Patent ID: 8575837

Claim:
A high pressure discharge lamp comprising: a light-emitting bulb including a light-emitting part, and first and second sealing sections interposing the light-emitting part; first and second metal foils embedded in the first and second sealing sections, respectively; first and second electrodes each having one end protruding into the light-emitting part and having the other end embedded in the corresponding one of the first and second sealing sections and joined to the corresponding one of the first and second metal foils; and a sub-mirror covering at least a portion on a second electrode side of the light-emitting bulb without covering the first electrode side of the light-emitting bulb, wherein the light-emitting bulb comprises quartz glass, and an embedded length L (mm) of the second electrode that is defined as a distance from a border section between a protruding section and an embedded section of the second electrode to a light-emitting part side end of the second metal foil, and a temperature T (° C.) at a joint region of the second electrode and the second metal foil during a discharging of the lamp satisfy 1.8≦L≦2.8 and T≦970 so that the quartz glass and the second metal foil do not detach by the discharging of the lamp.