| 摘要 |
<p>PURPOSE:To eliminate the offset, which is generated at the time of digitizing a video signal, with a simple circuit by providing a difference means, a data compressing means, and an offset eliminating means which forcibly sets data outputted from the means to a prescribed value in the horizontal fly-back period of the video signal. CONSTITUTION:8-bit difference data from an adder 14 is inputted to an encoder 16, and the encoder 16 compresses 8-bit difference data to 4-bit data by, for example, a conversion table. In an offset eliminating circuit 20, respective bits of 4-bit difference data corrected by a correcting circuit 18 are given to one inputs of AND gates 20a to 20d, and a signal HB which goes to the low level in the horizontal fly-back period is given to the other inputs. 4-bit difference data is fixed to OH only in the horizontal fly-back period by the offset eliminating circuit 20. The offset in the horizontal fly-back period is eliminated by the simple circuit constitution.</p> |
