| 摘要 |
PURPOSE:To make the life of a discharge lamp equal to the life obtained at the rated output by setting the luminescent spot temperature to the specific temperature or lower when lighting at the high output the discharge lamp driven with the high frequency by the two-luminescent spot lighting. CONSTITUTION:The life of a discharge lamp is ended at the time when the emitter oxide of a filament has been evaporated, and the evaporation speed of an emitter is determined by the luminescent spot temperature. When the high output lighting of 150% of the one-luminescent spot lighting is performed by the two-luminescent spot lighting in a lighting system in which a discharge lamp with the rated output of 40W is lit with the high frequency of 30kHz or higher, the life of the discharge lamp is equal to that obtained by the one- luminescent spot lighting if the luminescent spot temperature is 1050 deg.C or lower as calculated by the Richardson-Dushmann equation indicating the relationship between the emitter evaporation speed and the luminescent spot temperature. In the actual example, the life of the discharge lamp by the two-luminescent spot lighting when driven with the frequency of 30kHz is longer than the life of 8000hr obtained by the one-luminescent spot lighting. |
