| 摘要 |
PROBLEM TO BE SOLVED: To provide a constant current light emitting diode drive circuit for saving space and cost by providing a function of a constant current circuit to a transistor device used for switching of a light emitting diode. SOLUTION: The light emitting diode drive circuit 50 stably supplies a sufficient constant current to a light emitting diode D with an extremely simple circuit configuration of a transistor device Q and an emitter resistance R. Since the light emitting diode drive circuit 50 utilizes the transistor device Q used for switching of the light emitting diode D also as a constant current circuit, space for parts for the constant current circuit are hardly required, resulting in cutback of space and cost. COPYRIGHT: (C)2010,JPO&INPIT
|
