| 摘要 |
<p>PURPOSE:To make a device small in size by using a flat fluorescent character display tube as a light source, and arranging this indication tube close to a shutter array. CONSTITUTION:A fluorescent character display tube 31 is provided on a shutter array 23 along the lengthwise direction of a light-transmissive slit so that this indication tube 31 is close to the shutter array 23 as much as possible. An anode 32 coated with fluorescent materials, filaments 33a and 33b, and a grid 34 between them are arranged in this fluorecsent character display tube 31, and they are covered with a glass 36 formed into a flat flume shape, and the inside is made vacuum. When a voltage is applied to filaments 33a and 33b and a negative voltage is applied to the grid 34 and the anode 32, thermoelectrons discharged from filaments 33a and 33b are accelerated by the electric field between the grid 34 and filaments 33a and 33b and collide with the anode 32, thus exciting fluorescent materials to emit light.</p> |
