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:
Mar. 17, 2009
Filed:
Mar. 22, 2005
Junichi Hasegawa, Neyagawa, JP;
Hirofumi Konishi, Hirakata, JP;
Akihiro Kishimoto, Osaka, JP;
Koji Watanabe, Kadoma, JP;
Katsuyoshi Nakada, Katano, JP;
Junichi Hasegawa, Neyagawa, JP;
Hirofumi Konishi, Hirakata, JP;
Akihiro Kishimoto, Osaka, JP;
Koji Watanabe, Kadoma, JP;
Katsuyoshi Nakada, Katano, JP;
Panasonic Electric Works Co., Ltd., Osaka, JP;
Abstract
A discharge lamp lighting apparatus comprising a d.c. power source section which rectifies and smoothes an a.c. voltage; a current detecting circuit which detects a current which flows through a discharge lamp; a power source ripple detecting circuit which detects a voltage change of power supplied from the d.c. power source section and outputs a voltage obtained by superimposing the detected voltage over a detected voltage which is available from the current detecting circuit; and a control circuit which controls, based on the output voltage from the power source ripple detecting circuit, an output voltage to the discharge lamp so that the current flowing through the discharge lamp becomes a constant current. A rate of superimposition of the output voltage from the power source ripple detecting circuit may be switched in accordance with the discharge lamp voltage.