Encapsulated electrophoretic displays having a monolayer of capsules and materials and methods for making the same

• US 6,839,158 B2
• Filed: 10/06/1999
• Issued: 01/04/2005
• Est. Priority Date: 08/28/1997
• Status: Expired due to Term

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Loxley, Andrew, Crossley, Glen, Albert, Jonathan D., Steiner, Michael L., Comiskey, Barrett, Geramita, Katharine, Amundson, Karl R., Drzaic, Paul, Valianatos, Peter J.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): THOMPSON, TIMOTHY J
• Application Number:
  US09/413,444
• Publication Number:
  US 20030137717A1
• Time in Patent Office: 1,917 Days
• Field of Search: 359/296, 359/452, 359/253, 359/252, 345/107, 345/105, 430 32- 35, 430/58.8, 430/19, 264 4- 47, 252/586, 4284022-40224
• US Class Current: 359/296
• 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 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: G06F 3/1446 display composed of modules, e.g. video walls
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G06K 19/07703 the interface being visual
• CPC Class Codes: G09F 9/302 characterised by the form or geometrical disposition of the individual elements
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: G09G 2380/04 Electronic labels

Abstract

An encapsulated electrophoretic display having a plurality of non-spherical capsules disposed substantially in a single layer on a substrate.

Claims

1. An encapsulated electrophoretic element comprising an electrophoretic ink, the electrophoretic ink comprising a plurality of non-spherical capsules dispersed in a binder, at least one of the capsules being enclosed by a deformable membrane deformed into a non-spherical shape, wherein the plurality of capsules form substantially a single layer when the ink is disposed on a substrate.

2. The element of claim 1 wherein the capsules are substantially uniform in size.

3. The element of claim 1 wherein the capsules are substantially planar on at least one side proximate the substrate.

4. The element of claim 1 wherein the capsules are closely-packed.

5. The element of claim 1 wherein the binder comprises a binder solid and wherein a ratio of the mass of the binder solid to the mass of the capsules is between about 1:

2 and about 1;

20.

6. The element of claim 1 wherein at least a portion of the element has an optically active fraction of at least 70%.

7. The element of claim 1 wherein the single layer of capsules forms a film.

8. The element of claim 7 further comprising a layer of material substantially filling any interstices formed within the film.

9. The element of claim 8 wherein the layer of material is substantially planar on a side opposite the film.

10. The element of claim 8 wherein the capsules, the binder, and the layer of material comprise a stratum having a substantially uniform thickness.

11. The element of claim 10 wherein the stratum has a thickness of about 10 μ

m to about 500 μ

m.

12. The element of claim 8 wherein the layer of material comprises the binder.

13. The element of claim 8 wherein the layer of material comprises an insulator.

14. The element of claim 8 wherein the layer of material is tacky during at least one of prior to, during, and after substantially filling the interstices within the film.

15. The element of claim 8 wherein the layer of material is in a liquid state during at least one of prior to, during, and after substantially filling the interstices within the film.

16. The element of claim 8 wherein the capsules, the binder, and the layer of material comprise a stratum that is substantially free from voids.

17. The element of claim 8 wherein the layer of material has a thickness of less than or equal to about 50 μ

m.

18. The element of claim 8 wherein the layer of material comprises a conductor.

19. The element of claim 8 wherein the layer of material comprises a semiconductor.

20. The element of claim 8 wherein the layer of material comprises an adhesive containing a material selected from the group consisting of carbon particles, gold particles, aluminum particles, platinum particles, silver particles, plated polymer spheres, plated glass spheres, and indium tin oxide particles.

21. The element of claim 8 wherein the layer of material comprises an adhesive containing a material selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polyethylene dioxythiophene, and polythiophene.

22. The element of claim 8 further comprising a rear substrate disposed adjacent the layer of material.

23. The element of claim 22 wherein the layer of material is associated with the film before a lamination procedure of the film is completed.

24. The element of claim 22 wherein the layer of material is associated with the rear substrate before a lamination procedure of the film is completed.

25. The element of claim 22 wherein the rear substrate comprises a material selected from the group consisting of a polymeric material, a glass, and a metal.

