High-pressure mercury-vapour lamp and emission apparatus for a high-pressure mercury-vapour lamp

摘要

The object of the present invention is to provide a high-pressure mercury lamp which is lit at an internal pressure equal to or more than a hundred and several ten times the atmosphere and for which thermal load and gas convection are considered. Particularly, there is provided the tube of a high-pressure mercury lamp which is vertically lit and considers the above problems. The present invention is characterized in that: a positive electrode 4 located on the upper side and a negative electrode 5 located on the lower side are oppositely arranged in a discharge container 2 formed of quartz glass; mercury and a noble gas of 0.15 mg/mm3 of more are filled in the discharge container 2; the length L1 (mm) of the positive electrode 4 projecting in the discharge container 2 is larger than the length L2 (mm) of the negative electrode 5 projecting in the discharge container 2, and their relationship with lamp power W is expressed by 0.35 x (W)SP1/2/SP ≤ L1 ≤ 0.69 x (W)SP1/2/SP and L2 ≤ 0.76 x (W)SP1/2.64/SP; and the relationship with the maximum value D (mm) of the inside diameter in the direction perpendicular to an axis connecting both the electrodes 4, 5 in the discharge container 2 is expressed by (2.5)eSP0.0022w/SP ≤ D ≤ (5.0)eSP0.0034w/SP.