A device for lighting a discharge lamp has a drive circuit to feed
alternating power the discharge lamp, and a control circuit. The control
circuit controls the drive circuit by a drive pulse to perform a burst
dimming control over the discharge lamp. The control circuit has
detector, subtractor, a digital filter, and pulse generator. The
subtractor subtracts the detected lamp current by the detector from a
reference value. The digital filter integrates the output of the
subtractor as an integrator. The pulse generating means generates the
drive pulse based on the output of the digital filter. The lighting time
period has a first time period immediately after a start of the lighting
time period and a second time period following the first time period. The
control circuit sets the reference value to a target current value in the
second time period. The control circuit increase the reference value in
the first time period to the target current value until an end of the
first time period. The digital filter retains the output obtained at an
end of the lighting time period until a next lighting time period starts.
The control circuit adjusts the lamp current to the target current value
during the lighting time period.