Optical arrangement for use in a microfiche reader and method
US4334743A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 4, 1980 |
| Grant date | Jun 15, 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 optical arrangement for providing an image of a supported microfiche on a projection screen. This optical arrangement utilizes a beam of light which is directed from a light source along a path through the microfiche and towards the back side of the screen. A condenser lens is located on this beam path between the microfiche and light source and includes a focal point also located on the path but on the other side of the microfiche. A projection lens assembly is located between the microfiche and the focal point of the condenser lens, again on the beam path, such that there is a predetermined spacing between the projection lens assembly and focal point. This spacing is selected to increase and preferrably maximize illumination efficiency of the overall optical arrangement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.