KR100910593B1 - Faulty pixel detecting method and faulty pixel detecting system for led electric sign board - Google Patents

Abstract

A faulty pixel detecting method and faulty pixel detecting system for an LED electric sign board are provided to exchange the faulty cell in use by determining a cell which is intersected with a vertical line and a horizontal line as the faulty cell. A faulty pixel detecting method and faulty pixel detecting system for an LED electric sign boar are comprised of the steps: turning on pixels comprising an LED display panel by a horizontal line unit(S40); measuring horizontal line luminance value at each horizontal line(S41); determines whether the measured horizontal line luminance value is included within a reference luminance value or not(S42); and If the horizontal line luminance value is out of range of reference luminance range, a corresponding horizontal line is determined as a faulty line(S43).

Description

DEFECTIVE METHOD AND FAULTY PIXEL DETECTING SYSTEM FOR LED ELECTRIC SIGN BOARD

The present invention relates to a bad pixel detection method and a bad pixel detection device of an LED sign, and more particularly, to a bad pixel detection method and a bad pixel detection of an LED sign that can detect a bad pixel in units of pixels on the entire screen of the LED sign. Relates to a device.

LED (Light Emitting Diode) refers to a light emitting diode that emits light, and is widely used in various electronic products and electronic display panels such as instrument panels in various colors such as red, green, blue, and yellow.

Among these, the LED display board arranges a plurality of LEDs in a matrix form, and a plurality of LEDs arranged in a matrix form a pixel for displaying an image, thereby displaying an image. Such LED signboards are installed and used in various forms outside or inside the building for advertisement or delivery of various information.

Typically, the entire screen of the LED signboard, as shown in Figure 1, is composed of N × M pixels, one pixel is composed of a red LED, a green LED and a blue LED to determine whether the light emission and the emission intensity of each LED Therefore, full color is realized. That is, by selectively turning on the LEDs constituting each pixel in accordance with image data applied from an image source such as a computer, various texts, pictures, and moving images are displayed.

Defective pixels may occur due to a problem in the manufacturing process of the LED display board or a failure of the LED itself, or a disconnection or short circuit of a wire connected to supply power to each LED. Such defective pixels act as a factor of degrading the image quality of the LED display. In order to replace the defective pixels during the manufacturing process or use of the LED display board, the process of detecting the defective pixels among all the pixels constituting the entire screen of the LED display board must be preceded.

Korean Patent No. 0815587 discloses a failure detecting apparatus for a light emitting diode dot matrix module capable of detecting a bad pixel. The failure detecting apparatus disclosed in the Korean Patent Registration discloses a main controller for outputting data and control signals; It is provided with a normal mode and a sensing mode, each open if a short / open abnormality occurs in at least one light emitting diode of the LED dot matrix module to receive data and control signals from the main controller and output display information in the normal mode or the sensing mode. / Including a detection unit for outputting the sensing information corresponding to the short / short to the main control unit, by detecting the open / short and the normal state of the light emitting diodes corresponding to various operation modes, the current operation of the light emitting diodes and LED dot matrix module I can confirm the state .

However, in the case of the failure detection device disclosed in the Korean Patent Registration, there is a disadvantage in that a separate circuit configuration is added in order to detect a failure in the LED display board, which increases the manufacturing cost, and an error such as a failure occurs in the failure detection device itself. In case of occurrence, there is a disadvantage in that detection of defective pixels is impossible.

In addition, in the manufacturing process of the LED display board, the LED module is manufactured in n × m, for example, 16 × 16 units, and then the plurality of LED modules are arranged in a matrix to form the entire screen of the LED display board. In order to measure the luminance in the LED module unit, and if the measured luminance is out of a predetermined range, it is determined that the defective LED module is used, and then the defective pixel inside the corresponding LED module is found.

Here, although it is more accurate to measure luminance in pixel units to detect bad pixels, measuring luminance in LED module units is technically difficult to measure luminance in pixel units, and requires a lot of cost and time. Considered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a bad pixel detection method and a bad pixel detection apparatus of an LED light plate that can detect bad pixels without adding a separate circuit configuration in the LED light plate. The purpose is.

According to the present invention, in the method for detecting a bad pixel of the LED sign, (a) lighting the pixels constituting the LED sign in units of horizontal lines, and measuring the horizontal line luminance value for each horizontal line Wow; (b) lighting the pixels constituting the LED display board in a vertical line unit and measuring vertical line luminance values of the vertical lines; (c) determining whether the measured horizontal line luminance values and the measured vertical line luminance values deviate from a preset reference luminance range; and (d) determining the pixel at the position where the horizontal line and the vertical line intersect with the horizontal line luminance value and the vertical line luminance value that are outside the reference luminance range as the defective pixel. It is achieved by the pixel detection method.

