公开(公告)号：DE69739787D1

公开(公告)日：2010-04-08

申请号：DE69739787

申请日：1997-12-17

Applicant: PANASONIC CORP

Inventor： OSHIMA MITSUAKI ,  KONISHI SHINICHI ,  TANAKA ,  KOISHI KENJI ,  MORIYA MITSUROU ,  GOTOH YOSHIHO ,  TAKEMURA YOSHINARI ,  MIYATAKE NORIO ,  MURAKAMI MOTOYOSHI

IPC: G11B11/10 ,  G06T1/00 ,  G11B7/0037 ,  G11B7/0045 ,  G11B7/007 ,  G11B7/24 ,  G11B11/105 ,  G11B20/00 ,  G11B20/10 ,  G11B20/12 ,  G11B23/28 ,  G11B23/40

Abstract: An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time of reproduction, the write-once information is detected from differential signals.