| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform copyright management to a recording medium wherein illegal copying is difficult, and a device for the management is produced at low costs. <P>SOLUTION: A recording medium 1 has an optical disk 3 rotatably housed in a cartridge 2. RF-ID chips 8-1 and 8-2 e.g. whose one side is about 5 mm are embedded in an unrecorded region on an inner peripheral side of the optical disk 3. Positions (radius positions and angles) in which the RF-ID chips 8-1 and 8-2 themselves are embedded are recorded in the RF-ID chips 8-1 and 8-2. A recording and reproducing device detects the positions (the radius positions and the angles) in which the RF-ID chips 8-1 and 8-2 are embedded and compares the detected positions with information recorded in the RF-ID chips 8-1 and 8-2. If they are coincident with each other as the result of comparison, the recording medium is judged as an authenticated article and reproduction is permitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
