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:
Jan. 21, 2014
Filed:
Apr. 22, 2011
Toshifumi Tanaka, Toyonaka, JP;
Toshifumi Tanaka, Toyonaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A lighting device includes: a power converting unit; a voltage measuring unit for measuring an output voltage from the power converting unit or a value equivalent to the output voltage; a current measuring unit for measuring an output current from the power converting unit or a value equivalent to the output current; and a control unit for controlling the power converting unit. When one of the output voltage and the output current of the power converting unit is changed by a specific magnitude per unit hour, the control unit determines that a change in a load status has occurred and controls the power converting unit by switching constant current control in which a measurement value of the current measuring unit is kept at a specific current designated value to constant voltage control in which a measurement value of the voltage measuring unit is kept at a specific voltage designated value.