Inspection method for lens products, and apparatus for the same

摘要

An inspection method that enables efficient inspection operations before the shipment of a sheet lens product. A sheet-like Fresnel lens sheet having a masking material bonded on its light-incidence surface is placed on an operation surface equipped with a black color system of background with the light-incidence surface up. On the operation surface the masking material is exfoliated. At the same time the Fresnel lens sheet is inspected by the reflected light to thereby make an inspection of the presence or absence of a white color system of defects. Thereafter, the Fresnel lens sheet is inspected by a the transmission light.