HEATABLE WINDOW WITH HIGH-PASS FREQUENCY SELECTIVE SURFACE

• US 20150229030A1
• Filed: 02/11/2014
• Published: 08/13/2015
• Est. Priority Date: 02/11/2014
• Status: Active Grant

• Current Assignee: Vitro Automotive Holdings Corporation
• Original Assignee: Pittsburgh Glass Works LLC (LKQ Corporation)
• Inventors: Dai, David, Dishart, Peter T., Mehta, Kaushal
• Granted Patent: US 9,673,534 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/1077 containing polyurethane
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3673 specially adapted for use in heating devices for rear window of vehicles
• CPC Class Codes: C03C 2218/328 Partly or completely removing a coating
• CPC Class Codes: C03C 27/10 with the aid of adhesive specially adapted for that purpose
• CPC Class Codes: H01Q 1/1278 in association with heating wires or layers
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
• CPC Class Codes: H05B 2203/011 Heaters using laterally extending conductive material as connecting means
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• CPC Class Codes: H05B 3/0042 used in motor vehicles
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

An electrically conductive coating of an automotive heatable windshield having a frequency selective surface area that facilitates the transmission of radio frequency signals. The FSS area may be a high-pass filter such that RF signals at any polarization can pass through the glazing over a wide frequency band. The FSS area is defined by a pattern in the conductive coating such that, when the conductive coating is used to heat the windshield, electrical current flows through the FSS area to mitigate hot and cold spots.

Claims

1. A heatable window comprising:

a transparent substrate sheet having at least one major surface;

a coating on said surface of said substrate sheet, said coating being responsive to electrical voltage to heat said window, an area of said coating defining at least two elements wherein each of said elements includes a first set of slots that are parallel to each other and a second set of slots that are parallel to each other with the slots in said first set being oriented orthogonally to the slots of said second set, each of said slots being a strip of predetermined width and predetermined length that is void of said coating, said at least two elements, in combination with the coating adjacent and between the slots thereof, defining a frequency selective surface that passes signals within at least one predetermined frequency range and that also provides thermal heating to at least a portion of said transparent substrate that defines said frequency selective surface.

2. The heatable window of claim 1 wherein said frequency selective surface mitigates thermal extremes in areas of said sheet that are adjacent to said frequency selective surface.

3. The heatable window of claim 2 further comprising apparatus for applying an electrical voltage across said coating, said apparatus being electrically connected to said coating.

4. The heatable window of claim 2 wherein the elements of said frequency selective surface are aligned in at least one linear array with a portion of the coating separating adjacent elements of said array.

5. The heatable window of claim 2 wherein the length of the slots in said first set of slots corresponds to one-half of the wavelength corresponding to a selected frequency of vertically polarized signals within said at least one predetermined frequency range.

6. The heatable window of claim 2 wherein the length of the slots in said second set of slots corresponds to with one-half of the wavelength corresponding to a selected frequency of horizontally polarized signals within said at least one predetermined frequency range.

7. The heatable window of claim 4 wherein the adjacent elements of said at least one linear array of elements are separated by a group of two or more channels, each of said channels being parallel to each other and also parallel to the slots of one of said first set of slots of said elements or said second set of slots of said elements, each of said channels having a predetermined width.

8. The heatable window of claim 7 having at least two linear arrays of said elements, each of said channels having a length that corresponds to the length of at least one of said linear arrays.

9. The heatable window of claim 4 wherein the slots of said first set of slots repeat at a predetermined dimension and the slots of said second set of slots repeat at the same predetermined dimension.

10. The heatable window of claim 9 wherein each of said elements is a regular grid of intersecting slots.

11. The heatable window of claim 8 wherein each of the channels of each said group are oriented in a direction that is parallel to the slots of said first set of slots in each element, said channels being spaced apart from each other by a predetermined, constant dimension.

12. The heatable window of claim 8 wherein each of the channels of each said group are oriented in a direction that is parallel to the slots of said second set of slots in each element, said channels being spaced apart from each other by a predetermined constant dimension.

13. The heatable window of claim 1 wherein said frequency selective surface includes a two-dimensional array of said elements, said array having a plurality of elements in the direction that is orthogonal to the direction of the slots of said second set of slots in each element to form a row of elements, the adjacent elements of said row of said array being spaced apart from each other by a constant predetermined dimension.

