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:
Oct. 21, 2003
Filed:
Sep. 15, 1999
Levinus P. Bakker, Utrecht, NL;
Gerardus M. W. Kroesen, Utrecht, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The invention relates to a method of adjusting a desired spectrum of light emitted by a gas discharge lamp during its operation, said gas discharge lamp comprising a first ionizable substance and a second substance which is less readily ionizable than the first substance. According to the invention, the gas discharge lamp is operated such that gases of both substances cans be excited, while the partial pressure of the first substance is adjusted in dependence on the desired spectrum. For this purpose, for example, the current through the lamp may be modulated. In an alternative embodiment, this is suitably achieved in that the partial mercury pressure is varied, for example through an adjustment of the temperature of a mercury amalgam present in the gas discharge lamp. The invention also relates to a gas discharge lamp whose color can be varied during its operation, and to a luminaire provided with a supply for such a lamp.