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KR-102962909-B1 - APPEARANCE INSPECTION METHOD AND APPEARANCE INSPECTION APPARATUS

KR102962909B1KR 102962909 B1KR102962909 B1KR 102962909B1KR-102962909-B1

Abstract

The present invention relates to an appearance inspection method and an inspection apparatus capable of detecting even minute defects existing between a substrate and an anti-reflection layer. An optical member (11) to be inspected has an anti-reflection layer (1) on one side of a substrate (6). Light with a wavelength of 410 nm or less is irradiated from a light-emitting unit (21) onto the first side of the optical member (11), and reflected light from the optical member is captured by an imaging unit (31). It is preferable to position the imaging unit (31) in the direction of the normal of the optical member or in one direction with the normal between them, and to position the light-emitting unit (21) in the other direction with the normal between them. Inspection may also be performed while moving the optical member (11) in one direction.

Inventors

  • 백 세찬
  • 노 해일
  • 카시마 쇼지

Assignees

  • 닛토덴코 가부시키가이샤

Dates

Publication Date
20260511
Application Date
20191018
Priority Date
20181130

Claims (19)

  1. A method for inspecting the appearance of an optical member having an anti-reflection layer on a first main surface of a substrate having a first main surface and a second main surface, Light with a wavelength of 410 nm or less is irradiated from a light-emitting unit onto a first main surface of the optical member, and reflected light from the optical member is captured by an imaging unit, The above-mentioned imaging unit is positioned in the normal direction of the optical member or on one side with the normal in between, and the above-mentioned light-emitting unit is positioned on the other side with the normal of the optical member in between, A method for visual inspection in which the projection angle (φ) based on the normal direction of the optical member is greater than the imaging angle (θ) based on the normal direction of the optical member.
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  4. In Article 1, An appearance inspection method in which the difference between the above-mentioned imaging angle (θ) and the above-mentioned light projection angle (φ) is 7° or more.
  5. In Article 1, An appearance inspection method in which the sum of the above-mentioned imaging angle (θ) and the above-mentioned light projection angle (φ) is 35° to 55°.
  6. In Article 1, An appearance inspection method in which the above-mentioned imaging angle (θ) is 0° to 30° and the above-mentioned light projection angle (φ) is 5° to 50°.
  7. In any one of Article 1 and Articles 4 through 6, An appearance inspection method that moves the optical member in one direction while irradiating light from the light-emitting part onto a first main surface of the optical member, and captures the reflected light with the imaging part.
  8. In any one of Article 1 and Articles 4 through 6, A visual inspection method for detecting defects present at the interface between the above-mentioned material and the above-mentioned anti-reflection layer.
  9. In Article 8, A method for inspecting the appearance of the above defect, which is a contaminant attached to the surface of the above-described material.
  10. In Article 9, A method for inspecting the appearance of the above defects in white.
  11. In any one of Article 1 and Articles 4 through 6, The above description is an appearance inspection method including a polarizer.
  12. In any one of Article 1 and Articles 4 through 6, An appearance inspection method in which the above-described material has a hard coat layer on a first surface and the anti-reflection layer is formed on the hard coat layer.
  13. An appearance inspection device used for appearance inspection of an optical member having an anti-reflection layer on a first main surface of a substrate having a first main surface and a second main surface, A light-emitting member disposed on the first main surface side of the optical member and irradiating light with a wavelength of 410 nm or less onto the first main surface of the optical member, and On the first main side of the optical member, an imaging unit is provided that is arranged to capture reflected light from the optical member. The above-mentioned imaging unit is positioned in the normal direction of the optical member or on one side with the normal in between, and the above-mentioned light-emitting unit is positioned on the other side with the normal of the optical member in between, and An appearance inspection device in which the projection angle (φ) based on the normal direction of the optical member is greater than the imaging angle (θ) based on the normal direction of the optical member.
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  16. In Article 13, An appearance inspection device in which the difference between the above-mentioned imaging angle (θ) and the above-mentioned light projection angle (φ) is 7° or more.
  17. In Article 13, An appearance inspection device in which the sum of the above imaging angle (θ) and the above light projection angle (φ) is 35° to 55°.
  18. In Article 13, An appearance inspection device having an imaging angle (θ) of 0° to 30° and a light projection angle (φ) of 5° to 50°.
  19. In any one of Articles 13 and 16 through 18, An appearance inspection device further comprising a conveying mechanism for continuously conveying the above optical member in one direction.

