| 摘要 |
PURPOSE:To sufficiently supply an operating current required for an image converter tube and reduce consumption of a battery as small as possible, by interrupting a continuous oscillator circuit through a switching element. CONSTITUTION:Light from a target object 1 irradiated by an infrared projector 16 or the like is focused by an objective lens 2 and imaged to a photoscreen 3 of an image converter tube 6. By this image, an optical current in accordance with a quantity of light is emitted from the screen 3, accelerated and focused by an electrode 4 to collide against a fluorescent screen 5. The screen 5 is excited by a colliding electron to emit light and the light is intensified by a magnifying glass 7 and can be observed by the naked eye 15. Negative high voltage required for the tube 6 is obtained in such a manner that primary voltage supplied by a battery 14 is applied by a power source switch 13 and oscillated by a continuous oscillator circuit 9 then the voltage is boosted to a requied level by a multi- stage rectifier circuit 8. Here a switching element 11 is turned on and off by a switching circuit 10 to interrupt a feed current and oscillation and enable the supply of a required current at high voltage. |
