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:
Jun. 12, 2012
Filed:
Nov. 20, 2009
Nancy H. Chen, North Andover, MA (US);
Nancy H. Chen, North Andover, MA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
Techniques are disclosed that allow for the use of metal halide lamps in dimming applications, as well as other discharge lamps susceptible to dimming-induced chromaticity drift. Examination of such lamps reveals that some of the spectral changes that cause chromaticity drift during dimming are localized in narrow band regions of the spectrum, and lamp emission in these regions is enhanced (either increased or decreased) relative to the rest of the spectrum. Selective filtering of the enhanced emission caused by dimming can be used to reduce chromaticity shift. For instance, a filter deposited on and/or integrated into a lamp component (such as the arc tube, shroud, and/or outer jacket) operates to block transmission of those regions of the spectrum.