JP2003329597A - Method for inspecting stain in color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter stain inspecting method for humans to perform final judgment on quality by observing the enlarged picked-up image of a color filter on the vicinity of a defect location and a detected location at an automatic visual inspection apparatus and to easily inspect local stains without requiring time or labor. <P>SOLUTION: The vicinity of the detected location in an enlarged state of the color filter 16 is picked up by a color camera 11 and displayed on a monitor 14a. Acquired picked-up image data is resolved into the three primary colors of red, green, and blue at an image processing device 15 to acquire red component image data, green component image data, and blue component image data. Pixel data of color components having large absorption is selected from among the red component image data, the green component image data, and the blue component image data on picture element parts of the color filter to be observed. The pixel data of the selected color components is selectively highlighted in light and shade and displayed on a monitor 14b, and quality is judged by observing the displayed image on the monitor. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes a final OK / NG determination by observing a photographed image in which a color filter is enlarged in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus. The present invention relates to a stain inspection method for a color filter to be emitted.

[0002]

2. Description of the Related Art In recent years, with the progress of computerization, display devices have been used in many fields and places.
LCD that operates as a shutter to block external light from passing through instead of the cathode ray tube type display unit
A liquid crystal display (abbreviation of Liquid Crystal Display, also called a liquid crystal display) is often used as a display unit of a personal computer or a color television. The demand for LCDs for personal computers or mobile phones is rapidly increasing, and these LCDs are increasingly required to have finer pixels and lower costs. With this, these LCDs
As for the color filter (hereinafter, also referred to as CF) for use in the pixel, further refinement of the pixel and cost reduction of its manufacture are required. For the production of color filters for these liquid crystal displays, the pigment dispersion method,
A dyeing method, an electrodeposition method, a printing method, and an inkjet method are known. In the pigment dispersion method, a step of forming a photosensitive resin layer in which a pigment is dispersed on a substrate and patterning the photosensitive resin layer to obtain a monochromatic pattern is repeated three times.
The G and B color filter layers are formed. The dyeing method is to coat a glass substrate with a water-soluble polymer material, which is a material for dyeing, pattern it into a desired shape by a photolithography process, and then immerse the obtained pattern in a dyeing bath for coloring. The step of obtaining the pattern is repeated three times to obtain R, G, B color filter layers. In the electrodeposition method, a transparent electrode is patterned on a substrate and immersed in an electrodeposition coating solution containing a pigment, a resin, an electrolytic solution, etc.
The step of electrodepositing the color is repeated three times to apply R, G, and B separately, and then the resin is heat-cured to form the color layer. In the printing method, a pigment is dispersed in a thermosetting resin, R, G, and B are applied separately by repeating printing three times, and then the resin is thermally cured to form a colored layer. In the inkjet method, a liquid containing a colorant (hereinafter, also referred to as ink or paste) is discharged from an opening such as a nozzle or an orifice to form a color filter portion.

However, in the electrodeposition method, since the pattern shape that can be formed is limited, in the current technology, the TFT is used.
It is difficult to apply to the LCD of the system, the printing method is
Fine pitch patterns are difficult to form due to poor smoothness, and there is a problem that inkjet control and adjustment are difficult with the inkjet method, and it cannot be said that it is in a practical stage yet. Therefore, finer pixels are required. At present, the pigment dispersion method and the dyeing method are the mainstream as a method for manufacturing a color filter for a liquid crystal display. In the pigment dispersion method and the dyeing method, it is necessary to repeat the same process three times in order to color the three colors of R, G, and B, and the entire process is long and complicated, and the created filter part has a defect. In many cases, the defective portion is detected, and after that, a correction process for correcting the defective portion is performed as necessary.

In such a color filter manufacturing process, it is difficult to completely prevent foreign matter from adhering to a mask for photolithography even in an environment such as a clean room in which a small amount of dust is generated. Various defects occur due to the adhesion of particles, defective exposure, and the like. And
White areas of the color filter, black matrix (B
(Also referred to as M), a local defect such as a protrusion (also referred to as a micro defect) is detected by a person by magnifying and observing the vicinity of the detection position where the defect candidate is detected by the automatic visual inspection apparatus, or Further, visual observation is further performed by a predetermined method to determine the final OK / NG.

