JP2009264942A - Visual inspection method of color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection method of a color filter for performing defect inspection applying different specifications in each color by specifying which color coloring pixel the defect of the color filter is in an inspection stage. <P>SOLUTION: (A) The visual inspection method sets a contour inspection pixel KR on a circumference from a coordinate of a defect inspection pixel KD of a defect, and obtains numeral values of each brightness of the R, G and B signals. (B) The visual inspection method compares the numeral values with a threshold, and it is first determination as a black matrix 21 when all are the threshold or less. (C) The visual inspection method compares each numerical value among the R, G and B signals of the contour inspection pixel being no threshold and less, selects a color of the maximum numerical value, and it is second determination as a coloring pixel of the color. (D) The visual inspection method totals the number of pixels performing the first determination and the number of each coloring pixel performing second determination, and it is third determination as defect D3 in the maximum. (E) The visual inspection determines quality by comparing the size of defect with allowance of the color. <P>COPYRIGHT: (C)2010,JPO&INPIT

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. This brightness is represented by a numerical value displayed in 256 levels, for example, by dividing the brightness of the signal obtained by the inspection camera into 8 bits (256), and the difference between the numerical values is equal to or larger than a preset threshold value. The i-th inspection pixel (Ki) of the colored pixel (P2) is identified as a defect. Hereinafter, in the present invention, the brightness of the pixel signal is represented by a numerical value displayed in 256 levels. It means that the smaller value is darker and the larger value is brighter.

  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.
JP-A-8-94493 JP 2006-284217 A 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) 1) Detect defects for each of the R signal, G signal, and B signal obtained by imaging the color filter to be inspected with a color inspection camera,
2) When a defect is detected, a plurality of contour inspection pixels are set around the defect inspection pixel from the position coordinates of the plurality of defect inspection pixels constituting the defect, and an R signal of the plurality of contour inspection pixels Obtain the numerical value of each brightness of, G signal, B signal,
B) Next, 1) Determine the brightness values of the obtained R, G, and B signals for each contour inspection pixel to determine whether the contour inspection pixel is in the black matrix. In contrast to the signal brightness judgment threshold,
2) When all the brightness values of the R signal, the G signal, and the B signal in each of the contour inspection pixels are equal to or less than the determination threshold, the first determination is made that the corresponding contour inspection pixel is in the black matrix,
C) Next, 1) When the numerical values of all the brightness of each R signal, G signal, and B signal in each of the contour inspection pixels are not less than or equal to the determination threshold value,
2) The color signal having the largest brightness value (the above R) by comparing the brightness values between the R signal, G signal, and B signal in each contour inspection pixel that is not equal to or less than the determination threshold value. , G, B signals), and secondly determine that the contour inspection pixel is a colored pixel of the color,
D) Next, 1) the number of contour inspection pixels in the black matrix determined first in B), and each color of the contour inspection pixels in the color pixels of the color determined second in C) The number of
2) The black matrix or the colored pixel of the color having the largest number of the contour inspection pixels is selected, and the defect detected in the above A) is in the selected black matrix or the colored pixel of the color. And third judgment,
E) Next, the size of the third determined defect is compared with a defect size standard determined for each color of the black matrix and the colored pixel, and a fourth determination is made as to whether or not the defect is an acceptable defect.
A color filter appearance inspection method characterized by inspecting defects generated in a manufacturing process.

  According to the present invention, in the color filter appearance inspection method according to the invention described above, the defect generated in the manufacturing process is a black matrix chipping or a color pixel white spot (pinhole). This is an appearance inspection method.

  According to the present invention, in the color filter appearance inspection method according to the invention described above, when selecting the color of the color signal (the R, G, B signal) having the highest brightness value, the highest brightness is obtained. The color filter appearance inspection method is characterized in that a priority order for selecting a color signal is set in advance in response to a case where the numerical value is 2 or more.

  In the color filter appearance inspection method according to the present invention, when selecting the black matrix having the largest number of contour inspection pixels or the colored pixels having the color, the number of the colored pixels having the largest number is 2. Corresponding to the above case, the color filter appearance inspection method is characterized in that a priority order for selection is set in advance for the colored pixels of the color.

