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END CAVITY REFLECTOR

IP.com Disclosure Number: IPCOM000024779D
Original Publication Date: 1982-Feb-28
Included in the Prior Art Database: 2004-Apr-03

Publishing Venue

Xerox Disclosure Journal

Abstract

Fluorescent lamps are characterized by a light falloff at the ends of the lamp. The figure shows a reflector 2 located at the end of a lamp 4 which enhances the end illumination. The reflector consists of a cavity open on the end towards a document 6 to be illuminated. The side opposite the lamp is a continuation of the opposed reflector shape. A top, bottom and end completely encloses the area except for the open end and the area over the lamp aperture 8. In this configuration, a point on the edge of the document sees a large solid angle of illumination. The normal lamp and reflector geometric angle as well as the solid angle of the cavity combine to enhance the end illumination. The limited aperture lamp also has the effect of increasing the solid angle of the internal reflector and phosphor of the lamp resulting in higher brightness in that portion of the lamp. This cavity reflector has some of the same effect as the reflector cavity thereby becoming an extension of the lamp cavity and thus increasing lamp brightness.