| 摘要 |
PURPOSE:To suppress the deterioration of the brightness of a fluorescent material due to long time display, by providing an electrode for long time display on which the potential lower than that of the display anode is applied then adhering the fluorescent material to it. CONSTITUTION:The grid 6 except the electrodes 6a, 6b for long time display is controlled between -10V and +2V, for example, while +50V is applied on the display anode 5 during the lighting. The display anode to be lighted is specified by said grid 6 then the electron from the cathode 7 is radiated to it to emit the light from said fluorescent member thus to display the desired number or figure. While the potential lower than the lighting potential of the display anode 5 or same potential with that of the grid 6, for example, is applied on the long time display electrodes 6a, 6b and simultaneously or separately from the display anode 5, it is continuously displayed as the line for partitioning the area displayed by said anode 5. Consequently the deterioration of the brightness of the fluorescent material due to the long time display can be suppressed thereby the service life of the fluorescent material can be made approximately same with that of the display anode. |