By the way, local spots, which are one of the defects of the color filter, are often caused by defective projections.
Most of them can be detected by an automatic visual inspection device, but the final OK / NG judgment of the spot by magnifying the human is
In addition to requiring time and labor, the substrate on which the color filter is formed is manually handled, which may cause new scratches, stains, and defects. Note that, here, when the colored layer is formed on the foreign matter at a portion where the density is partially different from that of the peripheral portion, the portion becomes a raised protrusion, and this portion is called a protrusion. However, the protrusions are generally spot-shaped,
It becomes a stain part. Usually, the above-mentioned magnified observation of the person is to use a color video camera, photograph a color filter as it is, and observe the magnified photographed image. And
After this magnified observation, if necessary, for example, the color filter was further covered with a mask, and only one color portion was visually observed to determine OK / NG. As described above, determining the quality of a local stain (whether the stain is within an allowable range) requires complicated work and is time-consuming.

[0006]

As described above, the inspection of local spots, which is one of the defects of the color filter, is
The work is complicated and time-consuming, and it is necessary to deal with it. The present invention addresses this, and specifically, a person observes a photographed image in which a color filter is magnified in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus, and a final OK result is obtained. It is an object of the present invention to provide a color filter stain inspection method for determining / NG, which enables local stain inspection to be performed easily and easily.

[0007]

According to the method of inspecting a spot of a color filter of the present invention, a person observes a photographed image in which a color filter is enlarged in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus. A method for inspecting a spot of a color filter for making a final determination of OK / NG, in which a color camera captures an image in the vicinity of a detection position of the color filter in an enlarged state, and obtains captured image data as R, G. , B
R component image data, G component image data, and B component image data, and then R component image data, G component image data, for the picture element portion of the color filter to be observed. From the B component image data, the image data of the color component with a large amount of absorption is selected, the image data of the selected color component is displayed on the monitor in a state where the shade is selectively emphasized, and the image displayed on the monitor is observed. The feature is that the determination of OK / NG is made. Alternatively, in the color filter stain inspection method of the present invention, a person observes a magnified image of the color filter in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus, and finally a final OK /
A method for inspecting a stain of a color filter for making an NG judgment, wherein:
As a light source, the light band-limited to only the absorption wavelength band, which is a wavelength band with a lot of absorption, is attached to the front of the lens of the camera, and a filter that limits the band only to the absorption wavelength band is attached, and enlarged with a monochrome camera. In the state, the vicinity of the detection position of the color filter was photographed, the photographed image data was obtained as monochrome image data, and then the obtained monochrome photographed image data was displayed on the monitor in a state in which the gradation was selectively emphasized and displayed on the monitor. It is characterized by observing an image and making a judgment of OK / NG. In the above, the LCD (Li
It is a method for inspecting a color filter for a liquid crystal display (stain). The picture element portion here means a colored layer portion of a predetermined color.

[0008]

With the above-described structure, the color filter stain inspection method of the present invention allows a person to obtain a photographed image in which the color filter is enlarged in the vicinity of a detection position detected as a defect position by the automatic visual inspection apparatus. Observe and final OK
/ The stain inspection method of the color filter that makes the judgment of NG,
This makes it possible to provide an inspection method that can easily and locally inspect spots. Specifically, a color camera photographs the vicinity of the detection position of the color filter in a magnified state, and the obtained photographed image data is converted into R, G, and B data.
R component image data, G component image data, and B component image data, and then R component image data, G component image data, for the picture element portion of the color filter to be observed. From the B component image data, the image data of the color component with a large amount of absorption is selected, the image data of the selected color component is displayed on the monitor in a state where the shade is selectively emphasized, and the image displayed on the monitor is observed. To determine OK / NG, or for the pixel portion of the color filter to be observed, as a light source, or as a light source, light band-limited to only the absorption wavelength band, which is a wavelength band with large absorption. In front of the lens of the camera, attach a filter that limits only the absorption wavelength band of the lens, and take a photograph of the vicinity of the detection position of the color filter in a magnified state with a monochrome camera. After obtaining the black-and-white image data, the obtained monochrome photographed image data is displayed on the monitor in a state where the grayscale is selectively emphasized, and by observing the image displayed on the monitor and determining OK / NG, Has achieved. In particular, LCD (Liquor) that requires miniaturization of pixels
It is effective for the spot inspection of the color filter for the id Crystal Display).

