メタルハライドランプ and a lighting device using the same

文件类型：PDF文档
文件大小：717K
The arc tube 3 comprises : a translucent ceramic envelope 19 including a central tube 16 having an inner diameter of 5.5 mm or more, thin tubes 18 formed, on contact with joining portions 17 , onto both ends of the central tube 16 , and at least one rare earth halide enclosed therein; and electrode inductors 24 and 25 inserted and sealed in the thin tubes 18 . In a cross section of the arc tube 3 along a plane including the axis X in the longitudinal direction, an angle alpha between the straight-line section of the inner surface of the central tube 16 and that of each joining portion 17 is set to 85°-115°. Clearance gaps 26 are formed between the thin tubes 18 and electrode inductors 24 and 25 . The curvature radius of the inner surface of each boundary region 20 between the central tube 16 and joining portions 17 is set to 0.5 mm-2.5 mm.