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:
Jun. 20, 1989
Filed:
Apr. 11, 1984
Gijsbertus De With, Eindhoven, NL;
Hendricus J Van Dijk, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The invention relates to a high-pressure discharage lamp comprising a discharge envelope having a wall of ceramic translucent material consisting mainly of densely sintered polycrystalline yttrium aluminium garnet (YAG). According to the invention, the material of the wall of the discharge envelope contains a single phase of YAG and at least one of the substances MgO and SiO.sub.2 in at total quantity of at least 50 ppm by weight, the absolute value of the difference between the SiO.sub.2 and MgO contents being at least 50 ppm by weight, and an excess of MgO at most 1000 ppm by weight. It has been found that the material can be sintered without external pressure, and a lamp according to the invention can then be obtained comprising a discharge envelope having a satisfactory transluecence and a high resistance to attacks of filling constituents.