JPH07146253A - Tester for adhesive polarizing film - Google Patents

Abstract

PURPOSE:To provide a tester which achieves highly accurate detection of defects of an adhesive layer in an adhesive polarizing film with a simple processing. CONSTITUTION:A ring-type emission port 8 is arranged surrounding a camera 10 for photographing a subject. The ring type emission port 8 is connected to a light source 6 through an optical fiber 7 and light from the light source 6 is emitted from the ring type emission port 8 through an optical fiber 7. An image processing section 11 made up of a binary coding part 12 and a judging part 13 is connected to the camera 10. A polarization filter 9 is set on the front of the ring type emission port 8 to perform a polarization in the direction differing from the direction of polarization of a polarizing film 3 contained in the subject. On the other hand, the subject has an adhesive polarizing film comprising the adhesive layer 2 and the polarizing film 3 applied on at least a glass substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection apparatus for automatically detecting a foaming defect of an adhesive layer of an adhesive polarizing film by using image processing.

[0002]

2. Description of the Related Art Conventionally, a defect inspection device using image processing is disclosed as a circuit pattern defect inspection device.
The one disclosed in Japanese Patent No. 133883 is known. In this defect inspection apparatus, two thresholds are set, a light and shade image is obtained by projecting light from an oblique direction to an object to be inspected, and then, based on the density distribution, a portion exceeding the brighter threshold is detected. The maximum value and the minimum value of a portion smaller than the darker threshold value are obtained, and when the two are adjacent to each other, the difference between the maximum value and the minimum value is compared with a predetermined value to detect an uneven defect.

[0003]

However, in such a conventional defect inspection apparatus, since it is necessary to use a multivalued density distribution for image processing, the amount of calculation is enormous and the inspection takes a long time. Have. In addition, when trying to use for a defect inspection of a so-called reflection type adhesive polarizing film in which an aluminum film or the like is attached to an adhesive polarizing film, irregularities of the aluminum film or the like that is a reflection plate are detected as a formation, and a foaming defect occurs. It also has the problem that it cannot be distinguished. The present invention is
The present invention has been made in view of the above problems, and an object of the present invention is to provide a defect inspection apparatus that accurately detects defects in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive polarizing film with a simple process.

[0004]

Therefore, the present invention provides an illuminating means for irradiating light onto a substrate surface of an object to be inspected, which includes a substrate having a light transmitting property and an adhesive polarizing film attached to the substrate. A polarizing member which is disposed between the inspection object and the illuminating means and which polarizes the light emitted by the illuminating means in a direction different from the polarization direction of the adhesive polarizing film of the inspection object; and the reflected light from the inspection object And image processing means for detecting a foaming defect of the adhesive layer of the adhesive polarizing film from the image taken by the imaging means.

[0005]

With the above configuration, the light from the illumination means is polarized in a direction different from the polarization direction of the adhesive polarizing film in the object to be inspected and then radiated to the object to be inspected. For example, a difference in the amount of light is clearly generated depending on the presence or absence of foaming in the adhesive layer, and the foaming defect can be detected.

[0006]

EXAMPLES The present invention will be described in detail below based on examples. FIG. 1 is a block diagram showing an embodiment of a defect inspection apparatus for an adhesive polarizing film according to the present invention. In the figure, a camera 10 is installed above the object A to be inspected, and a ring-shaped emission port 8 is arranged so as to surround the camera 10. The ring type emission port 8 is connected to the light source 6 via the optical fiber 7, and the light emitted from the light source 6 is emitted from the ring type emission port 8 through the optical fiber 7. An image processing unit 11 is connected to the camera 10, and the image processing unit 11 includes a binarization unit 12 and a determination unit 13. A polarizing filter 9 is installed on the front surface of the camera 10 and the ring-shaped exit 8 so as to polarize in a direction different from the polarization direction of the polarizing film 3 included in the inspection object A. FIG. 3 shows the polarizing film 3 and the polarizing filter 9.
FIG. 4 is a diagram for explaining the relationship of the above, and in this case, the polarization directions are arranged orthogonal to each other. It should be noted that the lightness and darkness are most emphasized in the image captured by the camera 10 when they are orthogonalized in this manner.

