| 摘要 |
An apparatus and a method for automatically controlling pulse generation. The apparatus comprises a drum having video heads, a pulse generating head and a frequency generation head, first and second wave-shapers for wave-shaping a pulse generation signal from the pulse generating head and a frequency generation signal from the frequency generating head, respectively. There is also provided a mono-multi signal generator outputting a mono-multi signal having a rising curve time, a servo device for outputting a head switching signal in response to the mono-multi signal and outputting a drum control signal in response to the pulse and frequency generation signals and the head switching signal to control the speed and phase of the drum. There is further provided a luminance/chrominance processing circuit for selecting a channel for inputting one of video signals played back by the video heads in response to the head switching signal, for processing luminance and chrominance of the video signal from the selected channel and for outputting the processed video signal, and an automatic mono-multi signal control circuit for separating a vertical synchronous signal from the video signal, varying the rising curve time of the mono-multi signal in accordance with a time interval between the separated vertical synchronous signal and the head switching signal for thereby correcting an error of the head switching signal based on the rising curve time of the mono-multi signal.
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