Transparent window pane provided with a resistive heating coating

• US 20090044464A1
• Filed: 10/12/2005
• Published: 02/19/2009
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Original Assignee: Saint-Gobain Glass France (Compagnie De Saint-Gobain)
• Inventors: Maurer, Marc, