Patent ID: 7826322
Filing Date: 2010-11-02
Classification: G11B

Abstract:
1. A tracking error control apparatus comprising: a reproduction signal detector for irradiating a light beam on an optical disk, and detecting information recorded in the optical disk as a reproduction signal, the optical disk having a track along a circumferential direction, a first pit string disposed on a surface of the optical disk so as to be displaced in a first side along a radial direction from a center of the track, and a second pit string disposed on the surface of the disk so as to be displaced in a second side along the radial direction opposite to the first side; a scanner for positioning the light beam irradiated on the optical disk; a first tracking error detector for detecting a first positional error of the light beam with respect to the track by a push-pull method and, outputting a first displacement detection result; a first tracking error controller for setting a target position of the light beam on the track based on the first displacement detection result so as to control the scanner in such a manner that the light beam follows the target position; a second tracking error detector for detecting a second positional error of the light beam with respect to the track based on comparison of the reproduction signal in the first string and the reproduction signal in the second pit string, and outputting a second displacement detection result; a second tracking error controller for correcting the target position of the first tracking error controller based on the second displacement detection result; and a third tracking error controller for calculating correction data for the first displacement detection result based on a correction amount of the target position corrected by the second tracking error controller, and correcting the first displacement detection result based on the calculated correction data.