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:
Jul. 05, 2011
Filed:
Aug. 27, 2007
Naoki Onishi, Kobe, JP;
Tetsuya Hamana, Amagasaki, JP;
Keisuke Ueda, Hirakata, JP;
Kouichi Ikegami, Himeji, JP;
Kazuhiko Tachibana, Kakogawa, JP;
Takuya Sakai, Himeji, JP;
Naoki Onishi, Kobe, JP;
Tetsuya Hamana, Amagasaki, JP;
Keisuke Ueda, Hirakata, JP;
Kouichi Ikegami, Himeji, JP;
Kazuhiko Tachibana, Kakogawa, JP;
Takuya Sakai, Himeji, JP;
Panasonic Electric Works Co., Ltd., Osaka, JP;
Ikeda Electric Co., Ltd., Hyogo, JP;
Abstract
In order to enhance stability of a discharge lamp at the time of dimming lighting even in the case where a light output is lowered, a direct current superimposing circuit superimposes a direct current voltage on an alternating current voltage applied to a fluorescent lamp, and a dimming signal correction circuit receives a detection value of a direct current voltage detection circuit and a dimming signal that is from an outside, outputs a dimming signal higher in level than the dimming signal in the case where the detection value of the direct current voltage detection circuit exceeds a first threshold value, and decreases the level of the outputted dimming signal to the level of the inputted dimming signal in the case where the detection value of the direct current voltage detection circuit falls down below a second threshold value that is equal to or less than the first threshold value. Then, an amount of alternating current power supplied to the fluorescent lamp by an inverter circuit is increased and decreased in response to fluctuations of the level of the dimming signal outputted by the dimming signal correction circuit, whereby the fluorescent lamp is dimmed.