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:
Nov. 20, 1990
Filed:
Mar. 15, 1989
Mikio Kariya, Nagoya, JP;
Hirotsugu Izumiya, Nagoya, JP;
NGK Insulators, Ltd., , JP;
Abstract
A ceramic envelope device for an HID lamp, wherein a translucent ceramic arc tube is closed at opposite end sections thereof by respective end caps which support respective discharge electrodes on their inner surfaces. At least one of the opposite end sections of the arc tube is sealed with a sealing layer, and each of the sealed end section of the tube includes a first axial portion having a first inside diameter, and a second axial portion having a second inside diameter smaller than the first inside diameter and disposed axially inwardly of the first axial portion. The first and second axial portions define an annular shoulder surface radially inwardly extending between the first and second inside diameters. The first axial portion preferably has a cylindrical wall thickness of 1.0-1.5 mm, and the annular shoulder surface preferably has a radial width of 0.2-0.8 mm. The sealing layer is interposed between the first axial portion of the arc tube and the corresponding end cap. The inner surface of the corresponding end cap includes a peripheral portion held in abutting contact with the annular shoulder surface. The first and second inside diameters are preferably formed by a stepped-diameter drill.