Electrochromic rearview mirror incorporating a third surface metal reflector

• US 6,064,508 A
• Filed: 07/13/1998
• Issued: 05/16/2000
• Est. Priority Date: 04/02/1997
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Genetex Incorporated
• Inventors: Tonar, William L., Bauer, Frederick T., Byker, Harlan J., Forgette, Jeffrey A.
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): BURKE, MARGARET A
• Application Number:
  US09/114,386
• Time in Patent Office: 673 Days
• Field of Search: 359/265, 359/267, 359/269, 359/271, 359/272, 359/274, 359/603
• US Class Current: 359/267
• CPC Class Codes: B60Q 1/2665 on rear-view mirrors lighting devices for vehicle interior on or for rear-view mirrors B60Q3/258
• 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 1/1506 caused by electrodeposition, e.g. electrolytic deposition of an inorganic material on or close to an electrode
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 2001/1502 complementary cell
• CPC Class Codes: G02F 2001/15145 the electrochromic layer comprises a mixture of anodic and cathodic compounds
• CPC Class Codes: G02F 2201/34 reflector
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: H10K 50/87 Arrangements for heating or cooling

Abstract

An electrochromic variable reflectance mirror for a vehicle includes a reflector/electrode on the third surface of the mirror. This reflector/electrode forms an integral electrode in contact with the electrochromic media, and may be a single layer of a highly reflective material or may comprise a series of coatings. When a series of coatings is used for the reflector/electrode, there should be a base coating which bonds to the glass surface and resists any adverse interaction, e.g., corrosive action, with the constituents comprising the electrochromic media, an optional intermediate layer (or layers) which bonds well to the base coating and resists any adverse interaction with the electrochromic media, and at least one highly reflective layer which directly contacts the electrochromic media and which is chosen primarily for its high reflectance, stable behavior as an electrode, resistance to adverse interaction with the materials of the electrochromic media, resistance to atmospheric corrosion, resistance to electrical contact corrosion, the ability to adhere to the base or intermediate layer(s) (if present) and to the epoxy seal, and ease of cleaning. If a base layer is deposited it preferably covers the entire third surface; however, when this is done the highly reflective layer may optionally only coat the central portion of the third surface and not the perimeter edge portion. The third surface reflector/electrode provides of improved electrical interconnection techniques used to impart a voltage drive potential to a transparent conductor on the mirror'"'"'s second surface.

Claims

1. An electrochromic variable reflectance mirror for automotive vehicles, comprising front and rear spaced elements, each having front and rear surfaces, said rear surface of said front element having a layer of transparent conductive material disposed thereon, said front surface of said rear element having a reflector/electrode including at least a layer of reflective material, where said front and rear spaced elements are sealably bonded together in a spaced-apart relationship to define a chamber, where said chamber contains at least one electrochromic material and a cross-linked polymer matrix, and where said reflector/electrode is effective to reflect light through said electrochromic material and said front element when said light reaches said reflector/electrode after passing through said front element and said at least one electrochromic material.

2. The mirror according to claim 1, where said reflective material is silver.

3. The mirror according to claim 1, where said reflector/electrode comprises a plurality of layers.

4. The mirror according to claim 3, where said reflector/electrode further includes a base layer disposed beneath said reflective material.

5. The mirror according to claim 4, where said base layer comprises a material selected from the group consisting of:

chromium;

chromium-molybdenum-nickel alloys;

nickel-iron-chromium alloys;

stainless steel; and

titanium.

6. The mirror according to claim 5, where said reflector/electrode further includes at least one intermediate layer disposed between said reflective material and said base layer, where said intermediate layer comprises a material selected from the group consisting of:

molybdenum;

rhodium;

stainless steel; and

titanium.

7. The mirror according to claim 6, where said reflector/electrode further includes at least one flash over-layer disposed over said reflective material, where said flash over-layer comprises a material selected from the group consisting of:

rhodium, molybdenum, and platinum.

8. The mirror according to claim 1, where said layer of transparent conductive material has a sheet resistance ranging from about 0.1 ohms per square to about 40 ohms per square.

