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:
May. 12, 2009
Filed:
Jun. 09, 2006
Masashi Okamoto, Hyogo, JP;
Izumi Takaya, Himeji, JP;
Masaaki Uehara, Himeji, JP;
Ushio Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A discharge lamp lighting device can reduce a variation in luminous flux at the time when the polarity of a voltage to be applied to the discharge lamp is inverted, prevent an excessively large amount of current from flowing through the discharge lamp at the time of starting, prevent the fade-out of discharge when the discharge mode returns from an arc discharge mode to a glow discharge mode, and reduce the ripple of a lamp current in a normal lighting mode. A coil is provided in an output current path of a power supply circuit comprising, for example, a step-down chopper, and a smoothing capacitor is provided in the next stage of the coil so that it selectively is turned on or off by a switching element. An inverter comprising, for example, a full bridge is provided in the next stage of the smoothing capacitor.