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US 2009/0267520 A1Published application
Lighting control device
AssigneeKoito Manufacturing Co., Ltd.
InventorsKotaro Matsui, Takayoshi Kitagawa, Takao Sugiyama
Life of this patent
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Abstract
A lighting control device includes a current driving portion for DC-controlling or PWM-controlling an LED unit, and a disconnection detection portion for detecting disconnection of the LED unit. The disconnection detection portion has a latch circuit and a reset portion. The latch circuit provides a disconnection detection signal after it is detected that disconnection has occurred for a prescribed time. The reset portion resets the disconnection detection signal based on prescribed conditions.
Claims5
A lighting control device comprising:
- a current driving circuit portion for DC-controlling or PWM-controlling a semiconductor light-emitting element;
- and a disconnection detection circuit portion for detecting disconnection of the semiconductor light-emitting element, wherein, the disconnection detection circuit portion has a detection time setting portion and a reset portion,
- wherein the detection time setting portion is arranged to provide a disconnection detection signal when it is detected that disconnection has occurred for a prescribed time, and
- wherein the reset portion is arranged to reset the disconnection detection signal based on prescribed conditions.
1 more element
Dependencies are inferred from the claim text.