GB1420137A - Display device - Google Patents

Abstract

1420137 Cathode-ray display tubes HITACHI Ltd 15 Feb 1973 [16 Feb 1972] 7582/73 Heading H1D [Also in Division H4] A display device comprises a glass faceplate 1 carrying conductive and phosphor layers 2, 3; a spacer 5; crossed conductor arrays 4, 7; perforated insulating plates 8, 10; perforated conducting plate 9 and a discharge space 12 defined by end plate 13 and spacer 11 in which electrodes 17, 18 are mounted. The device is filled with rare gas, Hg or both. In operation a voltage is applied between electrodes 17, 18 to produce a discharge; selected electrodes 4, 7 are earthed or are made positive allowing electrons to diffuse to spacer 5 where they are accelerated by a D.C. potential on layer 2 to produce luminescence in the phosphor. A metal plate may be added between spacer 11 and plate 13, to which an accelerating potential is applied when discharge between electrodes 17, 18 ceases. In TV display a video signal is applied to a delay line 22 in parallel with gates 23 and pulse width modulation devices 24. Synchronizing signals are applied to gates 23, horizontal line scanner 26 and voltage generator 28 connected across electrodes 17, 18. During each horizental scanning period a pulse Vd is applied to electrodes 17, 18 to produce a discharge and then pulses P are applied to electrodes 4, 7. The pulses P are applied when Vd ends to ensure that the electron streams are of uniform density and non-uniform space charge on plate 9 is eliminated. In another embodiment electrode pairs 17, 18 are energized sequentially as the horizontal lines are scanned. The number of electrode pairs 17, 18 may be less than the number of electrodes 7.