JPH0797086B2 - Optical LCD display defect inspection system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical liquid crystal display defect inspection device, and more particularly to an optical liquid crystal display defect inspection device for optically inspecting a pixel defect of a liquid crystal display.

[0002]

2. Description of the Related Art Recently, liquid crystal displays are being widely used in various electronic devices. Moreover, the amount of information displayed on the liquid crystal display is increasing, and a liquid crystal display with high display density is required. In order to increase the display density, it is necessary to make the wiring pattern between the liquid crystal display sections thin. However, if the pattern density is increased,
Adjacent patterns may be electrically connected to each other in a pattern etching process or the like. As a method of inspecting such a defect of the liquid crystal display, the liquid crystal display in a panel state is turned on, and it is optically read and compared with standard data, and if they do not match, it is determined that it is a defect. A method can be considered.

Conventionally, in order to detect such a defect, there has been used a probing method in which a visual inspection is performed or a pin is set up on an electrode to pass an electric current to check for contact. However, the visual method requires a long time for the inspection, and the probing method requires a pin to be placed on the electrode each time, which requires a lot of labor for the inspection.

[0004]

Therefore, a liquid crystal display is placed on a table, a pattern for inspection is displayed on the liquid crystal display while moving the table in one direction, and the pattern is displayed using an image sensor. A method of inspecting the liquid crystal display for defects may be conceived by comparing reading and reading output with standard data, and if they match, it is judged as a good product, and if they do not match, it is judged as a defective product. However, there is a blinking pixel among the defective pixels, and it may be determined as a defective pixel or as a normal pixel depending on the data acquisition timing.

Therefore, a main object of the present invention is to provide an optical liquid crystal display defect inspection apparatus capable of detecting blinking pixels.

[0006]

SUMMARY OF THE INVENTION The present invention is an optical liquid crystal display defect inspection apparatus for inspecting a liquid crystal display for defects, which comprises a movable stage for moving the liquid crystal display in one direction and an inspection for the liquid crystal display. Control means for displaying a pattern for display, a linear image sensor for reading the display pattern of the liquid crystal display from above the movable stage, and a reading of the display pattern by the linear image sensor so as to be performed a plurality of times for each pixel of the liquid crystal display. A linear image sensor control means for controlling the timing to be different, and a discrimination means for discriminating a defect of the liquid crystal display based on a plurality of times of data read by the linear image sensor are provided.

[0007]

The optical liquid crystal display defect inspection apparatus according to the present invention displays a pattern for inspection on the liquid crystal display, moves the liquid crystal display in one direction by the movable stage, and reads the display pattern by the linear image sensor. The detection timing is improved by controlling the reading timing so that the reading is performed a plurality of times for each pixel of the liquid crystal display, and determining the defects of the liquid crystal display from the data read by the linear image sensor a plurality of times.

[0008]

1 is a schematic block diagram of an embodiment of the present invention.

Referring to FIG. 1, a movable stage 2 is provided on a table 1. The movable stage 2 moves the liquid crystal display 3 in one direction and the other direction, and is driven by, for example, a linear motor or a ball screw. A CCD unit 4 is provided above the movable stage 2. The CCD unit 4 reads from above the display pattern of the liquid crystal display 3 that moves in one direction by the movable stage 2.
An image sensor is used.

A personal computer 5 is provided to perform overall control. The personal computer 5 controls the CCD unit 4 by using the CCD control circuit 6
Outputs a control signal to the CCD drive circuit 7, and the CCD drive circuit 7 drives the CCD unit 4 according to the control signal. At this time, the personal computer 5 outputs a signal for reading data a plurality of times for each pixel of the liquid crystal display 3, and the CCD unit 4 causes the liquid crystal display 3 to read.
Is read multiple times for each pixel. The read output of the CCD unit 4 is given to the personal computer 5. Further, the personal computer 5 causes the pulse generator 8 to generate a pulse signal, which is applied to the table positioning unit 9. The table positioning unit 9 sequentially moves the movable stage 2 in one direction in accordance with the pulse signal to position the movable stage 2. The personal computer 5 further causes the pattern generator 10 to generate display pattern data for inspection. This pattern data is given to the liquid crystal display drive circuit 11. Liquid crystal display drive circuit 1
Reference numeral 1 drives the liquid crystal display 3 to display the pattern according to the given pattern data.

