JPH0720065A - Device for inspecting foreign matter on color filter for appearance - Google Patents

Abstract

PURPOSE:To surely detect the appearance of a fine foreign matter on a color filter by fetching a step pattern on the color filter illuminated with randomly reflected light rays as a picture when the color filter is moved forward and backward and performing binarization and logical operation on the picture based on positional data. CONSTITUTION:After placing a color filter (a) at a prescribed position on a moving section 2, the section 2 is operated while the filter (a) is irradiated with the light from one light source 5 of a lighting section 4. Upon receiving the light from the light source 5, the filter (a) becomes bright against a photographing section 3 and the entire area of a bright step pattern is latched as a picture. A control section 10 binarizes picture data sent from the photographing section 3 based on positional data representing a detected area as a division and stores the binarized data in a memory device 9. When a uniaxial table comes into contact with a forward movement completion detecting limit switch 15, the uniaxial table stops. When the table comes into contact with a backward movement completion detecting limit switch 16, the movement of the moving section 2 is stopped and the other light source 6 of the section 4 is also turned off. Thus the picture reading is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the appearance of minute foreign matter on a color filter (color filter for a liquid crystal display device) for inspecting the presence or absence of foreign matter.

[0002]

2. Description of the Related Art Conventionally, a visual inspection apparatus of this type irradiates light from an obliquely upper direction of an object, that is, a color filter, and a pattern which receives the light and shines due to irregular reflection is provided above the color filter. The image is taken by the installed camera, and the presence or absence of foreign matter is inspected from the bright pattern based on the obtained image.

FIG. 13 shows the principle of the appearance inspection apparatus 1. In FIG. 13, reference numeral 2 denotes a moving portion formed of a uniaxial table on which a color filter a is placed and which reciprocates.
Is a photographing unit composed of a CCD camera (or a camera row in which a plurality of CCD cameras are arranged), and 4 is an illuminating unit. And a light source 6 for
Then, the light source 5 of the illuminating unit 4 irradiates the color filter a with light from an obliquely upper direction to cause irregular reflection in a portion having a step on the color filter a so that the color filter a shines. While the color filter a is moved in one direction (the direction of arrow L: to the right in the figure), the image capturing unit 3 captures an image of the step pattern over the entire surface of the color filter a (FIG. 13B). The color filter a is irradiated with light from the light source 6 of FIG. 1 to make the step pattern shine, and the color filter a is illuminated on the other side (direction of arrow R: left in the figure).
The step pattern is photographed over the entire surface of the color filter a by the image pickup unit 3 while moving to the position (FIG. 13C). After that, the step pattern and the step pattern at the time of the forward movement of the color filter obtained as an image from the image pickup unit 3 are restored. The presence or absence of foreign matter is inspected by determining whether or not there is a bright portion other than the edge pattern of the pixel of the color filter from each of the step patterns during movement.
That is, if a foreign substance is present on the color filter, the stepped portion caused by the foreign substance is made to shine, and the shine is captured as an image.

[0004]

However, as described above, in the conventional appearance inspection apparatus, since the light is applied obliquely from above, the edge portion of the pixel formed on the color filter also shines and the step pattern is formed. When a foreign substance is attached and the foreign substance is large, it is possible to distinguish between the step pattern due to the edge of the pixel and the step pattern of the foreign substance. When the vehicle is on the edge portion, there is a problem that the determination cannot be made.

In view of the above-mentioned circumstances, the present invention has an object to distinguish the step pattern of the minute foreign matter located at the edge portion of the pixel from the step pattern of the edge portion of the pixel, and improve the foreign matter detection accuracy. With the goal.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and includes a moving part for moving a color filter back and forth, and a light from one side of the color filter moving direction when the color filter moves in the forward direction. Illuminating the color filter and irradiating the color filter with light from the other side of the color filter moving direction when the color filter moves in the backward direction, and the color filter moving direction fixed in the forward direction. An image capturing unit that captures, as an image, a step pattern on a color filter where the light from the illumination unit is irregularly reflected and shines during movement and in the backward movement,
Each of the image data at the time of moving in the forward direction and the image data at the time of moving in the backward direction obtained by the photographing unit is binarized based on the position data set for the color filter. Data, and performs a logical product operation of the binarized data when moving in the forward direction and the binary data when moving in the backward direction, and the result of the logical product operation by the control unit. An object of the present invention is to provide a visual inspection apparatus for minute foreign matter on a color filter, which is provided with an output section for outputting data based on data.

