| 摘要 |
PURPOSE:To execute exactly waveform shaping of a data even in case when a high frequency component of a signal is attenuated, by constituting a titled device of a delaying means for delaying an input digital signal, an operating circuit for operating a reference level in accordance with its delayed output, and a comparator for comparing a digital signal before it is delayed with said reference level. CONSTITUTION:A digital signal reproduced from a VTR is inputted to a delay element 5a, and its output is inputted to a delay element 5b. Each time shift corresponding to one bit exists among the input digital signal, an output of the element 5a and an output of the element 5b, and they are denoted as d(t+T), d(t) and d(t-T) in said order. An adder 6, an attenuator 7, an adder 8 and a reference voltage generating circuit 2 constitute an operating circuit for inputting d(t=T), d(t-T) and an output V of the reference voltage generating circuit 2, a reference level R(t) being its output becomes R(t)=1/K.[d(t-T)+d(t+T)]+ Vrr, and the reference level R(t) is varied so that the waveform shaping of data is executed more exactly, by information of one bit before and after d(t). |
