Secrecy-coded cassette
US4406426A · kind A · utility
6Cited by
5References
12Claims
0Family size
Inventor
Key dates
| Filing date | Jun 16, 1981 |
| Grant date | Sep 27, 1983 |
| Priority date | — |
| Expiry date | Jun 16, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B23/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A coded cassette for magnetic tape, film and the like, has a clutch mechanism which prevents transport of the record medium unless a complementally-coded key, as a part of the drive mechanism, is engaged therewith for operating the clutch to an unlocked condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.