JP2009041930A - Color filter appearance inspection method - Google Patents

Abstract

The present invention provides a color filter appearance inspection method for identifying in which color pixel a color filter defect has occurred at the stage of inspection, and performing defect inspection applying different standards for each color.
A density range of non-defective inspection pixels such as colored pixels is set in advance, and the number of detected inspection pixels for determining colored pixels of each color is set when an inspected object is imaged. A contour portion R3 is provided around the position information of D3, and each density of the contour inspection pixel is obtained and counted for each density range in comparison with the density range. Next, the number of contour inspection pixels is the number of the detection inspection pixels. If the number is greater than or equal to the number, the defect is determined to be the colored pixel, and the size of the defect is compared with the size of the allowable defect of the color to determine whether or not the defect is possible.
[Selection] Figure 11

Description

  The present invention relates to an appearance inspection of a color filter, and in particular, an inspection stage as to which color pixel is an appearance defect that occurs in a manufacturing process of a color filter for a liquid crystal display device. And a color filter appearance inspection method for performing defect inspection using different standards for each color of the colored pixels.

FIG. 7 is a plan view schematically showing an example of a color filter used in the liquid crystal display device. FIG. 8 is a cross-sectional view taken along line XX ′ of the color filter shown in FIG.
As shown in FIGS. 7 and 8, the color filter (4) used in the liquid crystal display device has a black matrix (41), a colored pixel (42), and a transparent conductive film (43) on a glass substrate (40). Are formed sequentially.
7 and 8 schematically show the color filter, and the color pixel has a square shape. In addition, although 12 colored pixels (42) are shown, in an actual color filter, for example, a large number of colored pixels of about several hundred μm are arranged on a 17-inch diagonal screen.

As a method for manufacturing a color filter having the above structure used in many liquid crystal display devices, a black matrix is first formed on a glass substrate to form a black matrix substrate, and then the black matrix on the black matrix substrate is used. A method is widely used in which a colored pixel is formed by aligning with the pattern, and a transparent conductive film is aligned and formed.
The black matrix (41) is a matrix having light shielding properties, the colored pixels (42) have, for example, red, green, and blue filter functions, and the transparent conductive film (43) is transparent. Provided as a simple electrode.

The black matrix (41) is composed of a matrix portion (41A) between the colored pixels (42) and a frame portion (41B) surrounding the peripheral portion of the region (display portion) where the colored pixels (42) are formed. Yes.
The black matrix determines the position of the colored pixels of the color filter, makes the size uniform, and shields unwanted light when used in a display device, making the image of the display device uniform and uniform. In addition, it has a function of making an image with improved contrast.

For the production of this black matrix substrate, a metal or a metal compound such as chromium (Cr) or chromium oxide (CrO _x ) as a black matrix material is formed into a thin film on a glass substrate (40). An etching resist pattern is formed on the formed thin film using, for example, a positive photoresist, and then an exposed portion of the formed metal thin film is etched and an etching resist pattern is stripped, and Cr, CrO _A method has been adopted in which a black matrix (41) made of a metal thin film such as _X is formed.
Alternatively, the black matrix (41) is formed on the glass substrate (40) by photolithography using a black photosensitive resin for forming a black matrix.

In addition, the colored pixels (42) are formed by providing a coating film on the black matrix substrate using, for example, a negative photoresist in which a pigment or other pigment is dispersed, and exposing and developing the coating film. A method of forming colored pixels is used.
The transparent conductive film (43) is formed on the black matrix substrate on which the colored pixels are formed by, for example, forming a transparent conductive film by sputtering using ITO (Indium Tin Oxide). .

The appearance defects generated in the manufacturing process of the color filter are divided into a wide area defect and a narrow area (point) defect depending on the size (range).
Wide area defects are represented by color unevenness, which is a color density defect over a wide range on a color filter. Color unevenness is a shade of color that slightly changes and covers a wide range, so it is easy to visually confirm and difficult to detect with an inspection apparatus.

