Microphonograph record
US4298976A · kind A · utility
Inventors
Key dates
| Filing date | Jan 31, 1977 |
| Grant date | Nov 3, 1981 |
| Priority date | — |
| Expiry date | Jan 31, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B25/046
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Microphonograph record which is to remain stationary while information is being reproduced therefrom formed from a sheet of material and having generally V-shaped locating means formed in the sheet of material which is accessible from one side of the sheet of material. The V-shaped locating means lies in a plane generally parallel to the plane of the sheet of material. The sheet of material is provided with first and second surfaces and has information carried by the sheet of material on at least one surface thereof and arranged in a generally concentric circular pattern. The circular pattern has at its center a point which lies in close proximity to the apex of the V-shaped locating means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.