Display systems

A method of reducing artefacts in an image displayed by an active matrix non-volatile electro-optic display and non-volatile electro-optic display driver, the non-volatile electro-optic display driver comprising a plurality of active matrix pixel drivers each driving a respective pixel of the non-volatile electro-optic display, each active matrix pixel driver having an associated storage capacitor coupled to a common backplane connection of the non-volatile electro-optic display driver, pixels of the non-volatile electro-optic display having a common pixel electrode, the method comprising:

• disconnecting said common pixel electrode from a common pixel electrode power supply such that said common pixel electrode is floating;
• controlling a common backplane power supply to clamp said common backplane connection to a first defined voltage level, wherein said first defined voltage level is a zero volts level;
• and
• after said disconnecting and said controlling, driving the non-volatile electro-optic display with a null frame during a power-down procedure of the display, wherein the non-volatile electro-optic display is driven with the null frame whilst the common pixel electrode is floating and the common backplane connection is clamped to the first defined voltage level, and wherein said null frame comprises a frame of data values defining no change in a displayed colour or brightness level.