, and blue signals extracted by the first to third color signal extraction units, counting the result values, and outputting a result value as a color bleeding inspection value due to a phase change; The video graphics signal determination unit determines color missing and color defect of the video graphics signal using the count values output from the first to third video graphic signal inspecting units, and determines the color bleeding using the count values output from the phase comparator. Is done.

Hereinafter, described in detail with reference to the accompanying drawings of the present invention.

3 is a block diagram of an apparatus for inspecting a video graphic signal according to the present invention.

As shown, the test pattern generator 100 outputs graphic data for searching for abnormality of the video graphic signal, and the video graphic signal (red, according to the graphic data generated by the test pattern generator 100). The high frequency filtering of the VGA card 101 scanning green and blue signals) to the monitor 102 and the color signals scanning to the monitor 102, and comparing the filtered color data with reference voltages respectively. Red, green, and blue signals extracted by the first to third color signal extractors 103-105 and the first to third color signal extractors 103-105 respectively, which output signals as detected color signals. And first to third video graphic signal inspecting units 106-108 for performing a logical operation on the horizontally inverted horizontal sync signal and counting the result for one horizontal period, and outputting the result as each color data check value. 1 to the third color A phase comparator 108 for performing a logical logic operation on the red, green, and blue signals extracted by the call extracting units 103-105, counting the result values, and outputting the result values as color blurring check values due to a phase change; Color missing and color defect of the video graphic signal are determined by count values output from the first to third video graphic signal inspecting units 106 to 108, and color is spread to the count values output from the phase comparator 108. It consists of a video graphics signal discrimination unit 109 for determining.

The operation and effects of the video graphic signal detection apparatus according to the present invention configured as described above will be described with reference to FIGS. 4 and 5.

First, the test pattern generator 100 generates graphic data to check R, G, and B signals, which are video graphic signals.

The generated graphic data causes the VGA card 101 to scan a video graphics signal, such as (a) of FIG. 4, to the monitor 102, where the high portion of the test pattern is white and low. ) Part is black.

The test pattern can be changed according to the inspection conditions, and can be simply generated by a personal computer (PC) or the like.

When the video graphic signal of the test pattern is output as described above, the high pass filter 103a in the first color signal extraction unit 103 passes only the high pass component of the R signal among the generated R, G, and B signals ((b) of FIG. Waveform), and the comparator 103b compares the signal through the high pass filter 103a with a preset reference voltage Vref for level comparison and outputs the resulting signal, where the output from the high pass filter 103a is performed. If the signal is greater than the reference voltage (Vref) outputs a high signal (5V), otherwise, if the signal through the high-pass filter 103a is less than the reference voltage (Vref) to output a low signal (0V) do.

In other words, when the phases are the same with respect to the detection level of the R signal in the test pattern, the first color signal extracting unit 103 generates a shaped pulse as shown in FIG. It generates a pulse shaped like f).

In addition, the second color signal extraction unit 104 also passes only the high frequency component of the G signal among the R, G, and B signals generated by the high pass filter 104a, and the comparator 104b passes the signal through the high pass filter 104a. The level signal is compared with a preset reference voltage Vref for level comparison, and the resultant signal is output. Here, the comparator 104b also outputs a high signal when the signal output from the high pass filter 104a is greater than the reference voltage Vref. When the signal through the high pass filter 104a is smaller than the reference voltage Vref, the low signal 0V is output.

That is, the second color signal extracting unit 104 generates a standardized pulse as shown in (b) of FIG. 5 when the phases are the same with respect to the detection level of the G signal in the test pattern. It generates a shaped pulse as shown in (g).

Similarly, the third color signal extractor 105 also passes only the high frequency component of the B signal among the R, G, and B signals generated by the high frequency filter 105a, and passes the signal through the high frequency filter 105a to the comparator 105b. For comparison of the level, the signal is compared with the preset reference voltage Vref and the resultant signal is output. Here, the comparator 105b also outputs a high signal when the signal output from the high pass filter 105a is greater than the reference voltage Vref. When the signal through the high pass filter 105a is smaller than the reference voltage Vref, the low signal 0V is output.

