| 摘要 |
PURPOSE:To control variable speed reproduction by controlling a head drum motor and a capstan motor on time-division basis, detecting the simultaneous input of rotation detection signals of both motors, and modifying time-division processing according to the detection result. CONSTITUTION:Detection pulses obtained from a rotating speed detector 125 for the head drum motor 124 are inputted to the external interrupt terminal INT0 of a microcomputer 12. Detection pulses obtained from a rotating speed detector 129 for the capstan motor 128, on the other hand, are amplified and inputted to the external interrupt terminal INT1 of the microcomputer 21. The microcomputer 11 compares it with a reference value to generate a speed error signal. The error signal is added to a tracking error signal obtained by digitizing the output of a tracking error generating circuit 131 through an A/D converter 130 and filter operation is further performed, so that the result is outputted to a converter 126 as a motor driving command. The motor driving command which is converted into an analog value by the converter 126 drives the capstan motor 128 by a driving circuit 127.
|