Here, a colored layer is formed on the foreign matter and colored.
The defect detection of the spot defect part when the layer is formed thick is
Easier to detect than conventional defect detection by observing captured images
The reason for this will be briefly explained below with an example.
Ku. Here, the film thickness of the spot defect part to be inspected is normal.
To simplify the explanation about the case of double the size
Therefore, the normal inspection wavelength is λ₁The transmittance is represented by τ₁
And the absorption wavelength of the colored layer to be inspected is λ₂Representative
The transmission factor τ₂And Where τ₁> τ₂so
is there. On the other hand, the transmittance of the normal part is τa, and the transmittance of the stain part is
When τn, the contrast of the stain area with respect to the normal area
Is defined as | τa−τn | / τa, Wavelength λ₁The contrast at │τ₁−τ₁ ²｜ / τ₁= 1-τ₁ Wavelength λ₂The contrast at │τ₂−τ₂ ²｜ / τ₂= 1-τ₂ Therefore, τ₁> τ₂From the wavelength λ₂In the
Last is wavelength λ ₁Greater than the contrast in
I hear The stain inspection method of the color filter of the present invention,
Basically, it is based on the same principle.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a color filter stain inspection method of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart of an embodiment of a color filter stain inspection method of the present invention, FIG. 2 is a schematic configuration diagram of an apparatus for carrying out an example of the embodiment, and FIG. 3 is an example of the embodiment. FIG. 4 is another schematic configuration diagram of an apparatus for carrying out the invention, FIG. 4 is a schematic configuration diagram of an apparatus for carrying out another embodiment of the color filter stain inspection method of the present invention, and FIG. 5 is a G component monochrome. 6 is a density histogram of an image, and FIG. 6 is a diagram for explaining the gradation enhancement. In FIG. 1, S1 to S10 indicate processing steps, and A1 is a view displaying photographed image data in the vicinity of a defect position of a color filter (a region including a defect portion). 1 to 4, 1 is an R colored portion (also referred to as a red colored portion or an R picture element portion), 2 is a G colored portion (also referred to as a green colored portion or a G picture element portion),
3 is a B coloring part (also called a blue coloring part or B picture element part), 11 is a color video camera, 12 is a microscope, 13 is a light source, 14
a and 14b are monitors, 15 is an image processing unit, 16 is a color filter (also referred to as CF), 17 is a holder, 21 is a color video camera, 22 is a microscope, 23 is a light source, and 24a.
24c are monitors, 25a to 25c are image processing units, 26
Is a color filter, 27 is a holder, 31 is a video camera, 32 is a microscope, 33 is a light source, 34 is a monitor, 35 is an image processing unit, 36 is a color filter, and 37 is a holder.

