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. 15, 2007
Filed:
Oct. 20, 2005
GE LI, Tokyo, JP;
Koichiro Miura, Tokyo, JP;
Takeshi Uematsu, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A discharge-lamp control device for lighting a discharge-lamp includes two electrodes, first and second driving units to supply power to the discharge-lamp through the electrodes, respectively. Each driving unit includes a transformer having primary and secondary coils and a capacitor connected in parallel to the secondary coil. The first driving unit has impedance characteristics with a minimum impedance at a first frequency and a maximum impedance at a second frequency lower than the first frequency. The second driving unit has impedance characteristics having a minimum impedance at a third frequency and a maximum impedance at a fourth frequency lower than the third frequency. The first frequency is set to be higher than the third frequency. The second frequency is set to be lower than the fourth frequency. An operating frequency of the driving circuit is selected within a frequency bandwidth from the fourth frequency to the third frequency.