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:
Aug. 21, 1984
Filed:
Sep. 03, 1981
Seth D Silverstein, Schenectady, NY (US);
Jerome S Prener, Schenectady, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
The efficacy of a high-pressure sodium lamp is increased significantly by enlarging the arc tube diameter and deploying a composite infrared-reflective film on the interior of the outer lamp envelope. The infrared-reflective film acts to maintain the wall temperature of the enlarged arc tube at the same optimum temperature as the arc tube wall in a conventional high-pressure sodium lamp. In one embodiment, the IR reflective film is a multi-layer composite film of In.sub.2 O.sub.3 :Sn or SnO.sub.2 :F overcoated with a TiO.sub.2 or SiO.sub.2 dielectric film. In another embodiment, a three-layer composite film is made up of TiO.sub.2, In.sub.2 O.sub.3 :Sn, or SnO.sub.2 :F, and SiO.sub.2 films sequentially overlaid on the outer envelope. The dielectric films improve lamp efficacy and enhance the high temperature chemical stability of In.sub.2 O.sub.3 :Sn and SnO.sub.2 :F. Such IR reflective films are substantially transparent to radiation in the visible region of the spectrum, but are highly reflective in the infrared portions of the spectrum.