| 摘要 |
PURPOSE:To record and reproduce high quality pictures, by converting a broad band video signal into plural polyphase signals, using a common D/A and an A/D converter in time division and preventing the inequality of phases. CONSTITUTION:A broad band picture signal is inputted from a terminal Ti, A/D-converted 11 via an LPF 10, and stored in memories 12a, 12b as signals DA, DB alternately at each 1H with a clock signal 13. The signals are expanded at a time axis by the clock signal 13 and read out into digital signals DA', DB'. Switching elements 14, 16 are switched synchronizingly with a pulse (p), the signals DA', DB' are D/A-converted 15 into signals A', B', converted into signals A, B at LPFs 17a, 17b, the signals A, B are FM-modulated at FM modulators 18a, 18b and recorded on a magnetic tape as two channels. At the reproduction, both demodulated channels are alternately D/A-converted and stored separately, the time axis is compressed at a controller and D/A conversion is performed. Thus, the recording and reproduction of pictures with good quality without phase difference is attained. |