Next, the operation at the time of defect inspection in the device thus constructed will be described. In this embodiment, a so-called reflective adhesive polarizing film in which an aluminum film or the like is attached to the adhesive polarizing film is subjected to defect inspection. In this case,
In the inspection object A, an adhesive polarizing film including an adhesive layer 2 and a polarizing film 3 is attached to a glass substrate 1, and an aluminum film 5 is attached to the polarizing film 3 via an adhesive layer 4. It becomes the structure. The light emitted from the light source 6 passes through the optical fiber 7 and is emitted from the ring-shaped emission port 8 to the glass substrate 1 of the inspection object A. At this time, the irradiated light passes through the polarization filter 9 and is polarized in a certain direction before reaching the inspection object A. Then, the light transmitted through the glass substrate 1 reaches the adhesive layer 2, and the adhesive layer 2
The subsequent action depends on the presence or absence of foaming. The action of this light will be specifically described with reference to FIG. When the light hits the foam 14 present in the pressure-sensitive adhesive layer 2, most of the light is reflected on the surface, so that the reflected light taking the optical path X is obtained. On the other hand, when it does not hit the foam 14, it passes through the pressure-sensitive adhesive layer 2 and the polarizing film 3 as in the optical path Y, so that even if it is reflected by the aluminum film 5 after that, it will be blocked by the polarizing film 3. , Almost no reflected light is obtained.

The reflected light from the inspection object A passes through the polarization filter 9 and is imaged by the camera 10. In the image captured by the camera 10, a portion where the reflected light is obtained is bright and a portion where the reflected light is not obtained is dark. The image processing unit 11 is the camera 1.
The image signal from 0 is binarized by a predetermined threshold value in the binarization unit 12, and the brighter one is assigned to “1” (black pixel) and the darker one is assigned to “0” (white pixel). As a result, an image is obtained in which the background portion is white pixels and the portion where foaming is present is represented by black pixel groups. The determination unit 13 detects the size of the black pixel group included in the binarized image, and determines the foaming defect of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive polarizing film depending on how many black pixels have a size equal to or larger than a predetermined value. Determine the presence or absence.

FIG. 2 is a block diagram showing another embodiment of the present invention. The configuration of the polarization filter 9 is different from that of the embodiment shown in FIG. That is, the polarization filter 9 is arranged only on the front surface of the ring-shaped exit 8. According to this structure, the reflected light from the inspection object A is directly captured by the camera 10, and an image in which the difference between light and dark is emphasized can be obtained.

[0010]

As described above in detail, according to the present invention,
Utilizing the fact that a polarizing film is contained in the object to be inspected, and only by providing a polarizing member that polarizes the light emitted by the illuminating means in a predetermined direction, the adhesive layer of the adhesive polarizing film can be accurately processed with extremely simple processing. Foaming defects can be detected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a polarizing film and a polarizing filter.

FIG. 4 is a diagram for explaining the action of light on the inspection object.

[Explanation of symbols]

 1 Glass 2 Adhesive Layer 3 Polarizing Film 5 Aluminum Film 6 Light Source 7 Optical Fiber 8 Ring Type Emitting Port 9 Polarizing Filter 10 Camera 11 Image Processing Section

Claims (1)

[Claims] 1. An illuminating means for irradiating light onto a substrate surface of an object to be inspected, the substrate including a light-transmitting substrate and an adhesive polarizing film attached to the substrate, and the object to be inspected and the illuminating means. A polarizing member that is disposed between the two, and that polarizes the light emitted by the illumination unit in a direction different from the polarization direction of the adhesive polarization film of the inspection object; and an imaging unit that images reflected light from the inspection object; An image processing means for detecting a foaming defect of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive polarizing film from an image picked up by the means, and a defect inspection device for the pressure-sensitive adhesive polarizing film.