Patent ID: 6515406
Filing Date: 2003-02-04
Classification: H01J

Abstract:
A short-arc high-pressure mercury vapor discharge lamp comprising a pair of discharge electrodes opposed to each other in an arc tube and enclosing only mercury and a rare gas in said arc tube, wherein:said high-pressure mercury vapor discharge lamp is so constructed as to be operated at a lamp current of 1.5 A or higher; the distance between said electrodes and the rated power are set so that the rated power per unit arc length P/d (W/mm) is such that P/d&gE;88 (W/mm), where d (mm) is the arc length and P (W) is the rated power; and the amount of fill material, the shape of said arc tube, the cross sectional area in the vicinity of tips of said electrodes, the distance between said electrodes, and the rated power are set so that the rated power per unit volume of a discharge arc formed between said electrodes EÂ·j (W/mm3) is such that EÂ·j&gE;700 (W/mm3), where E (E=V/d) (V/mm) is the lamp voltage per unit arc length, V (V) being the lamp voltage at stable operation and d (mm) being the arc length, and j (j=I/Se) (A/mm2) is the current density at the tips of said electrodes, I (A) being the lamp current at stable operation and Se (mm2) being the cross sectional area in the vicinity of the tips of said electrodes.