| 摘要 |
PURPOSE:To decrease the access time and to increase the recording capacity by rotating a disk at a fixed speed and using a clock corresponding to the position of the disk to perform modulation or demodulation in a record or reproduction mode. CONSTITUTION:A control circuit 15 decides the desired track range and clock speed information within a conversion table. Based on the result of said decision, both track number and start sector of a desired block are calculated. A programmable synthesizer 23 uses a reference clock signal given from a reference clock oscillator 22 to produce a clock signal having the time width corresponding to the clock speed information and supplies it to a modulation circuit 20 as well as to a demodulation circuit 14. Then the circuit 15 starts reproduction of the data to an optical disk 1 when coincidence is obtained between the count value of a sector counter 10 and the start sector. Thus it is possible to rotate the disk at a fixed speed. This decreases the access time and increases the recording capacity.
|
