GB1317926A - Display apparatus - Google Patents

Abstract

1317926 Matrix displays SCIENCE ASSOCIATES Inc 13 Aug 1970 [14 Aug 1969] 39001/70 Heading G5C A display device comprises a panel containing a plurality of passages extending therethrough, a plurality of cavities intersecting the passages and closure members in each cavity which can be moved into and out of the passages by selecting means which also move the panel. Panels 50 are connected by shafts 51 to form an endless belt mounted in a housing on sprockets 52, 60 of drive and idler shafts 46, 47. The sprockets engage rollers 56 at each end of shafts 51 and adjacent guide rollers engage in channels of the housing. An array of fluorescent lamps in front of a reflector is mounted within the belt. Each panel comprises inner and outer members 71, 70 secured together each with a plurality of cone shaped apertures 73, 74 extending through to internal recesses 75, 76. The aper - tures are covered on at least one side by a light diffusing plate 128. Each upper recess 75 has a lower arcuate edge (79) Fig. 7 (not shown) and contains a closure disc 82 of magnetic material moved between an inoperative position where it rests on edge 79 and a lower position where it closes the passage 72 formed by the apertures 73, 74. As the panels are inverted in the rear part C of the endless belt the discs all fall into their inoperative positions. Selected discs are then moved by a row of electromagnets 95 into operative positions such that unblocked passages form a character. To ensure that the electromagnets are actuated when a row of discs are exactly opposite, photosensors provide a signal when a reflecting strip on the panel adjacent each row is correctly aligned. In other embodiments the panels 50 are each formed of a plurality of sub-panels; the disc in its upper position closes the light passage; the discs are operated by a jet of air applied to the discs via a hole in the panel extending to the upper part of the cavity 78. To control the display a serial digit input signal is converted to a parallel output and passed to a buffer circuit. This provides a signal controlling the speed of motor 58 in accordance with the amount of data in the buffer. The buffer output passes to decoder, character generation and storage circuits, the latter having stages corresponding to each electromagnet. Selected electromagnets are operated on receipt of a signal from the photosensors. A foldover circuit senses the nature of incoming data to determine where in the panel the next row should start.