In addition, since the size of the narrow area (point) defect is minute, it is easy to detect with an inspection apparatus and difficult to visually confirm.
Point defects include: 1) black matrix chipping, colored pixel white spots (pinholes), colored pixel half white spots, transparent conductive film gaps (pinholes), 2) black matrix remaining, It is roughly divided into the remaining color pixels, the remaining pattern such as mixed colors, 3) adhesion of foreign matters (black defects), and 4) scratches.

  Inspection of these defective items is often performed for each manufacturing process. For example, after the black matrix is formed, items such as black matrix chipping and black matrix remaining generated during the manufacture of the black matrix are inspected. In addition, after the formation of the colored pixels, items such as white spots (pinholes) in the colored pixels, half white spots in the colored pixels, remaining of the colored pixels, adhesion of foreign matter (black defects), color unevenness, etc. Inspection is performed.

The above inspection is composed of two types of inspection, that is, transmission inspection of a color filter using transmitted light and reflection inspection using reflected light. Transmission inspection is performed for defects that are accurate and easy to detect defects and to identify good or bad by the transmission inspection. In addition, a reflection inspection is performed for a defect that is accurate and easy to detect a defect and to discriminate pass / fail by the reflection inspection. That is, a transmission inspection and / or a reflection inspection is performed depending on the nature of each defect.
In the above inspection, the defect item to be inspected, the level for identifying good or bad, etc. are appropriately set depending on the item.

FIG. 1 is a side view showing an outline of an example of an automatic visual inspection apparatus. FIG. 2 is a plan view thereof. As shown in FIGS. 1 and 2, the automatic appearance inspection apparatus includes a surface plate (11), an inspection stage (12), a reflection light source (13A), a reflection inspection camera (14A), and a transmission light source (13B). , A transmission inspection camera (14B), and an image processing device (15).
The color filter (inspected object) (10) placed on the inspection stage (12) undergoes inspection while being conveyed in the X-axis direction, as indicated by the white arrow in FIG.

The light source for reflection (13A) irradiates the surface of the color filter (inspected object) (10) that has been transported with the emitted inspection light obliquely from above. The reflected light reflected by the surface of the color filter (10) is received by the reflection inspection camera (14A), and the signal is transmitted to the image processing device (15).
Further, the transmission light source (13B) irradiates the back surface of the color filter (inspected object) (10) that has been transported with the emitted inspection light vertically from below. The transmitted light transmitted through the color filter (10) is received by the transmission inspection camera (14B), and the signal is transmitted to the image processing device (15). The image processing device (15) processes the transmitted signal to identify defects.

As shown in FIG. 2, the reflection inspection camera (14A) in this example has eight reflection inspection cameras (1) (14A (1)) to reflection inspection cameras (8) (14A (8)). It consists of a reflection inspection camera, which is the color filter (10) transport direction (X-axis direction)
Are arranged in a row at right angles to each other, that is, in the width direction (Y-axis direction) of the color filter (10).
The reflection light source (13A) is composed of eight reflection light sources including the reflection light source (1) (13A (1)) to the reflection light source (8) (13A (8)). Corresponding to the arrangement of the inspection cameras (1) (14A (1)) to the inspection cameras for reflection (8) (14A (8)), they are sequentially arranged in a line in the Y-axis direction.

  Further, the transmission inspection camera (14B) is composed of eight transmission inspection cameras of the transmission inspection camera (1) (14B (1)) to the transmission inspection camera (8) (14B (8)). This corresponds to the arrangement of the reflection inspection cameras (1) (14A (1)) to the reflection inspection cameras (8) (14A (8)) and is sequentially arranged in a line in the Y-axis direction. The transmissive light source (13B) is composed of eight transmissive light sources including a transmissive light source (1) (13B (1)) to a transmissive light source (8) (13B (8)). Corresponding to the array of transmission inspection cameras (1) (14B (1)) to transmission inspection cameras (8) (14B (8)) below the surface plate (11), sequentially in a line in the Y-axis direction. It is arranged.

