High pressure discharge lamp apparatus

摘要

A high pressure discharge lamp apparatus comprises: a discharge tube and a current limiting device such as a choke coil connected in series for connection across an A.C. power source, and a pulse generator connected by its output terminal in parallel to the discharge tube, the apparatus is characterized in that: said pulse generator impresses reignition pulses on said discharge tube at least during a period defined as from a zero-cross point of the source voltage of the power source to a phase defined by a peak of reignition voltage of lamp voltage waveform when no reignition pulse is impressed on the discharge tube, thereby retaining lamp current of the discharge tube without forming zero-current period, thereby the lamp is stably lit with such a high lamp voltage as is almost equal to the power source voltage and the power of reignition pulse can be saved without harming stability of lighting. Thus a stable lighting of the high pressure discharge lamp with a a high power efficiency becomes possible.