KR100658261B1 - How to detect line mura defects - Google Patents

Abstract

The present invention relates to a method for detecting a line mura defect of a flat panel display. The line mura detection method according to the present invention comprises a first step of driving one pixel line of a plurality of pixel lines composed of pixels connected to each data line in an image display unit, and measuring current supplied to the one pixel line. A second step, a third step of sequentially repeating the first and second steps with respect to the remaining pixel lines of the plurality of pixel lines, and one of the remaining pixel lines at a current value measured by the one pixel line And a fourth step of comparing the absolute value of the value obtained by subtracting the current value measured in the line by the average value of the currents measured in the plurality of pixel lines for each pixel line.

Flat panel display, line Mura defect, detection method

Description

Method for detecting line mura defects             

1 is a view showing a general Mura defect.

2 is a schematic block diagram of a system for implementing the line mura detection method according to an embodiment of the present invention.

3 is a block diagram illustrating a system and a flat panel display implementing the line mura detection method according to an exemplary embodiment.

4 is a flowchart illustrating a line mura detection method according to an exemplary embodiment of the present invention.

5 is a diagram illustrating a process of detecting a line mura defect of a flat panel display using the line mura detection method according to an exemplary embodiment of the present invention.

6 is a graph illustrating current values of respective pixel lines detected by the line mura detection method according to an exemplary embodiment of the present invention.

7A to 7C are diagrams illustrating a process of detecting a line mura defect of a flat panel display using a modification of the line mura detection method according to an exemplary embodiment of the present invention.

8 is a flowchart illustrating a modification of the line Mura detection method according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: detection device 110: processor

120: memory system 130: input and output devices

140: system bus 150: current measurement unit

200: flat panel display 210: image display unit

220: subpixel

The present invention relates to a method for detecting a line mura defect of a flat panel display.

The mura defect is a contrast type defect of a specific region of the flat panel display device, and the region where such mura defect is generated is a region where a group of pixels is lighter or darker than the surrounding pixels. Such contrast type defects are caused by contaminants between the layers in the flat panel display, uneven light emitting layers, incorrect connection of source lines or gate lines, and the like.

1 is a view showing a general Mura defect. As shown in FIG. 1, the flat panel display apparatus 10 may have various Mura defects on the screen displayed on the image display unit 12. Mura defects include irregular line mura, vertical line mura, horizontal line mura, thin rubbing line mura, wide rubbing area mura, irregular area mura, and the like.

The aforementioned Mura defect is usually caused by a manufacturing problem of the flat panel display. And when the Mura defect which has a characteristic shape generate | occur | produces, it can be judged that the characteristic problem exists in a manufacturing process. For example, block boundary line mura, such as vertical line mura or horizontal line mura, is often caused by improper driver block voltage.

Therefore, by detecting and analyzing Mura defects, manufacturing problems can be identified and eliminated, and Mura defects can be reduced in future processes. In addition, since a Mura defect having a specific shape is mainly generated in a manufacturing process having a specific problem, an improved method for detecting a particular Mura defect is required for each manufacturing process.

It is an object of the present invention to provide a method that can more easily and accurately detect line mura defects.

In order to achieve the above object, according to an aspect of the present invention, the first step of driving one pixel line of a plurality of pixel lines consisting of pixels connected to each data line in the image display unit, the one pixel line A second step of measuring a current supplied to the third step; the first step and the second step of sequentially repeating the first and second steps with respect to the remaining pixel lines of the plurality of pixel lines; and a current value measured at the one pixel line. A line mura including a fourth step of comparing the absolute value of a value obtained by subtracting a current value measured in one of the remaining pixel lines by an average value of currents measured in the plurality of pixel lines for each pixel line; A detection method is provided.

Preferably, the first step is through a power supply line to which one pixel line is connected while supplying a scanning signal to all the scanning lines of the image display unit at the same time and supplying a data signal of a predetermined level to a data line to which one pixel line is connected. Controlling the flat panel display to supply the pixel power.

