An electrophoretic display, its properties, model, and addressing

A model to describe the optical behavior of an electrophoretic display (EPD) device is developed. The model involves the particle size and mobility as well as the time of removal of particles from an electrode. The most important aspect of this model is the treatment of the dynamics of removing particle layers from an electrode. This process plays a significant role in controlling the optical off-response rate. The optical on-response is governed by the particle mobility or the spatial distribution of the particles through the cell. Various schemes for addressing the electrophoretic device are discussed. Only a display employing assisted array addressing appears capable of giving a large-area graphics quality display with short response time. Fringing field particle migration was found to seriously degrade image quality. A cell subdivision structure is used to overcome fringing field migration, particle settling, and electrohydrodynamic effects.