TRACKING ERROR GENERATING DEVICE, DISK TYPE DISCRIMINATING DEVICE, AND OPTICAL DISK REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To automatically discriminate type of disk for changing over a signal by making a tracking error signal generated by three-beam method and a track ing error signal. generated by a phase-difference method to be selective by changing over properly, in order to be suitable for a reproducing device served as DVD(Digital Versatile Disk) as well as CD(Compact Disc). ;SOLUTION: By providing a selection means 30 for selecting a tracking error signal by means of properly changing over two kinds of tracking error signals from one to the other, measuring a first and a second detected signals obtained respectively during focus searching, and discriminating a type of a disk-shaped optical recording medium by using the first and second measured detected signals, the selection means 30 is controlled according to the type of disk discriminated. Further, by measuring an amplitude and a frequency of the detected signals obtained at one focus during focus searching and discriminating a type of disk by using the measurement result, a timing for turning a servo control ON is controlled depending on a status adaptable to a lens disk.;COPYRIGHT: (C)1997,JPO