Nippon Columbia Co., Ltd.

Kazuho Kato

Akihiko Takasu

An optical information recording medium which can be played back by both a playback system for an SD (Super-density Disk) and a playback system for an HDMCD (High Density Multimedia Compact Disk), or by both the playback system for the SD and a playback system for a CD (Compact Disk). The optical information recording medium comprises a first transparent substrate which includes a smooth surface, and a first information surface bearing pits correspondent to first recorded information, the first information surface being covered with a semitransparent film which transmits part of a playback beam and reflects part thereof; and a second transparent substrate which includes a smooth surface, and a second information surface bearing pits correspondent to second recorded information, the second information surface being covered with a reflective film which reflects the greater part of the playback beam; the second transparent substrate being stacked on the first transparent substrate with the first information surface of the latter overlaid by the smooth surface of the former.

Optical information recording medium and method of manufacturing

Optical information recording medium

An optical information recording medium which can be played back by both a playback system for an SD (Superdensity Disk) and a playback system for an HDMCD (High Density Multimedia Compact Disk), or by both the playback system for the SD and a playback system for a CD (Compact Disk). The optical information recording medium comprises a first transparent substrate which includes a smooth surface, and a first information surface bearing pits correspondent to first recorded information, the first information surface being covered with a semitransparent film which transmits part of a playback beam and reflects part thereof; and a second transparent substrate which includes a smooth surface, and a second information surface bearing pits correspondent to second recorded information, the second information surface being covered with a reflective film which reflects the greater part of the playback beam; the second transparent substrate being stacked on the first transparent substrate with the first information surface of the latter overlaid by the smooth surface of the former.

Growing community of inventors

Atsugi, Japan

Kazuho Kato