SPINDLE CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a low-cost spindle control circuit which does not require an FG sensor in the case of applying constant angular velocity (CAV) servo in a spindle control circuit. SOLUTION: A synchronizing signal component 11 of a signal read from a disk 7 is extracted and a period detection circuit 2 detects the period of the synchronizing signal 11. An additional information decoding circuit 3 reads the additional information of the signal read from the disk 7 and a table ROM 4 converts the additional information into rotational speed reference data 41 by using a fixed function. By applying spindle servo with an error component 51 between a period detection signal 21 of the synchronizing signal 11 and the rotational speed reference data 41, the constant angular velocity (CAV) servo is applied without using the FG sensor. COPYRIGHT: (C)2005,JPO&NCIPI