HIGH-PRESSURE MERCURY LAMP AND HIGH-PRESSURE MERCURY LAMP LIGHT EMISSION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a high pressure mercury lamp that is lit at an inside pressure not less than a hundred and tens atm. and is excellent in thermal load and air convection. SOLUTION: This high pressure mercury lamp has a structure wherein an electrode 4 located on the upper side and an electrode 5 located on the lower side are arranged opposite to each other in a discharge container 2 formed from quartz glass and the discharge container 2 is filled with 0.155 mg/mm<3> or more of mercury and a rare gas; and has a feature that a length L1 (mm) at which the electrode 4 located on the upper side is projected into the discharge container 2 is larger than a length L2 (mm) at which the electrode 5 located on the lower side is projected into the discharge container 2, and lamp power W (W) and the maximum value D (mm) of the inside diameter in a direction perpendicular to the axis combining both the electrodes 4, 5 in the discharge container 2 satisfy 0.39×(W)<1/2> <=L1<=0.81×(W)<1/2> and (W/46)<1/1.21> <=D<=(W/1.8 5)<1/3> .