Here, in the steps (a) and (b), the horizontal line luminance value and the vertical line luminance value are the luminance of the image data obtained by photographing the camera in the state of being lit in units of the horizontal line and the vertical line. It is characterized in that it is measured according to the value.

On the other hand, the above object is, according to another embodiment of the present invention, in the bad pixel detection device of the LED display panel, comprising: a luminance measuring unit for photographing the screen of the LED display plate; A data storage unit for storing information on a reference luminance range; The luminance measuring unit controls the screen of the LED display board while the pixels constituting the LED display board are controlled to blink in a horizontal line unit and a vertical line unit, and the LED display plate is turned on in the horizontal line unit and the vertical line unit, respectively. Control to capture an image, and detect a horizontal line luminance value for each horizontal line and a vertical line luminance value for each vertical line based on the horizontal line unit and the image data captured in the horizontal line unit from the luminance measuring unit. And determining whether to deviate from a preset reference luminance range among the horizontal line luminance value and the vertical line luminance value, and horizontal and vertical lines corresponding to the horizontal line luminance value and the vertical line luminance value outside the reference luminance range. Bad pixel detection control which judges the pixel of this intersection position as bad pixel By the bad pixel detection device of the LED display comprising: a is achieved.

Here, the data storage unit for storing the information about the reference luminance range, and the bad line information for the horizontal line and the vertical line corresponding to the horizontal line luminance value and the vertical line luminance value outside the reference luminance range, and the image is displayed It further comprises a display unit; The bad pixel detection controller may generate a log file of the bad line information and the information on the bad pixel, and display the log file through the display.

According to the present invention by the above configuration, a horizontal line and a vertical line outside the reference luminance range are detected without adding a separate circuit configuration in the LED display board, and the pixel at the position where the detected horizontal line and the vertical line cross each other is detected. By judging and detecting a bad pixel, a bad pixel can be replaced easily at the time of manufacture or use of a LED display board.

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

The defective pixel detection device 30 of the LED display panel 10 according to the present invention, as shown in Figs. 1 and 2, the luminance measuring unit 31, the display unit 34, the data storage unit 33 and The bad pixel detection controller 32 may be included. The display unit 34, the data storage unit 33, and the bad pixel detection control unit 32 may be provided in the form of an information processing device such as a computer as illustrated in FIG. 1.

The luminance measuring unit 31 captures a screen of the LED sign 10 and measures the brightness of an image displayed on the screen. Here, the luminance measuring unit 31 is provided in the form of a CCD camera or a CMOS camera and transfers information on an image obtained by capturing the screen of the LED display board 10 to the defective pixel detection device 30.

The data storage unit 33 stores information on the reference luminance range RB _L to RB _H (refer to FIGS. 4 and 5) as a reference for detecting a bad pixel. The display unit 34 displays an image on the screen under the control of the bad pixel detection control unit 32, and displays a log file to be described later generated by the control unit 32 on the screen, thereby displaying information about the bad pixel. Display visually.

The bad pixel detection controller 32 controls the pixels constituting the LED display board 10 to blink in a horizontal line unit and a vertical line unit. In addition, the bad pixel detection controller 32 controls the luminance measuring unit 31 to capture the screen of the LED display panel 10 while the LED display panel 10 is turned on in the horizontal line unit and the vertical line unit, respectively.

Referring to FIG. 3, the bad pixel detection controller 32 controls the LED display panel 10 so that n horizontal lines constituting the LED display panel 10 are sequentially turned on, for example, from the top to the bottom. Here, the bad pixel detection controller 32 may control the LED display panel 10 to be turned on in units of horizontal lines by applying an image signal to the LED display panel 10 to turn on only a specific horizontal line.

In this process, the bad pixel detection control unit 32 controls the luminance measuring unit 31 to capture the screen of the LED display panel 10 while one horizontal line is turned on, so as to display image data for each horizontal line ( Hereinafter, "horizontal image data" is received from the luminance measuring unit 31.

In the same way, the bad pixel detection control part 32 controls the LED display board 10 so that m vertical lines which comprise the LED display board 10 light up sequentially from left to right, for example. In addition, the bad pixel detection controller 32 controls the luminance measuring unit 31 to capture the screen of the LED display panel 10 while one vertical line is turned on, thereby controlling image data (hereinafter, ' Vertical image data 'is transmitted from the luminance measuring unit 31.

