Method and device for preventing tape piracy
US4802212A · kind A · utility
16Cited by
5References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1987 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | Jun 1, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/00086
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device is disclosed to prevent the unauthorized copying of magnetic tapes (tape "piracy"). The device utilizes an inaudible signal encoded into the tape program as the master recording is being made. A separate decoding circuit is to be installed in commercially available stereo tape decks. Whenever the encoded signal is present on the original recording, the decoding circuitry will short the bias signal of the tape deck being used to attempt to make the copies. This will prevent the deck from recording any of the program on the original tape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.