JP2001174772A - Inferiority analysis method for liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to quantitatively judge, substantially shorten the time for analysis operation, and to easily presume the cause of an inferiority. SOLUTION: An image tester 1 detects luminescent spots by photographing a liquid crystal display panel 2 with a CCD camera 3. A terminal 4 records the luminescent spot pixel positions and levels of the luminescent spots in an external storage device 5 as a file for the image test results. In the file for the image test results, a panel numbers, luminescent spot pixel positions, and luminescent spot levels are recorded. Moreover, based on the recorded luminescent spot pixel positions and the luminescent spot levels, the terminal 4 displays a pseudo panel 6 presenting the luminescent spot levels (the number of the luminescent spots when summed by lots or pixels) of the pixels ever pixel composing the liquid crystal panel 2 by the height of a bar chart on a monitor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel failure analysis method for analyzing image quality defects such as bright spots and dark spots of a liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, as an automatic inspection apparatus for a liquid crystal display panel, while a liquid crystal display panel is driven, an image of the panel surface is taken by a television camera, and point defects, line defects, spot defects, chromaticity defects, etc. There is known an image tester for detecting the following. Further, by causing the image tester to actually display a predetermined image on a liquid crystal display panel that has failed due to a defective bright spot,
There is a method for analyzing the cause of poor image quality such as bright spots and dark spots.
The cause analysis of the poor image quality is performed by the following procedure and method.

[0003] First, liquid crystal display panels rejected due to defective bright spots from the inspection results of the image tester are collected in lot units.
Next, a picture is drawn on each of the liquid crystal display panels one by one with a picture-drawing jig, and the distribution state of the bright spots is handwritten one by one to take a memo. Then, by summing up the bright spot distribution state of each liquid crystal display panel written in the memo, it is determined whether or not there is a tendency in the bright spot distribution, and from the tendency, the process or process that causes the image quality failure is estimated. I do.

[0004]

However, in the prior art, it is often the case that the bright spot distribution of a liquid crystal display panel is manually counted up. However, there was a problem that it was not possible to perform quantitative processing and it took time.

Accordingly, the present invention provides a method for analyzing a defect of a liquid crystal display panel, which can make a quantitative judgment, greatly shorten the analysis work time, and can easily estimate the cause of the defect. The purpose is to provide.

[0006]

In order to achieve the above-mentioned object, a method for analyzing a failure of a liquid crystal display panel according to the first aspect of the present invention comprises the steps of determining a cause of failure based on a bright spot distribution caused by a pixel failure of the liquid crystal display panel. In the method for analyzing a failure of a liquid crystal display panel to be analyzed, a pixel array constituting the liquid crystal display panel is schematically displayed on a grid-like plane simulating the pixel arrangement, and a pixel position and a bright point level of a bright spot appearing on the liquid crystal display panel , The bright spot distribution of the liquid crystal display panel is displayed on the grid-like plane at the height of a bar graph for each pixel.

In a preferred embodiment, in the defect analysis method for a liquid crystal display panel according to the first aspect of the present invention, the bright spot distribution is tabulated for each lot. May represent the cumulative number of bright spots existing in the same pixel.

In a preferred embodiment, in the defect analysis method for a liquid crystal display panel according to the present invention, the bright spot distribution is expressed for pixels having a predetermined bright spot level or higher. You may.

In a preferred embodiment, in the defect analysis method for a liquid crystal display panel according to the present invention, the bright spot distribution is obtained for each block in which a predetermined number of adjacent pixels are collected. , The number of bright points present in the block may be represented.

[0010] In the present invention, the liquid crystal display panel is schematically displayed on a grid-like plane simulating the pixel arrangement, and based on the pixel position and the bright point level of the bright spot appearing on the liquid crystal display panel. The bright spot distribution of the liquid crystal display panel is displayed at the height of a bar graph for each pixel on the grid-like plane. Therefore, since the bright spot distribution is displayed on a grid-like plane simulating the liquid crystal display panel, the bright spot distribution on the liquid crystal display panel can be easily recognized,
Analysis time can be greatly reduced. In addition, even if the analysis depends on the senses, it is possible to make a quantitative determination because the analysis is quantified. Further, the tendency of the bright spot defect can be easily grasped, and the cause of the defect can be easily estimated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. A. Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of a failure cause analysis system according to an embodiment of the present invention. In the figure, an image tester 1
In the state where the liquid crystal display panel 2 is driven, the panel surface is photographed by the CCD camera 3 to detect a bright spot. The terminal 4 is composed of, for example, a personal computer or a workstation, and stores the bright spot pixel position and the bright spot level of the bright spot detected by the image tester 1 in an external storage device 5 such as a hard disk device as an image test result file. Record. In the image test result file, among the liquid crystal display panels for one lot, the panel number where the bright spot was located, the bright spot pixel position, and the bright spot level are recorded. The terminal 4 displays the pseudo panel 6 on the monitor based on the bright spot pixel position and the bright spot level of the recorded image test result file. The simulated panel 6 schematically represents the pixel array of the liquid crystal display panel 2 by a grid-like plane, and corresponds to the luminescent spot level of each pixel (the number of luminescent spots when counted in lot units or blocks described later). The pixel position is represented by the height of a bar graph. The details will be described later.

