COLD-CATHODE DISCHARGE TUBE

PROBLEM TO BE SOLVED: To enable to irradiate with high illuminance by setting specialized paper and a phosphor as near as possible in a certain printer. SOLUTION: It is so constructed that a glass sealing tube 1 for rare gas to be sealed inside is formed into a flat tube with a radial direction cross section almost oval, of which, the inner face except one shorter-radius face to be an aperture 3 is coated with a phosphor 2, and on the outer face, a pair of outer electrodes 4 are fitted for a whole length along an axis direction and on the shorter-radius face to form a luminous window 5. Since a width in a short radius direction is small enough, it does not take much space and irradiates a line light toward outside from the flat face, so that, ultraviolet rays emitted from the phosphor can be irradiated strongly and effectively on an irradiated face. COPYRIGHT: (C)2004,JPO