Optical information recording medium and method of manufacturing same

摘要

A film thickness inspecting mechanism includes a light source disposed below a substrate, a CCD unit for detecting a light beam (transmitted light beam) emitted from the light source and transmitted through the substrate and converting the detected light beam into an electric signal (detected signal) commensurate with the detected intensity of the light beam, a substrate feeder having a plurality of light shield plates for blocking a light beam emitted from the light source at given intervals, and a substrate holder for holding the substrate.