LIGHTING DEVICE

摘要

PURPOSE:To prolong the life of a gas discharge lamp by preventing losing alkali metal included in a sealed gas, from the inside of the gas discharge lamp. CONSTITUTION:An alkali metal halide is sealed in an arc tube body 2 of a gas discharge lamp 1. A reflecting body 3a is arranged optically opposite to the gas discharge lamp 1. An opposite surface part 6 of the reflecting body 3a facing the gas discharge lamp 1 is coated with a dielectric having transparency to be in an electrically insulated condition.