Diffracted light disturbance adjustment method for disk drive, involves calculating stable light emission variable when light is not diffracted, by calculating initial and influence value for diffracted light

摘要

A coarse control is carried out in the absence of the disk. An initial value and an influence value of a light emission variable corresponding to diffracted light, are calculated. A compensator (90) calculates a stable light emission variable when light is not diffracted, based on the calculated value. The calculated variable is stored in the memory during the disk drive reading mode.