  FIG. 3 is a plan view for explaining a scanning area on the color filter (inspected object) (10) by the reflection inspection camera and the transmission inspection camera. The size of the color filter (10) shown in FIG. 3 is, for example, about width (W) 1500 mm × length (L) 1800 mm. As shown in FIGS. 1 and 2, the reflection inspection camera (14A) and the transmission inspection camera (14B) are fixed, and the color filter (10) is placed on the inspection stage (12). As indicated by the white arrow, the color filter (inspected object) (10) plane is scanned from the left to the right in FIG.

  Reference numeral (Sr (1)) represents a scanning region of the inspection camera for reflection (1) (14A (1)) and the inspection camera for transmission (1) (14B (1)). Similarly, reference numerals (Sr (2)) to (Sr (8)) denote [reflection inspection camera (2) (14A (2)) and transmission inspection camera (2) (14B (2)), respectively. ] To [scanning areas of the inspection camera for reflection (8) (14A (8)) and the inspection camera for transmission (8) (14B (8))].

For example, a line sensor is often used as an image sensor for the reflection inspection camera (14A) and the transmission inspection camera (14B).
In the example shown in FIG. 3, each of the reflection inspection camera (14A (1) to 14A (8)) and the transmission inspection camera (14B (1) to 14B (8)) corresponds to a color filter (inspected object). ) (10) This is an example in which imaging of the scanning region (Sr (1) to Sr (8)) on the upper side is completed by one scanning from right to left in FIG.
For example, in order to increase the imaging resolution, there are cases where one scan area is divided into two scans divided into two in the vertical direction in FIG. 3, or four scans divided into four in the vertical direction.

  FIG. 4 is an explanatory diagram schematically illustrating an example of a color filter image captured by the inspection camera. As shown in FIG. 4, the color filter as the object to be inspected is a state in which red, green, and blue colored pixels (22) are formed on the glass substrate on which the black matrix (21) is formed and the appearance inspection is finished. belongs to. Each of the colored pixels (22) of each color is continuously arranged in the Y-axis direction in FIG. In the X-axis direction, a continuous row of each color is repeatedly arranged in the order of red, green, and blue. This is an example in which a defect (D) occurs in a red colored pixel (P2).

FIG. 5A is an explanatory diagram in which a portion surrounded by a dotted line of the red colored pixel (P1) at the left end shown in FIG. 4 is enlarged. FIG. 5B is an explanatory diagram in which a portion surrounded by a dotted line of the adjacent red colored pixel (P2) is enlarged.
This inspection apparatus employs a comparison method in which defects are detected by comparing adjacent colored pixels (22) of the same color on the assumption that the defects occur randomly. In FIG. 4, the brightness (intensity of light incident on the inspection camera) of the specific portion (Ki) of the red colored pixel (P1) at the left end and the specific portion (Ki) of the adjacent red colored pixel (P2). Identify defects by the difference in brightness.

One colored pixel is divided into a plurality of regions (K1 to Kn). One area divided into a plurality is one unit on a colored pixel to be compared for inspection, and hereinafter, this one area is referred to as an inspection pixel in the present invention.
First, the brightness of the first inspection pixel (K1) of the red coloring pixel (P1) at the left end is compared with the brightness of the first inspection pixel (K1) of the adjacent red coloring pixel (P2). The brightness of the second inspection pixel (K2) of the coloring pixel (P1) is compared with the brightness of the second inspection pixel (K2) of the coloring pixel (P2). The presence / absence of a defect in the colored pixel (P2) with respect to the pixel (P1) is identified.

