| 摘要 |
PURPOSE:To simplify the circuit constitution by making an upper side inflection frequency of a linear pre-emphasis characteristic identical to a lower-side inflection frequency of nonlinear pre-emphasis characteristic. CONSTITUTION:For example, a video signal is supplied from an input terminal 1 and the said signal is fed to the nonlinear pre-emphasis circuit 13. An output signal of the circuit 13 is fed to an FM modulator 14 and the modulated output of the modulator 14 is recorded on a magnetic tape 17. The circuit 13 has a nonlinear pre-emphasis characteristic 24. The characteristic 24 is the combination of the nonlinear pre-emphasis characteristic 25 and the linear pre-emphasis characteristics 26. The characteristic 25 consists of a nearly flat frequency characteristic having an inflection frequency f2 and a high frequency emphasis characteristics in which the amount of emphasis is increased, as the level of the input signal level becomes lower. The characteristics 26 consist of a nearly flat frequency characteristic up to a frequency f1. That is, the inflecting frequency of the characteristics 25 and the high frequency inflecting frequency of he characteristic 26 are f2 for both the characteristics. |
