Switchable electrochromic devices with uniform switching and preferential area shading

• US 20030047457A1
• Filed: 10/08/2002
• Published: 03/13/2003
• Est. Priority Date: 08/03/2000
• Status: Active Grant

• Current Assignee: Chia-Cheng Lin, Thomas G Rukavina
• Original Assignee: Chia-Cheng Lin, Thomas G Rukavina
• Inventors: Lin, Chia-Cheng, Rukavina, Thomas G.
• Granted Patent: US 7,130,101 B2
• Time in Patent Office: Days
• US Class Current: 205/122
• 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

A method for providing preferential coloring to a portion of an electrochromic window assembly, includes the steps of providing an electrochromic window assembly comprising first and second spaced apart transparent substrates defining a chamber therebetween, the first transparent substrate having a first conductive coating and the second transparent substrate having a second conductive coating, the chamber containing an electrochromic medium capable of coloring upon application of electrical potential thereto to provide reduced luminous transmittance; electrically connecting a plurality of first spaced facilities to the first conductive coating for providing the electrical potential to the first conductive coating; electrically connecting a plurality of second spaced facilities to the second conductive coating for providing the electrical potential to the second conductive coating; and applying an electrical current to selected ones of the plurality of first spaced facilities and to selected ones of the plurality of second spaced facilities to establish the electrical potential through a selected portion of the electrochromic medium such that the selected portion changes color and reduces its luminous transmittance.

Claims

26. A method for providing uniform coloring to an electrochromic window assembly comprising:

providing an electrochromic window assembly comprising first and second spaced apart transparent substrates defining a chamber therebetween, said first transparent substrate having a first conductive coating and said second transparent substrate having a second conductive coating, said chamber containing an electrochromic medium capable of coloring upon application of electrical potential thereto to provide reduced luminous transmittance; and

applying an electrical current to opposing ends of said first conductive coating and to opposing ends of said second conductive coating to establish said electrical potential through said electrochromic medium, said opposing ends of said first conductive coating and said second conductive coating being spaced from each other,

wherein said coloring of said electrochromic medium is uniform.

27. The method according to claim 26, wherein said opposing ends of said first conductive coating and said opposing ends of said second conductive coating are at least in close proximity to a perimeter edge of said assembly.

28. The method according to claim 26, further comprising positioning a plurality of first spaced facilities along opposing ends of said first transparent substrate in electrical contact with said opposing ends of said first coating for providing said electrical current to said first conductive coating and positioning a plurality of second spaced facilities along opposing ends of said second transparent substrate in electrical contact with said opposing ends of said second coating for providing said electrical current to said second conductive coating.

29. A method for providing preferential coloring to a portion of an electrochromic window assembly, comprising:

providing an electrochromic window assembly comprising first and second spaced apart transparent substrates defining a chamber therebetween, said first transparent substrate having a first conductive coating and said second transparent substrate having a second conductive coating, said chamber containing an electrochromic medium capable of coloring upon application of electrical potential thereto to provide reduced luminous transmittance;

electrically connecting a plurality of first spaced facilities to said first conductive coating for providing said electrical potential to said first conductive coating;

electrically connecting a plurality of second spaced facilities to said second conductive coating for providing said electrical potential to said second conductive coating;

applying an electrical current to selected ones of said plurality of first spaced facilities and to selected ones of said plurality of second spaced facilities to establish said electrical potential through a selected portion of said electrochromic medium such that said selected portion changes color and reduces its luminous transmittance.

30. The method according to claim 29, comprising positioning opposing ends of said first conductive coating at least in close proximity to a perimeter of said assembly and positioning opposing ends of said second conductive coating at least in close proximity to said perimeter of said assembly, electrically connecting said plurality of first spaced facilities to said first conductive coating along said opposing ends of said first conductive coating, and electrically connecting said plurality of second spaced facilities to said second conductive coating along said opposing ends of said second conductive coating.

31. The method according to claim 30, comprising spacing said opposing ends of said first conductive coating from said opposing ends of said second conductive coating along said perimeter of said assembly.

32. The method according to claim 29, further comprising shorting said electrical current at other selected ones of said plurality of first spaced facilities and at other selected ones of said plurality of second spaced facilities.

33. The method according to claim 29, further comprising varying said electrical current applied to said selected ones of said plurality of first spaced facilities and to said selected ones of said plurality of second spaced facilities, to provide varying degrees of reduced luminous transmittance to said selected portion of said electrochromic medium.

34. The method according to claim 33, wherein said electrochromic window assembly is an automotive windshield and said portion of said electrochromic medium is a shade band.

35. The method according to claim 29, comprising positioning said first conductive coating at least in close proximity to a perimeter of said assembly and positioning said second conductive coating at least in close proximity to said perimeter edge of said assembly, electrically connecting said plurality of first spaced facilities to said first conductive coating about said entire perimeter, and electrically connecting said plurality of second spaced facilities to said second conductive coating about said entire perimeter

36. The method according to claim 35, comprising spacing said plurality of first spaced facilities at least 0.5 inches apart about said perimeter, spacing said plurality of second spaced facilities at least 0.5 inches apart about said perimeter, and spacing said plurality of first spaced facilities from said plurality of second spaced facilities at least 0.5 inches about said perimeter.

37. The method of claim 29, wherein said first and said second conductive coatings, each have a sheet resistance ranging from 1 ohm per square to 10 ohms per square.

38. The method of claim 29, wherein said first and said second conductive coatings, each have a thickness ranging from 5,000 Å

to 50,000 Å

.

39. The method of claim 29, 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.

40. The method of claim 33, comprising varying said electrical current such that 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.