GB479617A - Improved apparatus for increasing the size and/or brightness of pictures produced by picture projection apparatus for television and other purposes - Google Patents

Abstract

479,617. Image intensifiers; television. SKAUPY, F. Sept. 24, 1936, No. 25953. Convention date, Sept. 24, 1935. [Classes 39 (i)] and 40 (iii)] Apparatus for increasing the size and/or brightness of an optical image, for television and other purposes, comprises a system of light-amplifying cells 1, each consisting of an envelope containing a light-sensitive cathode 2, a grid anode 4, and a fluorescent screen 5, which cells are so arranged that all the individual cathodes lie substantially in one plane to form a common surface on which is projected the image to be amplified, and all the fluorescent screens lie substantially in a second plane to form a common surface on which the final picture is produced. The cells are connected in parallel, the grids being connected to the positive pole of the common voltage source. and the cathodes to the negative. The cells may be of square section, and form a mosaic, as shown in Fig. 1 (Fig. 2 showing diagrammatically a single cell); or the separate cells may be in the form of long narrow tubes which extend over the whole length of the image. In the latter case, Fig. 3 (not shown), the grid may be adjacent to the fluorescent layer. The image, e.g. that formed in a cathode-ray television receiver, or an infra-red image, may be projected by means of a lens on the common light-sensitive cathode surface, or rays from a receiver (e.g. one having a mirror screw) may form an image directly on the cathode surface. A small number of tubular cells may be used. the length of which corresponds to that of the final picture. On such an assemblage, an image from a television receiver may be projected by a cylindrical lens system which greatly contracts one dimension of the image. The image formed on the fluorescent surfaces is projected on to a viewing screen by a similar lens system which restores the correct dimension ratio of the picture. The apparatus may be used also for television transmission, the picture to be transmitted being projected on the cathode surface of the cell system, the fluorescent surface of which is scanned. The Specification as open to inspection under Sect. 91 describes also an image-amplifying system comprising an assemblage of photoelectric cells having their cathodes arranged to form a common surface, and a corresponding set of cathode-ray fluorescence tubes, each of which may be in series with the corresponding photo-cell or may have a control electrode to which are applied the current variations of the corresponding photo-cell. The cathodes of the fluorescence tubes (which tubes may be distant from the photo-cells) may be incandescent, cold, or excited by light. This subject-matter does not appear in the Specification as accepted.