When the horizontal image data and the vertical image data of each horizontal line and the vertical line of the LED display board 10 are obtained through the above-described method, the bad pixel detection controller 32 may be configured based on the horizontal image data and the vertical image data. The luminance values for each horizontal line and vertical line are detected. Here, the luminance value detected based on the horizontal image data is called a horizontal line luminance value (HB, see FIG. 4), and the luminance value detected based on the vertical image data is called a vertical line luminance value (VB, see FIG. 5). Define and explain.

On the other hand, when the bad pixel detection control unit 32 detects the horizontal line luminance value HB and the vertical line luminance value VB for each horizontal line and the vertical line of the LED sign 10 as described above, the horizontal line luminance value The HB and the vertical line luminance value VB are determined to be out of the reference luminance ranges RB _L to RB _H stored in the data storage unit 33, and are out of the reference luminance ranges RB _L to RB _H. Bad line information is generated for the horizontal and vertical lines corresponding to the horizontal line luminance value HB and the vertical line luminance value VB. Here, the bad pixel detection controller 32 may store bad line information in the data storage 33.

In addition, the bad pixel detection controller 32 may determine a position where the horizontal line and the vertical line corresponding to the horizontal line luminance value HB and the vertical line luminance value VB that cross the reference luminance range RB _L to RB _H cross each other. The pixel is judged as a bad pixel.

For example, referring to FIG. 3, the horizontal line luminance value HB for the third horizontal line of the horizontal lines is outside the reference luminance range RB _L to RB _H , and the second vertical line of the vertical lines is included in the second vertical line. If it is determined that the vertical line luminance value VB is out of the reference luminance range RB _L to RB _H , the pixel at which the third horizontal line and the second vertical line intersect, that is, 3 from the top of m × n pixels The second and second pixels from the left are detected as bad pixels.

Here, the bad pixel detection controller 32 may generate a log file for the bad line information and the bad pixel information and store the log file in the data storage unit 33. The log file may be generated as described above. 34) can be displayed.

Through the above configuration, without adding a separate circuit configuration in the LED display board 10, it detects the horizontal line and the vertical line outside the reference luminance range (RB _L ~ RB _H ), and vertical to the detected horizontal line By determining and detecting the pixel at the position where the line crosses as a defective pixel, it is possible to easily replace the defective pixel during the manufacturing process or use of the LED display board 10.

In the above-described embodiment, the bad pixel detection control unit 32 detects the horizontal line luminance value HB and the vertical line luminance value VB for the entire horizontal line and the vertical line, and then the reference luminance range RB _L to RB _H. ), The detection of the horizontal line luminance value HB (or the vertical line luminance value VB) for one horizontal line (or vertical line) and the reference luminance range RB _L to RB _H. Of course, the detection and comparison of the next horizontal line (or vertical line) may proceed after the detection of the defective line through the comparison is completed. In addition, the order of detection and comparison of the horizontal line and the vertical line may be changed.

Hereinafter, a method of detecting a defective pixel of the LED display panel 10 according to the present invention will be described in detail with reference to FIGS. 4 and 5. Here, the LED sign 10 is described as an example that is composed of m × n pixels, that is, composed of n horizontal lines and m vertical lines.

First, in a state in which the first horizontal line is turned on (S40), the horizontal line luminance value HB for the first horizontal line is measured (S41). Here, the measurement method of the horizontal line luminance value HB is as described above, and the detailed description thereof is omitted.

Then, it is determined whether the measured horizontal line luminance value HB is included in the preset reference luminance range RB _L to RB _H (S42), and the horizontal line luminance value HB is the reference luminance range RB _L. If it is determined that the ~ ~ RB _H ) to turn off the first horizontal line (S44).

On the other hand, if it is determined in step S42 that the horizontal line luminance value HB is out of the reference luminance range RB _L to RB _H , it is determined that the horizontal line is a bad line (S43), and the corresponding information is stored in the data storage unit ( 33) and extinguish the first horizontal line (S44).

Then, it is determined whether the measurement of the horizontal line luminance value HB and the determination of inclusion in the reference luminance range RB _L to RB _H have ended for all horizontal lines (S45). In this case, after turning on only the next horizontal line (S46), steps S41 to S45 are performed to detect a defective line among the entire horizontal lines.

On the other hand, when the detection of the defective line for all the horizontal line is finished (S45) through the above process, the detection of the defective line for the vertical line proceeds as shown in FIG.

