Apparatus and method for adjusting a rotational velocity of a disk storage medium with measuring the amount of time to reproduce address data stored thereon

摘要

Apparatus and method for reproducing data from a CD-ROM at a constant angular velocity and for recording and reproducing data to and from a magneto-optical compact disc (CD-MO) at a constant angular velocity. Data reproduced from the CD-ROM is demodulated in accordance with an amount of reproduction time of a sync signal contained in the reproduced data. The clock rate of data to be recorded to or reproduced from the CD-MO is determined in accordance with the position or zone on the CD-MO at which the data is to be recorded or from which it is reproduced. The position or zone may be identified by address data which is reproduced from the CD-MO. In addition, a constant rotational velocity of the CD-MO is maintained by measuring an amount of reproduction time of the address data and varying the rotational velocity of the CD-MO in accordance with the measured reproduction time.