| 摘要 |
<p>An optically readable data storage device in the form of a rotatable, disc-shaped body coated with a storage medium and in which a disc-shaped main body (2) is enlarged by a further disc-shaped data carrier which is smaller peripherally, and mechanically and rotationally rigidly joined to the main body (2), and in which the smaller data carrier has regions which can additionally store optically readable data via a write process. An independent claim is included for a method of attaining an effective and low-cost installation protection and copy protection with an optically readable data store.</p> |
