Fluorescent display tube

摘要

A fluorescent display tube having a structure in which only filament-shape cathodes corresponding to required display regions are selectively supplied with electric power and in which elongated cathode attaching plates are disposed apart from one another on an end of an anode substrate, a first support member is secured to the first cathode attaching plate disposed inwards when viewed in the lengthwise direction of the cathodes, while a second support member is secured to the second cathode attaching plate disposed outwardly. Each support member has a base portion secured to the cathode attaching plate, a securing portion for securing the cathode and a connection portion for connecting the base portion and the securing portion to each other. The plural cathodes are stretched to run parallel to one another. A connection portion of the inner support member is longer than a connection portion of an outer support member. The two support members secure the ends of the cathodes at the same positions. Operation voltage is supplied to each of the first or the second cathode attaching plate so that the cathodes divided into two groups are individually operated. Positions at which ends of the cathodes are aligned so that an end cool effect is made to be uniform.