Method of reading addresses on a magnetic recording medium and apparatus for putting it into effect
US4134138A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1977 |
| Grant date | Jan 9, 1979 |
| Priority date | — |
| Expiry date | Feb 2, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/105
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Items of information written in a binary code on a plurality of magnetic c tracks are read by a magnetic head. The address for each track is written in a reference zone having a plurality of cells equal to the number of bits in the address. A constant frequency cyclic reference signal H is divided by logic pulses from the head to produce a signal SYNCHRO. The bit of each address is determined by combining the SYNCHRO signals and a pulse representative of the binary value of each bit that depends on the temporal position of a pulse within a period of signal SYNCHRO. The number of cells is counted, each time a bit is determined. The address is sampled bit by bit and transferred to a storage member throughout the counting and sampling operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.