Color display devices

• US 8,976,444 B2
• Filed: 11/18/2013
• Issued: 03/10/2015
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink California, LLC (E Ink Holdings Incorporated)
• Inventors: Zhang, Xiaojia, Lin, Craig, Sprague, Robert A.
• Primary Examiner(s): CHOI, WILLIAM C
• Application Number:
  US14/083,317
• Publication Number:
  US 20140078036A1
• Time in Patent Office: 477 Days
• Field of Search: 359/296, 345/107, 430/32, 204/600
• US Class Current: 359/296
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 2001/1678 characterised by the composition or particle type
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• 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 3/3446 with more than two electrodes controlling the modulating element

Abstract

The present invention is directed to a color display comprising an electrophoretic fluid comprising two types of pigment particles of contrasting colors and carrying opposite charge polarities dispersed in a clear and colorless solvent, wherein said electrophoretic fluid is sandwiched between a common electrode and a plurality of colored sub-pixel electrodes or colored pixel electrodes.

Claims

1. A driving method for a color display comprising an electrophoretic fluid comprising two types of pigment particles carrying opposite charge polarities and having contrasting colors, wherein the particles are dispersed in a solvent, and said electrophoretic fluid is sandwiched between a common electrode and a plurality of colored sub-pixel or pixel electrodes, which method comprises

a) applying a constant driving voltage between the common electrode and the sub-pixel or pixel electrode where the pigment particles are to be gathered;

and

b) applying alternating positive driving voltage and negative driving voltage between the common electrode and the sub-pixel or pixel electrode which is to be exposed.

2. The method of claim 1 wherein the constant driving voltage in step (a) is 0V.