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:
May. 18, 2004
Filed:
Jul. 24, 2002
Kazuhisa Nishida, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A high-pressure discharge lamp is effective to prevent initial blackening on an outer casing thereof, is of a long service life, and can easily be manufactured. A tungsten wire is wound as a double coiled winding around an electrode metal rod, leaving a tip end thereof, and the double coiled winding is machined into a melted tip end by a YAG laser beam, with the remaining double coiled winding used as a coil. The left tip end of the metal rod is machined into a nipple on the distal end of the melted tip end. If it is assumed that the melted tip end has a diameter D and a length L up to its distal end, the nipple has a proximal end having a diameter D and a length L from the proximal end up to the distal end thereof, and the coil and the melted tip end (including the nipple) have a volume V and the melted tip end (including the nipple) has a volume V then the electrode assembly is machined to satisfy at least one of the conditions 0.15≦D /D ≦0.3, 0.2≦L /L ≦0.4, and 0.2≦V /V ≦0.4. The machined electrode assembly is incorporated as an electrode into a lamp bulb.