FLUORESCENT LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To improve luminous flux retaining ratio and prolong the life by suppressing the reaction of mercury ion with phosphors and a glass tube and suppressing deterioration of the phosphors and mercury elimination. SOLUTION: This fluorescent lamp 1 comprises a lighting circuit 2 to start lighting, a light transmissive conductive film 3 which is an electric potential applying member installed in the surrounding of the discharge plasma generated in the inside of a fluorescent lamp, an electric power circuit 4 for applying electric potential to apply higher electric potential to the light transmissive conductive film 3 than that of the discharge plasma. The electric power circuit 4 for applying electric potential and the light transmissive conductive film 3 are connected to keep the potential of the light transmissive conductive film 3 higher than the discharge plasma, so that an electric field in the direction from the tubular wall of a glass tube composing the fluorescent lamp 1 to the center part is generated and the density of the mercury ion in the peripheral part of the tubular wall. Consequently, the reaction of mercury with phosphors and the glass tube is suppressed and deterioration of phosphors and mercury elimination are prevented and the life of the fluorescent lamp 1 is prolonged.