JP3358331B2 - Color filter inspection device - Google Patents

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 apparatus for inspecting a color filter substrate for a liquid crystal display.

[0002]

2. Description of the Related Art Recently, color liquid crystal displays (640, etc.) such as TFTs compatible with multimedia have been used in laptop and notebook & book type personal computers in place of monochrome liquid crystals.
× 400 dots) have been widely adopted.

The structure of the liquid crystal panel in this color liquid crystal display is such that a transparent electrode and an FE are provided on a glass substrate.
T matrix layer, liquid crystal layer, transparent electrode, color filter,
Glass substrates are stacked, and polarizing plates are provided above and below both glass substrates.

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

[0005] The color filter is manufactured in a clean room. However, even if foreign matter of about several μm adheres to the color filter during manufacture, it is a defective product.

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

Therefore, as shown in Japanese Patent Application Laid-Open No. 5-332944, a foreign substance adhering to the surface of a color filter is exposed to light for inspection on the surface of the color filter by utilizing the fact that the surface protrudes in a mountain shape. There is an apparatus in which the presence or absence of a foreign substance is inspected by inspecting the smoothness of the surface of the filter by detecting the reflected light.

[0008]

However, the above-described inspection is based on the premise that the filter surface is raised by foreign matter, and if the surface is smooth even if foreign matter is mixed, there is a problem that the filter is regarded as a non-defective product. is there.

In addition to the contamination, it is necessary to check whether or not each of the RGB pixels has color unevenness in the surface direction in the inspection as a color filter. However, the color unevenness cannot be detected only by the foreign matter inspection. .

Japanese Patent Application Laid-Open No. 6-11455 discloses an apparatus for inspecting a defect of a color liquid crystal display.
This inspection method is to drive the manufactured color liquid crystal display and detect the luminance unevenness and the like. Even if the luminance unevenness is detected, this is an inspection of the final product. However, it cannot be determined whether the defect is caused by a defect of the FET or its driver.

An object of the present invention is to solve the above-mentioned problems and to provide a color filter inspection apparatus capable of detecting a defect for each color pixel and simultaneously detecting color unevenness.

[0012]

According to the present invention, there is provided a color filter inspection apparatus for optically inspecting each color pixel of RGB of a color filter substrate, wherein the color filter substrate is sandwiched between the color filter substrates. Line light sources arranged in the scanning direction and multiple division areas for each color pixel
With multiple line sensor cameras that inspect color pixels in the gamut
And optical detection means consisting of a constructed line sensor camera group, its every sub-scanning direction pixel causes relatively moving the optical detecting means and the color filter substrate in the sub-scanning direction
Stage synchronization control means for acquiring information on the divided areas of the line sensor camera group, and information on each divided area for each pixel from the line sensor camera group ,
Detects minute defects by detecting the difference in shading of each divided area in the cell image.
And an image processing device group for extracting color unevenness for each of the RGB colors of each pixel .

[0013]

According to the above arrangement, when inspecting the pixels on the color filter substrate, a plurality of line sensor cameras are prepared in the main scanning direction, and each of the pixels aligned in the main scanning direction is grouped by the line sensor cameras. Multiple for each pixel
Imported as image information in a number of divided areas at once
The image processing device detects defects for each pixel
Color unevenness is detected for each RGB color of each pixel.
As well as the image processing apparatus as an image processing apparatus group.
As a result, image data of a large number of pixels can be efficiently processed, and minute defects and color unevenness of each pixel can be simultaneously detected with high resolution.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 schematically shows a color filter inspection apparatus according to the present invention.

In the figure, a color filter substrate 1 for liquid crystal has a display size of, for example, 640.times.400 dots, and four displays are accommodated in one substrate 1. Each dot has a circle in the figure. As shown in the enlarged view, the pixels 2 of RGB are formed in alignment to form the dots 3 of the color filter. This pixel 2
Means that the horizontal direction of the CRT screen is 100 μm and the vertical direction is 3
At the time of inspection, the main scanning direction 5a
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 provided in the horizontal direction of the color filter substrate 1.
The horizontal direction of pixel 2 is detected,
The vertical direction of the pixel 2 may be detected.

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

A line light source 6 arranged in the main scanning direction is provided below the color filter substrate 1.
A line sensor camera group 7 composed of a CCD camera or 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, and each line sensor 8 of the camera performs main scanning for each dot, for example, one pixel is divided into seven parts. In the sub-scanning direction, inspection is performed in 20 divisions, that is, one pixel is inspected in a division area of 140 (= 7 × 20) dots. The image information of the line sensor camera group 7 is input to the image processing apparatus groups 9 corresponding to the number of the line sensors 8 as 8-bit signals of 256 gradations.

The input of image information from the group of line sensor cameras 7 to the group of image processing devices 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 the stage 4 pixels arranged in the sub-scanning direction of the color filter substrate 1 and sends a trigger signal 11 for each resolution of the line sensor camera to the image processing apparatus group 9.
The image processing apparatus group 9 takes in 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 on a pixel-by-pixel basis from the captured image information for one line in the main scanning direction to obtain grayscale image information and matches the main scanning direction with the sub-scanning direction. Each pixel is determined, and a density average is obtained for each pixel. The image processing apparatus group 9 binarizes each pixel at a predetermined threshold value with reference to the average density of the pixels in order to check whether or not each pixel has a minute defect. 4 to detect
A minute defect is extracted by extracting a connected component in the neighborhood or neighborhood of eight.

Processing information of the image processing apparatus 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 by the host computer 12 via the device control device 13, and moves the stage 4 on the color filter substrate 1 to be inspected continuously in the sub-scanning direction 5 in pixel units. 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 a 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 apparatus group 9 by the trigger signal 11.

