| 摘要 |
Servo control apparatus for controlling the speed and phase of a driven member. Reference signals, having a frequency determinative of the speed at which the member is driven, are compared to actual speed-representing signals in a servo loop, whereby the member is driven at the speed determined by the reference signals. An actual position-representing signal, representing the position, or phase, of the driven member, is derived. A window pulse generator generates window pulses corresponding to desired positions of the driven member. The occurrence of these position-representing signals within the duration of the window pulses is detected. A frequency modulating circuit modulates the frequency of the reference signals if the position-representing signals occur outside the window pulses, so as to adjust the speed and position, or phase, of the driven member until this member is driven such that its actual positions correspond to the desired positions. In accordance with a further aspect of this invention, the phase of the reference signals is adjusted such that the position-representing signals occur at a predetermined location within each window pulse. The driven member can be a rotary transducer or a movable record medium in, for example, a video signal recording/reproducing system. |
