Method and apparatus for preventing copying of an optical disk
US4975898A · kind A · utility
88Cited by
8References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 18, 1988 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Aug 18, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1259
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for preventing copying of an optical disk. A software program and the basic data necessary for executing the program, as well as an erasing program are nonrewritably recorded in advance on a predetermined region of the disk. The erasing program attempts to erase the non-rewritable portion, which has no effect on the original disk, but will erase that portion of a disk which is copied. Thus, if the software program and the basic data for executing the program are copied without authorization, the copy disk is prevented from being used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.