Method for controlling access to recorded data
US4677604A · kind A · utility
147Cited by
3References
28Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1985 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Feb 4, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2587
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Access to a complete data base stored on optical disk media is limited to portions of the data base to which individual users are entitled by provision of an additional code on the optical disk, indicating the portions of the data base which the customers may access. The disk reader comprises an additional reader for reading the additional code and means for preventing access to other portions of the data base. The additional code may be conventional bar code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.