  In FIG. 5, since the difference between the brightness of the i-th inspection pixel (Ki) of the colored pixel (P1) and the brightness of the i-th inspection pixel (Ki) of the colored pixel (P2) is large, it is identified as a defect. become. For this brightness, for example, a numerical value displayed in 256 levels obtained by dividing the luminance range reproduced by the inspection camera by 8 bits (256) is used. When the difference between the numerical values is equal to or larger than a preset threshold value, coloring is performed. The i-th inspection pixel (Ki) of the pixel (P2) is identified as a defect. Hereinafter, in the present invention, the numerical value displayed in 256 levels is referred to as the density of the inspection pixel, and the numerical value range is referred to as the density range.

  Now, the defect detected by the automatic visual inspection apparatus is confirmed by the operator on the monitor using, for example, a review apparatus installed in a subsequent process of the automatic visual inspection apparatus. The allowable defect size is not necessarily uniform, and in actual work, the allowable defect size may be defined as a different value for each color of the colored pixel.

However, since the automatic visual inspection apparatus cannot recognize the color of the colored pixel in which the defect has occurred, the automatic visual inspection apparatus has a defect if the allowable defect size differs for each color of the colored pixel. The defect size is detected by matching the detection size for detecting the smallest value.
Therefore, in the review apparatus, an operation is performed in which the defect detected by the automatic appearance inspection apparatus is reconfirmed according to a different numerical value for each color of the colored pixels.

FIG. 6 is an explanatory diagram of an example of a defect that has occurred in a red colored pixel. This is an example of a color filter in which a defect (D2) having a diameter (φ) of 40 μm is generated in a red colored pixel (22R).
For example, if the permissible defect size is 30 μmφ for the blue colored pixel (22B), 40 μmφ for the red colored pixel (22R), and 50 μmφ for the green colored pixel (22G), the automatic visual inspection apparatus detects the detected size. The defect is detected in accordance with the smallest value of 30 μmφ.

Since the defect (D2) of the red colored pixel (22R) shown in FIG. 6 is a defect having a diameter (φ) of 40 μm, it is detected as a defect by the automatic visual inspection apparatus set to 30 μmφ. On the other hand, in the review apparatus, since it is confirmed with 40 μmφ that is an allowable defect size in the red colored pixel (22R), it is confirmed that the defect is not a defect.
That is, in the review device, the burden of checking whether or not the defect is detected as a defect by comparing the defect detected by the automatic appearance inspection device with a standard different for each color of the colored pixel remains.
Japanese Patent No. 3287873

The present invention has been made in order to solve the above-mentioned problems, and in the inspection stage, it is specified which color defect is caused by an appearance defect generated in the color filter manufacturing process. Another object of the present invention is to provide a color filter appearance inspection method capable of performing defect inspection applying different standards for each color of colored pixels.
As a result, a color filter having a defect that does not correspond to a different standard for each color of the colored pixel is not reconfirmed by the review apparatus, which is a subsequent process, and the burden on the review apparatus is reduced.

The present invention is a method for inspecting defects that occur in the manufacturing process of a color filter.
A) In advance, 1) a non-defective color filter is imaged with an inspection camera, and the density range of the inspection pixel (non-defective product inspection pixel) in the colored pixels of the imaged first color is set.
2) Later, when the inspected object color filter is imaged by the inspection camera, the determination threshold of the first color necessary for determining that the imaged colored pixel is the first color is 1) above Set the number of inspection pixels (detection inspection pixels) with the density in the set density range,
3) The above 1) is performed for each of the second color pixel, the third color pixel, the black matrix, and the other parts, and the density range of the inspection pixel (non-defective inspection pixel) in each is set.
4) Perform the above 2) for each of the above parts, and set the number of inspection pixels (detection inspection pixels) as a determination threshold value in each of the parts,
B) Next, 1) An image of the color filter to be inspected is picked up by the inspection camera, and when a defect is detected, a contour having a constant width is formed around the defect from position information of a plurality of inspection pixels constituting the defect. Set the
2) The respective densities of a plurality of inspection pixels (contour inspection pixels) constituting the contour portion are obtained, and the respective densities of the obtained inspection pixels (contour inspection pixels) are set in A) 1) and 3). The number of inspection pixels (contour inspection pixels) having a density in the corresponding density range in comparison with the density range of the first color pixel and each inspection pixel (non-defective inspection pixel) in each of the above-mentioned parts. For each density range of inspection pixels (non-defective product inspection pixels)
C) Next, 1) The number of inspection pixels (contour inspection pixels) constituting the contour portion in the density range of the inspection pixels (non-defective inspection pixels) of the colored pixels of the first color obtained by aggregation is A) If the number of inspection pixels (detection inspection pixels) as the determination threshold of the first color set in 2) is equal to or greater than that, it is determined that the contour portion and the defect are in the colored pixels of the first color,
2) Perform 1) above for each part, and if the number of each inspection pixel (detection inspection pixel) set in A) 4) is equal to or greater than that, determine that the contour and the defect are in the part. And
D) Next, the size of the defect is compared with the size of the defect of the color of the standard of the size of the defect determined for each color of the colored pixel, and it is determined whether or not it is an allowable defect.
A color filter appearance inspection method characterized by inspecting a defect.