26. The element of claim 22 wherein the rear substrate comprises at least one electrode.

27. The element of claim 22 wherein the rear substrate comprises at least one transistor.

28. The element of claim 27 wherein the transistor comprises a silicon-based material.

29. The element of claim 27 wherein the transistor comprises an organic material.

30. The element of claim 22 wherein the rear substrate comprises at least one diode.

31. The element of claim 1 wherein the substrate comprises a polymeric material.

32. The element of claim 1 wherein the substrate comprises at least one electrode.

33. The element of claim 32 wherein the electrode comprises indium tin oxide.

34. The element of claim 1 wherein the substrate comprises a polyester film.

35. The element of claim 1 wherein the substrate has a thickness of about 25 μ

m to about 500 μ

m.

36. The element of a claim 1 wherein the membrane has a thickness from about 0.2 μ

m to about 10 μ

m.

37. The element of claim 1 wherein at least one of the capsules includes a suspending fluid and at least one species of electrophoretic particle.

38. The element of claim 1 wherein at least one of the capsules includes at least two species of electrophoretic particles, wherein an optical property of a first species of particle is different from a second species of particle.

39. The element of claim 1 wherein the binder comprises a curable material.

40. The element of claim 1 wherein the capsules are of more than one shape.

43. The electrophoretic element of claim 1 wherein at least one of the capsules comprises at least one electrophoretic particle dispersed in a mixture of two or more suspending fluids.

44. The element of claim 43 wherein the capsules are closely-packed.

41. An encapsulated electrophoretic element comprising an electrophoretic ink, the electrophoretic ink comprising a plurality of non-spherical capsules dispersed in a binder comprising a binder solid, at least one of the capsules being enclosed by a membrane, wherein the plurality of capsules form substantially a single layer when the ink is disposed on a substrate, and wherein a ratio of a mass of the binder solid to a mass of the capsules is between about 1:

2 and about 1;

20.

42. An encapsulated electrophoretic element comprising an electrophoretic ink, the electrophoretic ink comprising a plurality of non-spherical capsules dispersed in a binder, at least one of the capsules being enclosed by a membrane, and at least one of the capsules comprising at least one electrophoretic particle dispersed in at least one suspending fluid, wherein the plurality of capsules form substantially a single layer when the ink is disposed on a substrate and at least a portion of the element has an optically active fraction of at least 70%.

45. The element of claim 42 wherein the capsules are substantially uniform in size.

46. The element of claim 42 wherein the capsules are of more than one shape.

47. The element of claim 42 wherein the capsules are substantially planar on at least one side proximate the substrate.

48. The element of claim 42 wherein the binder substantially fills any interstices formed within the single layer of capsules.

49. The element of claim 42, wherein the binder comprises a material selected from the group consisting of resins, evaporative liquids, water-soluble polymers, water-dispersed polymers, oil-soluble polymers, thermoset polymers, thermoplastic polymers, radiation-cured polymers, ultraviolet-cured polymers, water-reducible monomers, and water-reducible oligomers.

50. The element of claim 42, wherein the binder comprises a material selected from the group consisting of polysaccharides, polyvinyl alcohols, polyurethanes, acrylics, polyesters, polycarbonates, silicones, and epoxies.

51. The element of claim 42, wherein the at least one suspending fluid is selected from the group consisting of halogenated solvents, saturated hydrocarbons, silicone oils, low molecular weight halogen-containing polymers, epoxides, vinyl ethers, and aromatic hydrocarbons.

52. The element of claim 42, wherein the at least one suspending fluids is selected from the group consisting of toluene, naphthalene, paraffinic liquids, and poly(chlorotrifluoroethylene) polymers.

53. The element of claim 42, wherein the at least one suspending fluid further comprises an additive selected from the group consisting of surface modifiers, dyes, surfactants, charge control agents, and stabilizers.

54. The element of claim 53, wherein the additive is selected from the group consisting of azo dyes, anthraquinone dyes, triphenylmethane dyes and sodium dodecylsulfate.

55. The element of claim 42, wherein the at least one electrophoretic particle is selected from the group consisting of neat pigments, dyed pigments, polymers, composites of pigment and polymer, scattering pigments, absorbing pigments, luminescent particles, and retroreflective particles.

56. The element of claim 42, wherein the at least one electrophoretic particle is selected from the group consisting of zinc sulfide particles and titania particles.

57. The element of claim 56, wherein the at least one particle comprises a metal oxide-coated titania particle.

58. The element of claim 42, wherein the at least one electrophoretic particle comprises a charge control agent.

59. The element of claim 42, further comprising at least one transparent electrode.

60. The element of claim 42, further comprising a black-and-white display.

61. The element of claim 42, wherein further comprising a multi-color display.

62. The element of claim 42, wherein the element is flexible.