Patent ID: 8014256
Filing Date: 2011-09-06
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 to zero-order light and diffraction light; an optical system for guiding the zero-order light and the diffraction light, which are diffracted, to one recording layer of the plurality of recording layers; an optical functional element for differentiating a phase difference of polarization of the zero-order light and a phase difference of polarization of the diffraction light; one or a plurality of light receiving devices for receiving at least the diffraction light; and an optical path branching device for guiding the zero-order light and the diffraction light coming from the one recording layer, to said light receiving device.