JPH08128920A - Color filter inspection equipment - Google Patents

Abstract

PURPOSE: To provide a color filter inspection equipment capable of detecting defects of an each pixel and detecting irregular color at the same time. CONSTITUTION: Color filter inspection equipment for optically inspecting each color pixel 2 in a color filter substrate 1 has an optical detecting device comprising a line light source 6 and a line sensor camera group 7 arranged in the main scanning direction on both sides of the color filter substrate 1. A stage synchronizing control device 10 which relatively moves the optical detecting device and the color filter substrate 1 in the sub-scanning direction and takes pixel information in the line sensor camera group 7 for every pixel in the sub- scanning direction and an image processing device group 9 which takes in image information from the line sensor camera group 7 and detects irregular color or defectives in each pixel 2 are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter inspection device for inspecting a color filter substrate for a liquid crystal display.

[0002]

2. Description of the Related Art Recently, a laptop or notebook & book type personal computer has a color liquid crystal display (640) such as a TFT compatible with multimedia instead of a monochrome liquid crystal.
X400 dots, etc.) have been widely adopted.

As a structure of a liquid crystal panel in this color liquid crystal display, a transparent electrode and an FE are provided on a glass substrate.
T matrix layer, liquid crystal layer, transparent electrode, color filter,
It is configured by stacking glass substrates and providing polarizing plates above and below both glass substrates.

The color filters are R (red), G (green),
B (blue) color pixels are arranged by coating them on a glass substrate in dot units, and the arrangement method is also RG.
There are various types such as a vertical stripe method in which B is aligned in the vertical direction and a mosaic method in which RGB are dispersed.

Although this color filter is manufactured in a clean room, even if a foreign matter of about several μm adheres during manufacturing, it will be a defective product.

Conventionally, as an inspection apparatus for this kind of color filter, Japanese Patent Application Laid-Open No. 5-34237 and Japanese Patent Application Laid-Open No. 5-99 are known.
As disclosed in Japanese Patent No. 787, there is one in which light is radiated from one side of the color filter and the light transmitted through the color filter is visually observed from the other side to inspect for defects in each color pixel. The inspection has problems such as inspection accuracy and variations.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 5-332944, foreign matter adhering to the surface of the color filter is exposed to the inspection light on the surface of the color filter by utilizing the fact that the surface is raised in a mountain shape. There is a device in which the smoothness of the surface of the filter is inspected and the presence or absence of foreign matter is inspected by projecting light and detecting the reflected light.

[0008]

However, the above-mentioned inspection is premised on that the filter surface is bulged by foreign matter, and if the surface is smooth even if foreign matter is mixed, there is a problem that it is judged as a good product. is there.

Further, in addition to the inclusion of foreign matter, it is necessary to inspect whether or not each RGB pixel has color unevenness in the surface direction in the inspection as a color filter, but it is not possible to detect color unevenness only by foreign matter inspection. .

Further, as a device for inspecting a color liquid crystal display for defects, there is Japanese Patent Laid-Open No. 6-11455.
This inspection method drives the manufactured color liquid crystal display to detect uneven brightness, etc. Even if uneven brightness is detected, this is an inspection of the final product, and it is caused by a defect in the color filter. It is not possible to determine whether it is caused by a defect in the FET or its driver.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a color filter inspection device capable of detecting defects in each color pixel and simultaneously detecting color unevenness.

[0012]

In order to achieve the above object, the present invention provides a color filter inspection device for optically inspecting each color pixel of a color filter substrate,
An optical detection unit composed of a line light source and a group of line sensor cameras arranged in the main scanning direction sandwiching the color filter substrate, and the optical detection unit and the color filter substrate are relatively moved in the sub scanning direction, and pixels in the sub scanning direction are arranged. A stage synchronization control means for fetching the pixel information into the line sensor camera group for each time, and an image processing device group for fetching the image information from the line sensor camera group and detecting color unevenness and defects of each pixel are provided. .

[0013]

According to the above construction, when inspecting the pixels of the color filter substrate, a plurality of line sensor cameras are prepared in the main scanning direction, and the image information of each pixel aligned in the main scanning direction by this line sensor camera group. By collectively capturing, the image processing becomes easy, and the image processing device group can efficiently process a large number of pixel image data.
It is possible to detect minute defects and color unevenness of each pixel simultaneously with high resolution.

[0014]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 schematically shows a color filter inspection device of the present invention.

In the figure, the color filter substrate 1 for liquid crystal has a display size of, for example, 640.times.400 dots, and four of the displays are contained in one substrate 1, and each dot is circled in the figure. As shown in the enlarged view in FIG. 3, the RGB pixels 2 are aligned to form the dots 3 of the color filter. This pixel 2
Is 100 μm in the horizontal direction and 3 in the vertical direction on the CRT screen.
00 μm, at the time of inspection, the main scanning direction 5a of the inspection described later.
May be inspected in the horizontal direction or the vertical direction of the color filter substrate 1. In this example, a line sensor group described later is arranged in the horizontal direction of the color filter substrate 1.
It is designed to detect the horizontal direction of pixel 2.
The vertical direction of the pixel 2 may be detected.

