Low-flash electrophoretic display updates using noise masks for waveform initiation

A method for updating an electrophoretic display, the electrophoretic display including:

• a light-transmissive electrode,
• an active matrix backplane comprising rows of pixel electrodes, wherein each pixel electrode is coupled to a thin-film transistor, and each thin-film transistor is coupled to a gate line and a source line,
• an electrophoretic medium disposed between the light-transmissive electrode and the active matrix backplane, wherein the electrophoretic medium includes at least three different types of charged pigment particles,
• a controller coupled to a plurality of gate lines, each gate line being coupled to thin-film transistors of a row of pixel electrodes, and the controller being coupled to a plurality of source lines, the controller being configured to address the pixel electrodes in a row-by-row fashion by providing both a gate voltage and a source voltage to each thin-film transistor,
• a processor coupled to the controller, and
• non-transitory memory coupled to the processor and the controller,
• wherein the method for updating the electrophoretic display comprises:
• accessing a color waveform look up table (LUT) including a plurality of waveforms for causing the electrophoretic medium to transition between a first color and a second color wherein each of the plurality of waveforms is offset by a different number of null frames such that a number of voltage pulses and a polarity and magnitude of each of the voltage pulses to cause the transition between the first color and the second color is the same, but wherein each waveform begins at a different time;
• accessing a spatial-temporal distributed start time look up table (LUT) including an offset start time based upon the position of each pixel electrode with respect to a noise mask that spans the area of the active matrix;
• offsetting the start time of at least some of the plurality of waveforms for causing the electrophoretic medium to transition between a first color and a second color based upon the position of the corresponding pixel electrode with respect to the noise mask by adding the offset from the spatial-temporal distributed start time look up table (LUT);
• sending instructions from the controller to the respective gate and scan lines so that pixel electrodes of the active matrix backplane cause the electrophoretic medium to transition between the first color and the second color with different start times.