Discharge lamp-lighting apparatus

摘要

An apparatus realizes the straight discharge arc during the whole lighting period , as well as provides a discharge lamp-lighting apparatus which can form a plurality of luminous intensity distribution patterns by changing the shape of the discharge arc. by supplying the lighting waveform having the acoustic resonance frequency component which excites the mode to make the discharge arc straight, which is determined by the sound velocity in the discharge space medium and the length of the section orthogonal to the electrode axis to the discharge lamp, the shape of the discharge arc at the time of rated lighting can be made substantially straight, and by supplying the lighting waveform which amplifies the amplitude of the compressional wave emitted from the discharge arc during the period when the vapor pressure of the filler of the discharge lamp is low , which is the lighting waveform having the acoustic resonance frequency component changing according to the change of the lamp characteristics , the shape of the discharge arc can be made straight during the whole lighting period, and by changing the ratio of the acoustic resonance frequency component, the shape of the discharge arc can be changed. <IMAGE>