Layered film fabrication method, layered film defect detection method, layered film defect detection device, layered film, and image display device

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 () having a polarizing plate () and a phase difference layer (separator ()) includes: a light source () arranged at one side of the film surfaces of the layered film (), an imaging unit () arranged on the other side of the film surface; an inspection polarization filter () arranged between the light source () and the imaging unit (); a defect detection unit () for detecting a defect existing on the polarizing plate () according to the captured image; and an optical axis adjusting unit () for adjusting a relative angle position of the polarization axis (L) of a polarizing filter () and a polarization axis (L) of a polarizer (). In the detection device, the relative angle position of the polarizing filter () is adjusted within a range of the polarization axis angle x of the polarizing filter satisfying the relationship 0 degrees<xf 15 degrees so as to minimize the visible light quantity inputted to the imaging unit.