GB729546A - Method and apparatus for optically projecting electron images - Google Patents

Abstract

729,546. Cathode-ray tubes. FRIES, G., and INGLESBY, J. C. VREDENBURG-. July 29, 1952 [July 31, 1951], No. 18118/51. Class 39 (1). A photo-electron image is concentrated onto alkali halide crystals on an endless movable film or disc through which light is thrown to give a visible picture. An electron beam is concentrated onto a different part of the film or disc to remove the electric charge on the crystals. Light from a lamp 25 is concentrated by the condenser 26 through a sensitized part 4 of the disc 1 and the lens 27, and is then reflected by the mirror 29 onto the translucent screen 30, or by rotation of the mirror by a knob 32 onto the reflecting screen 35. The band 1 is driven in a discontinuous manner by a motor 14 through a worm wheel 15, gear wheel 16, the rotatable pin 17 and Maltese Cross 18 which is fixed to the shaft 13. The light beams from the reflector 36 and the lamp 25 can be interrupted by mechanical shutters. Alkali halide is vapourdeposited in discrete parts 2 on the lower side of the glass or mica disc and the image from a cathode-ray tube 43 is concentrated by lenses 37, 38 onto the photo cathode 21. The photoelectrons are concentrated by the electrodes 22, 23 onto an image sector 2. The electron lenses may be electrostatic, magnetic or electromagnetic. For the projection of a coloured image filters 11, 12 are fixed to the shaft 13. The sectors are coated with chloride of sodium, lithium, potassium or rubidium, the bromide of sodium or potassium, the fluoride or iodide of potassium to give red, blue and green filters, and are provided with a protective layer as described in Specification 715,480. The disc can be moved continuously, and the electron image may then have a similar movement of translation. Alternatively, a sensitized film can be carried in a step-wise manner through a Lenard window in the cathode-ray tube 43. The image carrier 1, when constructed as a flexible film, can have the different parts which are exposed to the light and electron beams moved at different rates or intermittently. For the production of colour prints, the sensitized plates are arranged at the parts 30, 35; a cathode sensitized with caesium is preferable. X-rays, heat radiation, such as that from the human body or an engine, and infra-red radiation can be recorded onto a cinematographic film or a screen. The infra-red rays or the light rays from a mirror telescope are reflected onto the photo-electric cathode by a mirror which is mountable in gimbals.