The pixel image information input to the image processing apparatus group 9 is, as shown in an enlarged circle, if the color filter substrate 1 has a vertical stripe, the RGB image data in the sub-scanning direction.
Are arranged and there is regularity of each pixel of RGB, so that it is easy to determine which pixel image information is RGB. Therefore, the host computer 12 can determine which of the RGB pixel image information is input to the image processing apparatus group 9 by storing the type of the color filter substrate 1 to be inspected in advance.

The image processing apparatus group 9 determines each pixel (pixel number 1920 = 6) based on the acquired image information in the main scanning direction.
Image processing is performed every 40 dots × 3) to detect an average density value and a minute defect. The information for one line of the pixel is sent to the host computer 12 and stored therein.

When all of the pixels in the sub-scanning direction of the color filter substrate 1 have been inspected and stored in the host computer 12 in this manner, the computer 12 sends each display (in the example, one color filter substrate 1 4 displays are integrally manufactured), whether there is color unevenness for each of the RGB colors of each pixel, whether the color unevenness is within an allowable value, and whether there is a minute defect due to dust or the like. It determines whether each display is acceptable or not, and displays the contents of the acceptance or failure and the cause of the defect.

FIGS. 2 and 3 show a specific 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 a rotary table 4a of the stage 4, and the table 4a
Is finely adjusted so that the pixels of the color filter substrate 1 coincide 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
With the rotation of, the vertical position is finely adjusted, 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.

Each of the motors 16, 17, 18, and 22 is operated by a command signal from a motor drive unit 23.
Adjustment of the rotation angle θ of the table 4 a 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 sensors 25, 26, and 27, respectively.
The origin position and the upper and lower limit position signals of Y and Z 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 a linear encoder 31, and its signal is transmitted to a synchronous & 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. Further, a line sensor clock signal and a line sensor synchronization signal are input to the synchronization & servo circuit 32 from the line sensor camera group 7.

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

The synchronizing & servo circuit 32 receives the line sensor clock signal and the line sensor synchronizing signal, and outputs a sub-scanning instruction 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 a signal from the linear encoder 31, and after one line of pixel information in the sub-scanning direction is captured by the image processing device groups 35A and 35B, a trigger signal is output to the image processing device group 35A.

The image processing device groups 35A and 35B perform image processing on each pixel of the fetched one line,
The data is output to the host computer 12 via the bus 36.

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

In the figure, 40 is a memory, 41 is a CPU,
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 adjustment circuit 50 so that the light reception amount of each line sensor becomes constant. After the gain is adjusted, and then the amount of light 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 average density value and minute defect information of each pixel are detected. These pieces of information are sent to a data synthesizing circuit 53 via a data compression circuit 52, where they are synthesized into display 1 screen information, and information irrelevant to pixels is removed by a noise removing circuit 54, and then by a color separating circuit 55. The color unevenness of each color (RGB) and minute defects are detected by a color unevenness feature extraction circuit 56, and are determined by a defect pass / fail circuit 57.

In the above-described embodiment, the line sensors 8 are arranged in the main scanning direction to form the line sensor camera group 7.
Since the number of dots is limited, 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 illustrated example, 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 liquid crystal of the vertical stripe, the pixel information in one main scanning direction is any of RGB.
Inspection efficiency is improved.

[0041]

According to the above summary the present invention, when inspecting the color filter substrate pixels, providing a plurality of line sensor camera in the main scanning direction, in the line sensor camera groups, each aligned in the main scanning direction Pixel
Image information in multiple divided areas for each pixel
And captures them with an image processing device.
Detects defects for each pixel and the RGB color of each pixel
Color unevenness can be detected every time, and the image processing device
By using a group of processing devices , image data of a large number of pixels can be efficiently processed, and minute defects and color unevenness of each pixel can be simultaneously detected with high resolution.

[Brief description of the drawings]

FIG. 1 is a diagram showing one 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 example of a system configuration in FIG. 1;

[Explanation of symbols]

 Reference Signs List 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 device group 10 stage synchronization control means

Continuation of the front page (72) Inventor Tomohiko Shioda 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries Co., Ltd. East 2 Technical Center (72) Inventor Keizo Oishi 3-1-1, Toyosu, Koto-ku, Tokyo No. Ishikawa Shima-Harima Heavy Industries Co., Ltd., in Toji Technical Center (72) Inventor Kengo Matsuo 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries, Ltd. In Toji Technical Center (56) References JP-A-5 JP-A-288640 (JP, A) JP-A-7-103911 (JP, A) JP-A-7-98282 (JP, A) JP-A-6-58839 (JP, A) JP-A-7-146211 (JP, A) ) Jpn. 4-55535 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 11/00 G01N 21/84-21/958

Claims (1)

(57) [Claims] In a color filter inspection apparatus for optically inspecting each color pixel of RGB of a color filter substrate, a line light source disposed in a main scanning direction with a color filter substrate interposed therebetween and a plurality of pixels for each color pixel. Split
Multiple line sensor cameras inspect color pixels in an area
Optical detection means consisting of a group of line sensor cameras, and the optical detection means and the color filter substrate are relatively moved in the sub-scanning direction and each pixel in the sub-scanning direction.
Stage synchronization control means for taking the information of the divided area into the line sensor camera group, and taking the information of each divided area for each pixel from the line sensor camera group , and
Detects minute defects by detecting the difference in density of each divided area in the xel image
And color unevenness for each RGB color of each pixel.
And a group of image processing devices for detecting color filters.