| 摘要 |
PROBLEM TO BE SOLVED: To provide a long arc-type discharge lamp which is lighted stably for a long time by suppressing the exhaustion of an emitter (electron radiative substance) at an early stage and preventing melanism or white turbidity of a long and ultraviolet ray transmissive luminous tube, the long arc-type discharge lamp being lighted in an AC manner by oppositely disposing a pair of electrodes within the luminous tube, encapsulating a rare gas and a metal as a luminescent material and containing a rare earth oxide in the electrode.SOLUTION: When an average value of a lamp current is defined as I (ampere: A) and a volume for 3 mm from an electrode tip is defined as V (mm), 0.4≤(I/V)≤1.0 is established.SELECTED DRAWING: Figure 2 |
