A convenient multiplexing scheme for addressing small liquid crystal matrix displays

Abstract

In this paper, a convenient method for multiplexing small liquid crystal matrix displays is presented. For a matrix of N rows, the method consists of addressing the rows with all possible combinations of a binary voltage scheme. For each of these 2^N combinations, a proper binary voltage is selected for each of the columns to get a majority-advantage compared to the, picture pattern to be displayed. A mathematical analysis of this scheme is given. Though the contrast ratio with the present scheme is slightly less than that obtained with the conventional scheme it has the advantage of having a very large duty factor and of requiring only one power supply. The simplicity of the scheme is exploited to construct and operate a 16-segment alphanumeric display panel.