| 摘要 |
<p>PURPOSE:To exclude the influence of disturbance, to execute normal picture recording and to obtain a normal picture by increasing the gain of a drum speed servo system only when the condition of the strong disturbance is obtained. CONSTITUTION:A signal from an FG 2 fitted to a drum motor 1 is sent to a period detection circuit 4 and the error signal of a level corresponding to a period is formed and supplied to servo amplifiers 5 and 6. Gains G5 and G6 of the amplifiers 5 and 6 are set in the condition of G5>G6. Then, the output of the amplifier 5 is supplied to a terminal 7a of a switch circuit 7 and the output of the amplifier 6 is supplied to a terminal 7b. On the other hand, a control signal Sc from a terminal 8 is operated in correspondence to a photographic condition and given to a circuit 7. Under the condition that the disturbance is much and severe, the signal Sc goes to be '1' and terminals 7a and 7c are connected. Then, an error signal is selected by the circuit 7 and the rotational speed of the motor 1 is controlled to be a reference speed.</p> |
