Apparatus for removing air from between a master magnetic medium and a slave magnetic medium preceding anhysteretic transfer of signals from master to slave
US5426535A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1993 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Jul 29, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/244
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A prerecorded magnetic master web (54) and an unrecorded magnetic slave web (14), such as a photographic film having a magnetic coating, are brought into intimate contact for anhysteretic recording by wrapping the moving master web partially around a small diameter gimballed roller (66) positioned in close proximity to a rotating transfer drum (36); wrapping the moving slave web partially around a larger idler roller (34) positioned in close proximity to both the gimballed roller and the transfer drum; wrapping the slave web partially around the transfer drum with the master web wrapped outside the slave web; and evacuating a chamber or volume (68) formed among the webs, rollers and drum, to remove air from between the webs and cause them to converge into intimate contact at a nip upstream of a signal transfer zone in which a magnetic head (70) applies a decaying magnetic field to cause anhysteretic transfer from the master web to the slave web.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.