JPS6477387A - Color image display circuit - Google Patents

Abstract

PURPOSE:To make an A/D converter single, to cut cost and to reduce printed wiring board mounting area by multiplexing analogly chrominance signals of three colors, then, A/D converting them when a color image in triangle picture elements arrangement is displayed. CONSTITUTION:A video signal is separated into three primary colors, inputted to an analog multiplexer 1, a chrominance signal made single here is converted a digital value of N bits by an A/D converter 2 and inputted to an image driving circuit 3 as gradation data. Based on the gradation data, the circuit 3 changes a driving voltage, changes the torsion quantity of the respective liquid crystal elements of a liquid crystal image picture displaying body 4 and an image is reproduced. A three phases selecting signal generating circuit 6 consists of a 1/3 divided ring counter, only one out of three selecting signals goes to '1' and one of three analog switches in the analog multiplexer 1 is switched on. When a horizontal picture element group in an even number string, a selecting signal phase setting circuit 5 sets a phase so as to shift by 1.5 picture elements to an add number string in generating sequence at the screen left edge of the selecting signal.