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:
Apr. 26, 2011
Filed:
Apr. 06, 2009
Akitoyo Konno, Hitachi, JP;
Tsunenori Yamamoto, Hitachi, JP;
Tatsuki Inuzuka, Mito, JP;
Hitachi Displays, Ltd., Chiba, JP;
Abstract
A lighting device includes at least two lines connected in parallel, a constant current source for applying a constant current to at least one of the at least two lines, an ON/OFF controller, and a voltage detector for measuring a value of voltage flowing in each line of the at least two lines. Each line of the at least two lines is formed by one or more light-emitting diodes and a switch for turning ON/OFF the current flowing in the light-emitting diodes connected in series, and according to the voltage value of each line of the at least two lines measured by the voltage detector, the ON/OFF controller controls the duty ratio of the one or more light-emitting diodes of each line in accordance with the voltage measured.