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:
Oct. 14, 2008
Filed:
Nov. 29, 2005
Katsunobu Hamamoto, Neyagawa, JP;
Kazuhiro Nishimoto, Kashihara, JP;
Masahiro Yamanaka, Otsu, JP;
Toshiya Kanja, Uji, JP;
Katsunobu Hamamoto, Neyagawa, JP;
Kazuhiro Nishimoto, Kashihara, JP;
Masahiro Yamanaka, Otsu, JP;
Toshiya Kanja, Uji, JP;
Matsushita Electric Works, Ltd., Kadoma-shi, JP;
Abstract
An inverter controller dives an inverter to operate at a switching frequency selectively from one of a preheating frequency (f), a starting frequency (f), and a lighting frequency (f) which are different from each other, thereby giving a preheating mode, a starting mode, and a lighting mode. A reset means is provided to make the starting mode upon lowering of a voltage supplied to the inverter below a first threshold, while an inverter stop means is provided to stop the inverter upon detection of abnormality of a discharge lamp. A timer generates a signal determining the start of the preheating, starting, and/or lighting modes, and generates a reset signal disable signal for disabling the reset means, an inverter stop disable signal for disabling the inverter stop means. The inverter controller includes a frequency sweep means for varying the switching frequency gradually from the starting frequency to the lighting frequency. The timer disables the reset means only during a period starting from the selection of the preheating frequency and ending when the switching frequency varies to the lighting frequency, and disable the inverter stop means only during a period starting from the selection of the preheating frequency and ending when the switching frequency begins to vary from the starting frequency to the lighting frequency.