Patent ID: 6288988
Filing Date: 2001-09-11
Classification: G11B

Abstract:
An optical disc device comprising:a laser light source for radiating a laser light beam illuminated via an objective lens on a signal surface of an optical disc;return light detection means for detecting the reflected light radiated from the laser light source and reflected from the signal surface of said optical disc;disc discriminating means for discriminating the type of said optical disc based on a number of reflectivity peaks detected by said return light detection means in a sole focussing search operation for focussing said objective lens onto said signal surface, said number of reflectivity peaks corresponding to a same number of signal surfaces that said disc comprises;means for detecting tracking error signals of plural different types of different detection systems based on the detection output of said return light detection means;tracking means for displacing the objective lens along the radius of said optical disc responsive to said tracking error signals for tracking-controlling a laser spot of the laser light focussed on the signal surface of the optical disc; andcontrolling means for controlling operation of said optical disc device based on a discriminating output by said disc discriminating means.