Patent ID: 7817509

Claim:
An optical pickup apparatus which is used for recording information on or reproducing information from an optical disk having a plurality of recoding layers by irradiating the optical disk with light, the optical pickup apparatus comprising: a light source for emitting light; an optical system for condensing the light emitted from the light source onto a recording layer of the optical disk and condensing light reflected by the recording layer of the optical disk; a light-receiving unit for receiving light reflected by the recording layers of the optical disk through the optical system, the light-receiving unit having a first light-receiving portion for receiving light reflected by a light-condensing recording layer which is a recording layer of the optical disk and is currently involved in condensing the light emitted from the light source, the first light-receiving portion being disposed at a condensing position of the light reflected by the light-condensing recording layer, and a second light-receiving portion for receiving light reflected by a non-light-condensing recording layer which is another recoding layer of the optical disk and is currently not involved in condensing the light emitted from the light source, the second light-receiving portion being disposed adjacent to the first light-receiving portion and away from the condensing position of the light reflected by the light-condensing recording layer; and a compensating section for compensating a result of light reception by the first light-receiving portion based on a result of light reception by the second light-receiving portion, wherein the optical system splits the light emitted from the light source, into a main beam and a pair of sub beams, and condenses the main beam and sub beams on the recording layer of the optical disk, the first light-receiving portion has a main beam-receiving element, disposed at a condensing position of main beam reflected by the light-condensing recording layer, for receiving the main beam reflected by the light-condensing recording layer, and a pair of sub beam-receiving elements, disposed at condensing positions of sub beams reflected by the light-condensing recording layer, for respectively receiving the sub beams reflected by the light-condensing recording layer, the second light-receiving portion has a light-receiving part for main beam compensation, disposed away from a condensing position of a main beam reflected by the light-condensing recording layer, and condensing positions of sub beams reflected by the light-condensing recording layer, and adjacent to the main beam-receiving element, for receiving the main beam reflected by the non-light condensing layer, which is used for compensating a result of light reception by the main beam-receiving element, and the compensating section compensates a result of light reception by the main beam-receiving element based on a result of light reception by the light-receiving part for main beam compensation.