Digital FM demodulator, video signal processing apparatus, and digital FM demodulation method

摘要

PROBLEM TO BE SOLVED: To obtain a digital FM demodulator in a video signal processing apparatus for a SECAM signal that can realize correction of a demodulation range without remarkable increase in the circuit scale.;SOLUTION: An output of an adder 5 is connected to inputs of an adder 17a, a sbutractor 10, and a delay circuit 11, an output of a delay circuit 11 is connected to an input of the sbutractor 10, an output of the sbutractor 10 is connected to an input of a comparator circuit 12, an output of the comparator circuit 12 is connected to an input of an adder 13, an output of the adder 13 is connected to an input of a correction flag decision circuit 15a, an output of the correction flag decision circuit 15a is connected to an input of a delay circuit 14, and an output of the delay circuit 14 is connected to the input of the adder 13, respectively. Furthermore, an output of the correction flag decision circuit 15a is connected to a changeover switch 18. The changeover switch 18 connects either of constant storage sections 22a, 22b to the adder 17a. An output of the adder 17a is connected to an input of a clip circuit 19.;COPYRIGHT: (C)2002,JPO