WOBBLING DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To solve the problem of a reduction in a wobbling signal SN caused by a residual RF signal due to insufficient gain balance when a wobbling signal is detected. SOLUTION: The wobbling detecting device for detecting the wobbling of a groove formed on an optical disk by the mutual difference calculation of the output signals of light receiving elements divided into two in a disk radial direction is provided with first and second variable gain amplifiers for changing the amplitudes of the signals of the two outputs according to supplied gain setting signals, first and second full-wave rectifiers for subjecting the AC components of the output signals of the variable amplifiers to full-wave rectification, and a feedback means for complimentarily supplying gain setting signals to the first and second variable gain amplifiers based on the mutual difference of the output of the full-wave rectifiers. COPYRIGHT: (C)2005,JPO&NCIPI