APPARATUS FOR GENERATING SERVO CONTROL SIGNAL, OPTICAL DISK APPARATUS, AND METHOD FOR GENERATING SERVO CONTROL SIGNAL

摘要

<P>PROBLEM TO BE SOLVED: To generate a defect signal and a mirror signal for a high-to-low medium and a low-to-high medium. Ž<P>SOLUTION: The defect and mirror signals are generated by discriminating the type of an optical disk and switching between a top envelope signal and a bottom envelope signal of an RF signal. An apparatus for generating a servo control signal includes: an RF generating means for generating the RF signal from a reflected light of the optical disk; a disk discriminating means for discriminating the type of the optical disk from the RF signal; a top envelope generating means for generating the top envelope signal of the RF signal; and a bottom envelope generating means for generating the bottom envelope signal of the RF signal. The apparatus also generates the defect signal from the top envelope signal and the mirror signal from the bottom envelope signal when the reflectivity of the disk decreases after recording in comparison with that before recording, and generates the defect signal from the bottom envelope signal and the mirror signal from the top envelope signal when the reflectivity of the disk increases. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž