| 摘要 |
PURPOSE:To prevent the lowering of the luminous intensity of Sc and the rise of arc reignition peak voltage during life performance by filling specific amounts of ScI3 and metallic Sc in a lamp with a luminous tube into which at inert gas, Hg, ScI3, and NaI are to be filled. CONSTITUTION:The output bulb 1 of transparent glass is housed with the discharge lamp luminous tube 2 provided with the main discharge electrodes 3 and 4 and the auxiliary electrode 5 to form a metal halide lamp. The luminous tube 2 is enclosed with Ar as a starting inert gas, given amounts of mercury and NaI, 2.6X10<-3> mili moles/1cm of arc length of ScI3, and 0.1-1mole ratio (on the basis of the amount of ScI3 enclosed) of metallic Sc. Thus, the lowering of the output of a light with a wave length of 4,000-6,900Angstrom from Sc during life performance can be prevented and also the rise of the arc reignition peak voltage due to the generation of free iodine can be eliminated. Thus, the going-out pnenomenon can be prevented. |