The first step also includes driving a particular portion of one pixel line.

The first step may include dividing one pixel line into a plurality of sections and driving each section sequentially.

The second step may include measuring a current at a power supply unit of a flat panel display device that supplies pixel power to one pixel line.

In addition, the second step includes measuring a current at a power generation unit of the line Mura detection system for supplying pixel power to one pixel line.

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According to another aspect of the present invention, a first step of driving one subpixel line of a plurality of subpixel lines including at least a red subpixel, a green subpixel, and a blue subpixel, which constitutes one pixel, the one subpixel A second step of measuring a current supplied to a power line connected to the line; a third step of repeating the first and second steps sequentially with respect to the remaining subpixel lines of the plurality of subpixel lines; The absolute value of the value obtained by subtracting the current value measured in one of the remaining subpixel lines from the current value measured in the subpixel line of is divided by the average value of the currents measured in the plurality of subpixel lines. A line mura detection method comprising a fourth step of comparing each subpixel line is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, parts irrelevant to the present invention have been omitted for clarity, and like reference numerals denote like parts throughout the specification.

2 is a schematic block diagram of a system for implementing the line mura detection method according to an embodiment of the present invention.

Referring to FIG. 2, the system 100 is a device for detecting a line mura defect and detects a line mura defect of the flat panel display 200. To this end, the system 100 includes a processor 110, a memory system 120, an input / output device 130, a system bus 140, and a current measuring unit 150. The processor 110, the memory system 120, the input / output device 130, and the system bus 140 are representative of typical computer components.

The processor 110 includes various computing devices or image processing processors. In addition, the processor 110 transmits a control signal to the flat panel display 200 by a program stored in the memory system 120 and controls the flat panel display so that specific pixel lines of the flat panel display 200 are sequentially activated. . The current measurer 150 is controlled to measure the current supplied to the activated specific pixel line. In addition, the current value measured at each pixel line is compared by a predetermined comparison method.

Memory system 120 includes random access memory (RAM). In addition, the memory system 120 stores a predetermined program written according to a mechanism for detecting a line Mura defect according to the present invention. In addition, the current value measured by the current measuring unit 150 is stored.

The input / output device 130 functions to allow an operator or another system to access the system 100. In addition, the input / output device 130 includes various input devices such as a keyboard, a card reader, a biometric device, and various output devices such as a monitor and a printer. In addition, the input / output device 130 may include a communication device such as a modem.

The system bus 140 includes a PCI bus, a VME bus, and the like, and connects the processor 110, the memory system 120, the input / output device 130, the current measuring unit 150, and the flat panel display 200.

The current measuring unit 150 measures a current on a power supply line connected to a specific pixel line of the flat panel display 200 according to a control signal of the processor 110. In this case, the current measuring unit 150 measures the current supplied to the specific pixel line from the power supply unit in the flat panel display 200.

For example, the current measuring unit 150 is a flexible circuit connected to a DC-DC converter mounted on the flat panel display 200 as a power supply unit to deliver pixel power ELVDD to each pixel. A current supplied to a specific pixel line can be measured from a power line on the substrate FPC.

3 is a block diagram illustrating a system and a flat panel display implementing the line mura detection method according to an exemplary embodiment.

Referring to FIG. 3, the line mura detection system 100 of the present exemplary embodiment controls the flat panel display 200 having the image display unit 210, the scan driver 230, and the data driver 240 to control a plurality of pixel lines. The line mura defect generated on the selected pixel line is detected. The pixel line represents a group of pixels connected to each data line. The pixel includes a plurality of subpixels 220.

For example, a pixel includes a red subpixel displaying red, a green subpixel displaying green, and a blue subpixel displaying blue, and a white displaying white. It may further include a subpixel (white subpixel). One pixel line includes red, green, blue, and white subpixel lines adjacent to each other extending in a predetermined direction of the image display unit 210, for example, in a vertical direction of the image display unit 210. Each of the red, green, blue, and white subpixels in the red, green, blue, and white subpixel lines form one pixel.

