Multiple voltage level driving for electrophoretic displays

摘要

This application is directed to driving methods for electrophoretic displays. The driving methods comprise applying different voltages selected from multiple voltage levels, to pixel electrodes and optionally also to the common electrodes. In one embodiment, the different voltages are selected from a group consisting of 0V, at least two levels of positive voltage and at least two levels of negative voltage. The driving method is also suitable for a color display device.

主权项

1. A driving method for driving a color display device, which display device comprises an electrophoretic fluid sandwiched between a common electrode and a layer of pixel electrodes and the electrophoretic fluid comprises a first type of pigment particles, a second type of pigment particles and a third type of pigment particles, all of which are dispersed in a solvent or solvent mixture, wherein
(a) the first type of pigment particles and the second type of pigment particles carry opposite charge polarities; (b) the third type of pigment particles has the same charge polarity as the second type of pigment particles but at a lower intensity; and (c) the second type of pigment particles has a threshold voltage,the method comprising:applying to a pixel electrode a voltage of a high positive voltage;applying to the pixel electrode a voltage of a high negative voltage; andapplying to the pixel electrode a voltage of a low positive voltage or a low negative voltage, which is equal to or lower than the threshold voltage, wherein when the low positive voltage or low negative voltage having the same polarity as the second type of pigment particles is applied to the pixel electrode, a voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to a color state of the third type of pigment particles, at a viewing side, from a color state of the first type of pigment particles.