| 摘要 |
PURPOSE:To shorten a lead-in time to a PLL control at a constant speed and to shorten a seeking time by reading out data representing the rotating speed of an optical disk from a directory area at the time of regenerating and starting, and directly controlling the rotating speed. CONSTITUTION:When a spindle motor 2 is rotated, a FG pulse output from a frequency generator 3 is counted by a counter 4, and applied to a CPU 5. When the counted value input from the counter 4 becomes equal to that read out from a memory 20, the fact that the spindle motor 2 arrives at a predetermined rotating speed is judged by the CPU 5. Thus, a control signal is output from the CPU 5, and a switch 8 is switched from a terminal A to a terminal B. Then, it is shifted to a PLL control. In this manner, the spindle motor 2 rapidly arrives at a predetermined speed to shorten a seeking time. |
