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Patent Searching and Data


Title:
METHOD FOR DETECTING ORIENTATION NON-UNIFORMITY DEFECT IN RETARDATION FILM AND APPARATUS FOR DETECTING ORIENTATION NON-UNIFORMITY DEFECT IN RETARDATION FILM
Document Type and Number:
WIPO Patent Application WO/2021/010157
Kind Code:
A1
Abstract:
The present invention addresses the problem of providing a method for detecting an orientation non-uniformity defect in a retardation film and an apparatus for detecting an orientation non-uniformity defect in a retardation film that allow for more reproducible evaluation by performing detection and evaluation of an orientation non-uniformity defect in a retardation film through quantitative evaluation using an optical system. The method for detecting an orientation non-uniformity defect in a retardation film according to the present invention comprises the following steps (1) to (5). (1) Placing the retardation film between two polarizers arranged like crossed Nicols such that the slow axis of the retardation film is rotated and inclined at an angle of -10 to 10° with respect to the absorption axes of the polarizers. (2) Irradiating the retardation film with inspection light through one of the polarizers. (3) Obtaining a luminance image by capturing an image of the retardation film through the other polarizer. (4) Performing a differential operation (difference operation) on the captured luminance image in a direction oblique to the slow axis of the retardation film to enhance edges therein. (5) Binarizing the edge-enhanced luminance image using a predetermined threshold value to obtain bright pixels or dark pixels and detecting orientation non-uniformity from the pixels obtained.

Inventors:
HASHIMOTO SHOTA (JP)
MASUDA OSAMU (JP)
NANJIYOU TAKASHI (JP)
Application Number:
PCT/JP2020/025669
Publication Date:
January 21, 2021
Filing Date:
June 30, 2020
Export Citation:
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Assignee:
KONICA MINOLTA INC (JP)
International Classes:
G01N21/89; G01N21/892; G02B5/30
Foreign References:
JP2013050393A2013-03-14
JP2012013848A2012-01-19
JP2009236825A2009-10-15
Attorney, Agent or Firm:
KOYO INTERNATIONAL PATENT FIRM (JP)
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