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:
Apr. 14, 1992
Filed:
Sep. 14, 1990
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01K / ; H01K / ; H01K / ;
U.S. Cl.
CPC ...
313 51 ; 313315 ; 313318 ; 313578 ; 313634 ; 362216 ; 439229 ;
Abstract
A ring-shaped glass bulb includes a ring-shaped light permeable hollow body having opposite ends each disposed at a prescribed distance from one to the other, and a filament arranged in the hollow body of the bulb. The outer-most edge portion of the outer ring edge of one of the ends of the bulb is disposed at at least the intersecting point between an outer circumferential line extending from the outer-most edge portion of the outer ring edge of the other end of the bulb and a tangent line extending from the inner-most edge portion of the inner ring edge of the other end of the bulb. A desirable prescribed distance between the opposite ends of the bulb is equal to or greater than 30 mm.