Patent ID: 7876654

Claim:
An optical disk drive control circuit provided in an optical disk device including an objective lens for condensing a laser beam on a recording layer of a disk, and a pickup for focusing the laser beam on the disk and detecting reflected light from the disk, said optical disk drive control circuit comprising: a first means for holding a signal which drives the objective lens, the signal including at least one of a focus control signal (FC), a tracking control signal (TrC), a focus drive signal (FD), and a tracking drive signal (TrD); a second means for detecting a moving direction of the objective lens; and a third means for generating a signal which applies an acceleration to the objective lens, wherein, when a spot of the light beam passes through a flaw or defect present on the disk, the third means makes the objective lens stationary with a normal position as its center on the basis of the moving direction of the objective lens detected by the first and second means; wherein the second means has a differentiation circuit for differentiating the signal which drives the objective lens, and the third means generates, from an output of the differentiation circuit, a waveform which applies the acceleration to the objective lens to make the objective lens stationary; and wherein the waveform for applying the acceleration to the objective lens to make the objective lens stationary is a rectangular wave whose plus and minus polarities are alternately repeated.