Lens arrangements for microfiche reader assembly and method
US4339181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1980 |
| Grant date | Jul 13, 1982 |
| Priority date | — |
| Expiry date | Mar 4, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/115
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A microfiche reader is disclosed herein and includes an assembly for supporting a microfiche in a given area, a projection screen and an optical arrangement for providing an image of a segment of the microfiche on the screen. This arrangement utilizes a dual projection lens assembly and a dual condenser lens assembly which cooperate with one another so that the magnification of the projected image can be easily varied between two levels. As disclosed, the dual projection lens assembly itself includes two distinct projection lenses which are contained in collapsible housings. Moreover, each of these latter lenses is adjustably focused by rotational movement of its associated housing and remains in the focusing position selected unless its housing is again rotated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.