Switchable optical device and method for manufacturing of a switchable optical device

1. A switchable optical device ( 1 ) comprising: a first substrate ( 11 ), a second substrate ( 12 ) and a seal ( 114 ), the two substrates ( 11 , 12 ) and the seal ( 114 ) being arranged such that a cell having a cell gap is formed, a switchable medium ( 10 ) being located inside the cell gap, the first substrate ( 11 ) having a first transparent electrode ( 21 ) and the second substrate ( 12 ) having a second transparent electrode ( 22 ), the electrodes ( 21 , 22 ) facing towards the cell gap, the two substrates ( 11 , 12 ) being arranged such that the first substrate ( 11 ) has a first region ( 71 ) adjacent to a first edge ( 41 ) of the first substrate ( 11 ) which does not overlap with the second substrate ( 12 ) and that the second substrate ( 12 ) has a second region ( 72 ) adjacent to a second edge ( 42 ) of the second substrate ( 12 ) which does not overlap with the first substrate ( 11 ), a first electrically conducting busbar ( 31 ) being arranged in the first region ( 71 ) and a second electrically conducting busbar ( 32 ) being arranged in the second region ( 72 ), and a first terminal being electrically connected to the first busbar ( 31 ) and a second terminal being electrically connected to the second busbar ( 32 ), wherein the first substrate ( 11 ) and the second substrate ( 12 ) each have an edge deletion ( 116 ) in which the transparent conductive electrodes ( 21 , 22 ) are removed, wherein the edge deletion ( 116 ) is complete on the edges non-adjacent to a busbar ( 31 , 32 ) and there is no or only partial edge deletion on edges adjacent to a busbar ( 31 , 32 ).

2. The switchable optical device ( 1 ) according to claim 1 , wherein the first busbar ( 31 ) is constructed as a continuous soldered line ( 105 ) in contact with the first transparent electrode ( 21 ) and arranged in the first region ( 71 ) and/or the second busbar ( 32 ) is constructed as a continuous soldered line ( 105 ) in contact with the second transparent electrode ( 22 ) and arranged in the second region ( 72 ).

3. The switchable optical device ( 1 ) according to claim 1 , wherein the first busbar ( 31 ) is constructed as a first conductive strip ( 51 ) which electrically connects the first transparent electrode ( 21 ) in the first region ( 71 ) and/or the second busbar ( 32 ) is constructed as a second conductive strip ( 52 ) which electrically connects the second transparent electrode ( 22 ) in the second region ( 72 ).

4. The switchable optical device ( 1 ) according to claim 3 , wherein the electrical connection between the first conductive strip ( 51 ) and the first transparent electrode ( 21 ) and/or the electrical connection between the second conductive strip ( 52 ) and the second transparent electrode ( 22 ) is achieved by a continuous soldered line ( 105 ), continuous welded line or by a continuous line of a conductive adhesive.

5. The switchable optical device ( 1 ) according to claim 3 , wherein the electrical connection between the first conductive strip ( 51 ) and the first transparent electrode ( 21 ) and/or the electrical connection between the second conductive strip ( 52 ) and the second transparent electrode ( 22 ) is achieved by a plurality of soldered dots ( 106 ), weld spots or dots of a conductive adhesive distributed along the length of the respective conductive strip ( 51 , 52 ).

6. The switchable optical device ( 1 ) according to claim 1 , wherein the edge deletion ( 116 ) of the first substrate ( 11 ) further includes a portion at a first end and/or a second end of the first edge ( 41 ) and/or the edge deletion ( 116 ) of the second substrate ( 12 ) further includes a portion at a first end and/or a second end of the second edge ( 42 ), wherein the respective portion has a length parallel to the respective edge ( 41 , 42 ) of at least 2 mm.

7. The switchable optical device ( 1 ) according to claim 6 , wherein the first terminal is a first terminal wire ( 61 ) which is arranged parallel to the first edge ( 41 ) and the second terminal is a second terminal wire ( 62 ) which is arranged parallel to the second edge ( 42 ) and wherein the position and length of the first terminal wire ( 61 ) and/or the position and length of the second terminal wire ( 62 ) are chosen such that the first terminal wire ( 61 ) does not protrude from the first substrate ( 11 ) and/or the second terminal wire ( 62 ) does not protrude from the second substrate ( 12 ).

8. The switchable optical device ( 1 ) according to claim 6 , wherein the first terminal is a first terminal wire ( 61 ) or an extension of the electrical conductive part of the busbar which is arranged parallel to the first edge ( 41 ) and the second terminal is a second terminal wire ( 62 ) or an extension of the electrical conductive part of the busbar which is arranged parallel to the second edge ( 42 ) and wherein the position and length of the first terminal wire ( 61 ) or the extension of the electrical conductive part of the busbar and/or the position and length of the second terminal wire ( 62 ) or the extension of the electrical conductive part of the busbar are chosen such that the first terminal wire ( 61 ) or the extension of the electrical conductive part of the busbar protrudes from the first substrate ( 11 ) and/or the second terminal wire ( 62 ) or the extension of the electrical conductive part of the busbar protrudes from the second substrate ( 12 ).

9. The switchable optical device ( 1 ) according to claim 8 , wherein the wire or extension protrusion is applied with electrical insulation.

10. The switchable optical device ( 1 ) according to claim 1 , wherein the edge finish of at least the first edge ( 41 ) of the first substrate ( 11 ) and/or of at least the second edge ( 42 ) of the second substrate ( 12 ) is a rounded edge, pencil edge, bevel edge or arrised edge.

