Portable dual spool microfilm reading device
US4034540A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1975 |
| Grant date | Jul 12, 1977 |
| Priority date | — |
| Expiry date | Jul 18, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/11
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A portable dual spool cassette type microfilm reading device capable of storing a large quantity of microphotographic information in a relatively small space. The cassette contains a band of microfilm having information frames disposed in rows and columns thereon and windable from one spool to the other in the cassette. The cassette has a track which extends in the column direction of the microfilm and on which a direct view type microfilm viewer is mounted for movement. To access a column for a particular frame a manually operable knob is operated to wind the film on the spools to the column position and to locate the row the viewer is moved in the track to the row position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.