Patent ID: 7092325
Filing Date: 2006-08-15
Classification: G11B

Abstract:
1. A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, wherein the optical pickup system includes a light source, a diffractive optical element that diffracts a light beam incident from the light source and splits the light beam into at least three beams, a plate-type beam splitter that changes a propagation path of the light beam, and a photodetector comprising at least one main photodetector having at least four sections and a plurality of sub-photodetectors and is provided so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium, the method comprising: where the propagation path of the light beam transmitted through the plate-type beam splitter to the photodetector is an optical path axis, arranging the optical pickup system so as to tilt the optical path axis with respect to an axis in a tangential direction of the recording medium and to arrange the photodetector away from a rotation center of a motor that rotates the recording medium with respect to the axis of the tangential direction; and selectively optimizing the arrangement of the photodetector to detect a tracking error signal of the recording medium by a differential phase detection (DPD) method, wherein the optical pickup system detects the tracking error signal using a detection signal by the photodetector based on a three-beam method and the DPD method wherein the light source is placed at a location near the rotation center of the motor.