In addition, the system 100 may further include a power generator 160 in addition to the computer component and the current measuring unit 150 mentioned in the detailed description with reference to FIG. 2. By such a configuration, the present system 100 directly supplies pixel power to a specific pixel line of the flat panel display 200. Therefore, in the system 100, the power generation unit 160 in the system can measure the current at that time while supplying the pixel power to the specific pixel line. Here, when the flat panel display is an organic light emitting display, the pixel power represents the first pixel power ELVDD among the first pixel power ELVDD and the second pixel power ELVSS for driving the organic light emitting diode.

Hereinafter, the line mura detection method according to the present invention will be described in detail. 4 is a flowchart illustrating a line mura detection method according to an exemplary embodiment of the present invention. 5 is a diagram illustrating a process of detecting a line mura defect of a flat panel display using the line mura detection method according to an exemplary embodiment of the present invention. 6 is a graph illustrating current values of respective pixel lines detected by the line mura detection method according to an exemplary embodiment of the present invention.

A method of detecting a line Mura defect according to an embodiment of the present invention will be described with reference to FIG. 4. First, a system for detecting a line Mura defect is connected to a flat panel display device and drives one pixel line among a plurality of pixel lines of an image display unit of the flat panel display device (Step 310). As illustrated in FIG. 5, the system includes one of a plurality of pixel lines including red (R), green (G), and blue (B) subpixel lines in the image display unit 210 of the flat panel display 200. The pixel line is driven. Each pixel line includes a series of pixels formed in the vertical direction of the image display unit, and each pixel includes subpixels 220 of red, green, and blue. The pixel line may include a white subpixel line including white subpixels.

In the above-described first step, the system for performing the line mura detection method according to an embodiment of the present invention, wherein the flat panel display device simultaneously supplies the scanning signal to all the scanning lines of the image display unit, and one selected pixel line is connected. The flat panel display is controlled to supply pixel power through a power line to which one selected pixel line is connected while supplying a data signal having a predetermined level to the data line. In this case, if one pixel line selected in the first step 310 is a pixel line within a normal range, the selected one pixel line will display a predetermined gray level, and if it is an abnormal pixel line, the selected one pixel line will be lower than the predetermined gray level. Or will display high gradation.

Next, in operation 320, a current supplied to one pixel line is measured through a power line connected to one pixel line selected in the first step 310. The second step 320 includes measuring a current supplied to one pixel line selected by the current measuring unit in the system. In this case, the current measuring unit measures the current supplied to the pixel line selected from the power supply unit in the flat panel display at the power line on the flexible circuit board, or the current generation unit supplies the current supplied to the pixel line selected from the power generation unit in the line mura detection system. Can be measured directly.

Next, the line mura detection system repeatedly performs the first step 310 and the second step 320 for the plurality of pixel lines (step 330 and third step). As a result, the system measures current for each pixel line in the image display portion of the flat panel display device. At this time, the system stores the current measured in each pixel line in a predetermined memory or storage device in the system.

Next, if it is determined that the current measurement has been performed for all the pixel lines, the line mura detection system compares the measured current values for each pixel line (step 340, step 4).

For example, as illustrated in FIG. 6, the line mura detection system measures a current measured from the next pixel line n + 1 at a current value measured from a specific pixel line n with respect to an average value of all measured currents. You can compare the absolute values of subtracted values. In other words, according to the above-described method, the remaining pixel lines n + 1, n + 2, n + at the first current value measured on the power line for supplying pixel power to the first pixel line n of the plurality of pixel lines. 3, ..., n + 7, n + 8, ...) measured for each of the plurality of pixel lines a predetermined value obtained by subtracting the second current value measured on the same power supply line supplying the same pixel power supply to any one pixel line. Line Mura defects can be detected by comparing the absolute value of the value divided by the average value of the current with each other.