  Further, the present invention is the color filter appearance inspection method according to the above invention, wherein the constant width in the contour portion having a constant width around the defect is 1 to 5 in number of inspection pixels. This is a filter appearance inspection method.

In the present invention, A) in advance, 1) a non-defective color filter is imaged by an inspection camera, and the density range of inspection pixels (non-defective inspection pixels) such as colored pixels of each color is set. When each of the inspection pixels having the density in the density range set as described above is used as each determination threshold necessary for determining that the colored pixels of each color are the colored pixels of each color. Set the number of detection inspection pixels)
B) Next, 1) When an inspection object color filter is imaged by an inspection camera and a defect is detected, a contour portion having a constant width is formed around the defect based on positional information of a plurality of inspection pixels constituting the defect. 2) Obtain the respective densities of a plurality of inspection pixels (contour inspection pixels) constituting the contour portion, and determine the densities of the obtained inspection pixels (contour inspection pixels) for each color set above. In contrast to the density range of each inspection pixel (non-defective inspection pixel) such as a colored pixel, the number of inspection pixels (contour inspection pixels) having a density in the corresponding density range is determined for each inspection pixel (non-defective inspection pixel). Tally for each concentration range,
C) Next, 1) The number of inspection pixels (contour inspection pixels) constituting the contour portion in the density range of inspection pixels (non-defective inspection pixels) such as colored pixels of the respective colors obtained by aggregation is the A If it is equal to or greater than the number of inspection pixels (detection inspection pixels) as determination threshold values for each color set in (), the contour portion is determined to be in the coloring pixel,
D) Next, the size of the defect is compared with the size of the defect of the color of the standard of the size of the defect determined for each color of the colored pixel, and it is determined whether or not it is an allowable defect.
Since defects are inspected, the appearance defects that occur in the color filter manufacturing process are identified in the colored pixels of the color pixels at the inspection stage, and different standards are used for each color of the colored pixels. This is a color filter appearance inspection method capable of performing the applied defect inspection.
As a result, a color filter having a defect that does not correspond to a different standard for each color of the colored pixel is not reconfirmed by the review apparatus, which is a subsequent process, and the burden on the review apparatus is reduced.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 9 is an explanatory diagram schematically illustrating an example of a color filter image obtained by imaging colored pixels of a non-defective color filter with an inspection camera using a solid-state imaging device. As shown in FIG. 9, this non-defective color filter has red, green, and blue colored pixels (22R, 22G, and 22B) formed on a glass substrate on which a black matrix (21) has been formed and appearance inspection has been completed. Is in state. Each colored pixel is arranged continuously in the Y-axis direction in FIG. In the X-axis direction, a continuous row of each color is repeatedly arranged in the order of red, green, and blue.

