JPH08193916A - Inspection equipment for color sample - Google Patents

Abstract

PURPOSE: To surely detect a defect in a colored pixel, regardless of the size of color sample for the type of a product. CONSTITUTION: A set of two cameras 21, 22 for picking up the image of a color sample is arranged at an image input section 2 such that the cameras can move relatively depending on the width of the color sample and the change in the size of color sample can be dealt with by bringing two cameras 21, 22 closely to the color sample or separating the cameras therefrom. A transmission light source 11 and a reflection light source 12 are disposed at the light source section 1 such that they can be switched. The transmission light source 11 is used advantageously for detecting an uncolored or unevenly colored part whereas the reflection light source 12 is used advantageously for detecting a foreign matter. Consequently, an inspection equipment dedicated for specific type of defect is not required.

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 color samples such as color filters for liquid crystal displays and color filters for color television cameras, and more specifically, red (R), green (G) and blue (B). Of these, it relates to an apparatus for inspecting a color sample after forming colored pixels of at least one color.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for inspecting a color sample of this type, a white light such as a halogen lamp or a fluorescent lamp is used as a transmitted light source, and when a color sample is observed by the transmitted light, a defective portion is detected. It is commonly used that the transmitted light intensity is different from that of the part without defects, and the difference in the image level in the transmitted light image of the color sample taken by the camera is extracted to inspect the defect. There is.

[0003]

However, in the conventional inspection apparatus, since the transmitted light of the color sample is photographed by a single camera, when inspecting the color samples having different widths, the camera for each product item is used. However, there is a problem that this adjustment work is troublesome. There is also a problem that a reflection light source must be separately prepared depending on the type of defect. Furthermore, since white light is used as the light source, it is possible to determine the presence or absence of defects only at a fixed slice level.Therefore, if there is a colored pixel of another color, a blank defect or other color is found for each colored pixel. However, there is a problem that it is difficult to detect a mixed color defect with, a defect with dust containing various colors, uneven coloring density, and the like. There is also a problem that it is difficult to detect minute white defects.
The white spot defect here means a defect in which a predetermined colored pixel is not formed on a substrate on which a patterned colored pixel is to be formed with a colored material.

The present invention has been made in view of the above problems, and an object thereof is to cope with a difference in size of a color sample depending on a product or a defect of a different type. Accordingly, it is an object of the present invention to provide a color sample inspection device capable of reliably detecting a defect in a colored pixel.

[0005]

In order to achieve the above object, the first inspection apparatus according to the present invention irradiates a color sample in which patterned colored pixels are formed with a colored material of one or more colors. A light source section having a light source, an image input section for recognizing transmitted light or reflected light of the color sample for recognition, and an inspection processing section for comparing the recognized image with a reference value to determine the presence or absence of a defect. In the color sample inspection device, one set of two cameras for inputting an image of the color sample is arranged in the image input section, and the two cameras are relatively moved according to the width of the color sample. First
And a second control means for moving the two cameras in a direction of moving closer to or farther from the color sample.

The second inspection apparatus according to the present invention is
A light source unit having a light source for irradiating a color sample in which a patterned colored pixel is formed with a colored material of a color or more; and an image input unit that detects and recognizes transmitted light or reflected light of the color sample, In a color sample inspection device including an inspection processing unit that compares the recognized image with a reference value to determine whether there is a defect, a transmissive light source and a reflective light source are arranged in the light source unit, and these can be switched. It is characterized by that.

In the first and second inspection devices, the colored pixel to be inspected in the color sample is located between the light source and the color sample or between the color sample and the image input section. An optical filter having different peaks of spectral transmittance or spectral reflectance may be arranged. Further, a spectral light source having the same optical characteristics as the above-mentioned optical filter may be used as the light source itself.

[0008]

In the first inspection apparatus, the distance between the two cameras is narrowed or widened in accordance with the width of the color sample, and the two cameras are moved closer to or farther from the color sample to reduce the width. The shooting range can be easily adjusted for different color samples.

In the second inspection apparatus, the light source unit is switched to the transmissive light source for use to advantageously detect color loss and unevenness, and the reflective light source is used for detection of foreign matter. Can be advantageously performed.

Further, by using the above-mentioned optical filter or spectral light source, the defective portion can be clearly recognized in the image input section for each of the colored pixels of the specific color to be inspected.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an inspection apparatus according to the present invention. As shown in the figure, the inspection apparatus comprises a light source unit 1, an image input unit 2 and an inspection processing unit 3. ing.

The light source unit 1 is provided with a transmissive light source 11 for irradiating the color filter substrate from below and a reflective light source 12 for irradiating the color filter substrate from above, and these are switched and used. .

