Patent GB-1407623-A (GB)
Title: Gas discharge device and method for shifting a discharge  spot in a gas discharge device
IPC: G09G3/28
Filed: 1972-08-10
Abstract: 1407623 Gas discharge display panels FUJITSU Ltd 10 Aug 1972 [10 Aug 1971] 35832/72 Heading H1D [Also in Division G4] In a gas discharge panel including a conductor array insulated from the gas every third electrode is interconnected to form 3 groups. A display panel comprises a pair of glass plates supporting Au, X, Y conductor arrays covered with glass and is filled with Ne or N 2  and A. The Y array comprises 7 conductors l 1  ... l 7  extending from the second X conductor b 1 . Seven write conductors # 1  ... # 7  extend in the Y direction but spaced from the Y conductors, to the first X conductor a 1 . Leads are taken to both sides of the panel, crossing leads being separated by dielectric 11. The X conductors are sufficiently close so that a discharge in one site produces appreciable ionisation in adjacent sites thereby reducing the ignition voltage at the adjacent site. The Y conductors are all earthed and overlapping sustain pulses are applied sequentially to the three groups of X conductors. A write pulse is applied to a conductor # which with the sustain pulse produces a discharge. A sustain pulse on adjacent conductor b 1  is then sufficient to produce a discharge at the interesction of b 1  and the Y conductor adjacent to # 1 ; subsequent pulses move the discharge across the panel. Sites are not reignited because ionization from adjacent discharges neutralizes wall charges; alternatively erase pulses may be applied. The direction of movement can be reversed by altering the sequence in which pulses are applied, thereby removing incorrect data. Driving circuitry includes a pulse generator 22 connected via gates 23, G and amplifier 24, M to the conductors; a diode matrix 30 generating a character pattern and differentiation circuits D; a keyboard 21 and a register 31. A resistive layer of Pb may be provided on one or both dielectric layers over and parallel to the Y conductors to improve the shift action and the dispersal of wall charges. The Y electrodes may be replaced by an array similar to the X array at least over part of the panel to enable discharges to be moved in the X and Y directions. To enable a pattern to be superposed on an existing display subelectrodes 1 1b , l 1c  ..., l 2 b, l 2e  ... are added adjacent electrodes l 1  l 2  ... (Fig. 16) and electrodes b, c are brought closer to electrodes a at their intersections with the sub-electrodes. A pattern generated on electrodes l 1  l 2  ... is shifted to the sub-electrodes and stored on subelectrodes l 2b  l 2c  .... When further discharges are generated the stored pattern is unaffected as the distance between adjacent electrodes b, c is too great to produce appreciable ionisation. Another embodiment (Fig. 11A) comprises a substrate 41 supporting shift conductors a, b, c and write conductors 42, a cover 46 containing grooves 45 and a dielectric layer 44 separating the electrodes from the gas space. The shift conductors are interconnected in three groups and sustain pulses applied as before. A discharge is produced first between write conductors and a first shift conductor a 1 , then between adjacent shift conductors. The output of the last X conductor can be read out by photoelectric elements or recorded via light guides on to photosensitive paper.