Recording layer determination apparatus, recording layer discrimination program, and a recording layer discrimination method

摘要

PROBLEM TO BE SOLVED: To exactly determine DVDs of single layer and of multi-layer.;SOLUTION: An objective lens 32 of an optical pickup 2 is made to move from a far position to a near position with respect to DVD 1 with constant speed and a timer 7 counts time taken for the movement of a focus of a laser beam between recording layers of the DVD 1 on the basis of a focus error signal obtained from this movement. In the case of the DVD of the single-layer, since the recording layer is one-layer, and there is not interlayer, a count value becomes a small value. While, in the case of DVD of the multi-layer, the recording layer has a plurality of layers, thus one or plural-interlayer exists, therefore, a count value becomes a large value. Accordingly, it is exactly discriminated that if a small count value is obtained, its DVD 1 is of the single-layer and while, if a large count value is obtained, its DVD 1 of the multi-layer.;COPYRIGHT: (C)2003,JPO