| 摘要 |
PURPOSE:To obtain a light source for a facsimile able to illuminate uniformly with a high luminosity by arranging a cathode in a stretched form between a transparent front anode portion and a light shielding rear electrode portion both applied with phosphorous layers and having slits lengthwise and layed on internal surfaces of a front plate and a rear plate respectively. CONSTITUTION:A document 2 is placed on the front plate 3 of a vacuum fluorescent tube 1 and sent to the direction of an arrow mark, and a reflected light is photo- electrically converted by an image sensor 6 through a converging lens 4. The front plate 3 has transparency and insulation character, and a transparent anode conductor 7 is applied and formed upon it. Together with providing a slit 8 at a center part along the lengthwise direction of the conductor 7, a transparent phosphorous layer 9 is applied in order to form a front surface anode part A. The rear plate 5 has tran sparency and insulation character, and a light shielding anode conductor 11 having a slit 12 corresponding to the slit 8 is applied upon it. A phosphorous layer 13 is applied on the conductor 11 so as to form rear surface anode part B. A plurality of cathode 15 of a filament shape are stretched between anode parts A, B and are sealed tightly with side plates 10. Consequently, uniform illumination of a high luminosity can be performed with little power consumption. |