[0007]

In the present invention, by receiving light from different directions, the step pattern when the color filter moves forward and the step pattern when the color filter moves backward are taken into the photographing section as different patterns. The principle is shown in Figure 11.
As shown in (a), when the light b is irradiated from the diagonally left upper direction of the color filter a in the figure, the left edge portion d of the pixel c is
Irregular reflection occurs at the pixel c, and the bright step pattern is captured by the imaging unit 3.
The right edge portion e does not shine against the photographing unit 3 side. Further, as shown in FIG. 11B, when the light b is irradiated from the diagonally right upper direction in the drawing, diffuse reflection occurs at the right edge portion e of the pixel c, and the image shines, and the step pattern is captured by the imaging unit 3. , The left edge portion d of the pixel c is the imaging unit 3
It will not shine to the side. And FIG. 12 (a)
When the minute foreign matter f is on the left edge portion d of the pixel c as shown in FIG.
The left one surface g of the minute foreign matter f and the left edge portion d (the portion other than the minute foreign matter) shine, and the step pattern (including the step pattern of the minute foreign matter) is taken in by the imaging unit 3. When the light b is further radiated from the obliquely upper right side, the right one surface h and the right edge portion e of the minute foreign matter f shine, and the step pattern (including the step pattern of the minute foreign matter) is captured by the imaging unit 3. As shown in FIG. 12B, different patterns are thus obtained between the forward movement and the backward movement.
It will be taken in by the side.

The step pattern at the time of forward movement and the step pattern at the time of backward movement captured as image data by the photographing section 3 are converted into binarized data based on the position data of the color filter in the control section. To be converted. For example, position data such as 11, 12, 13, 14 are set for the cross-section shown in FIG. 11, and 21, 22, 23, 24 are set for the cross-section shown in FIG. If position data like this is set,

[0009]

[Table 1] Fig. 11 Position data 11, 12, 13, 14 (a) Binarized data during forward movement 1, 1, 0, 0 (b) Binarized data during backward movement 0, 0, 0, 1 Fig. 12 Position data 21, 22, 23, 24 (a) Binarization data during forward movement 1, 1, 0, 0 (b) Binarization during backward movement Data 0, 1, 0, 1

It is binarized as follows. Then, the binary data at the time of forward movement and the binary data at the time of backward movement are logically ANDed,

[0011]

[Table 2] Fig. 11 Position data 11, 12, 13, 14 Results of AND operation 0, 0, 0, 0 Fig. 12 Position data 21, 22, 23, 24 Results of AND operation 0, 1 , 0, 0

As described above, the result of the logical product operation corresponding to the position data is obtained, and by outputting the result, the presence / absence of foreign matter can be determined.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to an embodiment shown in FIGS. As shown in FIG. 1, the apparatus 1 for inspecting minute foreign matter on a color filter comprises a moving section 2 which is a uniaxial table on which a color filter a is mounted and which reciprocates, and a camera row in which a plurality of CCD cameras are arranged. 3 fixed on the moving path of the light source 5, the light source 5 for irradiating light from one side of the moving direction X of the color filter
And a light source 6 for irradiating light from the other side,
The control unit 10 includes a computer device and has an input / output interface device 7, a CPU device 8, and a memory device 9, and an output unit 13 having a display device 11 for outputting a calculation result by the control unit 10 and a printer 12. is doing. As will be described later, the control unit 10 converts the captured image data into binarized data, performs a logical product operation of the binarized data, and controls the entire apparatus. The drive device 14 for the moving section 2 and the forward movement completion detection limit switch 1 having a function
5, the return operation completion detection limit switch 16 is the control unit 10
Is connected to the input / output interface device 7 to control the operation of the uniaxial table, and the photographing unit 3 and the illumination unit 4 are also connected to the input / output interface device 7 so as to operate when necessary. Further, in addition to the output unit 13 connected to the input / output interface device 7, a console panel (operation panel) 17 is connected so that a desired condition can be input and set.

