| 摘要 |
PURPOSE:To obtain an excellent recording carrier signal even if the interval between horizontal synchronizing signals is distributed by installing a 1/2 frequency divider at the latter stage of a PLL circuit generating a frequency signal twice a carrier signal synchronizing with the horizontal synchronizing signal and setting the output signal of said divider to a carrier signal. CONSTITUTION:The titled device is provided with the PLL circuit which consists of an LPF 9, a 1/13 frequency divider 11, a phase comparator 14 and a voltage controlled oscillator 15, and generates the frequency signal twice the carrier signal synchronizing with the horizontal synchronizing signal included in a video signal, and the 1/2 frequency divider 16 which sets the frequency signal outputted by the PLL circuit to a 1/2 frequency signal and outputs it. The output signal of the 1/2 frequency divider 16 is given as a carrier signal to a modulator circuit 12. Since the PLL circuit generates the frequency signal twice the carrier signal, and the locked state of the PLL circuit is maintained to stabilize the output signal even if the interval of the horizontal synchronizing signals included in the video signal changes from 1H to 0.5H, whereby the excellent carrier signal can be obtained without fail.
|