Accordingly, the third color signal extracting unit 105 also generates a shaped pulse as shown in (d) of FIG. 5 when the phase is the same with respect to the detection level of the B signal in the test pattern. It generates a standardized pulse like (i).

When the detection signal is output for each of the R, G, and B signals, the first to third video graphic signal inspection units 106 to 108 count the detected signal during the 1H section and output the result value. Done.

That is, the first video graphic signal inspecting unit 106 phase inverts the horizontal synchronizing signal generated by the VGA card 101 to the inverter 106a, and the phase inverted horizontal synchronizing signal and the first color signal extracting unit. The R signal C1 extracted at 103 is logically multiplied by the AND gate 106b. As a result, the signal is applied to the counter 106c in a waveform as shown in FIG.

Then, the counter 106c counts the input signal during the 1H period and applies the result value to the video graphic signal discrimination unit 110.

In addition, the second video graphic signal inspection unit 107 also uses the end gate 107a to convert the horizontal synchronization signal phase-inverted from the inverter 106a and the G signal C2 extracted from the second color signal extraction unit 104. The result is logical multiplication, and the result is a signal applied to the counter 107b.

Then, the counter 107b counts the input signal during the 1H period and applies the result value to the video graphic signal discrimination unit 110.

In addition, the third video graphic signal inspecting unit 108 also performs a horizontal analysis signal phase-inverted by the inverter 106a and an B signal C3 extracted by the third color signal extraction unit 105. The result is logical multiplication, and the result is a signal applied to the counter 108b.

The counter 108b then counts the input signal during the 1H period and applies the result to the video graphics signal discrimination unit 110.

Then, the video graphic signal discrimination unit 110 searches for counting values of the input video graphic signals R, G, and B, respectively, to determine color missing or color defect of the video graphic signal.

In other words, as shown in (a) of FIG. 4, when a test pattern in which white and black are alternated is scanned in a graphic mode of 1024 * 768, 512 logic highs and 512 lows are displayed during the 1H (single line) section (1024 pixels) of the screen. An open pulse is generated.

If the count is 512, the video graphic signal discrimination unit 110 searches the counted values for each of the R, G, and B signals, and if the counting value is 512, it is determined as good. If the counting value is 512 or less, Discrimination is caused by missing or poor color.

Next, the phase comparator 109 performs an AND gate on the signal C1 output from the first color signal extractor 103 and the signal output from the second color signal extractor 104 to check color blurring. Multiplying by 109a and outputting the resultant signal as shown in (c) or (h) of FIG. 5, and the signal C3 extracted by the third color signal extracting section 105 is buffered by the buffer 109b. Will print.

Then, the output signal of the AND gate 109a and the output signal of the buffer 109b are exclusive-ORed to the exclusive logical sum element 109c, and the resultant signal is converted into a signal as shown in (e) or (j) of FIG. ) Will be entered.

Then, the counter 109d counts the input signal and transfers the count value to the video graphic signal discrimination unit 110. The video graphic signal discrimination unit 110 determines the color bleeding by searching the count value. .

That is, the phase comparison unit 109 causes the pulse corresponding to the phase difference to be generated as (j) when the phases of the pulses output from the first color signal extraction unit 103 and the second color signal extraction unit 104 are different. On the other hand, when the phases are the same, a signal without a waveform is generated as shown in (e), so that color blur can be determined by the phase difference.

As described above, the present invention accurately inspects defects such as color darkening (saturation), color bleeding, and color missing (broken screen) on R, G, and B signals in pixels that are difficult to be distinguished by the human eye. It can work.

