| 摘要 |
PROBLEM TO BE SOLVED: To reduce cost, by miniaturizing a lighting device, by reducing the number of part items, in the lighting device used by switching a plurality of DC power circuits. SOLUTION: The DC power circuits 111 and 112 generate DC voltage. A power source selecting circuit 160 selects one from the DC power circuits 111 and 112, and operates the selected DC power circuit. A light source circuit 140 turns on a light source by inputting DC voltage generated by the DC power circuit selected by the power source selecting circuit 140, A current detecting circuit 150 measures an electric current flowing in the light source circuit 140, and generates first detection voltage and second detection voltage. The DC power circuit 111 generates the DC voltage having a voltage value determined based on a voltage value of the input second detection voltage by inputting the second detection voltage generated by the current detecting circuit 150. The DC power circuit 112 generates the DC voltage having a voltage value determined based on a voltage value of the input first detection voltage by inputting the first detection voltage generated by the current detecting circuit 150. COPYRIGHT: (C)2009,JPO&INPIT
|
