Optical pickup capable of optically sensing a direction of a beam deflected by a deflecting device based on a partial component of the beam incident on the deflecting device

Abstract

An optical pickup comprises a light source section for emitting a parallel light beam, an optical head for converging the light beam onto a recording medium, and a deflecting device for deflecting the beam from the light source section toward the optical head. The deflecting device is capable of adjusting the direction of the deflected beam, so that the beam converged by the optical head onto the recording medium is moved for tracking control. The optical pickup further comprises partially directing means for partially directing the beam incident on the deflecting device in a direction different from the direction of the beam deflected toward the optical head so as to generate a partial light beam, and a sensor for optically sensing the direction of the beam deflected by the deflecting device on the basis of the partial light beam from the partially directing means. The deflecting device comprises a transparent optical element which, for example, allows most of the components of the incident beam to pass through and reflects the remaining few components, and a driving mechanism for rotating the optical element. The partially directing means comprises the optical element.