| 摘要 |
PURPOSE:To prolong the life of a discharge lamp by enhancing the neon partial pressure in a luminous tube like a metal halide lamp, etc., by a certain amount above the neon partial pressure in an outer tube in order to stabilize the starting characteristics. CONSTITUTION:Ne-N2 mixed gas with a certain pressure is enclosed in an outer lamp 1 like a metal halide lamp, etc., while Ne-Ar which is the mixed rare gas including neon is enclosed in a luminous tube 2 together with a certain amount of mercury, scandium iodide and sodium iodide, then the Ne partial pressure in the luminous lamp 2 is made higher than the Ne partial pressure in the outer tube 1 by 50-60%. Therefore, Ne in the luminous lamp 2 being in durability limit flows into the outer tube 1 positively and the ratio of Ne-Ar remaining in the luminous lamp 2 is gradually enhanced in the lapse of burning time, so the concentration of arc spot of discharge at the beginning time is facilitated, resulting in improvement of the starting characteristics and extension of the life of the lamp. |
