SINGLE ENDED HIGH INTENSITY DISCHARGE LAMP WITH A SPECIFIC VOLUME

摘要

A high intensity discharge lamp includes an envelope formed of vitreous high temperature resistant material, and a pair of electrodes each having a metal rod and an arc supporting electrode, each of the metal rods being sealed at one end of the envelope. The lamp further includes a portion for adjusting the temperature at the wall of the envelope adjacent to the arc supporting rods, to minimize the differences in the wall temperature under different lighting postures of the lamp, whereby the luminous efficiency of the lamp is substantially independent of the lighting postures of the lamp.