Illumination – Light modifier – Reflector
Reexamination Certificate
2000-06-13
2002-12-17
O'Shea, Sandra (Department: 2875)
Illumination
Light modifier
Reflector
C362S340000, C362S430000, C362S309000
Reexamination Certificate
active
06494596
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to a reflector for a lighting fixture. Specifically, the reflector has a portion of its inner surface that is textured to diffuse the light rays from the light source of the lighting fixture, and an outer surface with a plurality of prisms that reflect the lights rays, creating an even dispersal of light.
BACKGROUND OF THE INVENTION
A reflector for a lighting fixture, in particular a surface of revolution type reflector, reflects light from the light source of the fixture in an attempt to produce even illumination on a surface perpendicular to its axis of revolution. Surface of revolution style reflectors are easier to make than other reflectors, such as square or rectangular shaped reflectors. In addition, surface of revolution style reflectors can capture and redirect a greater amount of light with a smaller sized reflector.
However, the prior art surface of revolution reflectors tend to reflect light rays parallel to the axis of revolution, usually downward, and those light rays tend to overwhelm any light projected outwardly away from the axis of revolution, thereby causing a hot spot or spike in the intensity distribution of the reflector which prevents even illumination.
Also, the prior art reflectors fail to counteract the portion of the inner surface of the reflector that is closest to the light source, which contributes the most to creation of hot spots. These hot spots result in light puddles, or bright areas of illumination, and a general uneven overall illumination. In addition, as a consequence of hot spots, in the illumination, smaller fixture spring to mounting ratios are calculated and such that prior art downlights must placed closer together to evenly illuminate a certain area.
Prior attempts to avoid the problem of hot spots, such as varying the location of the light source, have resulted in additional hot spots or undesirable voids in the lighting distribution. In addition, shape variances in the prior art reflectors, light source tolerance, and mounting hardware tolerances can lead to inaccurate light source positioning, increasing the potential for hot spots or voids. Thus, the prior art reflectors require that the light source be critically placed in a specific orientation and location to avoid additional hot spots and voids in the light distribution.
Examples of prior art reflectors are disclosed in the following U.S. Pat. No. 1,412,315 to Correll; U.S. Pat. No. 1,543,606 to Harrison; U.S. Pat. No. 1,891,846 to Stauber, Jr.; U.S. Pat. No. 2,132,784 to Guth; U.S. Pat. No. 3,825,742 to Levin; U.S. Pat. No. 4,285,034 to Sullivan; U.S. Pat. No. 4,987,524 to Miller; and U.S. Pat. No. 5,957,565 to Hofmann.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a reflector for a surface of revolution style light fixture, such as a downlight, that provides an even distribution of light.
Another object of the present invention is to provide a reflector for a downlight that avoids hot spots and voids in the distribution of light from the light source simply, efficiently, and inexpensively.
A further object of the present invention is to provide a reflector for a downlight that allows movement and varying of the placement of the light source while avoiding hot spots and voids in the distribution of light.
A yet further object of the present invention is to provide a reflector for a downlight that allows several downlights to be installed further apart even when the ceiling or mounting surface is low.
The foregoing objects are basically attained by a reflector for a lighting fixture having a light source, comprising a reflector wall including, opposing first and second ends, the first end having a first opening disposed therein, and the second end having a second opening disposed therein, the second opening being substantially larger than the first opening, an inner surface, the inner surface including, a first portion located adjacent the first opening and remote from the second opening, and having a textured surface for diffusing light rays from the light source, and a second portion being located adjacent the second opening and remote from the first opening with the second portion being substantially larger than the first portion, and having a smooth surface, and an outer surface having a plurality of curvilinear prisms thereon extending between the first and second ends for reflecting light rays from the light source.
By structuring the reflector in this fashion, light rays from the light source are diffused by the inner surface of the reflector at the particular problem area portion of the inner surface and reflected by the outer prismatic surface, resulting in an even distribution of light.
REFERENCES:
patent: 821307 (1906-05-01), Mygatt
patent: 1413315 (1922-04-01), Correll
patent: 1543606 (1925-06-01), Harrison
patent: 1891846 (1932-12-01), Stauber, Jr.
patent: 2132784 (1938-10-01), Guth
patent: 3466437 (1969-09-01), Ruehl
patent: 3800138 (1974-03-01), Shadwick
patent: 3825742 (1974-07-01), Levin
patent: 4285034 (1981-08-01), Sullivan
patent: 4611266 (1986-09-01), Schwartz
patent: 4839781 (1989-06-01), Barnes
patent: 4987524 (1991-01-01), Miller
patent: 5121309 (1992-06-01), Ewing et al.
patent: 5444606 (1995-08-01), Barnes et al.
patent: 5957565 (1999-09-01), Hofmann
'Hubbell Incorporated
Goodman Alfred N.
Hoffman Tara L.
O'Shea Sandra
Truong Bao
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