Transparent window panel with a field of view that can be partially darkened and method of controlling a surface element that can be electrochromically lightened inside a transparent window panel

• US 20070133078A1
• Filed: 02/03/2005
• Published: 06/14/2007
• Est. Priority Date: 02/05/2004
• Status: Active Grant

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Dubrenat, Samuel, Fanton, Xavier, Schuett, Juergen, Claude, Laurent
• Granted Patent: US 7,649,668 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10513 Electrochromic layer
• CPC Class Codes: B60J 3/04 adjustable in transparency
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/1557 Side by side arrangements of working and counter electrodes

Abstract

A transparent glazing, and a control method thereof, with a field of view that can be darkened over a portion of its surface by electrically controlling at least one functional element incorporated into a multilayer composite, the light transmission of which glazing can be varied reversibly. The functional element, for example a solid-state electrochromic multilayer system, includes at least one electrochromic functional layer enclosed between two surface electrodes. The surface electrodes and their leads are matched to one another and spaced spatially with respect to one another such that darkening starts at one edge of the functional element and, with a remaining voltage applied between the surface electrodes, propagates continuously over the surface of the functional element until it is completely and uniformly colored. The glazing can be used as an electrically controllable sunshield for windshields of vehicles or the like.

Claims

1-18. -18. (canceled)

19. A transparent glazing with a field of view that can be darkened over a portion of its surface by electrically controlling at least one functional element incorporated into a multilayer composite, the light transmission of which glazing can be varied reversibly, in which portion the functional element, comprises:

at least one electrochromic functional layer enclosed between two surface electrodes,

wherein the surface electrodes of the functional element and their leads are matched to one another and spaced spatially with respect to one another such that darkening starts at one edge of the functional element and, with a remaining voltage applied between the surface electrodes, propagates continuously over the surface of the functional element until the functional element is completely and uniformly colored.

20. The transparent glazing as claimed in claim 19, wherein at least one of the surface electrodes is connected to at least one connection conductor having a low ohmic resistance, which conductor is parallel to and is placed close to a lateral edge of the functional element.

21. The transparent glazing as claimed in claim 19, wherein at least one of the surface electrodes includes two connection conductors of low ohmic resistance, which are placed on either side of the functional element and can be subjected to electrical potentials independently of each other via suitable external leads.

22. The transparent glazing as claimed in claim 19, wherein the functional element extends along one side of the glazing and, from the one side, into the field of view of the glazing, the darkening of which field of view starts in the region of the one side.

23. The transparent glazing as claimed in claim 21, wherein a first of the connection conductors is placed near a first side of the glazing and a second of the connection conductors is placed on a second side of the functional element, in a region lying between a boundary located in the field of view and the opposite side of the glazing.

24. The transparent glazing as claimed in claim 23, wherein the second connection conductor, which is in the field of view of the glazing, is in a form of at least one thin metal wire.

25. The transparent glazing as claimed in claim 19, wherein the functional element extends from a first side of the glazing and then between two mutually opposite sides of the glazing and being angularly connected to the first side, in which glazing one of its surface electrodes is brought into electrical contact toward the outside from at least one surface extending along the opposite sides.

26. The transparent glazing as claimed in claim 25, wherein the surface electrode remote from the substrate is electrically connected to at least one lead lying at the edge of the glazing by at least one thin metal wire extending over that surface of the functional element that lies in the field of view of the glazing.

27. The transparent glazing as claimed in claim 19, wherein the surface electrode close to the substrate is in a form of a substantially complete coating of the glazing, the functional element is formed only over a portion of the coating, such that lateral bands not covered by the functional element are formed on at least two sides of the glazing forming an angle between them, the lateral bands of the surface electrode are electrically isolated from one another, and a connection band, one of which is electrically connected to the surface electrode close to the substrate and the other of which is electrically connected to the surface electrode remote from the substrate of the functional element, is provided on each of the lateral bands.

28. The transparent glazing as claimed in claim 19, wherein the two surface electrodes have different surface resistances.

29. The transparent glazing as claimed in claim 28, wherein the surface electrode closer to the substrate has a lower surface resistance than the surface electrode more remote from the substrate.

30. The transparent glazing as claimed in claim 28, wherein the surface resistance of the surface electrode closer to the substrate lies within a range from 0.01 to 100 ohms per unit area, preferably from 2 to 10 ohms per unit area, and more preferably about 6-7 ohms per unit area, and wherein the surface resistance of the surface electrode more remote from the substrate is about 10 times these values.

31. The transparent glazing as claimed in claim 19, wherein an opaque edge frame extends over at least a portion of its perimeter along the edge of the latter, and wherein electrical leads for the surface electrodes are placed on the surface of this edge frame.

32. The use of transparent glazing as claimed in claim 19 as a windshield for a vehicle, in which the functional element is an all-solid-state electrochromic multilayer system placed, as an electrically controllable sunshield, in a region of a top edge in a mounted state.

33. A method for controlling a functional element in a form of an all-solid-state electrochromic surface element in a transparent glazing unit, which all-solid-state surface element includes a functional layer that can be reversibly decolored electrochromically, and inserted between two surface electrodes, wherein the surface electrodes have different surface resistances from which an increase in supply voltage in the surface of the surface electrodes proceeds at different rates for any one voltage level, the method comprising:

introducing an effective electrical potential into one of the surface electrodes relative to the other surface electrode, forcing an electrochromic change of color on one side of the electrochromic surface element so as to control one direction of propagation of the change of color of the electrochromic surface element.

34. The method as claimed in claim 33, wherein at least one supply lead for electrical potentials causing the electrochromic color change is provided on at least one of the surface electrodes on either side of the all-solid-state electrochromic surface element.

35. The method as claimed in claim 33, wherein a first effective potential is applied via a first supply lead for the surface electrode relative to the other surface electrode to induce a coloration in a predetermined direction of propagation of the color change, and wherein a second effective potential, of reverse polarity, is applied via a second supply lead for the surface electrode relative to the other surface electrode to produce decoloration in a predetermined direction of propagation of the color change.

36. The method as claimed in claim 33, in an application for controlling an electrochromic functional element incorporated as a sunshield in a windshield of a vehicle.