GB960093A - Projection apparatus for presenting information - Google Patents

Abstract

960,093. Film-strip projection apparatus. M. M. LEVY. March 12, 1963 [March 13, 1962], No. 9823/63. Heading G2J. In projection apparatus for simulating the operation of a post office coding machine, a film strip is used in which the serially arranged frames 102, 103 &c. are successively projected on to screen 113, each frame containing two separate, different images such as A, N in Fig. 1 arranged so that each frame has one image identical with an image of one adjacent frame and a second image identical with an image of the other adjacent frame. By this means, each image is projected twice. The operator records the images seen, which may be letter addresses, in coded form on keyboard 201 and his choice of code is compared automatically with the correct code 111 simultaneously projected with images A, N on to photo-sensing elements 208. In the projector 150 film strip 10 is wound from spool 11 to spool 17 passing over tension rollers 12, 99, loop-forming sprockets 13, 98, through gate 15 and over drive sprocket 16, lamp and lenses 80, 81 projecting images A, N &c. on to sections 114, 115 respectively of screen 113. Various methods of arranging images A, N and their codes, as the film are given. As shown in Fig. 7, sprocket 16 is driven by motor 20 through a geneva mechanism 19 powered by a clutch 22 operated by solenoid 51. On the output side of clutch 22 is a cam 21 operating shutter 23 and micro-switch 24 which controls another solenoid 26 operating clutch 27 to drive loop forming sprockets 13, 98 through differential 28. Motor 20 drives clutch 27 through belt 61. Shutter 23 cuts off light during the single frame advance which is controlled by a relay 50 energizing solenoid 51 and a further solenoid 52 used to remove lock 61a on clutch 27. For fast forward or reverse operation, relay 55 energizes solenoid 53 to release the lock 60 which, during single frame operation, locks the shaft at fast running motor 32. The relay 55, also energizes solenoid 39 to move guides 15 to disengage the film from drive sprocket 16, and extends roller arms 37, 96 to support the free length of film between loops 75, 76, during fast running. Centrifugal switch 56 operates solenoids 39, 53 as long as motor 32 is running. A schematic diagram of the control circuit is given, in which the operators code selection is compared with the correct code, and errors are recorded and/or displayed. If the errors exceed a certain rate, the film is reversed and the exercise repeated. In another mode of operation, an error causes the device to stop.