| 摘要 |
<p>PURPOSE:To lower a transmission speed without sacrificing a deterioration in a picture quality by converting a vertical synchronous pulse part, a horizontal synchronous pulse part and a burst signal inserted into a back porch into a specific pattern when A/D converting a picture signal and transmitting the pattern in place of the synchronous pulse. CONSTITUTION:A horizontal synchronous pulse 1 is inserted into an NTSC signal waveform every 15.75kHz. When A/D converting this picture signal, it is converted to a binary code as shown in 3, 4 within a level shown in 2. At this time, the part of the horizontal synchronous pulse is converted to 00...00, so that it is detected by an ALLO detecting circuit and a pattern in which '0' continues several times is converted into a pattern of a certain specific numerical bit. Namely, in a horizontal synchronous pulse interval 1, N1-N6 shown in 2 are all '0' patterns. Since the N1-N6 are the same patterns, they are converted into a fixed pattern of a numerical bit as P, thereby a bit number is lowered.</p> |
