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.

Date of Patent:
Oct. 08, 1991

Filed:

Dec. 12, 1989
Applicant:
Inventors:

Takashi Yorifuji, Zushi, JP;

Masashi Saigo, Kamiya, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313490 ; 313493 ; 313609 ;
Abstract

A low-pressure mercury vapor discharge lamp is composed of a glass tube which has a discharge passage having two end portions arranged in the same direction, a folded portion in the direction opposite the portions, a pair of electrodes provided between the portions and amalgam provided in an end portion and for controlling the mercury vapor pressure. The tube has a configuration such that a low temperature region is formed in an inner face of the tube adjacent to the folded portion when the lamp is turned on in the state where the folded portion is oriented in a direction where it is affected by gravity, whereas, the low temperature region is formed in an inner face of the tube other than the folded portion when the lamp is turned on in the state that the folded portion is oriented in a direction where it is not affected by gravity, at a room temperature.


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