Patent ID: 6363042
Filing Date: 2002-03-26
Classification: G11B

Abstract:
An optical disk drive comprising:an voltage-controlled oscillator for generating an inner reference clock signal; a data extraction section for extracting data from a reproduction signal read from a disk medium with the use of the inner reference clock signal; a phase comparator for comparing in phase the reproduction signal with the inner reference clock signal to send a phase error signal to said voltage-controlled oscillator; a frequency comparator for comparing in frequency the reproduction signal with the inner reference clock signal to send a frequency error signal to said voltage-controlled oscillator through switching means; and a defect detection section for detecting a defect on the disk medium from the envelope of the reproduction signal to output a defect detection signal, wherein the switching means is switched so as to break a connection between said voltage-controlled oscillator and said frequency comparator when the defect detection signal is output.