When inspecting a foreign substance on a color filter using the above-mentioned device 1, when an inspection area E of the color filter is input and designated from the console panel 17 as shown in FIG. 2, the photographing section 3 is constituted. According to the resolution of the CCD camera, the inspection area E is laterally divided into n equal parts,
M in the vertical direction according to the number of CCD cameras 3b
The data is equally divided and divided into m × n grids, and position data is attached to each of them on the control unit 10. This corresponds to the step of forming the memory maps A, B, C (m × n × 3) in the flowchart shown in FIG. The memory map A is an area on the memory in which the binary data when moving in the forward direction, which will be described later, can be written in correspondence with the position data, and the memory map B is the binary data when moving in the backward direction. The memory map C, which is an area on the memory in which data can be written in correspondence with the position data, stores the result of the logical product operation in the position data.
It is an area on the memory that can be written corresponding to the data.

A color filter a was placed at a predetermined position of the moving section 2 (the color filter a was placed in the inspection area E).
(Corresponding to the region to be inspected), the color filter a moves in the L direction by the operation of the moving unit 2 in the state where the light source 5 of the illumination unit 4 irradiates the color filter a. The stepped pattern shining with a is the photographing unit 3
Is taken into. The light source 5 of the illumination unit 4 is arranged on one side of the moving direction X of the color filter a and irradiates light from diagonally above toward the color filter a moving in the L direction (when moving in the forward direction). The light source 6 is arranged so as to irradiate light from diagonally above toward the color filter a which is located on the other side of the moving direction X and moves in the R direction (irradiation when moving in the backward direction).

FIG. 3 shows a color filter a in which a pixel pattern is formed and a minute foreign substance f is located at the left edge portion d of one pixel c.
When the light b is received from the light source 5 as described above, the left edge portion d of each pixel c and the left side surface g of the minute foreign matter f shines on the photographing unit 3 as shown in FIG. Therefore, the entire surface of the bright step pattern is captured as an image. Further, when the light b from the light source 6 is received, as shown in FIG. 5, the right edge portion e of each pixel c and the right one surface h of the minute foreign matter f shine against the photographing unit 3, The entire bright step pattern is captured as an image.

On the other hand, in the control section 10, the image data sent from the photographing section 3 by moving the color filter a in the L direction is binarized based on the position data representing the detection area as a section, The binarized data is stored in the memory device 9. As shown in FIG. 6, the color filter a moves in the L direction, and the image capturing unit 3 causes the first row of partitions on the color filter a (for example, the position data is 11 and 2).
The information (image data) in the aligned sections 1, 31, ..., M1) is fetched by the control unit 10 (CCD signal fetch in FIG. 9), and the binarized data A11, A2.
, A31, ..., Am1 are converted and written in the memory device 9. The binarized data A12, A2 changed as the color filter a moves.
2, A32, ..., Am2, A13, A23, A33,
..., Am3, ..., A1n, A2n, A3n, ..., A
mn is written (writing to memory map A).
When the capturing of the image of the set inspection area E is completed and the uniaxial table and the forward movement completion detection limit switch 15 come into contact with each other, the uniaxial table stops. And light source 5
Is turned off and the light source 6 is turned on instead, the uniaxial table moves in the R direction.

