Improvements in arrangements for producing and viewing optical images produced by electron bombardment of fluorescent screens

摘要

542,245. Electronic image reproducers. ELECTRIC & MUSICAL INDUSTRIES, Ltd., McGEE, J. D., and LUBSZYNSKI, H. G. June 27, 1940, No. 10948. [Classes 39 (i) and 40 (iii)] An arrangement for producing and viewing optical images comprises an electron discharge device having a screen adapted to be rendered luminescent by electron bombardment, means for producing stream from a image of pre-determined size, and means for causing said stream to produce on said screen an optical image which is reduced in size with relation to the original image, and an optical lens or lens system for viewing the reduced image with magnification. In the arrangement shown in Fig. 1, an image 6 is focused by a lens 5 on a photo-cathode 1 at one end of a vacuum tube 2 provided with a tubular anode 7 and a fluorescent screen 3 at the other end and surrounded by a focusing coil 8. The electron stream from the cathode is focused to form a reduced image on the screen 3, and this fluorescent image is viewed through a magnifying optical system 4. A second focusing coil may be arranged nearer the cathode to reduce the divergency of the beam to be converged by the coil 8. In a modification, Fig. 2 (not shown), tubular electrodes are provided to focus the beam electrostatically.