The present invention
A) Defect detection is performed for each signal of the R signal, G signal, and B signal obtained by imaging the color filter to be inspected with a color inspection camera, and the R signal of the contour inspection pixel around the defect; Find the brightness values of the G and B signals,
B) Next, when this numerical value is compared with a predetermined determination threshold value for determining whether or not it is in the black matrix, if it is equal to or less than the determination threshold value, it is determined that the corresponding contour inspection pixel is in the black matrix. 1 judgment,
C) Next, a color signal having the largest brightness value by comparing each brightness value between the R signal, G signal, and B signal in each contour inspection pixel that is not equal to or less than the determination threshold value. The color of (the above R, G, B signals) is selected, and it is second determined that the contour inspection pixel is a colored pixel of the color,
D) Next, the number of contour inspection pixels in the black matrix and the number of contour inspection pixels in the colored pixels for each color are counted, and the black matrix having the largest number of contour inspection pixels or the color of the color A color pixel is selected, and the defect detected in the above A) is third determined to be in the selected black matrix or the color pixel of the color,
E) Next, since the defect size is compared with the defect size standard determined for each color of the black matrix and the colored pixels, it is determined whether or not the defect is an acceptable defect, and the defect is inspected. In the inspection stage, it is specified in the inspection stage which color defect of the color pixel is an appearance defect that occurs in the color filter manufacturing process, and a defect inspection that applies a different standard for each color of the color pixel is performed. This is a color filter appearance inspection method.
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.

In the present invention, since a defect is detected for each signal of an image using a color inspection camera, a normal portion of a colored pixel in an image signal obtained when a monochrome inspection camera is used as the inspection camera. The difference in brightness between the normal part of the colored pixel and the defective part in the divided color signal when the color inspection camera is used is more effective than the difference in brightness between the defective part and the brightness of the defective part. By making a choice, a large difference is obtained.
This means that the detection accuracy is excellent in defect detection, particularly in white spots (pinholes).

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 a colored pixel of a non-defective color filter with a color 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 color inspection camera) of the divided inspection pixels is compared and used for inspection. When expressing the brightness level, the brightness of the signal obtained by the color inspection camera is expressed by a numerical value displayed in 256 levels divided by 8 bits (256). It means that the smaller value is darker and the larger value is brighter.

  FIG. 10 shows an example of a color filter image when a defect color is detected by picking up an image of the color filter to be inspected with a color inspection camera. 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).

In the color filter appearance inspection method according to the present invention, first, an inspected object color filter is imaged by a color inspection camera, and an R signal, a G signal, and a B signal of an image constituting the inspected object color filter are obtained. For each obtained signal, a comparative inspection divided into a plurality of regions (inspection pixels) is performed to detect a defect.
In the present invention, a color inspection camera is used for imaging the color filter to be inspected, and is divided into an R signal, a G signal, and a B signal.

Compared to the difference in brightness between normal and defective colored pixels in the image signal obtained when a monochrome inspection camera is used as the inspection camera, the divided color signal when the color inspection camera is used. The difference between the brightness of the normal portion and the defective portion of the colored pixel is larger by selecting the color of the color signal.
This is especially noticeable when the defect is white (pinhole).

For example, when a white defect occurs in a blue colored pixel, a difference in brightness between the normal portion and the defective portion of the colored pixel appears greatly in the R signal and the G signal. The magnitude of the difference in brightness is significantly larger than the difference in brightness between the normal portion and the defective portion of the blue colored pixels obtained when the monochrome inspection camera is used.
Similarly, the difference between the brightness at the time of the divided color signal and the brightness at the time of the monochrome signal is similar to that of the G signal and the B signal when the white color defect is generated in the red colored pixel. The signal is remarkably large, and when the white defect is generated in the green colored pixel, the R signal and the B signal are remarkably large.

  That is, in the present invention, since a color inspection camera is used to detect a defect for each signal of an image, the detection accuracy is excellent in defect detection, particularly in white spots (pinholes).

  As shown in FIG. 10, the automatic visual inspection apparatus identifies the defect (D3) of the blue colored pixel (22B) as a defect, but at this stage, the defect has occurred in the blue colored pixel (22B). It is not specified.

Next, when the defect color is detected by picking up an image of the color filter to be inspected and a defect is detected, a plurality of defect inspection pixels are formed around the position coordinates of the defect inspection pixels constituting the defect (D3). Set contour inspection pixels.
FIG. 11 illustrates a state in which a plurality of contour inspection pixels (KR) are set around a plurality of defect inspection pixels constituting the defect (D3). FIG. 12 is an explanatory diagram showing the positional relationship between the defect inspection pixel (KD) and the contour inspection pixel (KR) by enlarging the portion. As shown in FIG. 12, the right side of the boundary line (Y ₀ ) is a blue colored pixel (22B), and the left side is a black matrix (21).

Reference numeral (K-22B) represents an inspection pixel of a blue colored pixel for comparison inspection of the blue colored pixel (22B). Reference numeral (K-BMX) represents a black matrix inspection pixel for comparatively inspecting the black matrix (21).
In FIG. 12, inspection pixels represented by x represent a plurality of defect inspection pixels (KD) constituting a defect (D3) detected as a defect as a result of the comparison inspection. In addition, the inspection pixel represented by the diagonally downward slanting line includes a plurality of contour inspection pixels (KR) set around a plurality of defect inspection pixels (KD) constituting the defect (D3) after the defect (D3) is detected. ).

