Optical disc drive for recording or reproducing data on a multilayer optical disc with a layer identification region

Abstract

The present invention provides a multilayer optical disc and an optical disc drive which can identify recording layers without performing tracking servo control or changing the structure of the disc. In a multilayer optical disc, the recording layer includes a layer identification regionhaving a recording pattern for layer identification, the layer identification regionincluding a layer specific regionhaving a specific pattern and a common regionhaving a common pattern different from the specific pattern, the layer specific regionbeing provided at a different radial position in each of the recording layers. The optical disc drive detects the layer specific regionhaving the specific pattern from the layer identification regionof the multilayer optical disc, and identifies the current layer based on the radial position of the layer specific region.