Patent ID: 7301869
Filing Date: 2007-11-27
Classification: G11B

Abstract:
1. A spherical aberration correcting apparatus comprising: a test recording unit configured to perform a test recording on an optical recording medium; a characteristic obtaining unit configured to obtain a characteristic corresponding to a parameter by the test recording, the parameter being correlated with a spherical aberration; a correction amount deciding unit configured to decide an optimum correction amount of the spherical aberration so as to minimize the spherical aberration according to the characteristic of the parameter; and a spherical aberration correcting unit configured to correct the spherical aberration according to the optimum correction amount of the spherical aberration, wherein the characteristic obtaining unit is configured to detect a pit level and at least one of a read level, a write level and a recording power according to a light reflected from the optical recording medium while the test recording unit performs the test recording, wherein the pit level represents a level of the optical beam reflected from the optical disk while the optical beam is forming a pit during the test recording operation, and to obtain the characteristic of a pit ratio, the pit ratio representing the ratio of one of the read level, the write level or the recording power to the pit level, wherein the spherical aberration is minimized when the characteristic of the pit ratio is maximized.