Abstract: A circular scanning system for an integrated camera and catadioptric display has a photon camera tube with a scanning beam, a pixel clock generator for generating a pixel clock signal, a clock dividing arrangement for generating beam rotation signals, and a ramp signal generator for generating a beam radius transversing ramp signal being synchronous with the beam rotation signals. It also has an arrangement for generating a beam angle step signal for moving said beam in alternating interlaced frames and can accommodate a plurality of viewing stations, each directed to viewing a selected section of the image.

Abstract: An image intensifier with an internal power supply that produces 20,000-25,000 Hz. noise in the output screen voltage is provided with an additional power supply coupled to the output screen through an R-C filter which removes that noise. The additional power supply produces the screen voltage at a current that is a large multiple of the current produced by the output screen voltage of the internal power supply, so that the screen voltage from the additional power supply prevails over the screen voltage from the internal power supply. The additional power supply is regulated by an optical coupler which responds to the light input level to the image intensifier, as follows: at light inputs above about 5.times.10.sup.

Abstract: A color separation filter arrangement for an image intensifier having separate blue, green and red filters which respectively have pass bands for visible blue light and its second order wavelengths, visible green light and its second order wavelengths, and visible red light. The blue, green and red filters are interposed individually in succession in the path of incident visible light and infrared energy to the photocathode of the image intensifier. Use of this color separation filter produces a relatively high signal-to-noise ratio at the output of the image intensifier when it is used under night sky illumination.

Abstract: The photocathode of an image intensifier is protected from undue exposure to excessive incident light by a variable density filter whose density is controlled by an optical coupler. The optical coupler has an LED which conducts power supply current to the image intensifier and a phototransistor in the energization circuit of a filter driver which operates the variable density filter.

Abstract: A detection system for a doorway discriminates between persons who are authorized to go through the doorway and those who are not. An oscillator with a resonant L-C circuit includes metallic capacitor plates on opposite sides of the doorway to reduce the oscillator frequency when a person walks through and to provide a transient frequency increase if the person wears or carries a small metal object. A discriminating circuit is connected to the oscillator output to discriminate between persons in the doorway with and without such a metal object.

Abstract: This invention relates to a gas powered, closed loop power generating system which generates power substantially as a result of the flow of gas through its power generating means. Gas flows through the power generating means because of a pressure drop caused by dissolving the gas in a solvent medium on the exit side of the power generating means. The solution is then separated into the solvent medium, and the gas. The gas pressure is raised and it is then fed back into the power generating means while the separated solvent medium is recycled to redissolve more exiting gas. A process for generating power is also disclosed.