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:
Mar. 09, 1999
Filed:
Aug. 21, 1997
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An apparatus for operating a high intensity discharge lamp that minimizes discharge arc curvature to form a straight discharge arc and thereby eliminate variations in the discharge arc color caused by cataphoresis is disclosed. The apparatus outputs a synthesize wave having a waveform with a frequency component of the acoustic resonance frequency to excite a mode straightening the discharge arc, and a waveform of a frequency less than the acoustic resonance frequency whereby the polarity of the waveform having a frequency less than the acoustic resonance frequency changes. The acoustic resonance frequency is determined by the speed of sound in the discharge space, and the length of the discharge space intersecting the discharge arc.