In addition, the line Mura detection system measures each pixel line by comparing the absolute value of the sum of adjacent pixel lines minus the sum of other adjacent pixel lines divided by the average value of currents measured in all pixel lines. The current can be compared. This method can be briefly represented by Equation 1 as follows.

Here, In, I (n + 1), I (n + 2), and I (n + 3) are current values measured at the first, second, third, and fourth pixel lines, and Iave is measured at each pixel line. Average value of the current value.

In addition, the line mura detection system may compare current values measured in each pixel line through various comparison methods in addition to the above-described comparison method. For example, a difference between currents measured in one pixel line and another pixel line may be compared, or a difference between current values measured in each pixel line may be compared.

7A to 7C are diagrams illustrating a process of detecting a line mura defect of a flat panel display using a modification of the line mura detection method according to an exemplary embodiment of the present invention. The pixel lines illustrated in FIGS. 7A and 7B include white subpixel lines.

7A to 7C, the system implementing the line mura detection method according to an exemplary embodiment of the present invention does not drive all selected one pixel lines when driving one pixel line among a plurality of pixel lines. Only part of it can be driven.

For example, as shown in FIG. 7A, a portion corresponding to an upper end portion of approximately one third of the selected one pixel line can be selected. At this time, the system measures and compares the current supplied to approximately one third of each pixel line while sequentially driving the upper end of approximately one third of each pixel line.

In the above-described case, in the system, the selected pixel line is supplied while the flat panel display device simultaneously supplies the scan signal to the scan line of approximately one third of the upper end of the image display unit and supplies the data signal of a predetermined level to the data line to which the selected one pixel line is connected. The flat panel display is controlled to supply pixel power through this connected power line. Then, the system measures the current supplied to approximately one third upper end of the selected pixel line through the current measuring unit, and compares the measured current to detect a partial line mura defect.

Further, for example, after the system has measured all of the respective currents for the upper end of approximately one third of each pixel line, as shown in FIG. 7B, each of the middle portions of approximately one third of each pixel line is shown. Measure and compare current. In this case, a method of measuring current with respect to an intermediate part of about one third of each pixel line may be implemented by the same method as in the case of the upper end part of about one third of each pixel line described above.

Further, for example, after the system has measured all of the respective currents for approximately one-third of each pixel line, respectively, as shown in FIG. Measure and compare current. In this case, the method for measuring the respective currents for the lower end of approximately one third of each pixel line may be implemented in the same manner as in the case of the upper end of approximately one third of each pixel line described above.

The method of comparing the currents measured at the upper, middle, and lower ends of each pixel line is the same as the detailed description with reference to FIG. 6 and the like. Therefore, in the present embodiment, the description thereof will be omitted in order to avoid duplication of description.

As described above, the system implementing the line mura detection method according to an exemplary embodiment of the present invention may select and drive only a specific portion of each pixel line in the image display unit of the flat panel display device, and then measure and compare the current supplied to the pixel line. have. Accordingly, the line mura detection method according to an embodiment of the present invention may be implemented to detect a partial line mura defect of the flat panel display device.

Meanwhile, the present invention divides each pixel line into two equal parts or four equal parts or more, in addition to a method of dividing each pixel line of the image display unit into approximately three equal parts and measuring and comparing the currents for the respective parts, as in the above-described embodiment. Can be implemented to detect partial line mura defects.

8 is a flowchart illustrating a modification of the line mura detection method according to an embodiment of the present invention.

Referring to Figure 8 describes a method for detecting a line Mura defect according to an embodiment of the present invention. First, a system for detecting a line Mura defect is connected to a flat panel display device and drives one subpixel line of a plurality of subpixel lines of an image display unit of the flat panel display device (step 410, first step).