Description

Appearance Inspection Method and Appearance Inspection Apparatus The present invention relates to an appearance inspection method and an appearance inspection device for optically inspecting defects in an optical member having an anti-reflection layer. Various optical components, such as polarizers, phase difference films, and cover windows, are used in image display devices such as liquid crystal displays or organic EL displays. In addition, optical components that have functional thin films, such as anti-reflective layers or transparent conductive films, on the surface of a substrate such as film or glass are also used. If defects such as deformation (e.g., scratches or dents), foreign matter inclusion, foreign matter adhering to the surface, or contamination exist in these optical components, it results in a degradation of display characteristics. Therefore, to prevent the leakage of products containing defects, visual inspection is performed during the manufacturing process of optical components or before the shipment of finished products. Visual inspection of optical components is performed, for example, by the visual inspection of an inspector. In addition, inspection is also performed using an inspection device that irradiates light onto the optical component, captures transmitted or reflected light using a camera, and determines the presence or absence of defects based on the obtained image. For example, Patent Document 1 discloses a method for inspecting the presence or absence of defects by irradiating light onto a transparent substrate equipped with an anti-reflective film and capturing the transmitted light. Patent Document 2 discloses a method in which a mirror is placed on the back surface of a transparent member to be inspected, ultraviolet light is irradiated onto the transparent member, and ultraviolet light that passes through the transparent member and is reflected from the mirror is detected by an ultraviolet camera, and it is described that defects present on the surface and inside of the transparent member can be identified by projecting them onto an image with high contrast. Figure 1 is a cross-sectional view showing an example of a laminated configuration of a polarizing plate with an anti-reflection layer attached. Figure 2 is a cross-sectional view showing an example of a laminated configuration of a polarizing plate with an anti-reflection layer attached. Figure 3 is a configuration diagram showing the shape of performing optical inspection while transporting an optical component. Figure 4 is a cross-sectional view showing the arrangement of lighting, a camera, and optical components. Figure 5 is a cross-sectional view showing the arrangement of lighting, a camera, and optical components. FIG. 6 is a cross-sectional view showing the arrangement of lighting, cameras, and optical components. Figure 7 is an inspection image of an example. Figure 8 is an inspection image of an example and a comparative example. One embodiment of the present invention relates to a method for inspecting the appearance of an optical member having an anti-reflection layer on one surface of a substrate, and an appearance inspection device for inspecting the appearance of an optical member, characterized by capturing reflected ultraviolet rays. [Composition of Optical Components] The optical member subject to visual inspection is provided with an anti-reflective layer on one of the main surfaces of a planar substrate. The substrate may be a rigid substrate such as glass, or a flexible substrate such as a resin film. Additionally, the optical member may be single-sheet or long-sheet shaped. When inspecting the appearance of a long-sheet shaped optical member, the inspection may be performed while conveying the optical member in one direction using a roll-to-roll method. FIG. 1 is a cross-sectional view of a polarizing plate with an anti-reflective layer attached, which is an example of an optical member having an anti-reflective layer. The polarizing plate (11) with an anti-reflective layer attached shown in FIG. 1 has an anti-reflective layer (1) on the surface of a polarizing plate (6) with a hard coat layer attached. The polarizing plate generally has a configuration in which a transparent protective film (4, 5) is bonded to one or both sides of a polarizer (3). As a polarizer (3), for example, a polyvinyl alcohol (PVA)-based polarizer is used in which a dichroic substance such as iodine or a dichroic dye is adsorbed onto a polyvinyl alcohol-based film and oriented in a predetermined direction. As a PVA-based polarizer, a thin polarizer with a thickness of 10 μm or less may be used. A flexible transparent film is used as a transparent protective film (4, 5) bonded to one or both sides of a polarizer (3). The visible light transmittance of the transparent film is preferably 80% or more, more preferably 90% or more. The thickness of the transparent film is approximately 10 to 300 μm. As resin materials cons