9. The mirror according to claim 1, where the sheet resistance of said transparent conductor ranges from about 0.5 ohms per square to about 15 ohms per square.

22. The mirror according to claim 1, wherein said reflector/electrode has a sheet resistance below 2 ohms per square.

23. The mirror according to claim 1, wherein said layer of transparent conductive material has a sheet resistance ranging from about 0.1 ohms per square to about 20 ohms per square.

24. The mirror according to claim 1, wherein said layer of transparent conductive material has a sheet resistance ranging from about 0.2 ohms per square to about 6 ohms per square.

25. The mirror according to claim 1, wherein said cross-linked polymer matrix cooperatively interacts with said front and rear elements.

26. The mirror according to claim 1, wherein said mirror is an outside mirror.

27. The mirror according to claim 26, wherein said mirror has a reflectance of at least about 50 percent.

28. The mirror according to claim 1, wherein said mirror is an inside mirror.

29. The mirror according to claim 28, wherein said mirror has a reflectance of at least about 70 percent.

30. The mirror according to claim 1, wherein said electrochromic material is a solution-phase electrochromic material contained within said chamber in contact with said reflector/electrode.

31. The mirror according to claim 1, wherein said electrochromic material is in a solution that is interspersed in said cross-linked polymer matrix.

10. An electrochromic variable reflectance mirror for automotive vehicles, comprising front and rear spaced elements, each having front and rear surfaces, said rear surface of said front element having a layer of transparent conductive material disposed thereon, said front surface of said rear element having a reflector/electrode comprising a base layer and at least one additional layer including a layer of a reflective material, where said front and rear spaced elements are sealably bonded together in a spaced-apart relationship to define a chamber, where said chamber contains a cross-linked polymer matrix and at least one solution-phase electrochromic material in contact with said reflector/electrode, and where said reflector/electrode is effective to reflect light through said electrochromic material and said front element when said light reaches said reflector/electrode after passing through said front element and said at least one electrochromic material.

11. The mirror according to claim 10, where said reflective material is a material selected from the group consisting of silver and silver alloys.

12. The mirror according to claim 10, where said base layer bonds to said front surface of said rear element and where one of said at least one additional layer bonds to said base layer.

13. The mirror according to claim 10, where said base layer comprises a material selected from the group consisting of:

chromium;

chromium-molybdenum-nickel alloys;

nickel-iron-chromium alloys;

stainless steel; and

titanium.

14. The mirror according to claim 10, where said reflector/electrode further includes at least one intermediate layer disposed between said reflective material and said base layer.

15. An electrochromic variable reflectance mirror for automotive vehicles, comprising front and rear spaced elements, each having front and rear surfaces, said rear surface of said front element having a layer of transparent conductive material disposed thereon having a sheet resistance of less than 6 ohms per square, said front surface of said rear element having at least one layer of a reflector/electrode comprising a reflective material covering an inner portion of said front surface of said rear element and extending to a small area of an edge thereof, said front and rear spaced elements being bonded together in a spaced-apart relationship to define a chamber by a seal member disposed on said conductive material, where said chamber contains a cross-linked polymer matrix and at least one solution-phase electrochromic material in contact with said reflector/electrode, and where said reflector/electrode is effective to reflect light through said electrochromic material and said front element when said light reaches said reflector/electrode after passing through said front element and said at least one electrochromic material.

16. The mirror according to claim 15, where said reflective material is a material selected from the group consisting of silver and silver alloys.

17. The mirror according to claim 15, where said reflector/electrode further includes a base layer that bonds to said front surface of said rear element and where one of said at least one additional layer bonds to said base layer.

18. The mirror according to claim 17, where said base layer comprises a material selected from the group consisting of:

chromium;

chromium-molybdenum-nickel alloys;

nickel-iron-chromium alloys;

stainless steel; and

titanium.

19. The mirror according to claim 15, where said reflector/electrode further includes at least one intermediate layer disposed between said reflective material and said base layer.

20. The mirror according to claim 15, where said reflector/electrode further includes a flash layer disposed over said reflective material.

21. The mirror according to claim 15, where said rear surface of said front element includes means for increasing conductance to said transparent conductive material.