Title:
ＬＥＤ駆動回路
Document Type and Number:
Japanese Patent JP5550716
Kind Code:
B2
Abstract:
The invention is directed to the provision of an LED driving circuit that switches the connection of LED blocks 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, a first current detection unit for detecting current flowing from the first LED array to the negative output of the rectifier, and a first current limiting unit for limiting the current flowing from the first LED array to the negative output of the rectifier in accordance with the current detected by the first current detection unit, and a second circuit which includes a second LED array and a current path passing through the second LED array and leading to the negative output of the rectifier, and wherein a current path in which only the first LED array is connected to the rectifier and a current path are formed in accordance with an output voltage of the rectifier, and the first current detection unit, upon detecting current flowing through the first and second LED arrays, operates the first current limiting unit to perform current path switching.
Inventors:
Shunji Egawa
Ochi 功
Ochi 功
Application Number:
JP2012501914A
Publication Date:
July 16, 2014
Filing Date:
February 25, 2011
Export Citation:
Assignee:
Citizen Holdings Co., Ltd.
International Classes:
H05B37/02; H05B44/00
Domestic Patent References:
| JP2009123427A | 2009-06-04 | |||
| JP2005122979A | 2005-05-12 | |||
| JP2009010100A | 2009-01-15 | |||
| JP2009290245A | 2009-12-10 | |||
| JP2011040701A | 2011-02-24 | |||
| JP2002025784A | 2002-01-25 |
Attorney, Agent or Firm:
Aoki 篤
Tsuruta Junichi
Tomohiro Minamiyama
Kawai Chapter
Ken-ichi Nakamura
Tsuruta Junichi
Tomohiro Minamiyama
Kawai Chapter
Ken-ichi Nakamura