B. Next, an operation of the above-described embodiment will be described. First, while the liquid crystal display panel 2 is driven by the image tester 1, the panel surface is photographed by the CCD camera 3 to detect a bright spot. When a bright spot or the like is detected, a panel number, a bright spot pixel position, and a bright spot level indicating a liquid crystal display panel in which a bright spot is detected in one lot are written out to an image test result file. Is recorded in the external storage device 5.

Next, in the terminal 4, the pseudo panel 6 is drawn on the monitor according to the bright spot pixel position and the bright spot level of the bright spot recorded in the external storage device 5. For example, in the case of a liquid crystal display panel of XGA (eXtended Graphics Array), an XY address (1,
For each of the addresses (1) to (1024, 768), the bright spot level (the number of bright spots in the case of totaling in lot units or block units described later) of the address (pixel) is displayed by the height of the bar graph. In the pseudo panel 6 shown in FIG. 1, V represents a vertical address (pixel position), and H represents a horizontal address (pixel position). The height direction of the simulated panel 6 indicates the luminance level of each address (pixel position).

Therefore, by looking at the pseudo panel 6 displayed on the monitor of the terminal 4, the bright spot distribution on the liquid crystal display panel 2 can be easily known, and the analysis work time can be greatly reduced. Further, since the panel number, bright spot pixel position and bright spot level of the liquid crystal display panel 2 at which the bright spot is detected are stored in the external storage device 5, there is no actual liquid crystal display panel 2 to be analyzed. Can also be analyzed. Further, even in the analysis relying on the senses, since the quantification is performed, a quantitative determination can be made.

The bar graph displayed on the simulated panel 6 has several display forms selectable by an operator. <Bright Point Level Limited Display> As a bar graph displayed on the pseudo panel 6, there is a bright point level limited display. In the bright point level limited display, when the bright point level is in the range of 0 to 10 over the entire liquid crystal display panel 2, when it is desired to see only the distribution of high bright points (one having a high bright point level), For example, the bright spot level is limited to 6 or more. As a result, a bar graph representing the luminous point level is displayed on the pseudo panel 6 for only the pixels having the luminous point level of 6 or more. This makes it possible to easily obtain a distribution diagram of the bright spots.

<Skewer display> Skewer display is a bar graph displayed on the pseudo panel 6. In the skewered display, as shown in FIG. 2, according to the bright spot pixel position and the bright spot level of the bright spot recorded in the external storage device 5, for each liquid crystal display panel in one lot (about 300 panels), Which XY
It is checked whether or not there is a bright point on the address. If there is a bright point, the number is counted for each XY address, and the accumulated value is displayed as a bar graph for each XY address.

For example, as shown in FIG. 3, one lot (5
XY addresses (20)
When there are three liquid crystal display panels each having a bright point at (0, 50), the cumulative value at the XY address (200, 50) is “3”. Therefore, on the pseudo panel 6, X
A bar graph of three heights is displayed at the Y addresses (200, 50). In the skewered display, in the pseudo panel 6 shown in FIG. 2, the vertical direction represents the number of bright spots.

According to the skewered display, it is possible to easily know the tendency of the bright spot defect in lot units. Further, by grasping the tendency of the bright spot defect in lot units, it is possible to easily estimate whether the cause of the defect is a defect of the inspection device or a defect of the process. For example, when bright spots are concentrated around the liquid crystal injection port, it can be assumed that the injection port sealing material is the cause. In the case where one pixel is concentrated, it can be assumed that the defect is a fixed defect of the CCD camera 3 of the inspection apparatus.