An example of an embodiment of the color filter stain inspection method of the present invention will be described with reference to FIG. This example is a spot defect inspection method for a color filter having an R colored layer, a G colored layer, and a B colored layer. A person expanded the color filter around the detection position detected as a defect position by an automatic visual inspection apparatus. Observe the captured image and make a final OK / NG
This is a method for inspecting a stain on a color filter for making the above judgment, which is carried out in the apparatus configuration shown in FIG. Simply,
In the apparatus configuration shown in FIG. 2, the color camera 11 photographs the vicinity of the detection position of the color filter 16 in an enlarged state, and the obtained photographed image data is decomposed into three primary colors of R, G, and B. After obtaining the component image data, the G component image data, and the B component image data, for each picture element of the color filter 16 to be observed, the R component image data,
From the G component image data and the B component image data, the image data of the color component that absorbs a lot is selected, and the image data of the selected color component is displayed on the monitor in a state where the shade is selectively emphasized and displayed on the monitor. The image is observed and the OK / NG judgment is made. The defect position of the manufactured color filter (S1) is detected in advance by an automatic visual inspection apparatus. (S2) Next, as shown in FIG. 2, an enlarged photographed image near the detection position is photographed by a color video camera (S3), and photographed image data (color image data) is obtained. (S4) The captured transmission magnified image of the color filter 16 is displayed as a color image on the monitor 14a for normal inspection. This image has an R colored portion (also referred to as a red colored portion and an R picture element portion) 1, a G colored portion (also referred to as a green colored portion and a G picture element portion) 2, and a B colored portion (blue) as indicated by A1 in FIG. It also includes a colored portion and a B picture element portion) 3 and can be seen on the monitor 14a shown in FIG. Next, the photographed image data (color image data) is decomposed into three primary colors of R, G, and B (S
5) Obtain R component image data, G component image data, and B component image data that are decomposed image data. (S
6) Next, for each picture element (which means each colored layer) of the color filter, the image data of the color component having a large absorption is selected from the R component image data, the G component image data, and the B component image data. , As image data for detecting a spot defect in each picture element. (S7) As described above, this is because defect detection can be obtained by obtaining image data of a color component having a large absorption for each picture element, rather than color image data captured by a color video camera. This is because it becomes easier. For example, R colored layer, G colored layer,
In the case of the spot defect inspection of the color filter having the B coloring layer,
Regarding the R colored layer, the G colored layer, and the B colored layer, the G component image data, the R component image data, and the G component image data thereof are set as the inspection target image data. Then, for each picture element, a gradation emphasis process for emphasizing the gradation of the image data of each component to be inspected is performed (S8), and the monitor display is performed on the monitor 14b. (S
9) Then, each displayed image is observed to judge the quality of the spot defect. (S10) In the device shown in FIG. 2, the captured image data (color image data) is output from the monitor 14b and input to the image processing device 15. The image processing unit 15 performs the processes from S4 to S8. To do.

The processing is basically the same for any of the picture elements (colored layers). Here, the B colored layer of the color filter having the R colored layer, the G colored layer, and the B colored layer (3 of A1 in FIG. 1) is used. (Corresponding to 1)), the density enhancement processing will be briefly described only in the case of the spot defect inspection. First, in the case of performing the spot defect inspection on the B colored layer, the image data of the G component is selected as the image data of the color component having a large absorption. (S7) For example, in the case of 8-bit gradation display, the gradation frequency distribution of the G component image data of the color filter having the R coloring layer, the G coloring layer, and the B coloring layer is as shown in FIG. The image data of the G component of the B coloring layer has a gradation width a in the range of gradation P1 to gradation P2. In this case, for the G component image data, the gradation enhancement processing is selectively performed with the gradation P1.
Since it is sufficient to emphasize the light and shade only in the range from to the gradation P2, the G component image data may be converted for each pixel by an output function as shown in FIG. 6, for example. In the case of the spot defect inspection on the R colored layer and the spot defect inspection on the G colored layer, basically, the same processing can be performed. In addition, a spot defect inspection in the R colored layer (corresponding to 1 of A1 in FIG. 1), the G colored layer (corresponding to 2 of A1 in FIG. 1)
The spot defect inspection in B and the spot defect inspection in the B colored layer (corresponding to 3 of A1 in FIG. 1) are inspection processes performed on the assumption that each colored layer has a spot defect.

Actually, since it is not known where the spot defect is located in the R coloring layer, the G coloring layer, and the B coloring layer, each coloring layer (each pixel) has a large absorption similarly. The image data of the color component is selected, and the gradation enhancement processing is selectively performed. For each colored layer, the three images that are shade-enhanced are arranged or displayed in a time-sharing manner. If the image processing apparatus 15 has a function of displaying different images on a plurality of monitors, it may be shown by connecting three RGB monitors to the image processing apparatus.

In the apparatus shown in FIG. 2, the R, G and B components are decomposed by using the image processing device 15. However, the color camera separately outputs the R, G and B components. Some models have functions, and if you use those functions,
As described above, a similar effect can be obtained by connecting an image processing device having a gradation enhancement function to each of the signals branched into R, G, and B. In FIG. 3, an image processing device 25a and a monitor 24a are for acquiring the image data of the R component and selectively displaying the image data in a shaded manner.
5b, the monitor 24b acquires the image data of the G component,
The image processing device 25c and the monitor 24c selectively display the image data of the B component and selectively display the image with the density enhancement. Depending on the degree of stains to be inspected, even if the image processing devices 25a, 25b, 25c of FIG.
The stains can be highlighted by only the image adjustment functions of a, 24b, and 24c.

