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:
Nov. 30, 1999
Filed:
Aug. 29, 1997
Dick Van der Voort, Eindhoven, NL;
Henricus C Verhaar, Turnhout, NL;
Jan W Dorleijn, Roosendaal, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A low-pressure mercury discharge lamp is provided with a discharge vessel (1) which encloses a discharge space (2) in a gastight manner and in which a filling including mercury is accommodated. The lamp is provided with means (3a, 3b) for maintaining an electric discharge in the discharge space. The discharge vessel is provided with a luminescent layer (5). The lamp generates light during operation with a spectrum which is substantially composed of radiation in a first wavelength region from 590 to 630 nm, a second wavelength region from 520 to 565 nm, and in a third wavelength region from 430 to 490 nm. The radiation in the wavelength interval from 590 to 600 nm accounts for at least 50% of the power of the radiation in the entire first wavelength region. A preferred embodiment of the lamp includes a luminescent material that complies with the formula M1.sub.x M2.sub.(1-x-y) BO.sub.3 :Eu.sup.3+.sub.y, in which M1 is an element from the group formed by Sc, In, and Lu, and in which M2 is an element from the group formed by Sc, Y, La, Gd, Ga, In, and Lu, where M1 is different from M2, with 0.01.ltoreq.y.ltoreq.0.2, x>0, x+y<1, while the luminescent material has a calcite lattice structure.