This color filter substrate 1 has a stage 4
And is moved in the sub-scanning direction 5b indicated by the arrow in the figure.

Below the color filter substrate 1, a line light source 6 arranged in the main scanning direction is provided.
A line sensor camera group 7 including a CCD camera and the like is arranged in the main scanning direction above.

The line sensor camera group 7 is composed of a plurality of line sensor cameras arranged in the main scanning direction. Each line sensor 8 of the camera is in the main scanning for each dot, for example, one pixel is divided into seven. The inspection is performed in 20 sub-scanning directions, that is, one pixel is inspected in a divided area of 140 (= 7 × 20) dots. The image information of the line sensor camera group 7 is an 8-bit signal of 256 gradations and is input to the image processing device group 9 of the number corresponding to each line sensor 8.

Input of image information from the line sensor camera group 7 to the image processing apparatus group 9 is performed by a trigger signal 11 from a stage synchronization control means 10 for controlling the movement of the stage 4. The stage synchronization control means 10 continuously sends pixels arranged in the sub-scanning direction of the color filter substrate 1 to the stage 4, and sends a trigger signal 11 for each resolution of the line sensor camera to the image processing device group 9.
The image processing device group 9 receives the image information from the line sensor camera group 7 by the trigger signal 11.

The image processing apparatus group 9 quantizes the image of each pixel from the captured image information for one line in the main scanning direction for each pixel to obtain grayscale image information, and matches the main scanning direction and the sub scanning direction. Each pixel is determined and the density average is calculated for each pixel. In addition, the image processing device group 9 binarizes each pixel with a predetermined threshold value by referring to the average density of the pixels in order to check whether or not each pixel has a minute defect, and then, the pixel image has a block having a difference in density. To detect 4
Small defects are extracted by extracting connected components in the vicinity or 8 vicinity.

The processing information of the image processing device group 9 is input to the host computer 12. Host computer 12
Controls the stage synchronization control means 10 via the device control device 13.

Next, the operation of FIG. 1 will be described.

The stage synchronization control device 10 is operated from the host computer 12 via the device control device 13, and continuously moves the stage 4 pixel by pixel in the sub-scanning direction 5 on the color filter substrate 1 to be inspected. During this movement, the stage synchronization control device 10 outputs a trigger signal 11 to the image processing device group 9.

The line sensor camera group 7 includes the line light source 6
The light transmitted through the pixel in the main scanning direction is received, and the image information of the pixel is input to the image processing device group 9 by the trigger signal 11.

Pixel image information input to the image processing device group 9 is RGB in the sub-scanning direction in the case of the color filter substrate 1 having vertical stripes, as shown by magnified circles.
The pixels are aligned and there is a regularity in the arrangement of the RGB pixels, so it can be easily determined which of the RGB pixel image information. Therefore, the host computer 12 knows whether the pixel image information input to the image processing apparatus group 9 is RGB by storing the type of the color filter substrate 1 to be inspected in advance.

The image processing device group 9 determines each pixel (pixel number 1920 = 6) from the captured image information in the main scanning direction.
Image processing is performed every 40 dots × 3) to detect the density average value and minute defects. The information for one pixel line is sent to the host computer 12 and stored therein.

When all the pixels in the sub-scanning direction of the color filter substrate 1 are inspected and stored in the host computer 12 in this manner, the computer 12 causes each display (in the example, one color filter substrate 1 to display). (4 displays are manufactured in one piece), whether there is color unevenness for each RGB color of each pixel, whether the color unevenness is within the allowable value, and whether there are minute defects due to dust etc. It is determined whether or not the display is successful, and the content of the success or failure and the cause of the defect are displayed for each display.

2 and 3 show a concrete system configuration of the embodiment shown in FIG.

The stage 4 supporting the color filter substrate 1 is screwed into a ball screw 15 extending in the sub-scanning direction, the ball screw 15 is connected to an X motor 16, and the ball screw 15 is rotated by the rotation of the X motor 16. Stage 4
Can be moved in the sub-scanning direction (X direction). The color filter substrate 1 is held on the rotary table 4a of the stage 4, and the table 4a is rotated by the rotation of the θ motor 17.
Is adjusted so that the pixels of the color filter substrate 1 are aligned with the sub-scanning direction. Also, Y
The position of the micro camera 19 is adjusted by the motor 18, and the defective portion of the color filter substrate 1 can be confirmed using the camera controller 20 and the monitor 21.

The line sensor camera group 7 includes a Z motor 22.
The vertical position is finely adjusted by the rotation of, and the focus of each pixel image received by the line sensor camera group 7 from the line light source 5 through the color filter substrate 1 can be adjusted.

