HIGH-PRESSURE DISCHARGE LAMP, LIGHTING EQUIPMENT, AND HIGH-PRESSURE DISCHARGE LAMP DEVICE

摘要

This invention provides a high-pressure discharge lamp characterized by comprising a light transparent hermetically sealed vessel having a discharge space in its inside, electrode means for inducing discharge within a discharge space in the light transparent hermetically sealed vessel, and an ionization medium sealed in the light transparent hermetically sealed vessel, including a metal halide and a rare gas, the metal halide including a halide of at least one of thulium and holmium, of which the sealing ratio to all the sealed metal halides is not less than 30% by mass, the rare gas being xenon (25ºC, 3 atm or higher), any metal halide for lamp voltage formation and mercury being substantially absent within the light transparent hermetically sealed vessel.