CORRECTION PARAMETER GENERATING DEVICE, ABERRATION CORRECTING DEVICE, CORRECTION PARAMETER GENERATING METHOD, ABERRATION CORRECTING METHOD, PROGRAM FOR GENERATING CORRECTION PARAMETER, AND PROGRAM FOR CORRECTING ABERRATION

摘要

A correction parameter generating device for acquiring a necessary correction parameter even if the optical disk is unrecorded and even if tracking servo is still not carried out while preventing the objective from striking the optical disk without modifying the structure of , e.g., a conventional pickup. The focus servo loop for focus servo of a light beam is closed. While the focus servo loop is closed, a disturbance signal is injected into the focus servo loop (step S5). The sensitivity of a focus error signal obtained by changing the correction parameter while the focus servo loop is closed is measured correspondingly to each changed correction parameter. The correction parameter of when the measured sensitivity is the greatest is used as the actually used correction parameter for correction of the spherical aberration (step S6).