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.

Date of Patent:
Feb. 28, 2017

Filed:

Feb. 03, 2016
Applicant:

Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;

Inventor:

Kazuya Kato, Osaka, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 41/16 (2006.01); H05B 41/292 (2006.01); H01J 61/54 (2006.01); H05B 41/288 (2006.01);
U.S. Cl.
CPC ...
H05B 41/2926 (2013.01); H01J 61/54 (2013.01); H05B 41/2887 (2013.01);
Abstract

The lighting device of one aspect according to the present disclosure calculates, based on a voltage value of an AC voltage applied to a discharge lamp and a current value of AC current flowing through the discharge lamp, a first power value defined as a value of power supplied to the discharge lamp in a first half period of the AC voltage and a second power value defined as a value of power supplied to the discharge lamp in a second half period of the AC voltage. The lighting device determines that a ground fault has occurred, when an imbalance state in which a difference between the first power value and the second power value is equal to or greater than a threshold value continues for a predetermined time period.


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