Patent ID: 7916618
Filing Date: 2011-03-29
Classification: G11B

Abstract:
1. An optical pickup for recording or reproducing an information signal with respect to an optical disc comprising a plurality of recording layers, each recording layer having a recording track in which information pits are arranged, the information signal being recorded in the information pits, said optical pickup comprising: a light source for irradiating a laser beam; a diffracting device for diffracting the irradiated laser beam; an optical system for guiding the diffracted laser beam to one recording layer of the plurality of recording layers; an optical element which functions as an amplitude grating with respect to (i) signal light generated in the one recording layer and (ii) stray light generated in another recording layer of the plurality of recording layers, if the guided laser beam is focused on the one recording layer; and one or a plurality of light receiving devices for receiving at least the signal light.