GB1501268A - Array of voltage responsive elements - Google Patents

Abstract

1501268 Matrix displays and circuits therefor INTERNATIONAL BUSINESS MACHINES CORP 8 April 1975 [7 June 1974] 14279/75 Heading G5C Driving signals applied to a matrix of liquid crystal display elements have relative phase angles of 2#/3, 0 and - 2#/3. The signals are combined to produce zero potential across selected elements and the same magnitude voltage across the remainder. A liquid crystal display device comprises crossed conductor arrays and crossed or parallel polarizing plates. A display is produced when the dielectric anisotropy is changed from positive to negative or vice versa by varying applied high and low frequency signals, e.g. from V H , V L to 3V H , 0 or V L to 0 with no high frequency signal. It is preferable to operate near the transition region to minimize the write time/decay time ratio whereby large matrices can be addressed. Both high and low frequency signals are applied to the panel in a line scanning mode. The low frequency voltage V<SP>1</SP> with a relative phase angle - 2#/3 denoted V<SP>1</SP>/ - 2#/3 is applied sequentially to the row conductors and a signal V<SP>1</SP>/-2#/3 to selected column conductors to produce zero voltage across selected cells 22. A signal V<SP>1</SP>/ + 2#/3 is applied to other column conductors to give voltages of magnitude V L = #3.V<SP>1</SP> and various relative phase angles across the remaining cells. In a similar way high frequency signals V H /#, V H /0, 2V H /0 and 0 are applied as shown in Fig. 6b thereby obtaining 3V/ H 0 across the selected cell and V H across the remainder.