Switchable electrochromic devices for use in aircraft transparency windows

• US 6,561,460 B2
• Filed: 07/31/2001
• Issued: 05/13/2003
• 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): Carone, Michael J.
• Assistant Examiner(s): Sukman, Gabriel S
• Application Number:
  US09/919,152
• Publication Number:
  US 20020113168A1
• Time in Patent Office: 651 Days
• Field of Search: 244/129.3, 244/118.5, 244/119, 359/230, 359/265, 359/273, 359/275
• US Class Current: 244/129.3
• 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

Abstract

An electrochromic aircraft window assembly includes: a) an outboard pane assembly; and b) a fog preventing electrochromic pane assembly spaced from the outboard pane assembly and defining a chamber therebetween, the fog preventing electrochromic pane assembly having: i) a first substrate having a first surface including a first conductive coating and a second surface including a second conductive coating; ii) a second substrate spaced from the first substrate, the second substrate having a first surface including a third conductive coating, the second surface of the first substrate and the first surface of the second substrate facing each other in spaced-apart relation to define a chamber therebetween; iii) an electrochromic medium contained in the chamber and in contact with the second and the third conductive coatings, the electrochromic medium having a luminous transmittance that varies upon application of an electrical potential through the electrochromic medium; iv) facilities for applying electrical current to the first conductive coating to heat the first conductive coating, thereby preventing fogging of the window assembly; and v) facilities for applying electrical current to the second and the third conductive coatings to establish the electrical potential through the electrochromic medium and vary the variable luminous transmittance of the electrochromic medium.

Claims

1. An electrochromic aircraft window assembly comprising:

a) an outboard pane assembly;

b) an electrochromic pane assembly comprising first and second spaced substrates defining a chamber therebetween and 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; and

c) an intermediate pane assembly having anti-fogging properties, wherein said outboard pane assembly and said electrochromic pane assembly have facing surfaces and said intermediate pane assembly is interposed between and spaced from said outboard pane assembly and said electrochromic pane assembly, said intermediate pane assembly preventing fogging of said respective facing surfaces of said outboard pane assembly and said electrochromic pane assembly.

2. The window assembly according to claim 1, wherein said intermediate pane assembly includes a first conductive coating and facilities for applying electrical current to said first conductive coating to heat said first conductive coating, thereby providing said anti-fogging properties.

3. The window assembly according to claim 2, further comprising a second conductive coating on a surface of said first substrate, a third conductive coating on a surface of said second substrate, and facilities for applying electrical current to said second and said third conductive coatings and impress said electrical potential through said electrochromic medium to cause said luminous transmittance of said electrochromic medium to vary, said second conductive coating and said third conductive coating on facing surfaces of said first and second substrates and being spaced from each other.

4. The window assembly according to claim 3, wherein said first, second and third conductive coatings are selected from metal and metal oxide coatings.

5. The window assembly according to claim 4, wherein said first, second and third conductive coatings are selected from fluorine-doped tin oxide, indium tin oxide, antimony-doped tin oxide, silver, gold, and combinations thereof.

6. The window assembly according to claim 3, wherein said electrical current is applied to said first conductive coating at a power density ranging from 0.25 to 0.40 watts/in² and said electrical current is applied to said second and said third conductive coatings at a power density ranging from 0.0001 to 0.01 watts/in².

7. The window assembly according to claim 1, wherein said electrochromic medium comprises at least one anodic electrochromic compound and at least one cathodic electrochromic compound, and 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.

8. The window assembly according to claim 7 wherein, said electrochromic medium is self-erasing upon elimination or reduction of electrical potential to said electrochromic medium.

9. The window assembly according to claim 1, wherein luminous transmittance of said electrochromic pane assembly of said window assembly varies from a minimum LTA ranging from 1 to 20 percent and a maximum LTA ranging from 60 to 80 percent.

10. The window assembly according to claim 1, wherein said first and second spaced substrates are glass.

11. The window assembly according to claim 1, wherein said outboard pane assembly comprises a laminated pane comprising an inboard acrylic layer, an outboard acrylic layer and an interlayer interposed between and adhering together said inboard acrylic layer and said outboard acrylic layer.

12. The window assembly according to claim 11, wherein said inboard acrylic layer is stretched acrylic ranging from 0.2 to 0.4 inches thick, said outboard acrylic layer is stretched acrylic ranging from 0.2 to 0.4 inches thick, and said interlayer is polyvinyl butyral ranging from 0.025 to 0.05 inches thick.

13. The window assembly according to claim 1, wherein said intermediate pane assembly comprises a vibration dampening/sound absorbing pane assembly laminate having a base substrate, an adhesive interlayer deposited over said base substrate and a sound dampening material layer deposited over said adhesive interlayer and adhered to said base substrate by said adhesive layer.

14. The window assembly according to claim 13, wherein said sound dampening material layer is a laminate comprising a polyvinyl butyral layer and a polyester disposed over and in contact with said polyvinyl butyral layer.

15. The window assembly according to claim 14, wherein a conductive coating is interposed between said adhesive layer and said base substrate of said vibration dampening/sound absorbing pane assembly.

16. An electrochromic aircraft window assembly comprising:

a) an outboard pane assembly;

b) a vibration dampening/sound absorbing pane assembly comprising a laminate comprising a base substrate, an adhesive interlayer deposited over a surface of said base substrate, a sound dampening material layer deposited over said adhesive interlayer and adhered to said base substrate by said adhesive layer, and a first conductive coating interposed between said adhesive layer and said base substrate;

c) an electrochromic pane assembly comprising a first substrate having a second conductive coating on a surface thereof and a second substrate having a third conductive coating on a surface thereof, said first and said second substrates spaced from each other with said second and said third conductive coatings facing each other to define a chamber therebetween, said electrochromic pane assembly further comprising an electrochromic medium contained in said chamber, said electrochromic medium having a luminous transmittance that varies upon application of electrical current to said second and said third conductive coatings to establish an electrical potential through said electrochromic medium; and

d) a spacer frame assembly for retaining said outboard pane assembly, said vibration dampening/sound absorbing pane assembly and said electrochromic pane assembly in spaced-apart generally parallel facing relationship with said vibration dampening/sound absorbing pane assembly positioned between said outboard pane assembly and said electrochromic pane assembly, said spacer frame assembly providing a first chamber between said outboard pane assembly and said vibration dampening/sound absorbing pane assembly and second chamber between said vibration dampening/sound absorbing pane assembly and said electrochromic pane assembly.

17. The window assembly according to claim 16, wherein said vibration dampening/sound absorbing pane assembly is retained by said spacer frame assembly with said sound dampening material layer disposed toward said outboard pane assembly.

18. The window assembly according to claim 16, further comprising facilities for applying electrical current to said first conductive coating to heat said first conductive coating and facilities for applying said electrical current to said second and third conductive coatings to vary the luminous transmittance of said electrochromic medium.