Electro-optic window assembly

• US 9,146,437 B2
• Filed: 01/31/2014
• Issued: 09/29/2015
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Driscoll, David I., Busscher, Bradley L., Ash, Kevin L.
• Primary Examiner(s): Spector, David N
• Application Number:
  US14/169,641
• Publication Number:
  US 20140268288A1
• Time in Patent Office: 606 Days
• US Class Current: 1/1
• CPC Class Codes: B64C 1/1484 Windows B64C1/1492 takes precedence
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for

Abstract

An electro-optic window assembly is provided that includes a first substantially transparent substrate comprising: a first surface, a second surface, and a first peripheral edge; and a second substantially transparent substrate comprising: a third surface, a fourth surface, and a second peripheral edge. The first and second substrates define a cavity. The assembly further includes an electro-optic medium at least partially filling the cavity and configured to reduce the transmission of light viewed through the electro-optic window assembly. Further, the electro-optic window assembly is configured such that the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa upon exposure of the window assembly to an application environment.

Claims

1. An electro-optic window assembly, comprising:

a first substantially transparent substrate comprising;

a first surface,

a second surface, and

a first peripheral edge;

a second substantially transparent substrate comprising;

a third surface,

a fourth surface, and

a second peripheral edge,

wherein the first and second substrates define a cavity; and

an electro-optic medium at least partially filling the cavity and configured to reduce the transmission of light viewed through the electro-optic window assembly,

wherein the electro-optic window assembly is configured such that the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa upon exposure of the window assembly to an approximately 50°

C. thermal gradient.

2. The electro-optic window assembly of claim 1, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 20 MPa.

3. The electro-optic window assembly of claim 1, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 15 MPa.

4. The electro-optic window assembly of claim 1, wherein the substrates each have a theoretical maximum thermal stress of less than or equal to approximately 12 MPa.

5. The electro-optic window assembly of claim 1, wherein the substrates consist essentially of a composition with a coefficient of thermal expansion of approximately 37×

10<sup>−

7</sup>°

C.<sup>−

1</sup> or less.

6. The electro-optic window assembly of claim 5, wherein the peripheral edges of the substrates are substantially defect free, indicative of a grinding operation.

7. An electro-optic window assembly, comprising:

a bezel having an inner edge, the bezel covering a peripheral portion of a first substantially transparent substrate and a peripheral portion of a second substantially transparent substrate;

a first substantially transparent substrate comprising;

a first surface with a portion in thermal communication with the bezel,

a second surface, and

a first peripheral edge;

a second substantially transparent substrate comprising;

a third surface,

a fourth surface with a portion in thermal communication with the bezel, and a

second peripheral edge,

wherein the first and second substrates define a cavity, and the fourth surface and the inner edge of the bezel define a visible area; and

an electro-optic medium at least partially filling the cavity and configured to reduce the transmission of light viewed through the electro-optic window assembly,

wherein the visible area and the peripheral portions are sized such that the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa upon exposure of the electro-optic window assembly to an approximately 50°

C. thermal gradient.

8. The electro-optic window assembly of claim 7, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 20 MPa.

9. The electro-optic window assembly of claim 7, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 15 MPa.

10. The electro-optic window assembly of claim 7, wherein the substrates each have a theoretical maximum thermal stress of less than or equal to approximately 12 MPa.

11. The electro-optic window assembly of claim 7, further comprising:

a high thermal conductivity layer between the bezel and the peripheral portions of the substrates.

12. The electro-optic window assembly of claim 7, wherein the substrates consist essentially of a composition with a coefficient of thermal expansion of approximately 37×

10<sup>−

7</sup>°

C.<sup>−

1</sup> or less.

13. The electro-optic window assembly of claim 12, wherein the peripheral edges of the substrates are substantially defect free, indicative of a grinding operation.

14. An electro-optic window assembly, comprising:

an exterior structure;

a bezel in thermal communication with the exterior structure, the bezel having an inner edge, and covering a peripheral portion of a first substantially transparent substrate and a peripheral portion of a second substantially transparent substrate;

a first substantially transparent substrate comprising;

a first surface with a portion in thermal communication with the bezel,

a second surface, and

a first peripheral edge;

a second substantially transparent substrate comprising;

a third surface,

a fourth surface with a portion in thermal communication with the bezel, and a

second peripheral edge,

wherein the first and second substrates define a cavity, and the fourth surface and the inner edge of the bezel define a visible area; and

an electro-optic medium at least partially filling the cavity and configured to reduce the transmission of light viewed through the electro-optic window assembly,

wherein the electro-optic window assembly is configured such that the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa when an approximately 50°

C. thermal gradient exists between the peripheral portions of the substrates and the visible area.

15. The electro-optic window assembly of claim 14, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa when an approximately 75°

C. thermal gradient exists between the peripheral portions of the substrates and the visible area.

16. The electro-optic window assembly of claim 14, wherein the substrates each have a theoretical maximum thermal stress of less than approximately 25 MPa when an approximately 100°

C. thermal gradient exists between the peripheral portions of the substrates and the visible area.

17. The electro-optic window assembly of claim 14, wherein the substrates each have a theoretical maximum thermal stress of less than or equal to approximately 25 MPa when an approximately 150°

C. thermal gradient exists between the peripheral portions of the substrates and the visible area.

18. The electro-optic window assembly of claim 14, further comprising:

a high thermal conductivity layer between the bezel and the peripheral portions of the substrates.

19. The electro-optic window assembly of claim 14, wherein the substrates consist essentially of a composition with a coefficient of thermal expansion of approximately 37×

10<sup>−

7</sup>°

C.<sup>−

1</sup> or less.

20. The electro-optic window assembly of claim 19, wherein the peripheral edges of the substrates are substantially defect free, indicative of a grinding operation.