| 摘要 |
PROBLEM TO BE SOLVED: To efficiently suppress generation of a surge current while suppressing an increase in the number of components and complication of a circuit. SOLUTION: A DC-DC conversion circuit 120 (a lighting circuit) generates DC power. A light source circuit 300 includes a light source 310 which is lighted by DC power generated by the DC-DC conversion circuit 120. A switch circuit 140 can cut off the DC power supplied from the DC-DC conversion circuit 120 to the light source circuit 300 through between the DC-DC conversion circuit 120 and the light source circuit 300. The switch circuit 140, while transiting from an off state (a cut-off state) to an on state (a conduction state), impedance gradually decreases from high impedance in an off state and reaches low impedance in an on state. COPYRIGHT: (C)2012,JPO&INPIT |
