| 摘要 |
PURPOSE:To prevent occurrence of a so called inverting phenomenon which changes a part on a reproduced picture which should be white to black, by providing an amplitude limiter which can remove the influence of an abrupt signal change on a video signal applied with frequency modulation, then recorded and reproduced. CONSTITUTION:A high-pass filter 9 and low-pass filter 11 have an attenuation characteristic of relatively gentle slope, and the FM carrier wave component of reproduced FM video signals are mainly filtered by the high-pass filter 9 and given to a phase correcting circuit 10 where the phase is corrected. On the other hand, the FM-side band component of the reproduced FM video signals are mainly filtered by the low-pass filter 11 and given to the 1st amplitude limiter 12 where the rising part of the level (level variation) is corrected and the component is shaped into a square wave which has the same level of a crest and bottom. This signal is given to the 2nd amplitude limiter 13 after it is combined with the output signal of the phase correcting circuit 10 and removes the level variation of an output composite signal. Moreover, an FM video signal outputted through an output terminal 14 is corrected in the drop down of the carrier wave. |
