Additive for improving optical performance of an electrophoretic display
AssigneeE Ink California, LLC
InventorsMing Wang, Yu Li, Hui Du, Xiaojia Zhang, Haiyan Gu, Roman Ivanov, Robert Sprague
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Abstract
The present invention is directed to an electrophoretic fluid which comprises uncharged or lightly charged neutral buoyancy particles. The resulting fluid can improve not only image stability but also contrast ratio of a display device, without significantly affecting the switching speed. The present invention is also directed to an electrophoretic display comprising display cells filled with the electrophoretic fluid.
Claims16
A method for improving performance of an electrophoretic display device comprising an electrophoretic fluid which comprises two types of charged pigment particles having contrasting colors and carrying opposite charges and the two types of charged pigment particles are dispersed in a solvent or solvent mixture, the method comprises adding about 3% to about 15% by weight of uncharged or lightly charged neutral buoyancy particles to the fluid and the uncharged or lightly charged neutral buoyancy particles have the same color as one of the two types of the charged pigment particles.
An electrophoretic display comprising display cells filled with an electrophoretic fluid comprising two types of charged pigment particles having contrasting colors and carrying opposite charges and uncharged or lightly charged neutral buoyancy particles all of which are dispersed in a solvent or solvent mixture, wherein the concentration of the uncharged or lightly charged neutral buoyancy particles in the electrophoretic fluid is in a range between 3% and 15% by weight and the uncharged or lightly charged neutral buoyancy particles have the same color as one of the two types of charged pigment particles.
Dependencies are inferred from the claim text.