| 摘要 |
At the time when an optical disc 10 is attached, a system controller 300 allows an optical pickup 220 to perform focus search and thereby recognizes the type of the optical disc 10 and, at the same time, rotates a spindle motor 212 at a constant linear velocity at the position at which the optical pickup reads the information. During the constant linear velocity control, the system controller 300 recognizes the position of the optical pickup 220 based on a count value of an internal counter, distance r between the recognized position and the center of the optical disc 10 , and rotation speed N. Based on the recognized information, the system controller 300 calculates the specific linear velocity L of the optical disc 10 according to the relational expression: L=2pirN. An actual predetermined position at which information processing is performed is calculated in a relative way based on the specific linear velocity. At the time when information processing is performed, it is possible to adequately move the optical pickup 220 to the actual information processing position, thereby reducing the time to start information processing and resulting in speedy information processing.
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