First, in the state in which the first vertical line is turned on (S50), the vertical line luminance value VB for the first vertical line is measured (S51). Here, the measuring method of the vertical line luminance value VB is as described above, and the detailed description thereof is omitted.

Then, it is determined whether the measured vertical line luminance value VB is included in the preset reference luminance range RB _L to RB _H (S52), and the vertical line luminance value VB is the reference luminance range RB _L. If it is determined that the ~ ~ RB _H ) to turn off the first vertical line (S54).

On the other hand, if it is determined in step S52 that the vertical line luminance value VB is out of the reference luminance range RB _L to RB _H , it is determined that the corresponding vertical line is a bad line (S53), and the corresponding information is stored in the data storage unit ( 33), the first vertical line is turned off (S44).

Then, it is determined whether the measurement of the vertical line luminance value VB and the determination of inclusion in the reference luminance range RB _L to RB _H have ended for all vertical lines (S55). In this case, after turning on only the next vertical line (S56), steps S51 to S55 are performed to detect a defective line among all vertical lines.

As described above, when the detection of the defective lines for all the horizontal lines and the vertical lines is finished (S55), the pixels in which the vertical lines and the horizontal lines determined as the defective lines intersect are determined (S57), and the corresponding pixels are detected as the defective pixels. In operation S58, information about the bad pixel is displayed on the display unit 34.

In the above-described embodiment, the reference luminance ranges RB _L to RB _H for the horizontal line and the vertical line have been described as an example, but the values may be different.

In addition, in the above-described bad pixel detection method, the bad pixels of the vertical lines are detected after the detection of the bad lines with respect to the horizontal lines. However, the order may be changed. After the horizontal line luminance value HB for the entire horizontal line is measured, the comparison with the reference luminance range RB _L to RB _H may be performed.

Although some embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that modifications may be made to the embodiment without departing from the spirit or spirit of the invention. . The scope of the alias will be defined by the appended claims and their equivalents.

1 is a view showing the configuration of a bad pixel detection device of the LED display panel according to the present invention,

FIG. 2 is a control block diagram of the bad pixel detecting apparatus of FIG. 1;

3 is a diagram illustrating a pixel configuration of an LED display panel according to the present invention;

4 and 5 are control flowcharts illustrating a method of detecting a bad pixel of an LED display board.

<Description of Major Numbers in Drawing>

10: LED display board 30: Bad pixel detection device

31: luminance measuring unit 32: bad pixel detection control unit

33: data storage 34: display

Claims (4)

In the bad pixel detection method of the LED display, (a) illuminating pixels constituting the LED display board in horizontal line units and measuring horizontal line luminance values for the horizontal lines; (b) lighting the pixels constituting the LED display board in a vertical line unit and measuring vertical line luminance values of the vertical lines; (c) determining whether the measured horizontal line luminance values and the measured vertical line luminance values deviate from a preset reference luminance range; and (d) determining the pixel at the position where the horizontal line and the vertical line intersect with the horizontal line luminance value and the vertical line luminance value that are outside the reference luminance range as the defective pixel. Pixel detection method. The method of claim 1, In the above steps (a) and (b), the horizontal line brightness value and the vertical line brightness value correspond to the brightness value of the image data obtained by photographing the camera in the state of being lit in units of the horizontal line and the vertical line. Defective pixel detection method of the LED sign, characterized in that measured according to. In the bad pixel detection device of the LED display, A luminance measuring unit for photographing the screen of the LED display board; A data storage unit for storing information on a reference luminance range; The luminance measuring unit controls the screen of the LED display board while the pixels constituting the LED display board are controlled to blink in a horizontal line unit and a vertical line unit, and the LED display plate is turned on in the horizontal line unit and the vertical line unit, respectively. Control to capture an image, and detect a horizontal line luminance value for each horizontal line and a vertical line luminance value for each vertical line based on the horizontal line unit and the image data captured in the horizontal line unit from the luminance measuring unit. And determining whether to deviate from a preset reference luminance range among the horizontal line luminance value and the vertical line luminance value, and horizontal and vertical lines corresponding to the horizontal line luminance value and the vertical line luminance value outside the reference luminance range. Bad pixel detection control which judges the pixel of this intersection position as bad pixel Bad pixel detection device of the LED display comprising: a. The method of claim 3, A data storage unit for storing the information on the reference luminance range, and the defective line information for the horizontal line and the vertical line corresponding to the horizontal line luminance value and the vertical line luminance value outside the reference luminance range; A display unit on which an image is displayed; The bad pixel detection control unit generates a log file of the bad line information and the information on the bad pixel, and displays the defective pixel of the LED display panel.

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