Electrochromic devices having no positional offset between substrates

• US 20040061920A1
• Filed: 09/30/2002
• Published: 04/01/2004
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Cammenga, David J., Tonar, William L., Poll, David L., Busscher, Bradley L., Kar, Kevin B.
• Granted Patent: US 7,064,882 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10321 Laminated safety glass or glazing containing liquid layers
• CPC Class Codes: B32B 17/10513 Electrochromic layer
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/161 Gaskets; Spacers; Sealing of cells; Filling or closing of cells
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor

Abstract

To allow an electrochromic device to have little or no offset between its front and rear elements, an electrical conductor may be provided to electrically couple a portion of a first conductive layer provided on the rear surface of the front element with a portion of a second conductive layer provided on the front surface of the rear element. The electrical conductor may be in the form of a conductive portion of the seal. To prevent shorting across the electrochromic medium, at least one of the first and second conductive layers is separated into a first portion and a second portion that is electrically isolated from the first portion and is in electrical contact with the electrochromic material. An elastomeric bezel may be utilized. Also, an edge seal may optionally be employed so as to reduce the need or width of the bezel.

Claims

1. An electrochromic device comprising:

a front element having a front surface and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a front surface and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber;

an electrochromic material disposed in said chamber; and

an electrical conductor provided to electrically couple a portion of said first conductive layer with a portion of said second conductive layer, wherein said electrical conductor is provided on an outside peripheral edge of at least one of said front and rear elements.

2. The electrochromic device of claim 1, wherein said electrical conductor includes electrically conductive particles dispersed within at least a portion of said seal.

3. The electrochromic device of claim 1, wherein said electrical conductor includes electrically conductive particles dispersed within at least a portion of the width of said seal.

4. The electrochromic device of claim 1, wherein said electrical conductor includes electrically conductive particles dispersed within at least a portion of the length of said seal.

5. The electrochromic device of claim 1, wherein said second conductive layer is reflective.

6. The electrochromic device of claim 1, wherein said electrical conductor extends between, and is provided on, outside peripheral edges of both of said front and rear elements.

7. The electrochromic device of claim 1, wherein said electrical conductor forms a continuous path onto said rear surface of said rear element for purpose of electrical contact.

8. The electrochromic device of claim 7, wherein said electrical conductor is configured to contact a second conductor on said rear surface of said rear element.

9. The electrochromic device of claim 1, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

10. An electrochromic variable reflectance mirror for a vehicle, comprising:

a front element having a front surface and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a front surface and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber;

an electrochromic material disposed in said chamber; and

a bezel disposed around the periphery of at least said front element and having front lip extending over part of said front surface of said front element, said front lip of said bezel having a width of about 4 mm or less.

11. The electrochromic mirror of claim 10, wherein said bezel has a width of about 3.6 mm or less.

12. The electrochromic mirror of claim 10, wherein one of said rear surface of said front element and said front surface of said rear element is tapered proximate its peripheral edge to provide a heavy seam, and wherein at least a portion of said seal is provided in said heavy seam.

13. The electrochromic mirror of claim 10, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

14. The electrochromic mirror of claim 10 and further including an electrical conductor provided to electrically couple a portion of said first conductive layer with a portion of said second conductive layer.

15. The electrochromic mirror of claim 10, wherein said front lip of said bezel has a sufficient width to extend over all of said seal.

16. The electrochromic mirror of claim 10, wherein said front lip of said bezel has a sufficient width to extend about 0.5 mm beyond an innermost edge of said seal.

17. An electrochromic variable reflectance mirror for a vehicle, comprising:

a front element having a front surface and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a front surface and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber;

an electrochromic material disposed in said chamber; and

an elastomeric bezel disposed around the periphery of at least one of said elements.

18. The electrochromic device of claim 17, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

19. The electrochromic device of claim 17 and further including an electrical conductor provided to electrically couple a portion of said first conductive layer with a portion of said second conductive layer.

20. The electrochromic device of claim 17, wherein said bezel is made of a material having a tensile modulus of less than about 72,000 psi.

21. The electrochromic device of claim 17, wherein said elastomeric bezel is disposed around the periphery of at least said front element.

22. The electrochromic device of claim 21, wherein the perimeter of said elastomeric bezel is smaller than the perimeter of said front element.