The image input section 2 includes two line sensor cameras 21 and 22 for inputting images of colored pixels formed on a color filter substrate, and these two cameras 21 and 22.
The width of the color filter substrate (may be the area you want to inspect)
Width direction motor 23a for moving the two cameras 21 and 22 closer to or farther from the color filter substrate, and width direction motor 23a for moving the two cameras 21 and 22 closer to or further away from the color filter substrate.
A focus motor 23c for adjusting the focus of one camera 21, a focus motor 23d for adjusting the focus of the other camera 2, and a sensor instruction mechanism control unit 24 for controlling these four types of motors. And driving devices 25 and 26 for driving the reflective fiber light source 11 and the transmissive fiber light source 12 of the light source unit 1, respectively.

The inspection processing unit 3 receives inputs from an inspection host personal computer 31 for executing inspection commands and controls, a CRT 32 as a display device thereof, and two cameras 21 and 22 of the image input unit 2. It is composed of two image processing devices 33 and 34 for performing the integration process, the first-order differentiation process, the second-order differentiation process, etc. of the image thus obtained, and the interface 35 for communication with other devices. Before starting the inspection, the item data is received from the host computer 4 via the interface 35, and the board size,
The inspection allowable value and the like are set in the host personal computer 31 of the inspection processing unit 3. On the contrary, the inspection result and the like are transmitted to the host computer 4 and used as quality control information.

FIG. 2 is a perspective view of an essential part for explaining a case where a transmission light source is used in the inspection apparatus of FIG. An inspection performed using this transmitted light source has a configuration in which it is easy to detect a color loss defect.

As shown in FIG. 2, when the transmissive light source 11 is used, the shooting angle θ of the line sensor cameras 21 and 22 is set to 0 degree, that is, it is set to be perpendicular to the color filter substrate CF. The support plate 24 is set so that the inspection is performed.

In accordance with a control command from the host personal computer 31 of the inspection processing unit 3 in which the board size, inspection allowable value and the like are set according to the item data received from the host computer 4 prior to the inspection, the sensor support mechanism control unit 24 causes the substrate The distance between the two line sensor cameras 21 and 22 and the color filter substrate CF is set by the forward / backward movement motor 23b according to the size, and the distance between the two line sensor cameras 21 and 22 is set in the width direction motor 2.
3a. Further, the color filter substrate C
The line sensor cameras 21 and 22 are respectively set to focus motors 23 so that the colored pixels formed on F are focused.
Adjust with c and 23d. Then, the color filter substrate CF is illuminated from below by the transmissive light source 11 arranged below the color filter substrate CF. At this time, the reflection light source 12 arranged above the color filter substrate CF is turned off.

When the color filter substrate CF is transported by a transport mechanism (not shown), a timing sensor (not shown) detects the color filter substrate CF, and image input from the two line sensor cameras 21 and 22. Determine the timing of. That is, when the host personal computer 31 detects a timing signal from the timing sensor via the interface 35, the host personal computer 31 outputs an image input command to the image processing devices 33 and 34. And two cameras 21,
An image is input on the color filter substrate CF on the front surface of 22. That is, the light transmitted through the color filter substrate CF is photographed by the image input cameras 21 and 22 arranged above the color filter substrate CF.

The photographed images are image processing devices 33, 34.
And is subjected to integration processing, primary differential processing, secondary differential processing, and the like. Then, these processing results are compared with a slice level (reference value) to determine the presence or absence of a defect. The determination result is output from the inspection host personal computer 31 via the interface 35 to the host computer 4, an alarm device such as a buzzer (not shown), an automatic ejecting device for the color filter substrate CF, or the like.

FIG. 3 is a perspective view of an essential part for explaining a case where a reflection light source is used in the inspection apparatus of FIG. In the inspection performed using this reflected light source, defects such as protrusions, pinholes, and stains are easily detected.

As shown in FIG. 3, when the reflection light source 12 is used, the support plate 2 is so set that the photographing angle θ of the line sensor cameras 21 and 22 is 3 to 15 degrees, preferably 6 to 8 degrees.
Set 4 to perform inspection. At this time, the reflection light source 12 preferably has an irradiation angle inclined by 5 to 20 degrees on the side opposite to the photographing angle θ, and preferably 8 to 11 degrees. In short, the shooting angle is set to be larger than the tilt angle by 2 to 5 degrees.

First, as in the case of the transmission type, but from the host personal computer 31 of the inspection processing unit 3 in which the board size, the inspection allowable value, etc. are set by the item data received from the host computer 4 prior to the inspection. In accordance with the control command, the sensor support mechanism control unit 24 sets the distance between the two line sensor cameras 21 and 22 and the color filter substrate CF according to the substrate size by the forward / backward motor 23b, and the two line sensor cameras 2
The width direction motor 23a sets the distance between 1 and 22. Furthermore, the line sensor camera 21, so that the colored pixels formed on the color filter substrate CF are in focus.
22 is adjusted by respective focus motors 23c and 23d.

