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:
Feb. 14, 2012
Filed:
Sep. 24, 2009
Daisuke Yamahara, Shijonawate, JP;
Nobutoshi Matsuzaki, Neyagawa, JP;
Takeshi Kamoi, Kyoto, JP;
Satoru Nagata, Kobe, JP;
Naoki Komatsu, Kobe, JP;
Jun Kumagai, Himeji, JP;
Daisuke Yamahara, Shijonawate, JP;
Nobutoshi Matsuzaki, Neyagawa, JP;
Takeshi Kamoi, Kyoto, JP;
Satoru Nagata, Kobe, JP;
Naoki Komatsu, Kobe, JP;
Jun Kumagai, Himeji, JP;
Panasonic Electric Works Co., Ltd., Osaka, JP;
Abstract
A high pressure discharge lamp lighting device includes a DC power source circuit; a power supply circuit for converting an output from the DC power source circuit into a square wave AC output to be supplied to a high pressure discharge lamp; a starting circuit for applying a high voltage output for lamp startup to the high pressure discharge lamp; a control circuit; and a half-wave discharge detection circuit for detecting a half-wave discharge. The detection circuit detects the half-wave discharge at an initial stage of the lamp startup and the control circuit controls the magnitude of a voltage of a square wave half period of one polarity having a load voltage of a larger magnitude and that of a square wave half period of the other polarity having a load voltage of a smaller magnitude to approximate to each other.