A device which improves the starting of a high pressure discharge lamp containing
a large amount of mercury, in which the amount of mercury adhering to the lamp
electrodes is not the same, by shortening the formation time of the glow discharge
in order to reduce the sputtering of the electrodes to a minimum. When the discharge
lamp starts, an AC voltage with rectangular waves produced by the full bridge circuit
is applied to the discharge lamp. Next, a high voltage pulse is superimposed and
applied by an igniter device; the pulse is synchronized to the polarity of the
above described AC voltage with rectangular waves. As a result, an alternating
current discharge is started in the discharge lamp. Then, the ON/OFF state of the
switching devices in the full bridge circuit is fixed and a direct current voltage
is applied to the lamp. After a pre-selected time has expired after the transition
into direct current operation, the full bridge circuit is operated such that rectangular
alternating current waves form. The AC voltage with rectangular waves is then applied
to the discharge lamp and a transition into steady-state operation is carried out.
