| 摘要 |
PURPOSE:To emit the light sufficiently from a phosphor film by means of a low voltage electron beam, by eliminating the aluminium film while arranging a light reflection board having specific structure between a phosphor film and an electron gun. CONSTITUTION:The electron beam 5 emitted from a cathode 10 toward a phosphor film 3 will pass through a central hole 15 of a light reflection board 16 then impinge against the phosphor film 3 as non-converging beam having predetermined diffusion angle to be determined by the diameter of a hole 12 made in the center of a grid 11, the gap between the grid 11 and the cathode 10, anode voltage, etc. to emit the light having the color corresponding to the phosphor film 3. Here the light 14 to be emitted to the electron gun 6 side is produced by the phosphor substance particle composing the phosphor film 3 for the light required for the observation or the light 13 emitted in front of the cathode ray tube. Said light 14 is reflected by a light reflection board 16 then passes through the phosphor film 8 and a face glass 2 and emitted in front of the cathode ray tube. Since the electron beam is not lossed by the aluminium film, the electron beam can completely contribute to the light emission. |