11. The switchable optical device ( 1 ) according to claim 1 , wherein an electrically insulating material ( 101 ) is arranged on the first substrate ( 11 ) such that a portion of the first transparent electrode ( 21 ) located in the first region ( 71 ) and the first busbar ( 31 ) are encapsulated by the insulating material ( 101 ) and/or an electrically insulating material ( 101 ) is arranged on the second substrate ( 12 ) such that a portion of the second transparent electrode ( 22 ) located in the second region ( 72 ) and the second busbar ( 32 ) are encapsulated by the insulating material ( 101 ).

12. The switchable optical device ( 1 ) according to claim 11 , wherein the insulating material ( 101 ) is selected from single component epoxy materials, two component epoxy adhesives, single component silicone materials, two component silicone adhesives, acrylate sealants, polyurethanes, hot melt sealants, UV curing sealants, and a combination of at least two of said materials.

13. The switchable optical device ( 1 ) according to claim 1 , wherein the first terminal and/or the second terminal are configured as terminal wires ( 61 , 62 ) having an electrically insulating jacket ( 112 ).

14. The switchable optical device ( 1 ) according to claim 1 , wherein a top coating is applied to the first transparent electrode ( 21 ) and/or the second transparent electrode ( 22 ).

15. The witchable optical device ( 1 ) according to claim 1 , wherein the first substrate ( 11 ) and second substrate ( 12 ) are of the same size and shape.

16. A method for designing a switchable optical device ( 1 ) according to claim 1 , the method comprising: selecting the sheet resistance of the first transparent electrode ( 21 ) and the second transparent electrode ( 22 ) to be in the range of from 10 to 150 Ohm/square, and selecting the cell gap to be in the range of from 6 μm to 50 μm so that a RC time constant T of a circuit formed between the first terminal ( 61 ) and the second terminal ( 62 ) is in the range of from 50 ms to 1 μs.

17. A method for electrically driving a switchable optical device ( 1 ) according to claim 1 , said method comprising: electrically connecting a signal source providing an AC driving signal is to the first terminal ( 61 ) and the second terminal ( 62 ), and generating an AC signal by the signal source, wherein the frequency of the AC signal is chosen such that the period T of the AC signal is larger than τ, wherein τ is the RC time constant of an RC circuit formed by the arrangement of the first transparent electrode ( 21 ), the second transparent electrode ( 22 ) and the switchable medium ( 10 ).

18. A method for manufacturing of a switchable optical device ( 1 ) according to claim 1 , said method comprising:

providing a first substrate ( 11 ) having a first transparent electrode ( 21 ) and a second substrate ( 12 ) having a second transparent electrode ( 22 ),

performing edge deletion on the first substrate ( 11 ) and on the second substrate ( 12 ) wherein the transparent conductive electrodes ( 21 , 22 ) are removed in an area adjacent to the substrate edges, the edge deletion ( 116 ) of the first substrate ( 21 ) being only partial for at least a first edge ( 41 ) and complete for all further edges of the first substrate ( 21 ) and the edge deletion ( 116 ) of the second substrate ( 22 ) being only partial for at least a second edge ( 42 ) and complete for all further edges of the second substrate ( 22 )

arranging the first substrate ( 11 ), the second substrate ( 12 ) and a seal ( 114 ) such that a cell having a cell gap is formed, and filing the cell with at least one switchable medium ( 10 ), the two substrates ( 11 , 12 ) being arranged such that the first substrate ( 11 ) has a first region ( 71 ) adjacent to the first edge ( 41 ) of the first substrate ( 11 ) which does not overlap with the second substrate ( 12 ) and that the second substrate ( 12 ) has a second region ( 72 ) adjacent to the second edge ( 42 ) of the second substrate ( 12 ) which does not overlap with the first substrate ( 11 ),

optionally pre-cleaning the portion of the first transparent electrode ( 21 ) located in the first region ( 71 ) and the portion of the second transparent electrode ( 22 ) located in the second region ( 72 ),

optionally pre-heating at least the first region ( 71 ) of the first substrate ( 11 ) and/or pre-heating at least the second region ( 72 ) of the second substrate ( 12 ),

connecting a first busbar ( 31 ) to the first transparent electrode ( 21 ) and connecting a second busbar ( 32 ) to the second transparent electrode ( 22 ),

optionally bonding a first terminal ( 61 ) to the first busbar ( 31 ) and bonding of a second terminal ( 62 ) to the second busbar ( 32 ),

dispensing of an insulating material ( 101 ) on the first substrate ( 11 ) such that the portion of the first transparent electrode ( 21 ) located in the first region ( 71 ) and the first busbar ( 31 ) are encapsulated by the insulating material ( 101 ) and/or on the second substrate ( 12 ) such that the portion of the second transparent electrode ( 22 ) located in the second region ( 72 ) and the second busbar ( 32 ) are encapsulated by the insulating material ( 101 ),

curing of the insulating material ( 101 ), and

optionally laminating of a glass sheet to the exposed face of the first substrate ( 11 ) and/or the second substrate ( 12 ) by means of an interlayer.

19. A system comprising at least one switchable optical device ( 1 ) according to claim 1 and at least one controller for applying an AC driving to the at least one switchable optical device, wherein the controller is configured to implement a driving method comprising: electrically driving the switchable optical device ( 1 ) according to claim 1 , wherein a signal source providing an AC driving signal is electrically connected to the first terminal ( 61 ) and the second terminal ( 62 ) and an AC signal is being generated by the signal source, wherein the frequency of the AC signal is chosen such that the period T of the AC signal is larger than τ, wherein τ is the RC time constant of an RC circuit formed by the arrangement of the first transparent electrode ( 21 ), the second transparent electrode ( 22 ) and the switchable medium ( 10 ).