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:
Nov. 12, 2002
Filed:
Mar. 01, 2000
Makoto Kai, Katano, JP;
Makoto Horiuchi, Sakurai, JP;
Mamoru Takeda, Soraku-gun, JP;
Takeharu Tsutsumi, Katano, JP;
Toshiaki Ogura, Hirakata, JP;
Abstract
An image projector has a lamp unit having a high-pressure mercury vapor discharge lamp and a parabolic mirror . To the high-pressure mercury vapor discharge lamp , a driving system applies an alternating voltage such that wandering of a cathode luminescent spot generated in the vicinity of a tip of each of the discharge electrodes of the high-pressure mercury vapor discharge lamp is suppressed, the frequency being within the range of 20-42 kHz. This construction allows to prevent flicker in a projected image of a liquid crystal projector and the like, and therefore achieves high quality in the projected image.