TIR-modulated wide viewing angle display

• US 10,705,404 B2
• Filed: 02/05/2018
• Issued: 07/07/2020
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: WUXI Clearink Limited
• Original Assignee: Concord HK International Education Limited
• Inventors: Sadlik, Bram M., Fleming, Robert J., Gou, Steven, Ferguson, Scott W., Hannebauer, Rob, Henzen, Alex
• Primary Examiner(s): Cherry, Euncha P
• Application Number:
  US15/888,956
• Publication Number:
  US 20180157144A1
• Time in Patent Office: 883 Days
• Field of Search: 359296
• 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 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/1677 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/1681 having two or more microcells partitioned by walls, e.g. of microcup type
• CPC Class Codes: G02F 1/195 by using frustrated reflection digital reflection using controlled total internal reflection G02F1/315
• 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 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/068 for control of viewing angle adjustment
• 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

Abstract

The disclosed embodiments relate to lateral migration of particles in a totally internally reflective displays. In certain embodiments, the reflective image displays include partial and full walls to form partitions within the display. The walls mitigate diffusion and lateral migration or drift of electrophoretically mobile particles due to lateral electric fields at adjacent pixels. This improves image quality, bistability and long-term display performance.

Claims

1. An image display device to limit particle drift and diffusion, the display comprising:

a front electrode;

an optically transparent sheet having a surface with a plurality of convex protrusions extending from a surface thereof;

a rear electrode positioned opposite the plurality of convex protrusions to form a cavity therebetween;

at least one electrophoretically mobile particle suspended within the cavity; and

a plurality of partitions to form one or more segments within the cavity, wherein at least one protrusion extends partially into the cavity;

wherein the plurality of partitions further comprises at least three or more partitions that form one or more partitioned space within the cavity and wherein a first partition of the plurality of partitions extends from a convex protrusion arch.

2. The image display device of claim 1, wherein the image display device defines a Totally Internally Reflective (TIR) device.

3. The image display device of claim 1, further comprising a medium disposed in the cavity.

4. The image display device of claim 1, wherein the at least one electrophoretically mobile particle defines a charged particle.

5. The image display device of claim 1, further comprising a voltage source to apply a voltage bias across the medium to form an electromagnetic field between the front electrode and the rear electrode to generate a field between the front and the rear electrodes.

6. The image display device of claim 1, wherein the three or more partitions extend from each of a respective convex protrusions towards the cavity.

7. The image display device of claim 1, wherein at least one of the plurality of partitions extends from a region proximal to the rear electrode into the cavity.

8. The image display device of claim 1, wherein a first of the plurality of partitions extends from a first convex protrusion towards the cavity and a second of the plurality of partitions extends from the bottom electrode towards the cavity.

9. The image display device of claim 8, wherein the first and the second partitions are substantially aligned in a first direction.

10. The image display device of claim 8, wherein the first and the second partitions are not aligned.

11. The image display device of claim 1, wherein a first partition of the plurality of partitions extends from an abutment of two adjoining protrusions.

12. An image display device to limit particle drift and diffusion, the display comprising:

a front electrode;

an optically transparent sheet having a surface with a plurality of convex protrusions extending from a surface thereof;

a rear electrode positioned opposite the plurality of convex protrusions to form a cavity therebetween;

at least one electrophoretically mobile particle suspended within the cavity; and

a plurality of partitions to form one or more segments within the cavity, wherein the plurality of partitions further include at least three or more partitions that form one or more partitioned space within the cavity and wherein the first of the plurality of partitions extends from a convex protrusion arch.

13. The image display device of claim 12, wherein the image display device defines a Totally Internally Reflective (TIR) device.

14. The image display device of claim 12, further comprising a medium disposed in the cavity.

15. The image display device of claim 12, wherein the at least one electrophoretically mobile particle defines a charged particle.

16. The image display device of claim 12, further comprising a voltage source to apply a voltage bias across the medium to form an electromagnetic field between the front electrode and the rear electrode to generate a field between the front and the rear electrodes.

17. The image display device of claim 12, wherein first of the plurality of partitions extends from a first convex protrusion towards the cavity and a second of the plurality of partitions extends from the bottom electrode towards the cavity.

18. The image display device of claim 17, wherein the first and the second partitions are substantially aligned in a first direction.

19. The image display device of claim 17, wherein the first and the second partitions are not aligned.