Abstract: Provided are a layered film defect detection device capable of performing defect detection considering irregularities of optical performance of a phase difference layer constituting the layered film without requiring insertion of a new part into an optical path; and a layered film defect detection method. A defect detection device used for a layered film (11) having a polarizing plate (1) and a phase difference layer (separator (2)) includes: a light source (12) arranged at one side of the film surfaces of the layered film (11), an imaging unit (13) arranged on the other side of the film surface; an inspection polarization filter (15) arranged between the light source (12) and the imaging unit (13); a defect detection unit (14b) for detecting a defect existing on the polarizing plate (1) according to the captured image; and an optical axis adjusting unit (16) for adjusting a relative angle position of the polarization axis (L2) of a polarizing filter (15) and a polarization axis (L1) of a polarizer (2).

Abstract: Provided are a layered film defect detection device capable of performing defect detection considering irregularities of optical performance of a phase difference layer constituting the layered film without requiring insertion of a new part into an optical path; and a layered film defect detection method. A defect detection device used for a layered film (11) having a polarizing plate (1) and a phase difference layer (separator (2)) includes: a light source (12) arranged at one side of the film surfaces of the layered film (11), an imaging unit (13) arranged on the other side of the film surface; an inspection polarization filter (15) arranged between the light source (12) and the imaging unit (13); a defect detection unit (14b) for detecting a defect existing on the polarizing plate (1) according to the captured image; and an optical axis adjusting unit (16) for adjusting a relative angle position of the polarization axis (L2) of a polarizing filter (15) and a polarization axis (L1) of a polarizer (2).

Abstract: A method of inspecting a defect on a surface of a printed matter includes a step of applying a gray scale erosion filter to a non-defect surface of a printed matter to prepare a gray scale erosion filter applied image and then adding a predetermined density value to the gray scale erosion filter applied image, thereby preparing a reference image, a step of subtracting a captured image of the surface of the printed matter to be inspected from the reference image, thereby preparing a differential image, and a step of applying a density compensation process to the differential image to prepare a density compensated image, then applying an edge detection filter to the density compensated image to prepare an edge detection filter applied image and then converting the edge detection filter applied image into binary data according to a predetermined threshold value.

Abstract: A method of inspecting a defect on a surface of a printed matter includes a step of applying a gray scale erosion filter to a non-defect surface of a printed matter to prepare a gray scale erosion filter applied image and then adding a predetermined density value to the gray scale erosion filter applied image, thereby preparing a reference image, a step of subtracting a captured image of the surface of the printed matter to be inspected from the reference image, thereby preparing a differential image, and a step of applying a density compensation process to the differential image to prepare a density compensated image, then applying an edge detection filter to the density compensated image to prepare an edge detection filter applied image and then converting the edge detection filter applied image into binary data according to a predetermined threshold value.