One colored pixel is divided into a plurality of regions (inspection pixels) for comparison inspection, and the brightness (intensity of light incident on the inspection camera) of the divided inspection pixels is compared and used for inspection. In order to express the brightness level, a numerical value displayed in 256 levels obtained by dividing the luminance range reproduced by the inspection camera by, for example, 8 bits (256) is used. In the present invention, this numerical value is called the density of the inspection pixel.
The brightness of the inspection pixel of the first color, for example, the red colored pixel is a density displayed in 256 levels of the inspection pixel obtained by dividing the red colored pixel captured by the inspection camera.
This density is determined by the product of the spectral characteristics of the red colored pixels and the spectral sensitivity of the inspection camera.

  In the present invention, first, a non-defective color filter is picked up by an inspection camera, and a density range of inspection pixels (non-defective inspection pixels) in the picked-up first color, for example, red colored pixels is set. Subsequently, when the inspection object color filter is imaged with an inspection camera, an inspection having a density in the above density range as a red determination threshold necessary for determining that the captured colored pixel is red The number of pixels (detection inspection pixels) is set.

Table 1 shows a red colored pixel, a green colored pixel, a blue colored pixel, a black matrix, and other density ranges that constitute a non-defective color filter in an example of a specific color filter. As shown in Table 1, the density of the inspection pixel (non-defective product inspection pixel) in the red colored pixel of this example is in a range of about 151 to 180 in numerical values displayed in 256 levels. It is set.

  Similarly, the density range of the inspection pixel (non-defective product inspection pixel) in the green colored pixel is set to 131 to 150, the density range of the inspection pixel (non-defective product inspection pixel) in the blue colored pixel is set to 101 to 130, and black The density range of inspection pixels (non-defective product inspection pixels) in the matrix is set to 000 to 100, and the density range of other inspection pixels (non-defective product inspection pixels) is set to 181 to 255.

また、表２に示すように、被検査体カラーフィルタを撮像した着色画素が赤色であることを判定するために必要な、上記１５１−１８０の範囲の濃度を有する検査画素（検出検査画素）の数は、精査した結果、５個以上であることを突き止め、赤色の判定閾値として、検査画素（検出検査画素）の数は５個と設定したものである。

Further, as shown in Table 2, the inspection pixels (detection inspection pixels) having the density in the range of 151 to 180 necessary for determining that the colored pixel obtained by imaging the color filter to be inspected is red. The number is determined to be 5 or more as a result of careful examination, and the number of inspection pixels (detection inspection pixels) is set to 5 as a red determination threshold.

  Similarly, the number of inspection pixels (detection inspection pixels) is five as the green determination threshold, the number of inspection pixels (detection inspection pixels) is five as the blue determination threshold, and the inspection pixels are as the black matrix determination threshold. The number of (detection inspection pixels) is set to 5, and the number of inspection pixels (detection inspection pixels) is set to 0 as another determination threshold.

  As shown in Table 1, the red color pixel, the green color pixel, the blue color pixel, the black matrix, and the other density ranges in the non-defective color filter are divided without overlapping each other. Thus, it can be said that it is preferable in the present invention for specifying which color pixel is a defect that each density range is clearly divided without overlapping.

In the color filter appearance inspection method according to the present invention, the inspection object color filter is inspected after setting the density range of the inspection pixels (non-defective inspection pixels) and the number of inspection pixels (detection inspection pixels). .
FIG. 10 shows an example of the color filter image when the inspection object color filter in the example of the specific color filter is imaged by the inspection camera and a defect is detected. As shown in FIG. 10, this example illustrates a color filter in which a defect (D3) having a diameter (φ2) of 40 μm is generated in a blue colored pixel (22B).
The automatic visual inspection apparatus identifies the defect (D3) of the blue colored pixel (22B) as a defect, but does not specify that the defect has occurred in the blue colored pixel (22B).

