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. 19, 1982
Filed:
Feb. 04, 1980
John Fitzgerald, Eindhoven, NL;
Willem L Van Hoorn, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
In electric incandescent lamps the efficiency can be increased by surrounding the filament with a light-pervious, infra-red radiation-reflecting filter. It has hitherto always been assumed that the geometry of the filter and that of the filament should be well matched to each other. This, however, results in a complex filament construction. According to the invention, near the center of a spherical filter, a flat filament consisting of several parts is accommodated, being situated within a square the sides of which are from 0.25 to 0.04 times the diameter of the filter. Such a filament has a relatively simple construction and provides a highly efficient lamp despite the fact that its geometry is very different from that of the filter.