Patent ID: 7746747
Filing Date: 2010-06-29
Classification: G11B

Abstract:
1. An optical recording medium drive apparatus comprising: head means for emitting a leaser beam so as to illuminate an optical recording medium via an objective lens which is disposed such that the objective lens is movable at least toward and apart from the optical recording medium in a focusing direction, and for detecting light reflected from the optical recording medium being illuminated with the laser beam; focusing means for driving the objective lens in the focusing direction; signal generation means for generating a reflected light signal in accordance with the reflected light detected by the head means; and control means for driving the objective lens via the focusing means, detecting a peak or peaks of the reflected light signal obtained when the objective lens is driven, determining whether a pattern of the detected peak(s) is similar to one of patterns which can occur when the optical recording medium is of a single layer type, and determining whether the optical recording medium is of the single layer type or a multiple layer type on the basis of the result of the determination as to the pattern.