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. 07, 2001
Filed:
Jun. 03, 1998
Akihiko Sugitani, Himeji, JP;
Hiroto Sato, Himeji, JP;
Takashi Ito, Tatsuno, JP;
Yoshihiro Horikawa, Himeji, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Abstract
A high pressure mercury lamp in which formation and spreading of milky opacification in the fused silica glass forming the discharge vessel can be advantageously prevented, and thus a rapid decrease of screen illuminance prevented, when it is used as the light source of a liquid crystal projector and the like by, in a high pressure mercury lamp in which a discharge vessel of fused silica glass contains a pair of opposed tungsten electrodes, mercury in an amount that is at least equal to 0.16 mg/mm,, rare gas, and at least one halogen, and in which the wall load is at least equal to 0.8 W/mm,, the amount of mercury added being fixed in a range from 2×10,to 7×10,&mgr;mole/mm,, and/or the at least one halogen being in the form of a carbonless halogen compound, and/or the average OH radical concentration in an area of a wall of the discharge vessel at a depth of 0.2 mm from an inner surface of the wall of the discharge vessel being at most 20 ppm.