发明名称 |
Light emission control apparatus and light emission control method with temperature-sensitive driving current control |
摘要 |
A temperature profile storage unit stores a Vf-Ta table showing a relationship between a forward voltage Vf and am ambient temperature Ta of an LED element, and a Ta-Ifmax table showing a relationship between the ambient temperature Ta and a maximum tolerable current Ifmax. The forward voltage Vf of the LED element driven by a power supply is detected and fed to a feedback point determining unit. A temperature computing unit determines the ambient temperature from the detected forward voltage Vf. A driving current determining unit determines a maximum tolerable current Ifmax from the ambient temperature Ta thus determined, by referring to the Ta-Ifmax table, and supplies a command value defining a current to drive the LED element to a constant current source via a D/A converter. The constant current source adjusts the current to drive the LED element in accordance with the command value.
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申请公布号 |
US2005082553(A1) |
申请公布日期 |
2005.04.21 |
申请号 |
US20040969628 |
申请日期 |
2004.10.20 |
申请人 |
YAMAMOTO ISAO;TAMEGAI YOICHI |
发明人 |
YAMAMOTO ISAO;TAMEGAI YOICHI |
分类号 |
H01L33/00;H01L27/15;H05B33/08;H05B37/02;(IPC1-7):H01L27/15 |
主分类号 |
H01L33/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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