Information recording medium and method for recording and reproducing information to a medium to prevent unauthorized copying
US5886979A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Mar 14, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2211/007
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information recording medium wherein the key information is recorded by arrangement of a unit area recorded irreversibly and a unit area not recorded irreversibly to effect the truth judgment of the medium in accordance with the result of whether or not the reproduction of the key information can be effected, the information recording medium where the illegal usage of the medium is adapted to be prevented without inputting the information on to the medium truth judgment into the processing apparatus by provision of the medium firm information, a reproducing method for the same, a truth judging method for the same, and a recording/reproducing apparatus for the same.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.