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:
May. 11, 1993
Filed:
Mar. 04, 1991
Dietrich Fromm, Warngau, DE;
Andreas Hohlfeld, Berlin, DE;
Abstract
Low-power, high-pressure discharge lamps, that is lamps having a power rag below and up to about 400 W, have a quartz discharge vessel retaining a metal halide fill which, to obtain a color temperature between 2700.degree. to 3400.degree. C. contains sodium and tin. To prevent deterioration of the electrode head (19; 39; 59), it is formed in essentially cylindrical or frusto-conical outer contour, which has a mass determined by the formula M=i.sub.L .times.(23.+-.8), and is retained on an electrode pin or shaft (17; 38; 58) having a diameter (d) in millimeters ##EQU1## wherein i.sub.L is the effective value of the lamp current in amperes. Preferably, the electrode head (19) extends beyond the end portion of the electrode pin to define a small depression with respect thereto. The particular shape and dimension of the electrode head and the electrode shaft reduces flicker and electrode burning.