| 摘要 |
A discharge lamp which is obtained by adding an emitter other than thorium to a cathode within an arc tube, and wherein early depletion of the emitter due to excessive evaporation from the cathode is prevented, while achieving stable lighting even at the initial lighting. A main body part (31) of a cathode (3) is configured from a high-melting-point metal material that does not contain thorium, and a front end part (32) thereof is configured from a high-melting-point metal material that contains an emitter (other than thorium). A sintered body (34), which contains an emitter (other than thorium) at a concentration higher than that of the emitter contained in the front end part (32), is buried in a hermetically sealed space (33) that is formed within the main body part (31) and/or the front end part (32); and the sintered body (34) and the front end part (32) are in contact with each other. |
