Invention Grant
- Patent Title: LED driving circuit
- Patent Title (中): LED驱动电路
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Application No.: US13576627Application Date: 2011-02-02
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Publication No.: US08933636B2Publication Date: 2015-01-13
- Inventor: Shunji Egawa , Keisuke Sakai , Isao Ochi
- Applicant: Shunji Egawa , Keisuke Sakai , Isao Ochi
- Applicant Address: JP Tokyo
- Assignee: Citizen Holdings Co., Ltd.
- Current Assignee: Citizen Holdings Co., Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
- Priority: JP2010-022099 20100203; JP2010-186251 20100823
- International Application: PCT/JP2011/052677 WO 20110202
- International Announcement: WO2011/096585 WO 20110811
- Main IPC: H05B37/02
- IPC: H05B37/02 ; H05B33/08

Abstract:
The invention is directed to the provision of an LED driving circuit that switches the connection of LED blocks with proper timing in accordance with the supply voltage and the Vf's specific to individual LEDs contained in each LED block. The LED driving circuit includes a rectifier, a first circuit which includes a first current detection unit for detecting current flowing through a first LED array, and a first current control unit for controlling current flowing from the first LED array to a negative power supply output in accordance with the current detected by the first current detection unit, and a second circuit which includes a second current detection unit for detecting current flowing through a second LED array, and a second current control unit for controlling current flowing from a positive power supply output to the second LED array in accordance with the current detected by the second current detection unit, and wherein a current path connecting the first LED array and the second LED array in parallel relative to the rectifier and a current path connecting the first LED array and the second LED array in series relative to the rectifier are formed.
Public/Granted literature
- US20120299492A1 LED DRIVING CIRCUIT Public/Granted day:2012-11-29
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