Patent ID: 6226246
Filing Date: 2001-05-01
Classification: G11B

Abstract:
An apparatus for measuring characteristics of an optical pickup and/or an optical disc comprising:focusing servo control means for controlling a focal point position of a laser light beam illuminated on the optical disc, based on an output of a photoelectric converting unit of the optical pickup, for focusing the laser light beam on a recording surface of the optical disc;rotational driving means for rotating the optical disc in an eccentric state; andcharacteristics detection means for detecting a signal for generating tracking error signals from an output of the photoelectric converting device of the optical pickup, detecting the vicinity of a transition point of an illuminated position of the laser light beam caused by eccentricity, removing signal portions of the vicinity of the transition point from the signal for generating tracking error signals and for measuring the characteristic values of the optical pickup and/or the optical disc based on the above signal freed of the signal of the vicinity of a transition point.