Improvement of Particle Velocity of an Electrophoretic Display by Introducing Guide Blocks in a Display Cell

Abstract

Electrophoretic display has been utilized for reflective display panel fit for e-book readers. However, its slow response speed is one of major weak points. We have focused on the liquid flow generated by particle movement when driving voltage is applied in a display cell. We suppose that the liquid flow affects to the particle movement and its possible turbulence probably prevents smooth particle movement expected under the applied electric field. We have tried to control the liquid flow in a display cell by introducing guide block structure in a display cell. We expected the guide blocks decrease the turbulence of the liquid flow and can improve moving speed of particles. We have prepared two types of display cell, with and without the guide blocks, and measured speed of particle movement in the display cells. As a result, we have found two times faster particle velocity when using the display cell with the guide blocks than when using the display cell without block. These results suggest that appropriate arrangements of display cell structure can effectively improve the response time of electrophoretic displays.