| 摘要 |
PURPOSE:To obtain an idealistic characteristic the frequency characteristics of a digital signal inputted to identification reproduction device by changing the gain of variable gain amplifier provided between the discrimination reproduction device and low pass filter in proportion to the level of reproduction digital signal. CONSTITUTION:A variable gain amplifier 15 is provided between a low pass filter 7 which picks up only a low frequency area including direct current area of recovery digital signal outputted from a discrimination reproduction device 6 and the one input terminal 8 of adder 3 of which the other terminal 4 is supplied with reproduction digital signal which is high-area-compensated by an equalizer 2. And the gain of the amplifier 15 is control in proportion to the digital signal reproduced from recording medium by a level detector 16 or the level of reproduction signal which is compensated in high area. In this way, the frequency characteristic of the digital signal inputted to a reproduction device 6 from the adder 3 can be compensated idealistically, and the erroneous identification by the reproduction device 6 can be prevented. |
