| 摘要 |
PURPOSE:To prevent the deterioration of picture quality for a video disk player, by detecting individually the upper and lower side band components of a carrier signal and then comparing these two signal components with each other to control the high band equalizing function of an FM reproduced signal. CONSTITUTION:The upper side band component of a color burst signal is extracted through a BPF1 for the reproduced signal obtained from a video disk. While the lower side band component of the color burst signal is extracted through a BPF2. The levels of the signals extracted through the BPF1 and 2 are detected by the detecting circuits 3 and 4. Then the level difference is detected by a comparator 5 for the output of detection. This differential output is applied to a frequency characteristic controlling circuit 6 to control the frequency characteristics. In such a way, the deterioration is always compensated for the signal component at a high band by compensating consecutively the aperture characteristics of a reproducing means. As a result, the quality of pictures can be unified and improved. |