As shown in FIG. 10, when an inspection camera color filter is imaged with an inspection camera and a defect is detected, the position information of a plurality of inspection pixels constituting the defect (D3) is used as shown in FIG. In addition, a contour (R3) having a constant width (j) is set around the defect (D3).
This constant width (j) is preferably 1 to 5 inspection pixels. Increasing the number of inspection pixels improves the accuracy of determination, but sufficient accuracy can be obtained within 5 pixels.

  Next, the respective densities of the plurality of inspection pixels (contour inspection pixels) (E1 to En) constituting the contour portion (R3) are obtained, and the respective densities of the obtained inspection pixels (contour inspection pixels) are shown in Table 1. In contrast to the density ranges of the red color pixel, the green color pixel, the blue color pixel, the black matrix, and each of the other test pixels (non-defective product test pixels) shown, the test pixel having a density in the corresponding density range The number of (contour inspection pixels) (E1 to En) is totaled for each density range of each inspection pixel (non-defective product inspection pixel).

  Table 3 summarizes the number of inspection pixels (contour inspection pixels) (E1 to En) having a density in the corresponding density range for each density range of each inspection pixel (non-defective product inspection pixel) in this example. is there. As shown in Table 3, the total number of inspection pixels (contour inspection pixels) (E1 to En) is 29, the number of inspection pixels (contour inspection pixels) corresponding to the density range 000 to 100 is 1, and the density range It is indicated that the number of inspection pixels (contour inspection pixels) corresponding to 101 to 130 is 25, and thereafter, 3, 0, and 0.

次に、集計して得られた赤色の着色画素の検査画素（良品検査画素）の濃度範囲（１５１〜１８０）にある、輪郭部（Ｒ３）を構成する検査画素（輪郭検査画素）の数が、表２に示す赤色の判定閾値としての検査画素（検出検査画素）の数である５個以上であれば、輪郭部（Ｒ３）は赤色の着色画素にあると判定し、輪郭部（Ｒ３）を構成する検査画素（輪郭検査画素）の数が、赤色の判定閾値としての検査画素（検出検査画素）の数である５個以下であれば、輪郭部（Ｒ３）は赤色の着色画素にないと判定する。

Next, the number of inspection pixels (contour inspection pixels) constituting the contour portion (R3) in the density range (151 to 180) of the inspection pixels (non-defective product inspection pixels) of red colored pixels obtained by aggregation is obtained. If the number of inspection pixels (detection inspection pixels) as the red determination threshold shown in Table 2 is five or more, the contour portion (R3) is determined to be a red colored pixel, and the contour portion (R3) If the number of inspection pixels (contour inspection pixels) constituting the number is five or less, which is the number of inspection pixels (detection inspection pixels) as a red determination threshold, the contour portion (R3) is not in the red colored pixels. Is determined.

  Table 4 is obtained by superimposing Table 3 on Table 2 in order to easily perform such a determination. As shown in Table 4, the number of inspection pixels (detection inspection pixels) as the blue determination threshold is 5, whereas the number of inspection pixels (contour inspection pixels) is 25. (R3) is in a blue colored pixel, and blue shown in Table 4 is determined as a colored pixel in which a defect has occurred.

Next, the size of the defect (φ2: 40 μm) is determined based on the size of the blue defect within the defect size standard defined for each color of the colored pixel, that is, the defect size in the allowable blue colored pixel. Compared with the size of 30 μmφ, it is determined that the defect is acceptable.
In addition, although the diameter was illustrated as an example of the size of the defect, since the shape of the defect is indefinite, the area of the defect, the long side of the defect, etc. are comparable to the diameter of the defect. It may define acceptable standards.

