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. 10, 2004
Filed:
Nov. 15, 2002
Tatsuya Uchikawa, Tokyo, JP;
Kazuhisa Nishida, Tokyo, JP;
NEC Microwave Tube, Ltd., Sagamihara, JP;
Abstract
A high pressure discharge lamp includes a quartz glass bulb, a conductive element which is sealed at a sealing portion of the bulb, and a pair of electrodes. Each electrode is disposed in the quartz glass bulb so as to be opposite the other and connected to the conductive element. A part of each electrode is sealed with the quartz glass bulb at the sealing portion so as to generate a contacting portion formed by the part of each electrode and the bulb. The maximum length, L , of the contacting portion is defined as: L ((mm))≦/200/(P×D); and the minimum length, L , of the contacting portion is defined as: L ((mm))≧0.8/(D ×&pgr;) or L ((mm))≧0.7 whichever is longer, where D is the diameter ((mm)) of the electrode and P is the power (W) supplied to the electrode.