Electro-optic displays with reduced remnant voltage

• US 9,881,564 B2
• Filed: 03/07/2016
• Issued: 01/30/2018
• Est. Priority Date: 11/20/2001
• Status: Expired due to Fees

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Wilcox, Russell J., Whitesides, Thomas H., Amundson, Karl Raymond, Danner, Guy M., Webber, Richard M., Honeyman, Charles Howie, Cao, Lan, Paolini, Jr., Richard J., Chebiyam, Rajesh
• Primary Examiner(s): Ben, Loha
• Application Number:
  US15/062,326
• Publication Number:
  US 20160189632A1
• Time in Patent Office: 694 Days
• Field of Search: 359228, 359245, 359253, 359296, 345 60, 345 76, 345 94, 345 95, 345103, 345107, 345204, 345205, 345208, 345214, 345690, 345691
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G02F 1/0018 Electro-optical materials
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 2001/1678 characterised by the composition or particle type
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3629 using liquid crystals having memory effects, e.g. ferroelectric liquid crystals

Abstract

The invention provides materials and methods (including driving methods) for reducing the effects of remnant voltages in electro-optic displays.

Claims

1. An electro-optic display comprising a layer of electro-optic material and voltage supply means arranged to apply a voltage not greater than a predetermined value in either direction across the layer of electro-optic material, wherein the electro-optic material has a threshold voltage which is greater than zero but less than about one third of the predetermined value.

2. An electro-optic display according to claim 1 wherein the electro-optic material has a threshold voltage which is not less than about one-fiftieth but less than about one third of the predetermined value.

3. An electro-optic display according to claim 2 wherein the electro-optic material comprises a particle-based electrophoretic material comprising a suspending fluid and a plurality of electrically charged particles held in the suspending fluid and capable of moving therethrough on application of the voltage across the layer of electro-optic material.

4. An electro-optic display according to claim 3 wherein the electrophoretic material is an encapsulated electrophoretic material, a polymer-dispersed electrophoretic material or a microcell electrophoretic material.

5. An electro-optic display according to claim 3 wherein the suspending fluid is gaseous.