COLOR DISPLAY DEVICE

摘要

The present invention provides a color display device in which each pixel or sub-pixel can display four high quality color states. More specifically, an electrophoretic fluid is provided which comprises four types of particles, dispersed in a solvent or solvent mixture. The fluid may further comprise substantially uncharged neutral buoyancy particles.

主权项

1. A display layer comprising an electrophoretic medium and having a first surface on a viewing side and a second surface on the opposite side of the viewing side, wherein the electrophoretic medium is sandwiched between a common electrode and a layer of pixel electrodes and comprises high positively charged particles, high negatively charged particles, low positively charged particles, and low negatively charged particles, all dispersed in a solvent or solvent mixture, the four type of particles having respectively optical characteristics differing from one another, such that:
(a) application of a high positive voltage potential difference between the common electrode and a pixel electrode will cause a pixel corresponding to the pixel electrode to display the optical characteristics of the high positively charged particles at the viewing side; or (b) application of a high negative voltage potential difference between the common electrode and a pixel electrode will cause a pixel corresponding to the pixel electrode to display the optical characteristic of the high negatively charged particles at the viewing side; or (c) once the optical characteristic of the high positively charged particles is displayed at the first surface, application of a low negative voltage potential difference between the common electrode and a pixel electrode will cause a pixel corresponding to the pixel electrode to display the optical characteristic of the low negatively charged particles at the viewing side and move the low positively charged particles to the pixel electrode side; or (d) once the optical characteristic of the high negatively charged particles is displayed at the first surface, application of a low positive voltage potential difference between the common electrode and a pixel electrode will cause a pixel corresponding to the pixel electrode to display the optical characteristic of the low positively charged particles at the viewing side and move the low negatively charged particles to the pixel electrode side.