Irradiating the light beam to the control characteristic evaluation device and

摘要

PROBLEM TO BE SOLVED: To evaluate the vibration-proof on the whole synthesizing a focus servo and a tracking servo when it is used under the condition where vibration exists. ;SOLUTION: This evaluating device generates a disturbance signal by a focus disturbance generator 16 and a tracking disturbance generator 17, and detects the level of a focus error signal S2 and the level of a tracking error signal S3 when a sound signal has not been detected by a sound detector 23 to store them in a storage means 24 as a set. The device stores at least two sets or more of the data, and evaluates a servo state by comparing the level of the focus error signal S2 and the level of the tracking error signal S3 with the data stored in the storage means 24 at the time of a real use time receiving the vibration.;COPYRIGHT: (C)2000,JPO