| 摘要 |
PURPOSE:To improve pitch precision between recording tracks by using a signal, which is obtained by a spindle servocontrol system and corresponds to the turning speed and rotary phase of a recording medium, as a reference signal for a carriage servocontrol system. CONSTITUTION:A spindle motor 2 is driven to rotate by the servo-control output of a spindle servocontrol circuit 1, and the rotation state of the motor 2 is detected 3 by a rotary encoder, etc., and fed back to the circuit 1, where it is compared with the horizontal synchronizing signal of a generating circut 4 or the frequency-division 6 signal of an oscillator 5. A switch 7 selects the output of the circuit 4 for a CAV system or the output of a frequency divider 6 for a CLV system as a reference signal. On the other hand, a carriage motor 10 is controlled by the servocontrol output of a carriage servocontrol circuit 9, and a relative position between recording laser light and a recording disk is detected 8 by a linear encoder, etc., and fed back to the servocontrol circuit 9 while supplied to the frequency divider 6 as a control input. Thus, the carriage servocontrol system is synchronized with the spindle servocontrol system. |