23. A method of making an electrochromic device, said method comprising:

providing a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

providing a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

coating an electrically conductive material to at least a portion of at least one of said peripheral edges;

providing a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber; and

dispensing an electrochromic material in said chamber.

24. The method of claim 23 and further comprising placing an electrically conductive wire between said first and second conductive layers and in electrical contact with at least one of said conductive layers.

25. The method of claim 23, wherein a peripheral area of said front surface of said front element is modified to obscure the view of said seal.

26. The method of claim 23, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

27. The method of claim 23 and further comprising providing an electrical conductor to electrically couple a portion of said first conductive layer with a portion of said second conductive layer.

28. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber;

an electrochromic material disposed in said chamber; and

an electrically conductive wire or strip disposed between said first and second conductive layers and in electrical contact with at least one of said conductive layers.

29. The electrochromic device of claim 28, wherein said electrically conductive wire comprises a plurality of twisted wire strands.

30. The electrochromic device of claim 29, wherein said wire strands are made of at least two different materials.

31. The electrochromic device of claim 28, wherein said wire is electrically coupled to said first conductive layer, and said device further comprises a second wire electrically coupled to said second conductive layer.

32. The electrochromic device of claim 31, wherein said wires are isolated from one another by said seal.

33. The electrochromic device of claim 31, wherein said wire is coated with electrically conductive material.

34. The electrochromic device of claim 31, wherein one of said rear surface of said front element and said front surface of said rear element is tapered proximate its peripheral edge to provide a heavy seam, and wherein at least a portion of said seal and said electrically conductive wire are provided in said heavy seam.

35. The electrochromic device of claim 31, wherein a peripheral area of said front surface of said front element is modified to obscure the view of said seal.

36. The electrochromic device of claim 31, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

37. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber, wherein said seal has at least two electrically conductive regions; and

an electrochromic material disposed in said chamber.

38. The electrochromic device of claim 37, wherein said electrically conductive regions are separated by electrically nonconductive regions of said seal.

39. The electrochromic device of claim 37, wherein said electrically conductive regions are separated by fill ports.

40. The electrochromic device of claim 37, wherein said seal has an electrically nonconductive inner portion disposed between said electrically conductive regions and said electrochromic medium.

41. The electrochromic device of claim 37, wherein said electrically conductive regions of said seal is made of electrically conductive epoxy.

42. The electrochromic device of claim 37, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

43. The electrochromic device of claim 37, wherein said electrically conductive regions of said seal extend less than all of the length of said seal.

44. The electrochromic device of claim 37, wherein said electrically conductive regions of said seal extend less than all of the width of said seal.

45. The electrochromic device of claim 37, wherein one of said rear surface of said front element and said front surface of said rear element is tapered proximate its peripheral edge to provide a heavy seam, and wherein said seal is provided in said heavy seam.

46. The electrochromic device of claim 37 and further comprising an electrically conductive wire provided between said first and second conductive layers and in electrical contact with at least one of said conductive layers.

47. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided to sealably bond said elements together in a spaced-apart relationship to define a chamber, wherein said seal has at least one electrically conductive region; and

an electrochromic material disposed in said chamber, wherein said electrically conductive region of said seal extends less than all of the height of said seal.

48. The electrochromic device of claim 47, wherein a peripheral area of said front surface of said front element is modified to obscure the view of said seal.

49. The electrochromic device of claim 47, wherein said seal has an electrically nonconductive inner portion disposed between said electrically conductive region and said electrochromic medium.

50. The electrochromic device of claim 47, wherein said electrically conductive region of said seal is made of electrically conductive epoxy.

51. The electrochromic device of claim 47, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.

52. The electrochromic device of claim 47, wherein said seal includes two electrically conductive regions separated by an electrically nonconductive region.

53. The electrochromic device of claim 52, wherein said electrically nonconductive region comprises an insulating strip and said electrically conductive regions include a first conductive strip applied to one side of said insulating strip and a second conductive strip applied to an opposite side of said insulating strip.

54. The electrochromic device of claim 53, wherein said electrically conductive regions each further comprise a coating of electrically conductive epoxy.

55. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided on both said front and rear elements to define a sealed chamber between said front and rear elements; and

an electrochromic material disposed in said chamber, wherein said seal comprises a thin member bonded to the peripheral edge of at least one of said front and rear elements.

