摘要 |
A long-life high-pressure discharge lamp suffers reduced blackening and luminance drop even after it has been turned on over a long period of time, and is arranged to prevent the internal gases from leaking out and also to prevent the lamp bulb from being ruptured. The high-pressure discharge lamp has a pair of confronting electrodes inserted in a lamp bulb which confines therein at least mercury and a halogen gas. The lamp bulb contains oxygen at a partial pressure lower than a partial pressure which can maintain a luminance of 80% after 100 hours of operation and equal to or higher than 1.0x10-5 Pa.
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