RECORDING MEDIUM AND ITS MANUFACTURING METHOD, AND RECORDING MEDIUM MASTER AND ITS MANUFACTURING METHOD

摘要

Provided is a recording medium capable of stably reproducing binary information recorded in advance in its innermost circumference area. The recording medium is formed by laminating a first information layer (2), an intermediate layer (3), a second information layer (4) and a cover layer (5) sequentially on a substrate (1). A first group is formed in advance in the innermost circumference area of the substrate (1), and a second group is formed in advance in the area to be recorded with data. The first group is set shallower and narrower than the second group. As a result, the BCA signal can be less modulated by the diffraction of the groups.