The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 28, 2004
Filed:
Oct. 04, 2002
Stéphane Frederick Jacob, Port Moody, CA;
Allan Brent York, Langley, CA;
TIR Systems Ltd., Vancouver, CA;
Abstract
The color temperature of light emitted by a luminaire having a hollow prismatic light guide is varied to counteract aesthetically undesirable reddening gradient of the emitted light. Reddening is caused by the light guide's dielectric material, which absorbs blue light rays such that proportionately more red than blue rays are guided to the light guide's far end than to points near the guide's light input end. Flare light rays which escape through the light guide near its light input end are color filtered and reflected back into the light guide. The filter color lies within a CIE-1931 chromaticity diagram {4800° Kelvin; 570 nm; 600 nm} color gamut triangle. Color filtering absorbs blue flare rays as a function of distance along the guide, imparting a near-end reddening gradient to the emitted light in inverse proportion to the far-end reddening gradient, giving the emitted light a constant apparent color, independent of distance along the guide.