GB1348833A - Indicator devices - Google Patents

Abstract

1348833 Matrix displays SONY CORP 17 Sept 1971 [18 Sept 1970] 43488/71 Heading G5C [Also in Division H1] An indicator tube comprises a planar base plate forming part of an envelope 3, a plurality of indicator units A1, A2, A3 aligned on one side of the plate, each unit comprising a plurality of cathode segments E1 to E10, which can be arranged as a cross in a rectangle, each indicator unit being provided with a surrounding barrier electrode B1, B2, B3 which, depending on the potential applied thereto, functions either as an anode when a discharge is desired or as a barrier to prevent a discharge being initiated by an adjacent unit. Normally electrodes B1, B2, B3 are held at a positive potential insufficient to cause discharge by a source 6 through diodes D1, D1, D3 and when a discharge is desired a higher potential from source 5 is applied by sequentially turning on the appropriate ones of transistors T1, T2, T3. The corresponding segments of all the indicating units are interconnected and held at a low or high potential, depending on whether they are required in the display or not, by the potential divider R1, R2, R3, R4 in dependence on the states of transistors T1<SP>1</SP> to T10<SP>1</SP>, the higher potential being applied through diodes d1 to d10 when the transistors T1<SP>1</SP> to T10<SP>1</SP> respectively are off. When the transistors T1, T2, T3 are sequentially turned on appropriate decoding signals in a corresponding sequence are applied to transistors T1<SP>1</SP> to T10<SP>1</SP> to provide an apparently continuous display.