Patent ID: 6999405
Filing Date: 2006-02-14
Classification: G11B

Abstract:
1. A master disc for the preparation of an optical recording medium having a groove formed along a recording track and illuminated by the light with a wavelength λ for recording and/or reproduction, comprising: a substrate having formed thereon a crest-and-groove pattern corresponding to said groove, a first groove pattern and a second groove pattern are formed to a first depth to describe a double helix and wherein a third groove pattern having a second depth shallower than said first depth is formed between said first and second groove patterns describing double helices, wherein said master disc being configured to receive thereon the optical recording medium which is subsequently removed although retaining a transcription of the crest-and-groove pattern and at least one of said first and second groove patterns is a wobbling groove pattern formed so that at least a portion thereof is meandered.