| 摘要 |
<p>In a high-pressure discharge lamp, when a vacant space (25) around an electrode (18) has an open area set to SN (mm2) and a discharge space has a maximum cross section set to Ss (mm2), the vacant space is set so as to obtain a diaphragm value in a range of 0.002 ≤ SN/Ss ≤ 0.03 and a low temperature distribution is set in the vacant space, thereby forming a pressure adjustment mechanism, a low load start mechanism, a halogen buffer mechanism, and an impurities getter mechanism. Thus, it is possible to absorb irregularities of the discharge vessel volume and pressure fluctuation, mitigate load at start, compensate the lowering of halogen as the time elapses, and trap impurities, thereby providing a high-pressure discharge lamp having a long service life and high stability. Moreover, by setting the temperature of the vacant space always at a low temperature, it is possible to reserve factor substance and suppress crystallization/blacking of the discharge lamp.</p> |