14. The heatable window of claim 1 wherein said array includes a plurality of elements in the direction that is orthogonal to the direction of the slots of said first set of slots in each element to form a column of elements, the adjacent elements of said column of said array being spaced apart from each other by a constant predetermined dimension.

15. The heatable window of claim 14 wherein said frequency selective surface includes at least two columns of said elements with each column of elements being separated from an adjacent column of elements by a group of two or more channels that are parallel to each other and parallel to the slots of said second set of slots of said elements, each of said channels having a predetermined width and a length that corresponds to the length of said column of elements in the frequency selective surface.

16. The heatable window of claim 15 wherein each of the channels of said group are spaced apart from adjacent channels in the same group by a constant predetermined dimension.

17. The heatable window of claim 4 wherein said first set of slots have first and second ends and wherein said second set of slots is arranged in first and second columns, with members of the first column of said second set of slots connecting respective first ends of adjacent members of said first set of slots and with members in the second column of said second set of slots connecting respective second ends of adjacent members of said first set of slots.

18. The heatable window of claim 17 wherein adjacent members of said first set of slots are connected to each other at only one end.

19. The heatable window of claim 18 wherein the length of each element of said array is defined by the length of the element in the direction that is parallel to the direction of said second set of slots, each element of said array being separated by a group of two or more channels that are parallel to each other and that are parallel to the slots of said second set of slots of said elements, each of said channels having a predetermined width and a length that corresponds to the length of each of said elements.

20. The heatable window of claim 19 having two or more groups of channels with each group of channels being separated by a predetermined dimension.

21. A coated window having a frequency selective surface, said window comprising:

a transparent substrate sheet that defines a major surface;

an electrically conductive coating that covers a major surface of said substrate sheet;

two or more spaced bus bars that are in electrical contact with said coating;

a first lead that contacts at least one of the bus bars and a second lead that contacts at least a second of said bus bar to provide electrical connections to the bus bars; and

an area of said coating that defines a frequency selective surface that passes signals within at least one predetermined frequency band, said frequency selective surface including;

at least two groups of channels, each channel being approximately parallel to the other channels in the same group and to channels in other groups, each of said channels having a predetermined width and a length that corresponds to one dimension of the frequency selective surface, each group of at least two groups of channels being spaced apart from each other in a direction that is orthogonal to said channels by a predetermined dimension; and

at least two sets of slots, the slots in each set defining a square-wave pattern, at least one square-wave pattern of said slots being situated between two groups of channels, each square-wave pattern having a predetermined width and a length that corresponds to the length of said channels, said groups of channels and said square-wave patterns combining to form a repeating pattern of channels, square-wave pattern, and channels to define said frequency selective surface.

22. The window as claimed in claim 21 wherein said slots in the channels in said groups and slots in said square-wave pattern that are parallel to the channels in said groups facilitate the passage of horizontally polarized signals through said frequency selective surface.

23. The window as claimed in claim 21 wherein said slots in said square-wave pattern that are orthogonal to the channels in said groups facilitate the passage of vertically polarized signals through said frequency selective surface.

24. The window as claimed in claim 21 wherein said square-wave pattern includes slots that have a length corresponding to at least one-half the wavelength of the lowest passing signal frequency.

25. The window as claimed in claim 21 wherein said frequency selective surface passes horizontally polarized RF signals from 3.5 GHz to 11.5 GHz with low loss.

26. The window as claimed in claim 21 wherein said electrically conductive coating is adapted to conduct electricity and wherein said frequency selective surface is oriented such that electric current flows between said channels of said group of channels from the first bus bar to the second bus bar.

27. A coated window having a frequency selective surface, said window comprising:

a transparent substrate sheet that defines a surface;

an electrically conductive coating that is deposited on the surface of said substrate sheet;

at least two spaced bus bars that are in electric contact with said coating;

a first lead that contacts at least one of the bus bars and a second lead that contacts at least a second of said bus bars to provide electrical contacts for the bus bars; and

an area of said coating that defines a frequency selective surface that passes signals within at least one predetermined frequency band, said frequency selective surface having at least two elements wherein each element has a first set of slots in combination with a second set of slots that are oriented orthogonally with respect to the first set of slots to form an element of predetermined length and predetermined width, the length and width of the slots of said first set being equal to the length and width of the slots of said second set.

