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. 08, 1978
Filed:
Apr. 23, 1976
George S Evans, Caldwell, NJ (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
Fast 'warm-up' of an amalgam-regulated fluorescent lamp under 'cold' starting conditions and safe failure of the lamp at the end of its useful life are achieved by coating selected portions of both stems with a material that contains indium or an indium alloy and initially is semiconductive. The coating is applied to portions of the stems adjacent the electrodes and covers a segment of one or both of the lead wires at the point where they emerge from the stem presses. The coating is thus rapidly heated and releases mercury vapor as soon as the lamp is energized. When the electrodes are devoid of emission material and the lamp has reached the end of its useful life, sputtered material from the metal parts of the mount renders the coating electrically conductive and causes the arc to impinge upon and finally puncture the stem. The coating accordingly serves both as an auxiliary-amalgam source and a 'fail-safe' component. Coatings of materials that are electrically conductive as soon as applied and contain an amalgamative metal can also be used, providing they do not contact both leads.