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:
Feb. 03, 1998
Filed:
Aug. 28, 1992
Roger B Hunt, Medfield, MA (US);
Lawrence L Hope, Maynard, MA (US);
William J Roche, Merrimac, MA (US);
GTE Products Corporation, Danvers, MA (US);
Abstract
A fluorescent lamp comprises at least one layer of a quad-phosphor blend for emitting visible illumination having a white color. The quad-phosphor blend comprising a first and second green emitting phosphor component with each green emitting phosphor component having different visible emission spectrum principally in the 520 to 560 nm wavelength range. A third blue emitting phosphor component has an emission spectrum principally in the 440 to 470 nm wavelength range. A fourth red emitting phosphor component has an emission spectrum principally in the 590 to 620 nm wavelength range. The first green emitting phosphor component is a alkaline earth metal activated phosphor and the second green emitting phosphor is a rare earth activated phosphor wherein the relative proportions of the phosphor components are such that an enhanced color rendering index is produced as compared to tri-component blends formed from three of the phosphor components.