When the color filter a starts to move in the R direction, the image data is picked up by the photographing unit 3 from the section (position data 1n, 2n, 3n, ..., mn) arranged in the nth row of the inspection area E. Data is taken in (CCD signal in FIG. 9 is taken in), and the control unit 10 binarizes the data B1n-.
1, B2n-1, B3n-1, ..., Bmn-1, B1n
-2, B2n-2, B3n-2, ..., Bmn-1,
, B11, B21, B31, ..., Bm1 are converted and written in the memory device 9 (writing to the memory map B). When the uniaxial table comes in contact with the backward movement completion detection limit switch 16, the movement of the moving unit 2 is stopped, the light source 6 is also turned off, and the reading of the image is completed.

FIG. 6A shows a step pattern (including a step pattern of minute foreign matter) obtained during forward movement (L direction).
And the inspection area E are overlapped with each other to represent the state of the binarized data in each section indicated by the position data, and the bright step pattern is captured and converted into the binarized data. The section that sometimes becomes "1" is shown by hatching, and the section that becomes "0" when converted to binarized data without a step pattern is not provided with diagonal lines. 6B shows the binarized data (Aij) in the inspection area E shown in FIG. 6A, which corresponds to the left side surface g of the minute foreign matter f captured as a step pattern. Binarization data A68 is also "1"
Obtained as. Further, FIG. 7A shows the state of the binarized data in each section indicated by the position data by superimposing the step pattern and the inspection area E obtained during the backward movement (R direction). It is a representation. Then, similarly to the case of the binarization conversion during the forward movement, when the right side surface g of the minute foreign matter f captured as the step pattern is also captured as the step pattern, it is changed to this as shown in FIG. The binarized data B68 of the corresponding section is also obtained as "1".

When the binarized data when moving in the forward direction and the binarized data when moving in the backward direction are obtained, the binarized data (Aij, Bij) read from the memory device 9 is stored. A logical product operation (Cij = Aij · Bij) is performed in the control unit 10. This is represented by the step in FIG. 10, and the calculation result is written in the memory map C (Cij). Specifically, the value of the binarized data Aij during the forward movement and the value of the binarized data Bij during the backward movement are "0"-
In the case of "0", "1"-"0", "0"-"1", the AND operation result data Cij becomes "0",
If it is "1"-"1", it is processed as "1". As shown in FIG. 8A showing the overlapping of the overlapping step patterns and the inspection area E,
As shown in FIG.
As shown in (b), "1" is added to the corresponding part of the memory map C.
Will stand. That is, the binarization data in the section of the position data 6-8 where the step patterns overlap is A68 = 1.
Since B68 = 1, C68 = 1 (C68 = A68 · B68) due to the AND operation. In this way, the memory maps C to C of the entire inspection area E are
ij is read and the result is output by the output unit 13 (in FIG. 9), and the presence of the minute foreign matter can be detected even when the minute foreign matter is on the edge portion of the pixel. Various output modes of the result of the logical product operation can be appropriately set.

FIG. 9 and FIG. 10 show the present fine foreign matter appearance inspection apparatus 1
2 is a flow chart showing an example of the flow of the operation of, wherein is a processing step at the time of forward movement, is a processing step at the time of backward movement, is a logical product operation processing step, and is an output step.

[0022]

As described above, the apparatus for inspecting the appearance of minute foreign matter on a color filter according to the present invention includes a moving portion for moving the color filter back and forth, and a color filter moving direction from one side when the color filter moves in the forward direction. An illumination unit that irradiates the color filter with light and also irradiates the color filter with light from the other side of the color filter moving direction when the color filter moves in the backward direction, and is fixed on the moving path of the color filter. An image capturing unit that captures, as an image, a step pattern on a color filter where the light from the illumination unit diffuses and diffuses during direction movement and backward direction movement, and image data obtained by the image capturing unit during forward movement And the image data when moving in the backward direction,
Based on the position data set for the color filter, it is converted into binarized data, and the binarized data when moving in the forward direction and the binarized data when moving in the backward direction are converted. It is characterized by comprising a control unit for performing a logical product operation and an output unit for outputting the result of the logical product operation by the control unit based on the position data. As described above, the present apparatus is provided with the control unit that works to remove the information of the step pattern composed of the edge of the pixel. Therefore, the control unit works to remove the fine foreign matter located at the edge portion of the pixel. It becomes possible to reliably detect even the above, and it becomes an apparatus having an improved detection accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing an embodiment of an apparatus for inspecting appearance of minute foreign matter on a color filter according to the present invention.