The motors 16, 17, 18, 22 are operated by command signals from the motor drive unit 23.
Adjustments of the rotation angle θ of the table 4a of the stage 4, the Y direction position of the micro camera 19 and the Z direction position of the line sensor camera group 7 are performed by the sensors 25, 26 and 27, respectively.
The Y and Z origin positions and the upper and lower limit position signals are detected, these signals are input to the pulse motor control circuit 30, and the origin position and the upper and lower limit position signals are output to the motor drive unit 23.

The rotation of the X motor 16 is detected by the linear encoder 31, and its signal is synchronized and servo circuit 32.
Is input to The origin position and the upper and lower limit positions of the stage 4 in the sub-scanning direction are detected by the sensors 33 and 34, respectively, and the sensor signals are input to the synchronization & servo circuit 32. A line sensor clock signal and a line sensor synchronization signal are input from the line sensor camera group 7 to the synchronization & servo circuit 32.

The image data, the synchronizing signal, and the clock signal from the line sensor camera group 7 are input to the image processing device groups 35A and 35B, respectively.

The synchronization & servo circuit 32 receives the line sensor clock signal and the line sensor synchronization signal and outputs a sub-scanning command to the motor drive unit 23 so that the stage 4 moves in the sub-scanning direction of the color filter substrate 1. The position is detected by the signal from the linear encoder 31, and the pixel information for one line in the sub-scanning direction is captured by the image processing device groups 35A and 35B, and then a trigger signal is output to the image processing device group 35A.

The image processing device groups 35A and 35B image-process each pixel for one line that has been taken in,
The data is output to the host computer 12 side via the bus 36.

In the line light source 6, a light source power source 38 is connected to the VME bus 36 via an input / output device 39, and the amount of light from the line light source 6 is adjusted.

In the figure, 40 is a memory, 41 is a CPU, 4
2 is a display keyboard controller, 43 is a color monitor, 44 is a keyboard and mouse, 45 is a hard disk, and 46 is an external network.

In the above, as shown in FIG. 2, the pixel image information from each line sensor 8 of the line sensor camera group 7 is input to the gain adjusting circuit 50 so that the light receiving amount of each line sensor becomes constant. After the gain is adjusted and then the light amount of the line light source 5 is adjusted by the illumination light correction circuit 51, pixel image information for one line is input to each picture element detection circuit (image processing device group) 9, The density average value and minute defect information of each pixel are detected. These pieces of information are sent to the data synthesizing circuit 53 through the data compressing circuit 52, where they are synthesized with the display 1 screen information, the information irrelevant to the pixel is removed by the noise removing circuit 54, and then by the color separation circuit 55. The color nonuniformity feature extraction circuit 56 detects the color nonuniformity of each color (RGB) and a minute defect, and the defect pass / fail circuit 57 discriminates them.

In the above-described embodiment, the line sensor camera group 7 is formed by arranging a plurality of line sensors 8 in the main scanning direction.
This is because the number of dots is limited, and if a long line sensor is prepared, the color filter substrate 1 may be detected by one line sensor. Further, the inspection direction of the color filter substrate 1 is not limited to the example shown in the figure, but may be rotated by 90 degrees and the vertical direction of the display may be detected as the main scanning direction. In this case, in the vertical stripe liquid crystal, the pixel information in one main scanning direction is either RGB,
The efficiency of inspection is improved.

[0041]

In summary, according to the present invention, when the pixels of the color filter substrate are inspected, the image information of each pixel is collectively fetched into the image processing device group by the line sensor camera group, thereby performing the image processing. Becomes easier,
Image data of a large number of pixels can be processed efficiently, and minute point defects and color unevenness of each pixel can be simultaneously detected with high resolution.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a block of a detection circuit in the present invention.

FIG. 3 is a diagram showing a specific system configuration example in FIG.

[Explanation of symbols]

 1 Color Filter Substrate 2 Pixel 4 Stage 5a Main Scanning Direction 5b Sub-scanning Direction 6 Line Light Source 7 Line Sensor Camera Group 9 Image Processing Group 10 Stage Synchronous Control Means

Front page continuation (72) Inventor Tomohiko Shioda 3-15-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toni Technical Center (72) Inventor Keizo Oishi 3-1-1, Toyosu, Koto-ku, Tokyo No. Ishikawajima Harima Heavy Industries Co., Ltd. Toni Technical Center (72) Inventor Kengo Matsuo 3-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd. Toji Technical Center

Claims (1)

[Claims] 1. A color filter inspecting device for optically inspecting each color pixel of a color filter substrate, wherein a color filter substrate is sandwiched between the line light source and a line sensor camera group arranged in the main scanning direction. Means, the optical detection means and the color filter substrate are relatively moved in the sub-scanning direction, and stage synchronization control means for fetching pixel information into the line sensor camera group for each pixel in the sub-scanning direction, and an image from the line sensor camera group An image processing device group that captures information and detects color unevenness and defects of each pixel.