Patent ID: 6137229
Filing Date: 2000-10-24
Classification: H01J

Abstract:
A metal halide lamp comprisinga discharge tube of transparent ceramic in which a discharge metal is sealed, said discharge tube having a main cylindrical portion, ring portions provided at both ends of the main cylindrical portion, and tubular cylindrical portions provided at the ring portions; anda pair of electrodes inside the discharge tube;wherein a wall thickness .alpha. (in mm) of said main cylindrical portion satisfies the relation0.0023.times.W+0.22.ltoreq..alpha..ltoreq.0.0023.times.W+0.62,and a wall thickness .beta. (in mm) of the ring portions satisfies the relation0.0094.times.W+0.5.ltoreq..beta..ltoreq.0.0094.times.W+1.5,wherein W is the lamp power expressed in Watt.