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. 06, 2004
Filed:
Apr. 29, 2003
Toshiyuki Noguchi, Nishinomiya, JP;
Yasuhiro Kakimoto, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A discharge-lamp lighting device is provided which decreases arc jumps, suppresses the fluctuation in brightness of the lamp, and prolongs a life of the lamp, by positively accelerating growth of spots even when an inexpensive, small and highly efficient lamp is used. A discharge-lamp controlling portion ( ) sets frequencies of drive-controlling signals (A and B) for drive-controlling a commutator ( ) within a predetermined frequency range so that spots formed by arc discharge on electrodes composing a high-pressure discharge lamp grow through a cycle of oxidation-reduction of a metal composing the electrodes, and superimposes a triangular wave signal generated on the basis of the drive-controlling signals onto a current-controlling signal (F) over an entire period of the drive-controlling signals so as to make a peak value of the triangular wave constant, thereby adjusting the waveform of current flowing in the high-pressure discharge lamp.