In addition, since the video graphic signal inspection method is an inspection method for counting pulses due to the level difference of the test pattern, the video graphics signal inspection method has an advantage that the speed is faster than the conventional method of reading and inspecting the level value.

Claims (9)

A VGA card 101 for scanning color signals (R, G, B signals) to the monitor 102 in accordance with graphic data generated in the test pattern; A first to high pass filtering of each color signal R, G, and B scanned by the monitor 102, and comparing the filtered color data with a reference voltage, respectively, and outputting the resulting signal as a detected color signal. A third color signal extracting unit (103-105); The red, green, and blue signals extracted from the first to third color signal extractors 103 to 105 and the horizontal inverted horizontal synchronization signals are respectively logically calculated, and the result values are counted for one horizontal period. First to third video graphic signal inspection units 106 to 108 outputting the color data inspection values of the first and third video graphics signals; Phases for logically calculating red, green, and blue signals extracted by the first to third color signal extracting units 103-105, and counting the result values to output the result values as color bleeding check values due to a phase change. A comparator 109; Color missing and color defect of the video graphic signal are determined by count values output from the first to third video graphic signal inspecting units 106 to 108, respectively, and color is spread to the count values output from the phase comparator 109. And a video graphic signal discrimination unit (110) for determining the video graphic signal inspection apparatus. The first color signal extracting unit 103 is a high pass filter 103a for high pass filtering the R signal output from the VGA card 101, and a signal output from the high pass filter 103a. And a comparator (103b) for comparing a preset reference arm (Vref) for level comparison and outputting a signal as a result. The second color signal extractor 104 further includes a high pass filter 204a for high pass filtering the G signal output from the VGA card 101 and a signal output from the high pass filter 104a. And a comparator (104b) for comparing a preset reference voltage (Vref) for level comparison and outputting a signal as a result. The third color signal extractor 105 further includes a high pass filter 105a for high pass filtering the B signal output from the VGA card 101, and a signal output from the high pass filter 105a. And a comparator (105b) for comparing a preset reference voltage (Vref) for level comparison and outputting a signal as a result. The inverter of claim 1, wherein the first video graphic signal inspection unit 106 phase-inverts the horizontal synchronization signal output from the VGA card 101, an output signal of the inverter 106a, and the first signal. An AND gate 106b for ANDing the R signal C1 output from the one color signal extracting unit 103, and a counter 106c for counting the output signal of the AND gate 106b for one horizontal section and outputting the result value. Video graphics signal inspection device, characterized in that consisting of. The questionnaire 107a of claim 1, wherein the second video graphic signal inspecting unit 107 logically multiplies the phase inverted horizontal synchronizing signal and the G signal C2 output from the second color signal extracting unit 104. And a counter (107b) for counting the output signal of the AND gate (107a) for one horizontal section and outputting the result value. The questionnaire 108a of claim 1, wherein the third video graphic signal inspector 108 logically multiplies the phase-inverted horizontal sync signal by the B signal C3 output from the third color signal extractor 105. And a counter (108b) for counting the output signal of the AND gate (108a) for one horizontal section and outputting the result value. The phase comparator 109 of claim 1, wherein the phase comparator 109 comprises an AND gate 109a for logically multiplying (C1) and C2 output from the first and second color signal extractors 103 and 104, respectively. The result signal is obtained by exclusively ORing the buffer 109b for buffering the signal C3 output from the third color signal extracting unit 104, the output signal of the buffer 109b, and the output signal of the AND gate 109a. And a counter 109d for counting the output signal of the exclusive logic sum element 109c for the one horizontal section and outputting the result as a color bleed discrimination value. Signal inspection device. The apparatus of claim 1, wherein the video graphic signal discrimination unit 110 searches for counting values output from the first to third video graphic signal inspection units 106 to 108 when the test pattern is a graphic mode of 1024 * 768. And if the counting value is 512, the video graphics signal is judged to be good, and if the counting value is 512 or less, the video graphics signal inspection device is discriminated.