To prevent an electric shock accident occurring as a socket in which a plug is not fitted among a plurality of sockets is touched with a hand by mistake.
A discharge lamp lighting device 8 includes the plurality of sockets which are attached to and detached from plugs fitted to lighting units 2, an external power source, a noise filter circuit 12, a rectifier circuit 13, a power factor improvement circuit 14, an inverter circuit 10, and a fitting state detection circuit 15 which detects a fitting state of the plugs and the respective sockets. The fitting state detection circuit 15 detects the fitting state of the lighting units 2 by connecting all switches SW1 to SW4 for fitting detection in series. The discharge lamp lighting device is made to start voltage supply to the lighting units 2 when the fitting state detection circuit 15 detects all the sockets being fitted to the plugs, and is not made to start the voltage supply to the lighting units 2 when the fitting state detection circuit 15 detects at least one of the sockets being not fitted to the plug.
KITAMURA JUNICHI
MORIBE NAOMI
HAMADA NAOYA
Makoto Suhara