Toward Red Color Display via Step-By-Step Scheme Design in Particle Activation Stage for Three-Color Electrophoretic Displays

Abstract

Red particles are the basis of red color display in a three-color electrophoretic display, but driving voltage of red particles overlaps with black gray scales, resulting in a low red saturation and poor display effect. In order to improve the red saturation, a step-by-step driving scheme was proposed with an optimized in the activation stage, which is a part of a driving waveform. Firstly, Stokes law and electrophoretic law were used to analyze and calculate overall driving wave-form, and a positive pulse in activation stage was modulated into a mixture of +3 V and +15 V. Then, mixing duration ratio of +3 V and +15 V was adjusted to improve the activity of red particles. Finally, the number of pulse cycles of the driving waveform in activation stage were optimized to reduce viscous force of red particles. Experimental results showed that compared with ordinary three-color Electrophoretic Displays driving waveform, the proposed driving waveform increased red saturation by 12.915%.