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:
Apr. 29, 2003
Filed:
Nov. 09, 1999
Ingrid J. M. Snijkers-Hendrickx, Eindhoven, NL;
Volker D. Hildenbrand, Eindhoven, NL;
Johannes H. Roes, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
Low-pressure mercury vapor discharge lamp provided with a discharge vessel ( ). The discharge vessel ( ) encloses a discharge space ( ), provided with a filling of mercury and a rare gas, in a gastight manner. At least a part of an inner surface of the discharge vessel ( ) is provided with a transparent layer ( ) comprising an oxide of scandium, yttrium, or a rare earth metal (lanthanum, cerium, gadolinium, ytterbium, and/or lutetium). The discharge lamp is characterized in that the transparent layer ( ) comprises a borate or a phosphate of an alkaline earth metal and/or of scandium, yttrium or a further rare earth metal. Preferably, the alkaline earth metal is calcium, strontium and/or barium. The further rare earth metal is preferably lanthanum, cerium and/or gadolinium. The oxide is preferably Y O or Gd O . Preferably, the transparent layer ( ) has a thickness of between 5 nm and 200 nm. A luminescent layer ( ) is preferably provided on top of the transparent layer in the discharge vessel. The lamp according to the invention has a comparatively low mercury consumption.