Lamp with improved color rendering

摘要

A discharge lamp for providing visible radiation includes a lamp envelope which is made of light transmissive material a fill in the envelope including either calcium halide or strontium halide together with either elemental sulfur or elemental selenium in gaseous form which is obtainable when the fill is excited by sufficient power in operation, in an amount such that the excited fill emits a discharge of visible radiation from the fill with substantially all of the radiation being molecular radiation which is emitted in the visible region of the spectrum. The calcium halide or strontium halide operates at a vapor pressure which provides a significant amount of radiation in the red region of the spectrum therefrom and the overall spectrum has a color rendering index of about 87 or more.