Abstract:
Disclosed is a metal halide discharge lamp which essentially permits disusing mercury. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide and a rare gas, the first halide being a halide of a metal which achieves a desired light emission, the second halide having a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide, and acting as a buffer gas.
Abstract:
A metal vapor discharge lamp whose near-infrared radiation is stronger than a conventional high-pressure discharge lamp, a projector utilizing this discharge lamp, and a metal vapor discharge lamp lighting device are disclosed. The metal vapor discharge lamp comprises a refractory light-transmitting hermetic vessel, a pair of electrode fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a halide and a rare gas. Most of the light irradiated when the discharge lamp is in the ON state has near-infrared wavelengths (750-1100 nm).