Compact microform reader
US4082440A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 14, 1975 |
| Grant date | Apr 4, 1978 |
| Priority date | — |
| Expiry date | Oct 14, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A portable microform reader is provided with a microform carrier and a projection system for projecting an enlarged real image of the information carried on a portion of the microform onto a viewing screen. A binocular magnifying system is arranged for viewing the screen and for further enlarging the image thereon to produce a virtual image of acceptable reading size. The projection system comprises a source of illumination, a condenser lens, and a projection lens for projecting an image of the information carried on the microform onto the screen. The magnifying system may consist of appropriate binocular lenses where such lenses, in combination with prismatic converging means, produce the desired magnification. Beam splitting means may alternately be provided to eliminate the need for prismatic converging means, and a mirror arrangement may be provided to "fold" the projected beams for further limiting the size of the reader.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.