| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp capable of preventing early breakdown and devitrification of a light emitting section.SOLUTION: A high-pressure discharge lamp 100 includes a light-emitting tube 104 which has a light emitting section 102 having a generally ellipsoidal shape; and a sealing part 103 extending at both sides of the light emitting section 102 sealing the base end of an electrode 101, in which the amount of mercury sealed in the light-emitting tube is within a range of 0.2 [mg/mm3] or more and 0.4 [mg/mm3] or less; and the rated power of the lamp is within a range of 355 [W] or more and 600 [W] or less. Defining the rated power as P[W]; the diameter of the light emitting section 104 at the intermediate point between a pair of electrodes 101 as D[mm]; the thickness of the light emitting section 104 at the intermediate point between the pair of electrodes 101 as X [mm], when 355<P≤380, when 5.4≤D≤5.8[mm] and 3.1≤X≤D-2.3380<P≤450, when 5.8≤D≤6.2[mm] and 3.1≤X≤D-2.7450<P≤600, the relational expressions of 6.2≤D≤6.6[mm] and 3.1≤X≤D-3.3 are satisfied. |
