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:
Jul. 15, 2003
Filed:
Jan. 13, 2000
Mituru Ikeuchi, Himeji, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Abstract
The invention relates to a discharge lamp with a discharge vessel of silica glass which has a higher operating pressure than atmospheric pressure, where the high temperature viscosity (VA) in the outer surface area of the arc tube portion of the discharge vessel is lower than the high temperature viscosity (VB) at a depth of 100 microns from the outer surface of the arc tube portion. Since the high temperature viscosity (VA) in the outer surface area of the arc tube portion of the discharge vessel is lower than the high temperature viscosity (VB) at a depth of 100 microns from the outer surface of the arc tube portion, formation of thermal distortion in the vicinity of the outer surface of the arc tube portion can be suppressed. This prevents the discharge vessel from being damaged or from breaking by thermal distortion even after operation for a long time.