Patent ID: 8773420

Claim:
A method comprising: generating display driver signals that vary between only two levels, wherein the display driver signals comprise common drive signals and segment drive signals; applying the display driver signals to opposing electrodes of a display element within a display device; and controlling the display device in a first mode by varying a pulse density of the display driver signals applied to the opposing electrodes to select or de-select the display element and filtering the display driver signals applied to the opposing electrodes using electrical characteristics of at least a portion of the display device in the first mode to provide voltage levels at the display element to vary according to pulse density; wherein the display element is activated in the first mode when a first average voltage magnitude across the element exceeds a first minimum average voltage over a first time period, and varying a correlation between the common drive signals and the segment drive signals in a second mode to select or de-select the display element based on a second average voltage magnitude across the display element over a second time period, wherein the display element is activated in the second mode when the second average voltage magnitude exceeds a second minimum average voltage over the second time period, wherein the second average voltage magnitude exceeds the second minimum average voltage when a respective one of the common drive signals and the corresponding one of the segment drive signals are correlated and the second average voltage magnitude does not exceed the second minimum average voltage when the respective one of the common drive signals and the corresponding one of the segment drive signals are not correlated.