Abstract: A method for providing user adjustable variable gain for a night vision device which utilizes an image intensifier tube, wherein the image intensifier tube has a given life expectancy, the image intensifier tube is subjected to factory calibration for providing an optimum output during operation, wherein the calibration undesirably differs from tube to tube and is adjustable by variable control means coupled to the tube, whereby when one tube is substituted for another the difference in calibration causes non-optimum performance, the method including the steps of: determining minimum and maximum gain limits associated with the optimum output of the night vision device; factory calibrating gain limiting means according to the determined minimum and maximum gain limits, wherein the gain limiting means are associated with the image intensifier tube and for limiting the variable control means; and, tethering the gain limiting means to the image intensifier tube.

Abstract: An improved image intensifier tube having electrically operative components that include a photocathode having a photoemissive layer, a microchannel plate having a conductive input surface and a conductive output surface, and a vacuum housing for retaining the photocathode, the microchannel plate and a fiber optic inverter in a predetermined arrangement within an evacuated environment, the fiber optic inverter having a phosphor screen for receiving the electrons emitted by the cathode and converting the electrons into a visual image, the improvement therewith comprising a ring assembly disposed in the housing comprising first and second rings, the first ring being a metallized snap ring conductively contacting the input surface of the microchannel plate for providing electrical contact to and retaining the plate within the housing, the second ring being a metallized ceramic ring having a first chamfered metallized surface in electrical contact with the metallized snap ring and a second metallized surface oper

Abstract: An image intensifier tube having a conductive coating for draining away accumulated electrons that cause the image intensifier tube to lose resolution. The conductive coating is formed on the insulating surface of the image intensifier tube microchannel plate. The conductive coating is formed from the evaporation of cathode sublimation products which include barium, nickel and tungsten.