Patent ID: 6069456
Filing Date: 2000-05-30
Classification: H01J

Abstract:
Lighting system, comprising a mercury-free metal halide lamp with a light yield of at least 75 lm/W and a colour rendition index of at least 75 and an electronic ballast which supplies AC voltage, the lamp comprising a discharge vessel into which electrodes are inserted in a vacuum-tight fashion, characterized in that the electronic ballast provides the lamp with a change in voltage during the polarity reversal at a rate of voltage change of at least 0.3 V/.mu.s, preferably at least 1 V/.mu.s, the filling comprising the following components:a buffer gas which also acts as starting gas to start the lamp,a voltage gradient generator, comprising at least one metal halide which vaporizes readily and which is responsible for generating a voltage gradient of at least 45 V/cm which preferably corresponds approximately to that of mercury, anda light generator comprising at least one metal halide and/or one metal.