FIG. 2 is a flow chart for explaining the concrete operation of the embodiment of the present invention, and FIG. 3 is a diagram showing an example of the blinking cycle and fetch timing of the blinking pixel.

Next, referring to FIGS. 1, 2 and 3,
A specific operation of the embodiment of the present invention will be described.
First, the liquid crystal display 3 is loaded on the movable stage 2. The personal computer 5 causes the pattern generator 10 to generate pattern data. This pattern data includes bright pixels such as a checkerboard pattern,
A display pattern is used in which the number of dark pixels is approximately the same, and the liquid crystal display drive circuit 11 causes the liquid crystal display 3 to display the display pattern according to the pattern data.

The personal computer 5 causes the pulse generator 8 to generate a pulse signal, and the table positioning unit 9 sequentially moves the movable stage 2 in one direction according to the pulse signal. A CCD control circuit 6 generates a CCD control signal in response to a control signal from the personal computer 5, and the CCD drive circuit 7 drives the CCD unit 4 in accordance with the control signal. CCD unit 4
Is a liquid crystal display 3 on a movable stage 2 that moves sequentially
The pattern displayed at is read from above and the read output is given to the personal computer 5. At this time, CC
The D unit 4 fetches data for each pixel of the liquid crystal display 3 a plurality of times and outputs the data to the personal computer 5. For example, in the case of a blinking pixel as shown in FIG. 3, the location data taken in when sampling is performed at the timing of or is about the same as the data of a normal pixel, and it is determined to be a normal pixel. Further, when sampling is performed at the timing of or, the data is in the middle of the data of the normal pixel and the data of the defective pixel or is approximately the same as the data of the defective pixel, and it is determined that the pixel is a defective pixel or an abnormal pixel. Since it is not possible to make an accurate determination if the same pixel is close to normal and if data close to a defect is captured,
As shown in FIG. 3, the measurement data of two times captured at the timing of and 2 captured at the timing of
The captured data such as batch measurement data is output to the personal computer 5 a plurality of times.

The personal computer 5 calculates the read output of the CCD unit 4 a plurality of times, and determines whether the result matches the standard data. If they do not match, it is determined that the inspected liquid crystal display 3 is a defective product, and if they match, the product is processed as a non-defective product, and the result is printed on a printer or displayed on a CRT display. After that, the personal computer 5 moves the movable stage 2 in the opposite direction, and when returning to the original position, the liquid crystal display 3 is unloaded. Then, the above operation is repeated to inspect the next liquid crystal display.

In the embodiment shown in FIG. 1, the liquid crystal display 3 is of the reflection type, but the liquid crystal display 3 is not limited to this and may be of the transmission type. In that case,
A light source may be provided below the table 1 so that the liquid crystal display 3 is irradiated with light from the light source.

[0016]

As described above, according to the present invention, a pattern for inspection is displayed on the liquid crystal display, the liquid crystal display is moved in one direction, and the display pattern is read by the linear image sensor of the liquid crystal display. By controlling the reading timing so that the reading is performed a plurality of times for one pixel, and determining the defect of the liquid crystal display from the data read by the linear image sensor a plurality of times, the blinking defect of the pixel on the liquid crystal display is surely detected. be able to.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 3 is a diagram showing a change in pixel data depending on the fetching timing of a blinking pixel.

[Explanation of symbols]

 1 table 2 movable stage 3 liquid crystal display 4 CCD unit 5 personal computer 6 CCD control circuit 7 CCD drive circuit 8 pulse generator 9 table positioning unit 10 pattern generator 11 liquid crystal display drive circuit

Claims (1)

[Claims] 1. An optical liquid crystal display defect inspection apparatus for inspecting a defect of a liquid crystal display, comprising a movable stage for moving the liquid crystal display in one direction, and displaying an inspection pattern on the liquid crystal display. Display control means, a linear image sensor for reading the display pattern of the liquid crystal display from above the movable stage, and different reading timings so that the display pattern is read by the linear image sensor a plurality of times for each pixel of the liquid crystal display. An optical liquid crystal display defect inspecting apparatus comprising: a linear image sensor control unit for performing a control for determining a defect in the liquid crystal display based on a plurality of times of data read by the linear image sensor.