Patent ID: 6469446
Filing Date: 2002-10-22
Classification: H01J

Abstract:
Mercury-free metal halide lamp with a warm white luminous colour and a high colour rendering index Ra, the lamp comprising a discharge vessel into which electrodes are introduced in a vacuum-tight manner and with an ionizable fill in the discharge vessel, characterized in that the fill comprises the following components:an inert gas which acts as a buffer gas, a first group of metal halides (MH), the boiling point of which is over 1000Â° C., the first group comprising at least Dy and Ca used simultaneously as metals, and the molar ratio of the two metal halides Ca-MH:Dy-MH being between 0.1 and 10; a second group of metal halides, the boiling point of which is below 1000Â° C., the second group comprising at least one of the elements In, Zn, Hf, Zr as metals; the total fill quantity of the first group of metal halides being between 5 and 100 &mgr;mol/cm3; the total fill quantity of the second group of metal halides being between 1 and 50 &mgr;mol/cm3; the colour temperature being between 2700 and 3500 K; the general colour rendering index being at least Ra=90, while at the same time the red rendering index is at least R9=60.