COLD CATHODE FLUORESCENT LAMP

摘要

PROBLEM TO BE SOLVED: To provide a cold cathode fluorescent lamp starting without the existence of outside light and generating no variation of characteristics during the duration of life by making the shape of a cold cathode 3 cylindrical, forming a metal film 5 comprising an exoelectron emissive material at only the inner end part on the outer circumferential surface, and specifying a gap h to a glass bulb 1. SOLUTION: A pair of cylindrical cold cathode 3 is sealed to both end insides of the glass bulb 1. The gap h between the outer circumferential surface of the cylindrical cold cathode 3 and the inner circumferential surface of the glass bulb 1 is set so as to keep the relation of 0<h<=0.15 mm. The metal film 5 comprising the exoelectron emissive material is formed over the whole circumference of the inner end part on the outer circumferential surface. The metal film 5 comprising the exoelectron emissive material is composed of one kind of a Cs compound or a mixture of two or more kinds of Cs compounds. The forming amount of the metal film 5 is 0.1-1.2 mg.