NOISE REMOVING CIRCUIT AND A NOISE REMOVING METHOD, PARTICULARLY IN RELATION TO IMPROVING AN S/N RATIO OF A WOBBLE SIGNAL

摘要

PURPOSE: A noise removing circuit and a noise removing method are provided to output a 180-degree shift signal for shifting a phase of an input signal for 180-degree odd-numbered times, and to output the difference between the input signal and the 180-degree shifted signal, thereby effectively reducing noise components of the input signal. CONSTITUTION: A (2n-1)*180-degree phase shift circuit(180-degree odd-numbered times shift unit)(100) generates a signal which has shifted a phase at (2n-1)*180 degrees for signal components of an input signal 'I', and outputs the generated signal to a non-inverting input terminal(+) of an operational amplifier(OP10). The input signal 'I' is inputted to an inverting input terminal(-) of the operational amplifier(differential output unit)(OP10). 'n' is a fixed number.