Patent ID: 8427402

Claim:
A method of driving a passive matrix electroluminescent display, the display having a plurality of rows and columns of emissive elements addressed by respective row and column electrodes, the method comprising: addressing said row electrodes, one at a time; driving a set of said column electrodes while addressing each said row electrode; converting drive level data for a set of said emissive elements into first data defining column drive current signal ratios of a drive current for a particular column electrode to an overall column drive current for said set of said column electrodes and second data defining an overall row drive current, wherein said column electrode driving comprises driving said set of said column electrodes at said column drive current signal ratios for said set of column electrodes; and driving each said addressed row at said overall row drive current to control a drive current to said emissive elements in each said addressed row, wherein said driving comprises driving said column electrodes with a current driver comprising a current mirror having a reference input and a plurality of outputs, and wherein said outputs are coupled to said column electrodes and one of said column electrodes is coupled to said reference input of said current mirror.