Switchable electrochromic devices with uniform switching and preferential area shading

• US 6,471,360 B2
• Filed: 07/31/2001
• Issued: 10/29/2002
• Est. Priority Date: 08/03/2000
• Status: Expired due to Term

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Lin, Chia-Cheng, Rukavina, Thomas G.
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US09/919,151
• Publication Number:
  US 20020135881A1
• Time in Patent Office: 455 Days
• Field of Search: 359/609, 359/602, 359/603, 359/604, 359/266, 359/265, 359/267, 359/269, 359/271, 359/452, 359/272, 252/582, 252/583, 427/108, 427/109, 427/162, 427/164, 427/126
• US Class Current: 359/609
• CPC Class Codes: B64C 1/1484 Windows B64C1/1492 takes precedence
• CPC Class Codes: B64C 1/1492 Structure and mounting of the transparent elements in the window or windscreen
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor

Abstract

An electrochromic window assembly includes: a first transparent substrate having a first conductive coating on a surface thereof; a second transparent substrate having a second conductive coating on a surface thereof, the first transparent substrate and the second transparent substrate being spaced from each other to define a chamber therebetween; an electrochromic medium contained in the chamber, the electrochromic medium having a luminous transmittance that varies upon application of an electrical potential through the electrochromic medium; a plurality of first spaced facilities contacting the first conductive coating and capable of delivering electrical current to the first conductive coating; and a plurality of second spaced facilities contacting the second conductive coating and capable of delivering electrical current to the second conductive coating to establish the electrical potential through the electrochromic medium. The plurality of first spaced facilities and the plurality of second spaced facilities can be bus bars arranged about the perimeter of the window assembly. In addition, the window assembly can include a controller capable of controlling delivery of electrical current to selected ones of the plurality of first spaced facilities and selected ones of the plurality of second spaced facilities, such that the luminous transmittance through a first portion of the electrochromic medium is different from the luminous transmittance through a second portion of the electrochromic medium.

Claims

1. An electrochromic window assembly comprising:

a first transparent substrate including a first conductive coating on a surface thereof;

a second transparent substrate including a second conductive coating on a surface thereof, said first transparent substrate and said second transparent substrate being spaced from each other to define a chamber therebetween;

an electrochromic medium contained in said chamber, said electrochromic medium having a luminous transmittance that varies upon application of an electrical potential through said electrochromic medium;

a plurality of first spaced facilities contacting said first conductive coating and capable of delivering electrical current to said first conductive coating;

a plurality of second spaced facilities contacting said second conductive coating and capable of delivering electrical current to said second conductive coating to establish said electrical potential through said electrochromic medium;

a first plurality of connectors, each one of the first plurality of connectors being individually and separately connected to at least a corresponding one of the plurality of first spaced facilities to deliver electrical current to the at least corresponding one of the plurality of first spaced facilities; and

a second plurality of connectors, each one of the second plurality of connectors being individually and separately connected to at least a corresponding one of the plurality of second spaced facilities to deliver electrical current to the at least corresponding one of the plurality of second spaced facilities.

2. The window assembly of claim 1, wherein said plurality of first spaced facilities and said plurality of second spaced facilities are bus bars.

3. The window assembly of claim 1, wherein at least one of said plurality of first spaced facilities and at least one of said plurality of second spaced facilities are positioned about a perimeter of said window assembly.

4. The window assembly of claim 3, wherein said plurality of first spaced facilities and said plurality of second spaced facilities are arranged about said perimeter.

5. The window assembly of claim 4, wherein said plurality of first spaced facilities are arranged between said plurality of second spaced facilities about said perimeter.

6. The window assembly of claim 1, wherein said first transparent substrate and said second transparent substrate have a non-symmetric geometry.

7. The window assembly of claim 1, wherein said plurality of first spaced facilities contact said first conductive coating along opposing ends thereof, and said plurality of second spaced facilities contact said second conductive coating along opposing ends thereof, said opposing ends of said first conductive coating and said opposing edges of said second conductive coating being spaced from each other.

8. The window assembly of claim 7, wherein at least one of said opposing edges of said first conductive coating is in at least close proximity to said perimeter of said widow assembly.

9. The window assembly of claim 8, wherein said opposing ends of said first conductive coating and said opposing ends of said second conductive coating are in at least close proximity to said perimeter of said widow assembly.

10. The window assembly of claim 1, wherein each of said plurality of first spaced facilities are equal in size and each of said plurality of second spaced facilities are equal in size.

11. The window assembly of claim 1, wherein at least one of said plurality of first spaced facilities is of a different length than another of said plurality of first spaced facilities.

12. The window assembly of claim 1, wherein each of said plurality of first spaced facilities and said plurality of second spaced facilities is at least 0.5 inches in length.

13. The window assembly of claim 1, wherein said plurality of first spaced facilities are spaced apart at least 0.5 inches, and said plurality of second spaced facilities are spaced apart at least 0.5 inches.

14. The window assembly of claim 11, wherein each of said plurality of first spaced facilities is spaced from each of said plurality of second spaced facilities about said perimeter at a distance of at least 0.5 inches.

15. The window assembly of claim 1, further comprising resistors positioned to adjust said electrical current delivered to at least one of said plurality of first spaced facilities.

16. The window assembly of claim 1, further comprising a controller capable of controlling delivery of said electrical current to selected ones of said plurality of first spaced facilities and selected ones of said plurality of second spaced facilities, such that said luminous transmittance through a first portion of said electrochromic medium is different from said luminous transmittance through a second portion of said electrochromic medium.

17. The window assembly of claim 16, wherein said controller is capable of shorting said electrical current at other selected ones of said plurality of first spaced facilities and at other selected ones of said plurality second spaced facilities.

18. The window assembly of claim 1, wherein said electrochromic medium comprises at least one anodic electrochromic compound and at least one cathodic electrochromic compound, wherein application of electrical potential to said electrochromic medium causes simultaneous oxidation of said anodic electrochromic compound and reduction of said cathodic electrochromic compound, thereby causing reduced luminous transmittance.

19. The window assembly of claim 1, wherein the electrochromic medium is self-erasing.

20. The window assembly of claim 1, where in said first and second transparent substrates are selected from glass, polymeric materials and combinations thereof.

21. The window assembly of claim 1, wherein said electrochromic window assembly is selected from automotive windshields, automotive side windows, automotive sunroofs, architectural glazings, and aircraft windows.

22. The window assembly of claim 1, wherein said first and said second conductive coatings have a sheet resistance ranging from 1 ohm per square to 10 ohms per square.

23. The window assembly of claim 1, wherein said first and said second conductive coatings have a thickness ranging from 5,000 Å

to 50,000 Å

.

24. The window assembly of claim 1, wherein said electrical current is applied to said first and said second conductive coatings in the range of 0.5 volts to 1.0 volt.

25. The window assembly of claim 1, wherein said luminous transmittance of at least a portion of said assembly varies from a minimum LTA ranging from 1 to 20 percent and a maximum LTA ranging from 60 to 80 percent.