Patent ID: 6489599
Filing Date: 2002-12-03
Classification: G11B

Abstract:
A light receiving method in an optical pickup device, comprising the steps of:providing a first light source and a second light source, light emission points of which are not on an identical optical axis; providing a common light receiving element; emitting a first laser light beam and a second laser light beam respectively from the first and second light sources, wavelengths of which are different from each other; converging the first and second laser light beams onto a record face of an optical recording medium; and diffracting the first and second laser light beams reflected from the optical recording medium based on different diffraction order, such that the diffracted first and second laser light beams are received by the common light receiving element, wherein the different diffraction order for the first and second laser light beams are respectively selected from the following combinations: positive primary diffraction and positive secondary diffraction; and negative secondary diffraction and negative primary diffraction.