MULTI-LAYERED OPTICAL RECORDING MEDIUM AND MULTI-LAYERED OPTICAL RECORDING MEDIUM MANUFACTURING METHOD

摘要

A multi−layered optical recording medium (1) includes a substrate (D) having on its one surface of laser beam incident direction side a tracking groove (GR), on surface of which a recording layer (L1) is formed, and a spacer layer (SP) having on its surface a tracking groove (GR), on surface of which a recording layer (L0) is formed. Each of the guide grooves (GR, GR) is formed with a greater depth at the substrate (D) side. Thus, it is possible to maintain a high signal level of a tracking difference signal during the tracking servo for the recording layer (L1) susceptive to the film thickness distribution of the spacer layer (SP). Accordingly, it is possible to preferably perform recording data recording and read out to/from the recording layer (L1) in the same way as the recording data recording and read out to/from the recording layer (L0).