Indicia display for electro-optic devices wherein the indicia comprises a dielectric material extending at least partially into the electro-optic medium

• US 5,189,537 A
• Filed: 01/28/1991
• Issued: 02/23/1993
• Est. Priority Date: 01/28/1991
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: O'Farrell, Desmond J.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US07/647,296
• Time in Patent Office: 757 Days
• Field of Search: 350/338, 350/339 R, 350/343, 350/331 R, 350/355, 350/356, 350/357, 350/344, 359/70, 359/71, 359/79, 359/80, 359/74, 359/839, 359/838, 359/843, 359/245, 359/267, 359/38, 359/254, 362/83.1
• US Class Current: 349/195
• CPC Class Codes: B60R 1/0602 comprising means for cleaning or deicing
• CPC Class Codes: B60R 1/082 using a single wide field mirror or an association of rigidly connected mirrors
• 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 1/133374 for displaying permanent signs or marks
• CPC Class Codes: G09F 9/35 being liquid crystals G09F9/302 takes precedence; liquid crystal materials C09K19/00; liquid crystal panels comprising a number of electrodes in a single cell per se G02F1/13

Abstract

An electro-optic device useful as a vehicular mirror or panel, an architectural panel, or the like includes two optically transparent substrates positioned in spaced relation to each other. An electro-optic medium having a light transmittance which is variable with the application of an electric field is captured in the space between the substrates. Indicia is applied to one of the inside surfaces of the substrates. In one aspect of the invention, a dielectric material is used for the indicia. The indicia remain visible for viewing at all times during operation of the device.

Claims

1. An electro-optic device comprising:

a pair of optically transparent substrates positioned in spaced relation to one another, each substrate having an inner surface facing the inner surface of the other substrate, an opposing outer surface and a perimeter edge, said inner surfaces defining a space between said substrates;

an electro-optic medium confined in said space and having a light transmittance which is variable by the application of an electric field;

a seal extending between said substrates near their respective perimeter edges, circumscribing said space between said substrates, and confining said electro-optic medium in said space;

electrical means for applying an electric field to said electro-optic medium; and

a dielectric material forming indicia on at least one of said inner surfaces, said indicia extending from said one surface toward the other of said surfaces and extending at least partially into said electro-optic medium.

2. The device of claim 1 wherein said indicia have thickness, said space has width and said thickness is not greater than said width.

3. The device of claim 2 wherein said indicia are a layer of epoxy material.

4. The device of claim 3 wherein said epoxy material of said indicia includes a substantially nonconductive coloring agent for enhancing the visibility of said indicia.

5. The device of claim 1 wherein said electrical means includes an optically transparent, electrically conductive layer on each of said inner surfaces.

6. The device of claim 5 wherein said electrical means further includes an electrical lead connected to each of said conductive layers.

7. The device of claim 5 wherein said seal is formed of a dielectric material.

8. The device of claim 7 wherein said seal is a layer of epoxy material.

9. The device of claim 7 wherein said seal is a layer of epoxy material incorporating a plurality of small glass beads mixed therein.

10. The device of claim 7 wherein said electro-optic medium is a liquid crystal material in which molecules are oriented to block the passage of light therethrough when an electric field is applied thereto.

11. The device of claim 7 wherein said electro-optic medium is one of an electrochemichromic material and an electrochromic material.

12. The device of claim 7 wherein said device further includes a reflective coating on one of said inner and outer surfaces of one of said substrates, said coating being adapted to reflect light incident thereon through said electro-optic medium and said other substrate.

13. The device of claim 12 wherein said indicia are located on said inner surface of said substrate which has said reflective coating thereon.

