To provide a structure having high capability in heat dissipation to solve a problem of overheating during continuous lighting in a portable device.
A portable electronic device includes a body and an LED light source having a circuit assembly structure. The circuit assembly structure covers a substrate including an electric circuit for repeatedly turning on/off an LED. The LED is adjacent to a first major surface of the substrate and is connected to the electric circuit. A heat sink including an exfoliated sheet of compressed natural graphite particles is disposed to transmit heat to a second major surface of the substrate. In this case, the surface area of the heat sink is larger than that of the LED which is in contact with the substrate. The heat sink acts to repeatedly turn on/off the light source in at least two cycles within ten seconds while hardly increasing the maximum temperature between the cycles. Since the operating temperature is dramatically reduced while the power level is greatly increased, lighting can be improved and the operating life of an electronic component can be increased.
COPYRIGHT: (C)2007,JPO&INPIT
SMALC MARTIN D
LASER BRIAN J
KOSTYAK GARY S
SKANDAKUMARAN PRATHIB
GETZ MATTHEW G
FRASTACI MICHAEL
| JP2003101836A | 2003-04-04 | |||
| JP2004215223A | 2004-07-29 | |||
| JP2003338973A | 2003-11-28 | |||
| JP2005136224A | 2005-05-26 | |||
| JP2003324214A | 2003-11-14 | |||
| JP2005250441A | 2005-09-15 |
Yukitaka Nakamura
Konno Akio
Noritaka Yokota
Mari Asano
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