| 摘要 |
PURPOSE:To suppress a white/black inversion phenomenon of an FM video signal for overlap recording and to avoid generation of smears to ensure the high picture quality, by attenuating the high band component of the video signal supplied to a frequency modulating circuit in response to the increase of a recording current and with no sudden change of phase. CONSTITUTION:The color video signal is attenuated down to a component equivalent to the high band component of a luminance signal which is separated by an LPF3 in a normal record mode through an LPF12. The mixture current of a color signal current and an FM luminance signal current is amplified by a record amplifier 8 and supplied to a record/reproduction head 9. This record current I is larger by about 2-3dB than that of a normal reprodution mode like a conventional case. Thus the high band component of the luminance signal is attenuated by the LPF21 despite the increase of the current I. Therefore a good balance is secured between the low band component and the level drop due to the attenuation of the carrier wave component at a high band of the FM luminance signal owing to the record/reproduction current characteristics of the head 9 despite the increase of the current I. Thus the frequency characteristics of the video signal is almost equal to those obtained in a normal record/reproduction mode. This suppresses a white/black inversion phenomenon and avoids the deterioration of quality of reproduced pictures. |
