| 摘要 |
PROBLEM TO BE SOLVED: To provide the method and device for removing coma aberration from each light beam, in an optical pickup that forms multiple light beams each forming a focal point. SOLUTION: In a multiple focus optical pickup capable of tilting alternately and independently an actuator, which consists of an objective lens and a diffraction grating, and a pickup body; first, the pickup body with the actuator fixed on is tilted, and from that reproducing signal, the optimum angle that minimizes the error ratio is determined for each light beam (step S1). Next, using a relation between the optimum angle so calculated and the tilt angle of various coma aberrations previously measured, the pickup body is tilted with the fixing angle determined, so that the pickup body is fixed (step S2). Then, using a relation between the optimum angle and the tilt angle of various coma aberrations, the actuator is tilted with the fixing angle determined, so that the actuator is fixed (step S3). |