Then, the color filter substrate CF is illuminated from above by the reflection light source 12 disposed on the color filter substrate CF. At this time, the transmissive light source 11 arranged below the color filter substrate CF is turned off.

When the color filter substrate CF is transported by a transport mechanism (not shown), the timing sensor (not shown) detects the color filter substrate CF, and image input from the two line sensor cameras 21 and 22. Determine the timing of. That is, when the host personal computer 31 detects a timing signal from the timing sensor via the interface 35, the host personal computer 31 outputs an image input command to the image processing devices 33 and 34. And two cameras 21,
An image is input on the color filter substrate CF on the front surface of 22. That is, the light reflected from the color filter substrate CF is photographed by the image input cameras 21 and 22 arranged above the color filter substrate CF.

The captured images are used as image processing devices 33 and 34.
And is subjected to integration processing, primary differential processing, secondary differential processing, and the like. Then, these processing results are compared with a slice level (reference value) to determine the presence or absence of a defect. The determination result is output from the inspection host personal computer 31 via the interface 35 to the host computer 4, an alarm device such as a buzzer (not shown), an automatic ejecting device for the color filter substrate CF, or the like.

Next, a method of improving the detection performance by devising the optical system will be described. The method described here is particularly effective in the case of a transmissive light source.

FIG. 4 shows a block diagram of a light source device used in this system. This light source device is used as the transmissive light source 11 and the reflective light source 12 in the light source section of the above-mentioned inspection device, and as shown in FIG. 4, guides the light source 13 and light from this light source 13 to the object to be inspected. Optical fiber 14
And an optical filter 15 arranged between the light source 13 and the optical fiber 14 for selecting the wavelength of light. The optical fibers 14 are arranged so as to be in a single row (may be a plurality of rows) on the irradiation side and orthogonal to the traveling direction of the inspection object. That is, the fibers are arranged one by one so that the light is uniformly irradiated in the width direction of the inspection object. As the light source 13, a white light source whose light intensity is substantially uniform over the entire wavelength range may be used. When the object to be inspected is the color filter substrate CF, R, G,
Since the colored material of B is applied (or transferred) in a pattern to form colored pixels, a three-wavelength light source having peaks in R, G, and B may be used.

The optical filter 15 is shown in FIGS.
There are 6 types (yellow filter, magenta filter, cyan filter, blue filter, green filter, red filter) showing the optical characteristics, and these are selected according to the type of colored pixel to be inspected. That is, the optical characteristics of the colored pixels formed on the color filter substrate CF are as shown in FIG. 11, and these colored pixels R,
The defect is efficiently detected by appropriately using the optical filter 15 having the characteristics shown in FIGS. 5 to 10 so that G and B can be easily detected. In these figures, λ is the wavelength and T is the spectral transmittance.

A procedure for inspecting the color filter substrate CF, which is the object to be inspected, by the inspection apparatus having the above light source device will be specifically described with reference to FIGS. 12 (a) to 12 (c).

FIG. 12A is an image diagram in which only one color pixel of red (R) is formed on the color filter substrate CF. Here, by using the blue filter of FIG. 8 having a spectral transmittance different from that of the red (R) colored pixel, the normal red (R) colored pixel is almost black and is not detected.
Only white spot defects, color mixture defects with other colors, and red (R) density unevenness can be detected. Although the detection sensitivity is slightly inferior, it is also possible to use the cyan filter of FIG. If the colored pixel is not red (R), the same idea can be applied.

FIG. 12B is an image diagram in which colored pixels of two colors of red (R) and blue (B) are formed on the color filter substrate CF. Here, by using the red filter of FIG. 10 having a spectral transmittance similar to that of the red (R) colored pixel, the normal blue (B) colored pixel becomes almost black and is not detected, and white is not detected. Missing defect, mixed color defect with other colors,
Only the density unevenness of blue (B) can be detected. Although the detection sensitivity is slightly inferior, it is also possible to use the yellow filter shown in FIG. When the two colored pixels are not red (R) and blue (B), the same idea can be applied.

FIG. 12C is an image diagram in which colored pixels of three colors of red (R), blue (B) and green (G) are formed on the color filter substrate CF. Here, the spectral transmittances similar to those of the red (R) colored pixel and the blue (B) colored pixel are shown in FIG.
By using the magenta filter of normal green (G)
The colored pixels of No. 2 are almost black and are not detected, and only white spot defects, mixed color defects with other colors, and density unevenness of green (G) can be detected.

