GB1194042A - Variable Message Displays - Google Patents

Abstract

1,194,042. Displays: shift registers. W. BROOKS. 9 June, 1967 [13 June, 1966], No. 26772/67. Heading G4H, G4C. The stages of an electronic shift register control respective display elements by means of silicon-controlled-rectifiers. In the shift register of Fig. 7, having data input at 86, shift pulses at 90 reset transfluxors 71-77 to "zero". Those not already at "zero" charge following capacitors 94 to set the respective next transfluxors to "one". Each cycle of an oscillator 70 non-destructively reads out the transfluxor state via silicon-controlledrectifiers 61-67 to lamps 11-17. In the shift register of Fig. 8, an input of "one" at 104 causes silicon-controlled rectifier 131 to fire, lighting lamp 111, discharging capacitor 161 and charging capacitor 141. A shift pulse opening switch 103 cuts off S.C.R. 131 so that capacitor 141 starts to discharge via lamp 111. The shift pulse ends before this discharge has proceeded far whereupon capacitor 141 charges capacitor 161 causing siliconcontrolled-rectifier 132 of the second stage of the register to fire. The next shift pulse cuts off both S.C.R's 131, 132 and so on. Had the input at 104 been "zero", S.C.R. 131 would not have fired, capacitor 141 would not have charged so it could not subsequently discharge to fire S.C.R. 132 via capacitor 161. The "lamps" above may each be a bar consisting of several neon tubes or a single fluorescent lamp, the bars being arranged in a figuregram or &c. to permit a selected numeral or letter or &c. to be built up by energizing selected bars. Alter natively, the lamps may illuminate respective masks for optical projection on to a screen. A row of figuregrams may be controlled ,by respective shift registers connected in series. Alternatively, each row of an elongated matrix of individual lamps may be controlled by a respective shift register to allow a message to be displayed and moved along. The data and shift input switches 86, 90, 104, 103 may be controlled by stepping switches or other shift registers. Input may be manual or on punched tape or cards. Blue, green and red lamps may be used at each lamp position and scanned in sequence.