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:
Jan. 28, 2014
Filed:
Sep. 24, 2010
Jun Kumagai, Suita, JP;
Naoki Komatu, Kobe, JP;
Nobuo Ukita, Himeji, JP;
Kazuhiko Harada, Himeji, JP;
Jun Kumagai, Suita, JP;
Naoki Komatu, Kobe, JP;
Nobuo Ukita, Himeji, JP;
Kazuhiko Harada, Himeji, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A discharge lamp ballast and method of operation are provided for generating a DC component in an output voltage during a lamp starting operation having a predetermined duration. The ballast includes an inverter having four switches arranged in a full-bridge configuration, a resonant circuit having a resonant frequency, and a control circuit. The method includes a step of sweeping an inverter operating frequency within a predetermined frequency range including the resonant frequency, wherein a high voltage is generated for igniting the lamp. The method further includes periodically and alternately repeating a first state of turning on a first set of diagonally positioned switching elements and turning off a second set of diagonally positioned switching elements, and a second state of turning on only one of the second set of switching elements and turning off the remaining three switching elements, respectively.