It is a side view which shows the outline of an example of an automatic external appearance inspection apparatus. It is a top view of the automatic external appearance inspection apparatus shown in FIG. It is a top view explaining the scanning area | region by the inspection camera for reflection on a to-be-inspected color filter, and the inspection camera for transmission. It is explanatory drawing which shows typically an example of the color filter image imaged with the inspection camera. (A) is explanatory drawing to which the part enclosed with the dotted line of the red coloring pixel of the left end shown in FIG. 4 was expanded. (B) is explanatory drawing to which the part enclosed with the dotted line of an adjacent red coloring pixel was expanded. It is explanatory drawing of an example of the defect which generate | occur | produced in the red coloring pixel. It is the top view which showed typically an example of the color filter used for a liquid crystal display device. It is sectional drawing in the X-X 'line | wire of the color filter shown in FIG. It is explanatory drawing which shows typically an example of the color filter image which imaged the coloring pixel of the good quality color filter with the inspection camera using a solid-state image sensor. It is explanatory drawing by which the to-be-inspected object color filter was imaged with the inspection camera, and the defect was detected. It is explanatory drawing which sets the outline part of a fixed width around a defect from the positional information on the some test | inspection pixel which comprises a defect.

Explanation of symbols

4 ... Color filter 10 ... Object color filter 11 ... Surface plate 12 ... Inspection stage 13A ... Reflection light source 13B ... Transmission light source 14A ... Reflection inspection camera 14B ... Transmission inspection camera 15 ... Image processing device 21, 41 ... Black matrix 22, 42 ... Colored pixel 22R ... Red colored pixel 22G ... Green colored pixel 22B ... Blue colored pixel 40 ... glass substrate 43 ... transparent conductive films D, D2, D3 ... defects E1 to En ... a plurality of inspection pixels (contour inspection pixels) constituting the contour portion
K1 to Kn: First inspection pixel to nth inspection pixel R3: Outline Sr: Scanning region of reflection inspection camera and transmission inspection camera

Claims (2)

In the inspection method of defects that occur in the color filter manufacturing process,
A) In advance, 1) a non-defective color filter is imaged with an inspection camera, and the density range of the inspection pixel (non-defective product inspection pixel) in the colored pixels of the imaged first color is set.
2) Later, when the inspected object color filter is imaged by the inspection camera, the determination threshold of the first color necessary for determining that the imaged colored pixel is the first color is 1) above Set the number of inspection pixels (detection inspection pixels) with the density in the set density range,
3) The above 1) is performed for each of the second color pixel, the third color pixel, the black matrix, and the other parts, and the density range of the inspection pixel (non-defective inspection pixel) in each is set.
4) Perform the above 2) for each of the above parts, and set the number of inspection pixels (detection inspection pixels) as a determination threshold value in each of the parts,
B) Next, 1) An image of the color filter to be inspected is picked up by the inspection camera, and when a defect is detected, a contour having a constant width is formed around the defect from position information of a plurality of inspection pixels constituting the defect. Set the
2) The respective densities of a plurality of inspection pixels (contour inspection pixels) constituting the contour portion are obtained, and the respective densities of the obtained inspection pixels (contour inspection pixels) are set in A) 1) and 3). The number of inspection pixels (contour inspection pixels) having a density in the corresponding density range in comparison with the density range of the first color pixel and each inspection pixel (non-defective inspection pixel) in each of the above-mentioned parts. For each density range of inspection pixels (non-defective product inspection pixels)
C) Next, 1) The number of inspection pixels (contour inspection pixels) constituting the contour portion in the density range of the inspection pixels (non-defective inspection pixels) of the colored pixels of the first color obtained by aggregation is A) If the number of inspection pixels (detection inspection pixels) as the determination threshold of the first color set in 2) is equal to or greater than that, it is determined that the contour portion and the defect are in the colored pixels of the first color,
2) Perform 1) above for each part, and if the number of each inspection pixel (detection inspection pixel) set in A) 4) is equal to or greater than that, determine that the contour and the defect are in the part. And
D) Next, the size of the defect is compared with the size of the defect of the color of the standard of the size of the defect determined for each color of the colored pixel, and it is determined whether or not it is an allowable defect.
A method for inspecting the appearance of a color filter, which comprises inspecting for defects.   The color filter appearance inspection method according to claim 1, wherein the constant width in the contour portion having a constant width around the defect is 1 to 5 in number of inspection pixels.

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