In the above example, the optical filter is used in the light source device to arrange the optical filter between the light source and the color sample. However, a similar optical filter is arranged between the color sample and the image input means. May be arranged. Further, a spectral light source having the same optical characteristics as the above-mentioned optical filter may be used as the light source itself.

[0035]

As described above, the color sample inspecting apparatus of the present invention has two units for inputting an image of a color sample.
By arranging a pair of cameras in the image input unit and adjusting the distance between the two cameras and the distance between the two cameras and the color sample, even if the size of the color sample varies depending on the product, The width direction of the camera can be easily adjusted according to the size.

Further, since the transmissive light source and the reflective light source are arranged in the light source section and these are switchable, color loss and unevenness can be advantageously detected by the transmissive light source, and foreign matter can be advantageously detected by the reflective light source. Since it can be performed, it is not necessary to separately prepare an inspection device depending on the type of defect, which is convenient.

Further, by using an optical filter or a spectral light source, a defective portion can be clearly recognized for each of the colored pixels of a specific color to be inspected, so that a white spot defect for each colored pixel which is difficult to detect with white light. , It is possible to easily detect color mixture defects with other colors, defects with dust including various colors, uneven coloring density, etc., and it is possible to detect fine white spot defects etc. by setting a small slice level. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an inspection device according to the present invention.

FIG. 2 is a perspective view of a main part for explaining a case where a transmissive light source is used.

FIG. 3 is a perspective view of a main part for explaining a case where a reflection light source is used.

FIG. 4 is a configuration diagram of a light source device using a method of improving detection performance.

FIG. 5 is a graph showing the optical characteristics of a yellow filter of the optical filters.

FIG. 6 is a graph showing the optical characteristics of a magenta filter of the optical filters.

FIG. 7 is a graph showing optical characteristics of a cyan filter of optical filters.

FIG. 8 is a graph showing optical characteristics of a blue filter of optical filters.

FIG. 9 is a graph showing optical characteristics of a green filter of optical filters.

FIG. 10 is a graph showing the optical characteristics of a red filter of the optical filters.

FIG. 11 is a graph showing optical characteristics of colored pixels formed on a color filter substrate.

FIG. 12 is an image diagram showing a state in which R, G, and B colored pixels are sequentially formed on a color filter substrate.

[Explanation of symbols]

 CF color filter substrate (color sample) 1 light source unit 11 transmissive light source 12 reflective light source 13 light source 15 optical filter 2 image input unit 21, 22 camera 23a width direction motor 23b forward / backward motor 24 sensor instruction mechanism control unit 3 inspection processing unit

Claims (8)

[Claims] 1. A light source unit having a light source for irradiating a color sample formed by patterning colored pixels made of a coloring material of one or more colors, and detecting and recognizing transmitted light or reflected light of the color sample. In a color sample inspecting apparatus including an image inputting unit for inputting a color image and an inspection processing unit for comparing the recognized image with a reference value to determine the presence / absence of a defect, a set of two cameras for inputting an image of the color sample Is disposed in the image input section, and the first control means for relatively moving the two cameras according to the width of the color sample, and
An apparatus for inspecting a color sample, comprising: a second control unit that moves a camera in a direction toward or away from the color sample. 2. An optical filter having a peak of spectral transmittance or spectral reflectance different from a colored pixel to be inspected in the color sample is arranged between the light source and the color sample. Item 1. A color sample inspection device according to item 1. 3. An optical filter having a peak of spectral transmittance or spectral reflectance different from that of a colored pixel to be inspected in the color sample is arranged between the color sample and the image input section. The color sample inspection device according to claim 1. 4. The spectral light source having a spectral intensity peak different from the spectral transmittance or spectral reflectance peak of a colored pixel to be inspected in a color sample is used as the light source. Color sample inspection device. 5. A light source section having a light source for irradiating a color sample formed by patterning colored pixels of one or more color materials, and detecting and recognizing transmitted light or reflected light of the color sample. In an inspection device for a color sample including an image input unit that performs, and an inspection processing unit that determines the presence or absence of a defect by comparing a recognized image with a reference value, a transmissive light source and a reflective light source are arranged in the light source unit, An inspection device for color samples that can switch between these. 6. An optical filter having a peak of spectral transmittance or spectral reflectance different from that of a colored pixel to be inspected in the color sample is arranged between the light source and the color sample. Item 5. The color sample inspection device according to item 5. 7. An optical filter having a peak of spectral transmittance or spectral reflectance different from that of a colored pixel to be inspected in the color sample is arranged between the color sample and the image input section. The color sample inspection device according to claim 5. 8. A spectral light source having a spectral intensity peak different from a spectral transmittance or spectral reflectance peak of a colored pixel to be inspected in a color sample is used as the light source. Color sample inspection device.