Tape running time indication system
US4338645A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1979 |
| Grant date | Jul 6, 1982 |
| Priority date | — |
| Expiry date | Nov 2, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a video tape recorder or audio tape recorder, the remaining tape length indicated as time or taken-up tape length indicated as time is calculated by use of microcomputer and then accurately indicated as a time length by detecting the angular velocities of a supply reel and a take-up reel. A rotational period of time of each reel is detected twice, so that the tape running speed is calculated from the two detected values and the known tape caliper thickness, thus calculating and indicating the remaining tape length indicated as time and the taken-up tape length indicated as time. The remaining tape length and taken-up tape length indicated as time in such operation modes of a tape recorder as fast forward, and rewind, as well as recording and reproduction are accurately indicated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.