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:
Jan. 09, 1996
Filed:
Jan. 18, 1994
Michael Boenigk, Berlin, DE;
Klaus Guenther, Berlin, DE;
Hans-Georg Kloss, Hohen Neuendorf, DE;
Teja Tehmann, Berlin, DE;
Abstract
To control the color temperature of a sodium high-pressure discharge lamp, preferably having a sodium and xenon fill, which may also include mercury, without essentially affecting the color rendition index of the emitted light, or the light flux or intensity of light radiation emitted, the lamp is operated under pulsed conditions, in which the instantaneous pulse power of recurring power pulses, separated by a holding phase to prevent extinction of the lamp, is controlled. Preferably, the overall energy of any one of said power pulses and the intervening holding pulse is maintained essentially constant, for example by varying the frequency of sub-pulses or oscillations of which the sequential power pulses are constituted. A frequency and power controllable oscillator (1) is connected to the lamp (3) through a series LC network to effect such control, thereby permitting adjustment of color temperature and matching of the light output to selective color reflectivity of illuminated objects.