As another example of the embodiment of the color filter stain inspection method of the present invention, a color camera is not used for each of the R component image data, the G component image data and the B component image data in FIG. Then, the form to obtain can also be mentioned. For example, a device as shown in FIG. 4 is used. For the picture element part of the color filter to be observed,
As a light source, a light band-limited to only the absorption wavelength band, which is a wavelength band with a large amount of absorption, is attached to the camera lens in front of the lens of the camera, and a filter that limits the band to only the absorption wavelength band is attached to the microscope. 32 is photographed in the vicinity of the detection position of the color filter 16 in the enlarged state. Then, after the captured image data is obtained as monochrome image data, the obtained monochrome captured image data is displayed on the monitor in a state where the grayscale is selectively emphasized, and the image displayed on the monitor is observed to determine OK / NG. It is something to put out. The grayscale highlighting method can be performed in the same manner as in the embodiment shown in FIG. In these cases, an optical filter is attached to the light source, the lens, or the camera. In these cases, the image is displayed on the monitor while the filter is exchanged and the image processing device emphasizes the shade depending on the color of the observation target.

[0016]

As described above, according to the present invention, in the vicinity of the detection position detected as a defect position by the automatic visual inspection apparatus, a person observes a photographed image in which the color filter is enlarged, and the final OK / NG result is obtained. It has become possible to provide an inspection method that can easily and locally perform an inspection of a local stain by a stain inspection method of a color filter that makes the determination.

[Brief description of drawings]

FIG. 1 is a flow chart of an embodiment of a color filter stain inspection method of the present invention.

FIG. 2 is a schematic configuration diagram of an apparatus for carrying out the example of the embodiment shown in FIG.

FIG. 3 is another schematic configuration diagram of an apparatus for carrying out the example of the embodiment shown in FIG.

FIG. 4 is a schematic configuration diagram of an apparatus for carrying out another embodiment of the color filter stain inspection method of the present invention.

FIG. 5 is a density histogram diagram of a G component monochrome image.

FIG. 6 is a diagram for explaining gradation enhancement.

[Explanation of symbols]

1 R colored part (also called red colored part or R picture element part) 2 G colored part (also called green colored part or G picture element part) 3 B colored part (also called blue colored part or B picture element part) 11 colors Video camera 12 Microscope 13 Light sources 14a and 14b Monitor 15 Image processing unit 16 Color filter (also called CF) 17 Holder 21 Color video camera 22 Microscope 23 Light source 24a to 24c Monitor 25a to 25c Image processing unit 26 Color filter 27 Holder 31 Video camera 32 microscope 33 light source 34 monitor 35 image processing unit 36 color filter 37 holder

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G051 AA73 AB06 AC04 CA04 CA11                       CB02 DA07 ED30                 2G086 EE05

Claims (3)

[Claims] 1. A stain inspection of a color filter, in which a person observes a photographed image in which a color filter is magnified and makes a final OK / NG determination in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus. In the method, a color camera captures an image in the vicinity of the detection position of the color filter in an enlarged state, and the obtained captured image data is set to R, G, and B.
Separated into primary colors, R component image data, G component image data,
After obtaining the B component image data, the image data of the color component having a large absorption is selected from the R component image data, the G component image data, and the B component image data for the picture element portion of the color filter to be observed. A stain of a color filter characterized in that the image data of the selected color component is displayed on the monitor in a state where the gradation is selectively emphasized, and the image displayed on the monitor is observed to determine OK / NG. Inspection method. 2. A stain inspection method for a color filter, in which a person observes a magnified image of a color filter and makes a final OK / NG determination in the vicinity of a detection position detected as a defect position by an automatic visual inspection apparatus. That is, with respect to the picture element portion of the color filter to be observed, as a light source, light band-limited to only the absorption wavelength band, which is a wavelength band with large absorption,
Or, in front of the camera lens, attach a filter that limits only the absorption wavelength band of the camera lens, and take a picture with the monochrome camera near the detection position of the color filter in a magnified state. After that, the obtained monochrome photographed image data is displayed on the monitor in a state where the grayscale is selectively emphasized, and the image displayed on the monitor is observed to make an OK / NG determination. Blemish inspection method. 3. The LCD (L
A stain inspection method for a color filter, which is a stain inspection method for a color filter for an equal crystal display.