<Block Display> A bar graph displayed on the pseudo panel 6 includes a block display. In the liquid crystal display panel 2 having a large number of pixels, it is difficult to display one pixel at a time. Therefore, for example, 50 × 50 pixels are defined as one block, and as shown in FIG. 4, a bar graph representing the number of bright points is displayed for each block. At this time, the pixel information in the block is displayed in the sub-window (pop-up window) 10 by using a pointing device such as a mouse provided in the terminal 4 to place a pointer on a bar graph for which the user wants to know the pixel information. Subwindow 1
In XY, there is an XY where a bright point exists in the block.
The address and the number of bright points are displayed in descending order of the number of bright points.

In the above-described embodiment, skewered display or block display may be performed after limiting the bright spot level, which is very useful for analysis. In this case, the unit of the vertical axis of the bar graph is the number of bright spots.

[0021]

According to the first aspect of the present invention, the liquid crystal display panel is schematically displayed on a grid-like plane that simulates a pixel arrangement, and a pixel position of a luminescent spot appearing on the liquid crystal display panel. And the bright spot level of the liquid crystal display panel based on the bright spot level is displayed at the height of a bar graph for each pixel on the grid plane, so that a grid-like pattern simulating the liquid crystal display panel is displayed. Since the bright spot distribution is displayed on the plane, the bright spot distribution on the liquid crystal display panel can be easily recognized, and the advantage that the analysis work time can be greatly reduced is obtained. Further, even in the case of analysis that relies on sensation, since it is quantified, there is an advantage that a quantitative determination can be made. Further, it is possible to easily grasp the tendency of the bright spot defect, and it is possible to obtain the advantage that the cause of the defect can be easily estimated.

According to the second aspect of the present invention, the bright spot distribution is represented by the cumulative number of bright spots present in the same pixel in each of the liquid crystal display panels, which are tabulated for each lot. The advantage is that the bright spot distribution on the liquid crystal display panel can be easily recognized, and the analysis operation time can be greatly reduced. Further, even in the case of analysis that relies on sensation, since it is quantified, there is an advantage that a quantitative determination can be made. Further, it is possible to easily grasp the tendency of the bright spot defect, and it is possible to obtain the advantage that the cause of the defect can be easily estimated.

According to the third aspect of the present invention, the bright spot distribution is represented for pixels having a predetermined bright spot level or higher, so that the bright spot distribution on the liquid crystal display panel can be easily recognized. And the advantage that the analysis operation time can be greatly reduced can be obtained. Further, even in the case of analysis that relies on sensation, since it is quantified, there is an advantage that a quantitative determination can be made. Further, it is possible to easily grasp the tendency of the bright spot defect, and it is possible to obtain the advantage that the cause of the defect can be easily estimated.

According to the fourth aspect of the present invention, the bright spot distribution represents the number of bright spots present in each block in which a predetermined number of adjacent pixels are grouped. The advantage is that the bright spot distribution on the panel can be easily recognized, and the analysis work time can be greatly reduced. Also, even if the analysis depends on the senses,
Since it is quantified, there is an advantage that a quantitative judgment can be made. Further, it is possible to easily grasp the tendency of the bright spot defect, and it is possible to obtain the advantage that the cause of the defect can be easily estimated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a failure cause analysis system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a skewering display example according to the embodiment.

FIG. 3 is a conceptual diagram showing a procedure for performing skewering display according to the embodiment.

FIG. 4 is a conceptual diagram showing an example of a block display according to the embodiment.

[Explanation of symbols]

1. Image tester 2. Liquid crystal display panel 3. CC
D camera, 4 terminal, 5 external storage device, 6 pseudo panel, 10 sub window

Claims (4)

[Claims] 1. A failure analysis method for a liquid crystal display panel for analyzing a cause of failure based on a bright spot distribution appearing due to a pixel failure of the liquid crystal display panel, wherein a grid-like pattern simulating a pixel arrangement constituting the liquid crystal display panel is provided. A bar graph is displayed for each pixel on the grid-like plane based on a pixel position and a luminous point level of a luminous point appearing on the liquid crystal display panel while being schematically displayed on a plane. A defect analysis method for a liquid crystal display panel, characterized in that the display is performed at a height. 2. The liquid crystal display panel according to claim 1, wherein the bright spot distribution represents an accumulated number of bright spots existing in the same pixel in each of the liquid crystal display panels, which are totaled in lot units. Failure analysis method. 3. The method according to claim 1, wherein the bright spot distribution is represented for pixels having a predetermined bright spot level or higher. 4. The failure analysis of a liquid crystal display panel according to claim 1, wherein said bright spot distribution represents the number of bright spots present in each block in which a predetermined number of adjacent pixels are grouped. Method.