| 摘要 |
PURPOSE:To obtain an inexpensive color signal converting circuit by providing a horizontal synchronous separating circuit at only one position, by providing a signal processing circuit with an AFC circuit capable of following up even a discontinuous horizontal synchronizing signal. CONSTITUTION:An NTSC color signal to be recorded is inputted to a delay circuit 48 via a recording/reproduction switch SW1, and a delayed signal and an undelayed signal are selected alternately by a change-over switch SW2 inverted in every field according to the output of an FF50 inputting the output of a vertical synchronous separating circuit 49. A luminance signal component, on the other hand, is extracted through a low-pass filter 51, and a color signal component is extracted through a band-pass filter 52. The luminance signal component is inputted to an adding circuit 56 via an AGC circuit 53, an FM converting circuit 54 and a high-pass filter 55, and the color signal component is inputted to the adding circuit 56 via a mode switch SW3, a recording/reproduction switch SW4, an AGC circuit 57, and a frequency converting circuit 58 and applied to a video head via a recording/reproduction switch SW5. In this constitution, a horizontal synchronizing signal with discontinuation points is applied to the circuits 53 and 57 to reduce frequency fluctuations extremely. |
