| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to exactly and easily discriminate the kind of a loaded disk by utilizing the difference in the signal planes in the thickness direction of the disk and discriminating whether the loaded disk is a first kind or second kind by using reflected light information. SOLUTION: When the disk D is inserted, a DVD pickup 1b is set in a DVD pickup mode to be used. As the discrimination operation, an objective lens 2b for DVD is forcibly elevated or lowered within a focus search stroke range, and it is instructed to start the output of a focus search drive signal. A system controller 30 detects the discrimination signal DD supplied from a discrimination signal forming circuit 27 and measures the period between two pulses while executing the movement of the objective lens 2b for DVD within the prescribed region. A measured value and a reference value are then compared and the disk D is judged to be a CD when the measured value is longer. |
