Patent attributes
A backplane operative to drive an array of emissive pixel elements is disclosed. Each pixel element comprises a memory cell operative to modulate a plurality of current mirror drive elements configured to drive one emissive element, wherein one current mirror pixel drive element is always operative to provide current if the memory cell is on and all other current mirror pixel drive elements may enabled subject to external control signals and the memory cell data state. The W/L ratio of each reference current FET is equal to the W/L ratio of all other reference current FETs. The W/L ratio of the current source FETs in each of the current mirror pixel drive elements is equal to the others. The present invention allows adjustment of the current density within the current source FET as well as the sensitivity of the current source FET to threshold voltage variation.