28. The window of claim 27 wherein the slots oriented in one direction facilitate the passage of horizontally polarized RF signals through the frequency selective surface.

29. The window of claim 28 wherein the slots oriented in a direction that is orthogonal to said one direction facilitate the passage of vertically polarized RF signals through the frequency selective surface.

30. The window of claim 27 wherein the slots in at least one of said first set of slots or said second set of slots have a length that is at least one-half the wavelength that corresponds to signals having the lowest frequency in said at least one predetermined frequency band.

31. The window of claim 27 wherein said frequency selective surface is a high pass filter having a cut off frequency at 3.8 GHz.

32. The window of claim 27 wherein said frequency selective surface enables the passage of RF signals of polarizations that include horizontal, vertical, right-hand circular and left-hand circular polarizations.

33. The window of claim 27 wherein said metallic coating is adapted to conduct electricity and wherein said frequency selective surface is oriented such that electricity flows between said elements from first said bus bar to said second bus bar.

34. The window of claim 27 wherein said frequency selective surface includes at least four elements that are arranged in a regular grid pattern of columns and rows that define the area of the frequency selective surface

35. The window of claim 34 wherein groups of channels are located between two consecutive columns of elements of the grid of elements to improve passage of horizontally polarized RF signals.

36. The window of claim 35 wherein longer horizontal slots increase the passage of vertically polarized RF signals in the lower portion of the RF band.

37. The window of claim 36 wherein said frequency selective surface is a high pass filter with a cut off frequency of 2.4 GHz.

38. The window of claim 36 wherein said frequency selective surface passes RF signals of polarizations that include horizontal, vertical, right-hand circular and left-hand circular polarizations.

39. The window of claim 36 wherein said frequency selective surface passes RF signals having a frequency above 2.4 GHz, including vehicle electronic toll collection (ETC) signals operating at 2.5 GHz and 5.8 GHz

40. A coated window having a frequency selective surface, said window comprising:

a transparent substrate sheet that defines a major surface;

an electrically conductive coating that contacts the surface of said substrate;

at least two spaced bus bars that are in electrical contact with said coating,

a first lead that contacts at least one of the bus bars and a second lead that contacts at least a second of said bus bars to provide electrical contacts to the bus bars; and

an area of said coating that defines a frequency selective surface that passes RF signals within at least one predetermined frequency band, said frequency selective surface having;

a first array of groups of vertical channels, each group of such array having a plurality of vertical channels that are approximately parallel to each other, each vertical channel of said group being spaced apart from adjacent channels of the same group by a predetermined dimension, each vertical channel of said group also having a predetermined width and having a length that corresponds to the height dimension of the frequency selective surface; and

an second array of patches, each patch of said second array having a predetermined length and width, each patch of said second array also having a set of horizontal slots and a set of vertical slots wherein the horizontal slots are spaced equally apart from each other and the vertical slots are spaced equally apart from each other, all of said vertical slots and said horizontal slots having the same slot width, each patch of said array of patches being situated respectively between consecutive members of said first array of groups of vertical channels, the pattern of a group of vertical channels, a patch, and a group of vertical channels repeating to form a pattern throughout the frequency selective surface.

41. The window of claim 40 wherein said vertically oriented slots facilitate passage of horizontally polarized RF signals.

42. The window of claim 40 wherein said horizontally oriented slots facilitate passage of vertically polarized RF signals.

43. The window of claim 40 wherein said slot length is at least one-half of the wavelength corresponding to the lowest frequency signal that passes through the frequency selective surface.

44. The window of claim 40 wherein said frequency selective surface is a high pass filter with a cut off frequency of 2.5 GHz.

45. The window of claim 40 wherein said area of frequency selective surface passes RF signals of polarizations that include horizontal, vertical, right-hand circular and left-hand circular polarizations.

46. The window of claim 40 wherein increasing the length of said horizontal slots increases the passage of vertically polarized RF signals in the lower regions of the RF spectrum.

47. The window of claim 40 wherein said frequency selective surface passes RF signals above 2.5 GHz, including vehicle electronic toll collection (ETC) signals at 2.5 GHz and 5.8 GHz.

48. The window of claim 40 wherein said metallic coating is electrically conductive and said frequency selective surface is oriented such that current flows between said vertical channels from said first bus bar to said second bus bar.