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. 18, 2000
Filed:
Aug. 11, 1997
Walter P Lapatovich, Boxford, MA (US);
Gerhard W Doell, Beverly, MA (US);
Robert K Smith, Wilmington, MA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
An Electrodeless High Intensity Discharge (EHID) lamp for projection applications. The lamp has a small (nominal dimensions: 2 mm I.D., 3 mm O.D., 6 mm internal length) capsule, which is constricted in a mid-portion thereof. The constriction squeezes the plasma within the capsule and provides a higher power density. This in turn produces a higher luminance in the center of the arc. This focal point of the projection system is constant over the life of the lamp, owing to the fact that the system is electrodeless. The arc tube or capsule is thickened in the vicinity of the constriction to permit heat transfer through the vitreous silica (commonly called quartz). The thickening carries the heat away from the now hotter mid-portion area. This thickening cools by virtue of increasing the thermal conduction through the glass.