| 摘要 |
PURPOSE:To attain continuous change in the revolution speed of a motor by supplying alternately a reference signal driving the motor at high speed and a reference signal driving the motor at low speed to a servo circuit and controlling the period of the reference signals. CONSTITUTION:When the user designates the normal reproduction from the fast forward or rewinding state, a control circuit 27 instructs the movement from the high speed driving mode into the low speed driving mode to a servo control PWM circuit 28. The circuit 28 outputs a PWM output, that is, an alternate signal composed of a servo control signal SH for high speed drive and a servo control signal SL for low speed drive. During this period the increase in the revolution speed of the capstan motor by the signal SH and the decrease in the revolution speed of the capstan motor by the signal SL are repeated. Moreover, the width of the signals SH, SL is adjusted (PWM control) so as to decrease the revolution speed of the capstan motor gradually. Thus, the speed of the capstan motor is gradually decreased. |
