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. 04, 1987
Filed:
Nov. 24, 1986
Gijsbertus A Spierings, Eindhoven, NL;
Eddy F Van Hove, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A new type of glass, for example for use as a TL-envelope glass which as regards phosphor poisoning and Hg penetration has better properties than the present TL-envelope glasses. Phosphor poisoning occurs in particular upon fusing electrodes and bending and severing and bridging, respectively, during the manufacture of SL and PL lamps. Phosphor poisoning is controlled by incorporating little or no Na.sub.2 O in the glass. In order to nevertheless reach good processing properties, a combination of Li.sub.2 O and K.sub.2 O is used in the glass. The addition of only Li.sub.2 O or only K.sub.2 O does not result in a suitable glass. Hg penetration is controlled by the presence of a large quantity of alkaline earth metal oxides in the glass. The glass according to the invention has a good light transmission. A lamp comprising a lamp envelope of a glass according to the invention shows only a small luminous decline during operation of the lamp.