56. The electrochromic device of claim 55, wherein said thin member comprises one of a film, thin glass, and a strip of foil.

57. The electrochromic device of claim 55, wherein said thin member is electrically conductive and functions as an electrical buss to pass electrical current through said first and second layers of electrically conductive material.

58. The electrochromic device of claim 55, wherein said thin member is bonded to the peripheral edge by an electrically conductive adhesive.

59. The electrochromic device of claim 55, wherein said thin member bonded to the peripheral edge of both of said front and rear elements.

60. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided on both said front and rear elements to define a sealed chamber between said front and rear elements; and

an electrochromic material disposed in said chamber,

wherein said seal is provided predominately on the peripheral edges of said front and rear elements.

61. The electrochromic device of claim 60, wherein said seal comprises a first material having an oxygen permeability of less than 2.0 cm³·

mm/m²·

day·

atm.

62. The electrochromic device of claim 61, wherein said seal is adhered to the peripheral edges of said front and rear elements with a second material.

63. The electrochromic device of claim 62, wherein said second material has a higher oxygen permeability than said first material.

64. The electrochromic device of claim 61, wherein said first material is selected from the group of:

a metal, metal alloy, plastic, glass, and combinations thereof.

65. The electrochromic device of claim 60, wherein said seal comprises a metal, metal alloy, plastic, glass, and combinations thereof.

66. The electrochromic device of claim 60, wherein said seal comprises an electrically conductive adhesive.

67. The electrochromic device of claim 60, wherein said seal comprises an electrically conductive epoxy.

68. The electrochromic device of claim 60, wherein said seal comprises an electrically conductive material that makes electrical contact with at least one of said first and second layers.

69. The electrochromic device of claim 60, wherein said seal contacts said front element both on the peripheral edge and the rear surface of said front element, wherein a first contact area in which said seal contacts the peripheral edge of said front element is larger than a second contact area in which said seal contacts the rear surface of said front element.

70. The electrochromic device of claim 60, wherein said seal contacts said rear element both on the peripheral edge and the front surface of said rear element, wherein a first contact area in which said seal contacts the peripheral edge of said rear element is larger than a second contact area in which said seal contacts the front surface of said rear element.

71. The electrochromic device of claim 60, wherein an interface between said seal and said front element defines an oxygen penetration path length through which oxygen would have to travel to enter said chamber, wherein the portion of the path length extending along the peripheral edge of said front element is longer than the portion of the path length extending along the rear surface of said front element.

72. The electrochromic device of claim 60, wherein an interface between said seal and said rear element defines an oxygen penetration path length through which oxygen would have to travel to enter said chamber, wherein the portion of the path length extending along the peripheral edge of said rear element is longer than the portion of the path length extending along the front surface of said rear element.

73. The electrochromic device of claim 60, wherein said seal comprises a thin member bonded to the peripheral edges of said front and rear elements.

74. The electrochromic device of claim 73, wherein said thin member comprises one of a film, thin glass, and a strip of foil.

75. The electrochromic device of claim 73, wherein said thin member is electrically conductive and functions as an electrical buss to pass electrical current through said first and second layers of electrically conductive material.

76. An electrochromic device comprising:

a front element having a peripheral edge, a front surface, and a rear surface having a first layer of electrically conductive material disposed thereon;

a rear element having a peripheral edge, a front surface, and a rear surface, said front surface of said rear element having a second layer of electrically conductive material disposed thereon;

a seal provided on the peripheral edges of both said front and rear elements to define a sealed chamber between said front and rear elements, wherein said seal comprises a first material having an oxygen permeability of less than about 2.0 cm³·

ml/m²·

day·

atm; and

an electrochromic material disposed in said chamber.

77. The electrochromic device of claim 76, wherein said seal is adhered to the peripheral edges of said front and rear elements with a second material.

78. The electrochromic device of claim 77, wherein said second material has a higher oxygen permeability than said first material.

79. The electrochromic device of claim 76, wherein said first material is selected from the group of:

metal, metal alloy, plastic, glass, and combinations thereof.

80. The electrochromic device of claim 76, wherein said front and rear elements are substantially aligned with less than 0.5 mm offset in any lateral direction.