Dual lens image rotation system
US4494840A · kind A · utility
1Cited by
6References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 6, 1983 |
| Grant date | Jan 22, 1985 |
| Priority date | — |
| Expiry date | Sep 6, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/11
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A device for rotating the projected image in a dual lens microfilm reader. Each lens has an image rotation prism positioned above it with selector means for positioning either of the projection lenses and its prism in the image projection path. Gears surround each prism and are driven simultaneously an identical amount by means of a drive gear engaging both of the surrounding prism gears. The projected image is rotated an identical amount regardless of which projection lens is disposed in the image light path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.