For example, the system includes one subpixel selected while the flat panel display device simultaneously supplies scan signals to all scan lines of the image display unit and supplies data signals of a predetermined level to data lines to which one selected subpixel line is connected. The flat panel display is controlled to supply the pixel power through the power line to which the line is connected. In this case, if one subpixel line selected in the first step 310 is a normal subpixel line, the selected subpixel line will display a predetermined gray scale, and if it is an abnormal subpixel line, the selected one subpixel line will be defined. It will display a gradation lower or higher than gradation.

Next, in operation 320, a current supplied to one subpixel line is measured through a power line connected to one subpixel line selected in the first step 310. This second step 320 includes measuring the current supplied to one subpixel line selected by the current measurement unit in the system. In this case, the current measuring unit measures the current supplied to one subpixel line selected from the power supply unit in the flat panel display on the power line on the flexible circuit board or supplies the current to one subpixel line selected from the power generation unit in the line mura detection system. The current can be measured directly at the power generator.

Next, the line mura detection system repeatedly performs the first step 310 and the second step 320 previously performed on the plurality of subpixel lines (330 and third step). Thus, the system measures current for each of all the subpixel lines in the image display portion of the flat panel display. At this time, the system stores the current measured in each subpixel line in a predetermined memory or storage device in the system.

Next, when it is determined that the current measurement is performed for all the subpixel lines, the line mura detection system compares the measured current values for each subpixel line (340, step 4). At this time, the method of comparing the measured current value is the same as the detailed description described above with reference to FIG. Therefore, in the present embodiment, the description thereof will be omitted in order to avoid duplication of description.

On the other hand, the present modification includes selecting and driving a portion of each subpixel line when driving each subpixel line. This configuration is similar to the detailed description with reference to Figs. 7A to 7C. Therefore, detailed description thereof will be omitted.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

According to the present invention, the line mura defect of the flat panel display can be detected very easily. Therefore, it can contribute to confirming and eliminating the problem of the manufacturing process of a flat panel display device.

Claims (10)

A first step of driving one pixel line among a plurality of pixel lines composed of pixels connected to each data line in an image display unit;     A second step of measuring a current supplied to the one pixel line;     A third step of sequentially repeating the first and second steps with respect to the remaining pixel lines of the plurality of pixel lines; And The absolute value of the value obtained by subtracting the current value measured in one of the remaining pixel lines by the current value measured in the one pixel line divided by the average value of the currents measured in the plurality of pixel lines, respectively. Line mura detection method comprising a fourth step of comparing each. The method of claim 1, In the first step, a scan signal is simultaneously supplied to all scan lines of an image display unit, and a data signal having a predetermined level is supplied to a data line to which one pixel line is connected, through a power supply line to which one pixel line is connected. And controlling the flat panel display device to supply the pixel power. The method of claim 1, And said first step comprises driving a particular portion of said one pixel line. The method of claim 1, The first step includes dividing the one pixel line into a plurality of sections and driving each section sequentially. The method of claim 1, And the second step includes measuring the current at a power supply of a flat panel display that supplies pixel power to the one pixel line. The method of claim 1, And the second step includes measuring the current at a power generation unit of a line mura detection system for supplying pixel power to the one pixel line. The method of claim 1, And the pixel line includes a red subpixel line, a green subpixel line, and a blue subpixel line. The method of claim 7, wherein And the pixel line further comprises a white subpixel line. A first step of driving one subpixel line among a plurality of subpixel lines including at least a red subpixel, a green subpixel, and a blue subpixel forming one pixel;    A second step of measuring a current supplied to a power line connected to the one subpixel line;   A third step of sequentially repeating the first and second steps with respect to the remaining subpixel lines of the plurality of subpixel lines; And  Absolute value of a value obtained by subtracting a current value measured in any one subpixel line among the remaining subpixel lines by an average value of currents measured in each of the plurality of subpixel lines. Mura detection method comprising the fourth step of comparing the sub-pixel line by line delete

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