PURPOSE: To realize a high-brightness and uniform fluorescent character display at low power consumption, and achieve compactness of the whole body of a device by setting a distance between a filament and a fluorescent character display part to be small.
CONSTITUTION: A fluorescent character display part 26 is formed on a glass substrate 22 composing a lower surface of a flat vacuum container 21 through an anode 25, and a semiconductor chip 28 for driving is mounted on it. The fluorescent character display part 26 is covered with a mesh of a grid 27, and the semiconductor chip 28 is covered with a shield cover 30 provided over the glass substrate 22 to be protected. This shield cover 30 is also provided with function as a filament support electrode by fixing one end of a filament 31 disposed on the grid 27 with it. A fixing position of the filament 30 can thus be a desired position on the same level as an upper surface of the shield cover 30 or lower than that, and the whole tube length can be short.
FUJII TETSUO
KOBAYASHI MASAAKI
KANI YASUYUKI
MATSUMOTO SHUNICHI
ENDO NOBORU
MORI JUN
NORITAKE CO LTD
KYUSHU NORITAKE KK