  There are a total of 18 contour inspection pixels (KR) illustrated in FIG. 12 set around the collection of the plurality of defect inspection pixels (KD) constituting the defect (D3), and each has a number. Is given. In FIG. 12, from the first contour inspection pixel (KR1) on the left side, the second contour inspection pixel (KR2) and the third contour inspection pixel (KR3) to the 18th contour inspection pixel (KR18) are counterclockwise. Yes.

  Next, the numerical values of the brightness of the R signal, G signal, and B signal of each of the plurality of contour inspection pixels (KR1 to KR18) set as described above are obtained. Table 1 shows the numerical values of the brightness of the R signal, G signal, and B signal for each of the obtained contour inspection pixels (KR1 to KR18). This numerical value is a numerical value displayed in 256 levels, in which the brightness of the signal obtained by the color inspection camera is divided by 8 bits. It means that the smaller value is darker and the larger value is brighter.

次に、欠陥検査画素（ＫＤ）の周囲に設定した、複数の輪郭検査画素（ＫＲ１〜ＫＲ１８）の各輪郭検査画素が、ブラックマトリクス（２１）にあるか否かの第１判定を行う。この第１判定は、予め設定された、輪郭検査画素がブラックマトリクスにあるか否かを判定するための、信号の明るさの判定閾値と比較して行う。
この例では、判定閾値として、信号の明るさの数値で３０と設定されたものである。ある輪郭検査画素において、Ｒ信号、Ｇ信号、Ｂ信号のすべての信号で、その明るさの数値が３０以下の場合、すなわち、ブラックマトリクスの判定閾値より暗い場合に、その輪郭検査画素はブラックマトリクスにあると判定する。

Next, a first determination is made as to whether each of the contour inspection pixels of the plurality of contour inspection pixels (KR1 to KR18) set around the defect inspection pixel (KD) is in the black matrix (21). This first determination is performed in comparison with a threshold value for determining the brightness of the signal for determining whether or not the contour inspection pixel is in the black matrix.
In this example, the threshold value of the signal is set to 30 as the determination threshold value. In a certain contour inspection pixel, when all of the R signal, G signal, and B signal have a brightness value of 30 or less, that is, darker than the black matrix determination threshold, the contour inspection pixel is black matrix. It is determined that

  Table 2 shows the result of comparing the brightness values of the R signal, the G signal, and the B signal for each contour inspection pixel (KR1 to KR18) shown in Table 1 with the determination threshold value 30.

表２中、上段に示す、第１輪郭検査画素（ＫＲ１）〜第３輪郭検査画素（ＫＲ３）において、Ｒ信号、Ｇ信号、Ｂ信号のすべての信号で、その明るさの数値が３０以下であるので、第１輪郭検査画素（ＫＲ１）〜第３輪郭検査画素（ＫＲ３）は、ブラックマトリクスにあると第１判定する。表２中の丸印が、ブラックマトリクスにあると判定した第１判定である。

In Table 2, in the first contour inspection pixel (KR1) to the third contour inspection pixel (KR3) shown in the upper part, the brightness value is 30 or less for all signals of the R signal, the G signal, and the B signal. Therefore, the first contour inspection pixel (KR1) to the third contour inspection pixel (KR3) are first determined to be in the black matrix. The circle in Table 2 is the first determination that is determined to be in the black matrix.

  Next, the contour inspection pixels determined not to be in the black matrix by the first determination, that is, the fourth contour inspection pixel (KR4) to the eighteenth contour inspection pixel (KR18) are red, green, and blue. The second determination for determining which color pixel is present is performed. This second determination is performed by comparing the brightness values between the R signal, G signal, and B signal of a certain contour inspection pixel, and the color signal having the highest brightness value (the R, G, and B signals described above). ) Color is selected, and it is determined that the contour inspection pixel is a colored pixel of that color.

Table 2 shows the result of comparing numerical values of each brightness between the R signal, G signal, and B signal of the contour inspection pixels (KR4 to KR18) shown in Table 1. As shown in Table 2, in all of the contour inspection pixels (KR4 to KR18), the brightness value of the R signal, the G signal, and the B signal has the highest brightness value. Each of the contour inspection pixels (KR4 to KR18) is second determined to be in a blue colored pixel. The circle in Table 2 represents the color of the colored pixel determined second.

