| 摘要 |
PURPOSE:To obtain a new fluorescent light-source tube, in which any grid is not needed, by providing lead-out electrodes and focusing electrodes in the fluorescent light-source tube, in which a phosphor provided on an anode emits light by a cathode luminescence. CONSTITUTION:When lead-out electrodes 9a and 9b are biased positively to a cathode 6, and an arbitrary anode and external lead 2 which is led outside a vacuum case is biased positively to the cathode 6, thermions 11 flow out of the heated cathode 6. After that, when focusing electrodes 10a and 10b are biased negatively to the cathode 6, the thermions 11 led out of the cathode 6 are attracted toward the anode 2, the density of current flowing into a phosphor 3 increases, and the efficiency of the current increases. The above electrodes 9a and 9b and focusing electrodes 10a and 10b are made by forming an insulator layer 4 on the anode 2 by thick-film printing, and providing Ag or graphite on the layer 4 by thick-film printing. |
