Patent · US Expired

Light fixture, light aperture and method of uniformly illuminating an optically diffusive viewing area

US4335421A · kind A · utility

34Cited by
19References
22Claims
0Family size

Inventors

Key dates

Filing dateMar 17, 1980
Grant dateJun 15, 1982
Priority date
Expiry dateMar 17, 2000

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF21Y2103/30
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A light fixture having an optically diffusive viewing element having a viewing area across which apparent uniform brightness is achieved from a conventional light source and reflector by utilization of a light aperture. The light aperture comprises a tralucent substrate to which a plurality of reflective surfaces are affixed so as to partially redirect light incident thereon back to the reflector. Apparent uniform brightness of the light fixture viewing area is derived by a unique method of dividing the light from the light source into varying portions of direct and indirect illumination through the light aperture as well as direct illumination from the light source and indirect reflection from the reflector to the viewing area.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.