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:
May. 22, 2001
Filed:
Sep. 15, 1999
Herbert Friedrich Börner, Aachen, DE;
Wolfgang Busselt, Roetgen, DE;
Thomas Jüstel, Aachen, DE;
Hans Nikol, Aachen, DE;
Cornelis R. Ronda, Aachen, DE;
U.S. Philips Cororation, New York, NY (US);
Abstract
As a white light source, the lighting system (,) has at least three light-emitting diodes (,) for providing visible light at preselected wavelengths. The invention is characterized in that the lighting system (,) is provided with at least one fourth light-emitting diode (,) which, in operation, emits visible light in a further wavelength region, the maximum of the spectral emission of the fourth light-emitting diode (,) lying in the further wavelength region from 575 to 605 nm. Preferably, the further wavelength region ranges from 585 to 600 nm. Preferably, the color rendition of the lighting system (,) is above 60. Preferably, the luminous efficacy of the lighting system (,) is above 30 lm/W, preferably above 40 lm/W. In another preferred embodiment, the color temperature of the lighting system (,) can be adjusted by selectively switching the light-emitting diodes (,).