FIG. 2 is an explanatory diagram showing an inspection area.

3A and 3B show color filters, in which FIG. 3A is an explanatory view showing an array of pixels in a plane, and FIG. 3B is an explanatory view showing a cross-section taken along a line B-B in FIG.

FIG. 4 is a diagram showing a bright step pattern when the color filter is moved in the forward direction, (a) is an explanatory view showing the step pattern in a plane, and (b) is a cross section of the line portion of (a). It is an explanatory view shown.

5A and 5B show a step pattern which is bright when the color filter is moved in the backward direction. FIG. 5A is an explanatory view showing the step pattern in a plane, and FIG. 5B is a cross-sectional view taken along the line of FIG. It is an explanatory view shown.

FIG. 6 is a diagram showing an image data and a memory map captured when the color filter moves in the forward direction,
(A) is an explanatory view showing the superposition of the inspection area and the step pattern, and (B) is an explanatory view showing a memory map in which the image data at the time of the forward movement is binarized.

FIG. 7 shows image data and a memory map captured when the color filter is moved in the backward direction,
(A) is an explanatory view showing the superposition of the inspection area and the step pattern, and (B) is an explanatory view showing a memory map in which the image data at the time of backward movement is binarized.

8A and 8B show an overlapping portion of image data of a color filter and a memory map, FIG. 8A is an explanatory diagram showing superposition of an inspection area and a step pattern overlapping portion, and FIG. It is explanatory drawing which shows the memory map in which the result was written.

FIG. 9 is an explanatory diagram showing a flow chart of the operation of the apparatus.

FIG. 10 is an explanatory view showing a flow chart of the operation of the apparatus.

11A and 11B are diagrams showing a captured state of a bright step pattern, in which FIG. 11A is an explanatory diagram showing capturing during forward movement, and FIG. 11B is an explanatory diagram showing capturing during backward movement.

FIGS. 12A and 12B also show a captured state of a bright step pattern, in which FIG. 12A is an explanatory diagram showing capturing during forward movement, and FIG. 12B is an explanatory diagram showing capturing during backward movement.

13A and 13B are views showing a conventional example, in which FIG. 13A is an explanatory view schematically showing the apparatus configuration, FIG. 13B is an explanatory view showing image capturing during forward movement, and FIG. 13C is during backward movement. It is explanatory drawing which shows image acquisition.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Appearance inspection device 2 ... Moving part 3 ... Imaging part 4 ... Illumination part 5, 6 ... Light source 10 ... Control part 13 ... Output part a ... Color filter b ... Light c ... Pixel f ... Fine foreign matter E ... Inspection area A, B, C ... Memory map

Claims (1)

[Claims] 1. A moving part for moving a color filter back and forth, a color filter moving direction when the color filter moves backward, while irradiating light to the color filter from one side of the color filter moving direction when the color filter moves forward. The illumination unit that irradiates the color filter with light from the other side of the color filter is fixed on the moving path of the color filter, and the light from the illumination unit diffuses and shines when the color filter moves in the forward direction and in the backward direction. An image capturing unit that captures the step pattern on the color filter as an image, and image data obtained by the image capturing unit when moving in the forward direction and image data when moving in the backward direction are respectively supplied to the color filter. Based on the set position data, it is converted into binary data, and the binary data when moving in the forward direction and the binary data when moving in the backward direction are logically processed. A control unit for calculating the position of the result of the logical AND operation de by the control unit - the fine foreign matter inspection system on the color filter characterized by comprising an output section for outputting, based on the data.