System for illuminating a linear zone which reduces the effect of light retroflected from outside the zone on the illumination
US5179413A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1992 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Feb 5, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0435
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illuminating system, which illuminates a line and translates that line over a document on a platen of a scanner or copier which receives light from the line on an image (photo) receptor thereof, uses primary and secondary reflectors having internal reflective surfaces which are elliptical troughs. An elliptical trough is defined here as a surface having an elliptical cross section and maintaining that same cross section over its length. The primary reflector contains a lamp having a linear filament in a plane containing the major axis of the primary reflector ellipse and located at one of the focii thereof so as to provide a conjugate line for the light from the lamp along a line containing the other of the focii of the primary ellipse reflector. The primary elliptical trough is terminated by an aperture plate having an aperture in which the line is located. A secondary reflector has an internal reflective surface with a slit facing the document to be illuminated. The secondary reflector has focii, one of which is common with one of the focii of the first reflector located in the aperture while the other focii is along a line in the plane of the document being illuminated. The a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.