COMPOSITE OPTICAL SENSOR UNIT AND OPTICAL DISK INSPECTION DEVICE USING IT

摘要

Composite optical sensor unit and inspecting device comprises a laser beam source LD1, a scanner mirror (13) for distributing the laser beam high speed, a first beam splitter (15) for applying laser beams distributed by the scanner mirror vertically onto an object of inspection (16) having a concentric diffraction lattice. A fifth light receiving element PSD for two-dimensional position detection that receives a zero-order diffraction light (19) reflected from the object of inspection via the first beam splitter and detects the light receiving position, and a second light receiving element PD2 for receiving an n-order diffraction light (23) reflected from the object of inspection and detecting a received quantity of light.