Lensed indirect luminaire having improved light distribution control
US4644454A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1984 |
| Grant date | Feb 17, 1987 |
| Priority date | — |
| Expiry date | Dec 28, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21Y2113/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An elongated indirect luminaire is provided with two separate lens elements in the form of a primary trough-shaped lens cover supported over the luminaire's light source and at least one secondary lens strip supported laterally of the primary lens cover. A prismatic surface is formed on the lens cover for directing a portion of the available source light to the secondary lens strip; the secondary lens in turn has a prismatic surface designed for redirecting the light in a desired controlled fashion. The laterally placed secondary lens provides added control to the light distribution in the lateral regions of the luminaire near the luminaire's operative horizontal plane, and, in the illustrated embodiment, is designed to slightly boost the light in the lateral regions near the horizontal plane in a manner that provides improved control over the luminance of the secondary lens at viewing angles near the horizontal plane of the fixture. Such optical control provides a visible low brightness secondary lens in a fixture mounted at or near eye level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.