Patent ID: 7209427
Filing Date: 2007-04-24
Classification: G11B

Abstract:
1. An optical pickup for emitting a beam onto an optical recording medium and using a reflected beam from the recording medium to read recorded information, comprising: a light-emitting element operable to emit the beam; an objective lens unit in which a central part of a surface, facing the light-emitting element, of an objective lens disposed so that an optical axis is substantially aligned with a chief ray of the beam emitted by the light-emitting element, is a transmissive diffraction grating, and a central part of a surface of the objective lens that will face the optical recording medium is a convex mirror which bulges toward the light-emitting element; an annular reflecting mirror that encompasses the optical axis of the objective lens and is operable to reflect toward the objective lens, the beam from the light-emitting element that has passed through the transmissive diffraction grating and been reflected by the convex mirror; and a light-receiving element operable to receive first-order diffracted light, of the reflected beam from the recording medium, diffracted by the transmissive diffraction grating.