Discharge lamp lighting device

A discharge lamp lighting device comprising:

• a lamp socket including a pair of main electrodes for connecting a discharge lamp;
• a stabilizing circuit connected to a power source and outputting a first voltage and a second voltage that is lower than said first voltage;
• a starting circuit that is connected between said stabilizing circuit and said lamp socket, being activated when said first voltage is input from said stabilizing circuit to discharge said discharge lamp by generating a high voltage required to start said discharge lamp discharging, and being deactivated when said second voltage is input thereto after discharging begins, connecting said stabilizing circuit directly to said lamp socket to stably discharge said discharge lamp;
• means for deactivating said starting circuit in response to installation or non-installation of said discharge lamp to said lamp socket;
• and
• said deactivating means including an auxiliary electrode to deactive said starting circuit when said discharge lamp is not installed by interrupting a connection between said auxilialy electrode and one of said pair of main electrodes, and activating said starting circuit when said discharge lamp is installed by connecting conductively said auxiliary electrode and said one of said pair of main electrodes.

A discharge lamp lighting unit comprising

• a lamp socket member for connecting a discharge lamp;
• a case comprising a high voltage transformer housing and a main igniter circuit housing;
• a high voltage transformer housed in said high voltage transformer housing and forming part of a main igniter circuit embedded in a filler;
• and
• said main igniter circuit housed in said main igniter circuit housing and embedded in the filler.