WO2008120172A3 - Gas discharge lamp comprising a mercury-free gas fill - Google Patents

Abstract

A discharge lamp comprising a light-transmitting discharge vessel enclosing, in a gas-tight manner, a discharge space comprising a mercury- free fill, the mercury- free fill comprising a molecular radiator compound, selected from the group of metal halides of ruthenium(III), osmium(III,IV), rhodium(III) and rhenium(III), wherein the halide is selected from the group of chloride, bromide and iodide and combinations thereof, and a buffer gas for aiding in starting and buffering the discharge, the discharge lamp further comprising discharge means for igniting and maintaining a discharge in the discharge space emits radiation in the visible range as well as possibly in the UVA range. The visible radiation spectrum is of the cold- white type, while radiation in the UV range is reduced in comparison to mercury-dosed lamps. Losses in visible light, e.g. by Stokes' shift, are thereby reduced and less energy is wasted by radiative output in the ultraviolet. Another advantage of this lamp technology is that it does not require the use of mercury vapor, which is an environmentally hazardous material with known human toxicity. It is therefore environmentally safe.