GB786687A - A picture screen capable of providing a variable relief effect - Google Patents

Abstract

786,687. Local viewing. ROMOLI, M. Nov. 4, 1955, No. 31587/55. Class 40 (3). [Also in Group XX] In order to produce a three-dimensional picture from a projected still picture or cinematograph film a special screen is used comprising the ends 2 of a plurality of parallel rods arranged close together in a frame 1 and each capable of longitudinal displacement. Means are provided for moving each of the rods out of the frame to an extent determined by the amount of illumination falling on the end of that particular rod. Fig. 4 shows the construction of one of the rods and the means producing its movement. A photosensistive device 15 is incorporated in the rod end and causes deflection of a galvanometer 14 in accordance with the intensity of the illumination falling on the rod. A switch arm 12 attached to the galvanometer moves over a bank of contacts 11 coupled in sequence to electromagnets 8 mounted in the fixed support along which the rod slides. An insert of magnetic material 9 in the rod is drawn along the electromagnets whenever the arm 12 moves over the switch contacts and comes to rest above the energized magnet, thus moving the rod into a longitudinal position dependant on the amount of illumination falling on its end. In a modification (Fig. 5) a halfsilvered mirror 18 is inserted in the light path between the picture projector 17 and the screen 1. Instead of mounting the photosensitive devices 15 in the rods, they are mounted on a board 16 receiving the reflected light from the mirror. Each device is provided with its own galvanometer and switch controlling the movement of the corresponding rod in the manner above described. An advantage of this modification is that screens 21 can be provided to shield the board 16 from extraneous light.