Being the survey instrument of the optical disk which possesses uoburutoratsuku which uoburu is done the optical disk survey instrument,

摘要

PROBLEM TO BE SOLVED: To accurately inspect the phase modulating wobble track of an optical disk.;SOLUTION: The radial push-pull signal (wobble signal) of the optical disk is binarized by a binarizing unit 203 after a phase boundary section is smoothed by a low-pass filter 202, and it is supplied to a time interval analyzer 204. The time interval analyzer 204 analyzes the period of a binarized wobble signal and extracts its two peak values T1, T2. A computing element 205 computes the difference value of two periods T1, T2 and the standard deviation of each peak and compares with thresholds respectively to simultaneously evaluate a CNR and a phase shift.;COPYRIGHT: (C)2006,JPO&NCIPI