| 摘要 |
<p>PURPOSE:To improve the quantization precision of a video signal without increasing a quantization level by performing compression corresponding to the redundancy of the level of a synchronizing signal in a video signal and performing A/D conversion. CONSTITUTION:A video composite signal is inputted to the input terminal A of an A/D converter and applied to a synchronous separating circuit 1, which extracts and applies synchronizing pulses P1 and P2 to a video separating circuit 2. The composite signal is applied to the circuit 2, which holds the pulses P1 and P2 at last input voltage values to output video signals Q1 and Q2 containing neither the P1 nor P2; and those signals Q1 and Q2 are applied to the converter body 3. The pulses P1 and P2 from the circuit 1 are applied to the converter body 3. Then, nearly the whole of the quantization dynamic range of the converter body 3 is allotted to the voltage area Y of the video signals Q1 and Q2 to improve the quantization precision of the video signals Q1 and Q2 without a allotting the dynamic range to the voltage area X that the pulses P1 and P2 occupy and increasing the quantization level.</p> |
