Thin optical pickup unit, and lens therefor

摘要

An optical pickup unit for converging a laser beam produced by a semiconductor laser (LD) on a signal recording surface of an optical disc (Disc) through a polarized optical system, and for detecting a return beam from the signal recording surface by a photodetector (PD) through the polarized optical system. The polarized optical system includes a collimator lens (CL(WP)), which comprises a polished lens (GS) having two surfaces, a functional resin layer (RS(WP)) being attached on one of the surfaces of the polished lens. The functional resin layer functions as a wave plate. Such lens may comprise an objective lens. <IMAGE>