Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: A sticker media disk may be easily stuck on an old CD, DVD, or other optical disk as a base. The combination then becomes a media disk completely playable with content in audio players, computers drives, DVD, and/or high definition (HD) disk players.

Abstract: An optical disc (10) includes a substrate (11), which is formed from either a resin-impregnated paper produced by impregnating a paper with a resin, or a resin-coated paper produced by coating a surface of a paper with a resin, and a recording layer (13), wherein the resin contains at least one resin selected from the group consisting of polycarbonates, bisphenol A epoxy resins, copolymers of methyl methacrylate and styrene, and copolymers of acrylonitrile and styrene. Furthermore, a method of manufacturing an optical disc (20) includes: providing a recording layer sheet by forming tracks on a recording base material; and bonding the recording layer sheet to a resin-impregnated paper or a resin-coated paper, thereby providing a recording layer (13) formed from the recording layer sheet on the substrate (11).

Abstract: An optical recording medium includes a recording layer in or on a substrate, a light-transmitting cover layer over said recording layer, and a disc rib over an outer periphery of a first side of the substrate and delimiting an outer diameter of the cover layer.