Reflective image display with threshold

• US 9,897,890 B2
• Filed: 10/05/2015
• Issued: 02/20/2018
• Est. Priority Date: 10/07/2014
• Status: Active Grant

• Current Assignee: WUXI Clearink Limited
• Original Assignee: Clearink Displays, Inc.
• Inventors: Whitehead, Lorne A.
• Primary Examiner(s): Martinez, Joseph P
• Application Number:
  US14/874,565
• Publication Number:
  US 20160097961A1
• Time in Patent Office: 869 Days
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1675 Constructional details
• CPC Class Codes: G02F 2203/026 attenuated or frustrated internal reflection

Abstract

Reflective image display architecture embodiments are disclosed comprising a perforated continuous reflective sheet. The perforated continuous sheet comprises a coating that provides a threshold to particle movement. The coating may be designed to provide a passive or electro-active physical barrier. The coating improves bistability of the display.

Claims

1. A reflective image display, comprising:

a front electrode;

a rear electrode, the front and the rear electrode forming a gap therebetween;

a transparent medium disposed in the gap;

a plurality of mobile electrophoretic particles dispersed in the transparent medium and movable within the gap; and

a barrier comprising a stimuli-responsive coating interposed between the front electrode and the rear electrode, the coating configured to form a physical barrier to permit movement of at least one electrophoretic particle from the front electrode to the rear electrode.

2. The image display of claim 1, further comprising a voltage source to bias one or more of the front electrode or the rear electrode.

3. The image display of claim 2, wherein the barrier defines a perforated barrier and wherein the barrier permits movement of the at least one electrophoretic particle when biased by the biasing source.

4. The image display of claim 1, wherein the barrier further comprises at least one aperture.

5. The image display of claim 4, wherein the coating comprises a polymer with extendable chains.

6. The image display of claim 5, wherein the extendable chains extend or contract in response to an external stimulus.

7. The image display of claim 5, wherein the extendable chains extend or contract in response to an electromagnetic force.

8. A method for displaying a reflective image, the method comprising:

positioning at least one charged electrophoretic particle in a transparent medium disposed between a front electrode and a rear electrode;

biasing the front electrode relative to the rear electrode with a first voltage to form an electromagnetic field therebetween thereby attracting the at least one charged electrophoretic particle to one of the front electrode or the rear electrode; and

stimulating a stimuli-response coating on a barrier layer relative to one or more of the first or the second electrode to provide a threshold to movement of the at least one electrophoretic particle from the front electrode to the rear electrode.

9. The method of claim 8, wherein the barrier layer further comprises a perforation permitting movement of the at least one electrophoretic particle therethrough.

10. The method of claim 9, wherein the perforation is coated with a polymer having extendable chains.

11. The method of claim 10, further comprising activating the extendable chains by biasing the barrier layer with a second voltage.

12. The method of claim 10, wherein the extendable chains extend or contract when the barrier layer is biased relative to one or more of the front or the rear electrodes.

13. The method of claim 10, wherein the extendable chains extend or contract in response to an electromagnetic force.

14. A non-transitory computer-readable storage device having a set of instructions to cause a processor to perform a process comprising:

affecting movement of at least one charged electrophoretic particle in a transparent medium disposed between a front electrode and a rear electrode;

biasing the front electrode relative to the rear electrode with a first voltage to form an electromagnetic field therebetween thereby attracting the at least one charged electrophoretic particle to one of the front electrode or the rear electrode; and

stimulating a stimuli-responsive coating on a barrier layer relative to one or more of the first or the second electrode to provide a threshold to movement of the at least one electrophoretic particle from the front electrode to the rear electrode.

15. The non-transitory computer readable storage device of claim 14, wherein the barrier layer further comprises a perforation permitting movement of the at least one electrophoretic particle therethrough.

16. The non-transitory computer readable storage device of claim 15, wherein the perforation is coated with a polymer having extendable chains.

17. The non-transitory computer readable storage device of claim 16, further comprising activating the extendable chains by stimulating the barrier layer.

18. The non-transitory computer readable storage device of claim 16, wherein the extendable chains extend or contract when the barrier layer is biased relative to one or more of the front or the rear electrodes.

19. The non-transitory computer readable storage device of claim 16, wherein the extendable chains extend or contract in response to an electromagnetic force.

20. A reflective image display, comprising:

a front electrode;

a rear electrode, the front and the rear electrode forming a gap therebetween;

a transparent medium disposed in the gap;

a plurality of mobile electrophoretic particles dispersed in the transparent medium and movable within the gap; and

a barrier opening interposed between the front electrode and the rear electrode, the barrier opening configured to permit movement of at least one electrophoretic particle from the front electrode to the rear electrode, the barrier opening coated with a polymer having extendible chains.

21. The reflective image display of claim 20, wherein the polymer extends in response to one or more stimuli.

22. The reflective image display of claim 20, wherein the polymer extends in response to an electromagnetic force.

23. A method for displaying a reflective image, the method comprising:

positioning at least one charged electrophoretic particle in a transparent medium disposed between a front electrode and a rear electrode;

biasing the front electrode relative to the rear electrode with a first voltage to form an electromagnetic field therebetween thereby attracting the at least one charged electrophoretic particle to one of the front electrode or the rear electrode; and

stimulating a plurality of polymers coated on a barrier layer interposed between the front and the rear electrodes to substantially affect movement of the at least one electrophoretic particle between the front and the rear electrodes.

24. The method of claim 23, further comprising stimulating the plurality of polymers to thereby extend one or more polymer chains to substantially obstruct movement of the at least one electrophoretic particle.

25. The method of claim 23, further comprising stimulating the plurality of polymers to thereby contract one or more polymer chains to permit movement of the at least one electrophoretic particle.