14. The device of claim 13 wherein said reflective coating is on said outer surface.

15. An electro-optic device comprising:

a first optically transparent substrate having a front surface, an opposing rear surface and a perimeter edge;

a second optically transparent substrate having a front surface, an opposing rear surface and a perimeter edge, said second substrate being positioned in spaced relation to said first substrate to define a space having thickness between said rear surface of said first substrate and said front surface of said second substrate;

an electro-optic medium confined in said space and having a light transmittance which is variable by the application of an electric field;

a seal circumscribing said space and extending between said first and second substrates near their respective perimeter edges for spacing said substrates apart and confining said electro-optic medium in said space;

electrical means for applying an electric field to said electro-optic medium;

a reflective coating on one of said front surface and rear surface of said second substrate and adapted to reflect light incident thereon through said electro-optic medium and said first substrate; and

a dielectric material indicia on one of said rear surfaces of said first substrate and said front surface of said second substrate, said indicia extending from said one surface toward the other of said surfaces and extending at least partially into said electro-optic medium.

16. The device of claim 15 wherein said indicia has a thickness which is not greater than said space thickness.

17. The device of claim 16 wherein said indicia are located on said front surface of said second substrate.

18. The device of claim 17 wherein said indicia are a layer of epoxy material.

19. The device of claim 18 wherein said epoxy material of said indicia includes a substantially nonconductive coloring agent for enhancing the visibility of said indicia.

20. The device of claim 16 wherein said electrical means includes an optically transparent, electrically conductive layer on each of said rear surface of said first substrate and said front surface of said second substrate.

21. The device of claim 20 wherein said electrical means further includes an electrical lead connected to each of said conductive layers.

22. The device of claim 20 wherein said seal is formed of a dielectric material

23. The device of claim 22 wherein said seal is a layer of epoxy material.

24. The device of claim 22 wherein said seal is a layer of epoxy material incorporating a plurality of small glass beads mixed therein.

25. The device of claim 22 wherein said electro-optic medium is a liquid crystal material in which molecules are oriented to block the passage of light therethrough when an electric field is applied thereto.

26. The device of claim 22 wherein said electro-optic medium is one of an electrochemichromic material and an electrochromic material.

27. The device of claim 22 wherein said reflective coating is on said rear surface of said second substrate.

28. The device of claim 27 wherein said reflective coating is a layer of one of aluminum, a combination of silver and copper, chromium, stainless steel, rhodium, platinum and palladium.

29. An electro-optic device comprising:

at least a pair of optically transparent substrates positioned in generally parallel spaced relation to one another, each of said substrates having an inner surface facing the inner surface of the other substrate, an opposing outer surface and a perimeter edge, said inner surfaces defining a space having thickness between said substrates;

an electro-optic medium confined in said space and having a light transmittance which is variable by the application of an electric field;

a seal circumscribing said space and extending between said substrates near their respective perimeter edges for spacing said substrates apart and confining said electro-optic medium in said space;

electrical means including an optically transparent, electrically conductive layer on each of said inner surfaces for applying an electric field to said electro-optic medium;

a reflective coating on one of said inner and outer surfaces of one of said substrates and adapted to reflect light incident thereon through said electro-optic medium and said other substrate; and

a dielectric material forming indicia on one of said inner surfaces, said indicia extending from said one surface toward the other of said surfaces and extending at least partially into said electro-optic medium.

30. The device of claim 29 wherein said indicia has a thickness which is not greater than said space thickness.

31. The device of claim 30 wherein said indicia are located on said inner surface of said substrate which has said reflective coating thereon.

32. The device of claim 31 wherein said indicia are a layer of epoxy material.

33. The device of claim 32 wherein said epoxy material of said indicia includes a substantially nonconductive coloring agent for enhancing the visibility of said indicia.

34. The device of claim 29 wherein said electrical means further includes an electrical lead connected to each of the conductive layers.

35. The device of claim 29 wherein said seal is formed of a dielectric material.

36. The device of claim 35 wherein said seal is a layer of epoxy material.

37. The device of claim 35 wherein said seal is a layer of epoxy material incorporating a plurality of small glass beads mixed therein.

38. The device of claim 35 wherein said electro-optic medium is a liquid crystal material in which molecules are oriented to block the passage of light therethrough when an electric field is applied thereto.

39. The device of claim 35 wherein said electro-optic medium is one of an electrochemichromic material and an electrochromic material.

40. The device of claim 35 wherein said reflective coating is on said outer surface.

41. The device of claim 40 wherein said reflective coating is a layer of one of aluminum, a combination of silver and cooper, chromium, stainless steel, rhodium, platinum and palladium.