To provide a discharge lamp lighting device capable of improving on deterioration of a color rendering property by restraining changes of color temperature at light control.

On the discharge lamp lighting device made to light a discharge lamp 7 by outputting a rectangular wave from a full-bridge type inverter 4 after converting direct current voltage into an optional current and voltage by a chopper circuit 3, a control part 5 controlling a step-down chopper circuit is arranged, and a drive control signal driving the step-down chopper circuit is made to output from the control part so that a time dependent ratio of the current value of the driving signal is repeatedly output from the step-down circuit at every period corresponding to a half cycle, by making the output current of the step-down chopper circuit synchronize the timing of the signal with the rectangular wave form driving the inverter, and by changing the time dependent ratio of the output current at the period corresponding to the half cycle of the driving current.

COPYRIGHT: (C)2005,JPO&NCIPI