| 摘要 |
PURPOSE:To form and output video signals for an enlarged picture by simple constitution that does not use demodulation circuits of luminance and color etc. by processing the enlarged part making period of chrominance subcarrier signals in composite video signals a unit. CONSTITUTION:Signals of frequency K times, for instance three times, that of chrominance subcarrier signals are formed by a multiplying circuit 4 based on chrominance subcarrier signals of an input terminal 3 included in composite video signals of an input terminal 1. Timing signals of frequency 3fsc (K=3) are outputted from a timing generating circuit 7 to a transducer 9 based on signals of the multiplying circuit 4 and sampling a gate pulse,and the transducer 9 samples composite video signals of the input terminal 1 successively at a period T/3 and makes digital conversion. A transducer 10 converts three digital data of composite video signals of period T to a parallel data at every one period synchronous with the composite video signals,and outputs to a memory 11. A time base in horizontal direction of an enlarged part is expanded to M times by the memory 11.
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