As described above, in the present invention, an inspected color filter composed of colored pixels of the three primary colors of red, green, and blue is imaged by the color inspection camera of the three primary colors to obtain an R signal, a G signal, and a B signal. Yes. Between these three signals, when a color pixel of a certain color is color-separated, the color signal of that color is brighter than the color signals of other colors. For example, when a blue colored pixel is color-separated, a blue color signal is brighter than red and green color signals. In Table 2, the fourth outline inspection pixel (KR4) is second determined to be in the blue colored pixel, which is a numerical value of the brightness of the blue color signal (B signal) of the blue colored pixel. Is based on being brighter than the numerical values of the brightness of the R and G signals.
Therefore, according to the present invention, it is possible to easily and accurately determine which color pixel is selected from among red, green, and blue.

  Next, the number of contour inspection pixels determined to be in the black matrix (21) by the first determination and the number of contour inspection pixels in the color pixels of each color determined by the second determination are determined for each color. Tally. In this example, as shown in the lower part of Table 2, the number of contour inspection pixels in the black matrix is three, the number of contour inspection pixels in the red coloring pixel is zero, the number of green coloring pixels is zero, and blue It is counted that there are 15 colored pixels.

  Next, a third determination is made as to whether the defect (D3) detected by comparatively inspecting the inspection pixel is a defect in either the black matrix or the colored pixels of three colors. This third determination is made by comparing the aggregated numbers shown in Table 2, 3, 0, 0, and 15, and determines that there are defects (D3) in the most blue colored pixels.

Next, the size (φ2: 40 μm) of the defect (D3) is determined based on the size of the blue defect within the defect size standard determined for each color of the colored pixel, that is, the allowable blue colored pixel. Compared with the size of the defect 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 color inspection camera. It is explanatory drawing by which the to-be-inspected object color filter was imaged with the color inspection camera, and the defect was detected. A state in which a contour inspection pixel is set around a defect inspection pixel constituting a defect is illustrated. It is explanatory drawing which expands the said part and shows the positional relationship of a defect inspection pixel and a contour inspection pixel.

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 K-22B: Blue colored pixel inspection pixel K-BMX: Black matrix inspection pixel KD: Defect inspection pixel KR: Contour scanning area Y ₀ · · · border inspection pixel KR1～KR18 · · · first to 18 contour inspection pixel Sr · · · reflecting inspection camera and the inspection camera transmission

Claims (4)

In the inspection method of defects that occur in the color filter manufacturing process,
A) 1) Detect defects for each of the R signal, G signal, and B signal obtained by imaging the color filter to be inspected with a color inspection camera,
2) When a defect is detected, a plurality of contour inspection pixels are set around the defect inspection pixel from the position coordinates of the plurality of defect inspection pixels constituting the defect, and an R signal of the plurality of contour inspection pixels Obtain the numerical value of each brightness of, G signal, B signal,
B) Next, 1) Determine the brightness values of the obtained R, G, and B signals for each contour inspection pixel to determine whether the contour inspection pixel is in the black matrix. In contrast to the signal brightness judgment threshold,
2) When all the brightness values of the R signal, the G signal, and the B signal in each of the contour inspection pixels are equal to or less than the determination threshold, the first determination is made that the corresponding contour inspection pixel is in the black matrix,
C) Next, 1) When the numerical values of all the brightness of each R signal, G signal, and B signal in each of the contour inspection pixels are not less than or equal to the determination threshold value,
2) The color signal having the largest brightness value (the above R) by comparing the brightness values between the R signal, G signal, and B signal in each contour inspection pixel that is not equal to or less than the determination threshold value. , G, B signals), and secondly determine that the contour inspection pixel is a colored pixel of the color,
D) Next, 1) the number of contour inspection pixels in the black matrix determined first in B), and each color of the contour inspection pixels in the color pixels of the color determined second in C) The number of
2) The black matrix or the colored pixel of the color having the largest number of the contour inspection pixels is selected, and the defect detected in the above A) is in the selected black matrix or the colored pixel of the color. And third judgment,
E) Next, the size of the third determined defect is compared with a defect size standard determined for each color of the black matrix and the colored pixel, and a fourth determination is made as to whether or not the defect is an acceptable defect.
A method for inspecting the appearance of a color filter, characterized by inspecting defects generated in a manufacturing process.   The color filter appearance inspection method according to claim 1, wherein the defect generated in the manufacturing process is a black matrix chipping or a white spot (pinhole) of a colored pixel.   When selecting the color of the color signal having the highest brightness value (the R, G, B signals), the color signal is selected in advance corresponding to the case where the highest brightness value is 2 or more. The color filter appearance inspection method according to claim 1 or 2, wherein a priority order is set.   When selecting the black matrix having the largest number of contour inspection pixels or the color pixels of the color, the color pixels of the color in advance corresponding to the case where there are two or more color pixels of the color having the largest number, The color filter appearance inspection method according to any one of claims 1 to 3, wherein a priority order for selection is set in advance.

Images