GB1423368A - Gas discharge display devices electrolytic cells - Google Patents

Abstract

1423368 Matrix displays and circuits therefor FUJITSU Ltd 28 Dec 1972 [30 Dec 1971] 59928/72 Heading G5C [Also in Division H4] The brightness of a picture on a gas discharge display panel having crossed conductor arrays is controlled by using groups of 4 cells for each picture element and applying 4 different sustaining signals to the conductors of each group such that when energized by write pulses 2, 4, 8 and 16 discharges occur per unit of time in the 4 cells respectively, the brightness depending on which of the 4 cells are selected; groups of 6 and 8 cells may be used. Sustaining pulses to the conductors of each group may be of different duration or height. Alternatively, Fig. 5 (not shown), the memory function of the panel is not used and various pulse trains are applied to the conductors of each group to produce various numbers of discharges in the 4 cells. The apparatus may be used to display a TV picture, Fig. 6 (not shown), by energizing each row of picture elements, sequentially. The video signal is periodically sampled and converted to a 4-bit digital signal for each picture element and these are stored in a shift register. When this is full its contents are applied to a buffer which provides write pulses on selected lines 1, 4, 2, 8 ... (Fig. 7) and to AND gates G xa11 , G xa12 .... Timing pulses T A , T B , T S are sequentially applied to the AND gates G x and also to AND gates (G y ) Fig. 8 (not shown); pulses T s are equal to T A + T B . The gate outputs, either via OR gates GR or directly, control mixing currents which apply the different sustaining signals to the electrodes of the display panel. A portion of each line may be written enabling the size of the buffer to be reduced. Sustain voltage sources Figs. 10, 11 (not shown) each comprise a diode matrix and 4 transistors.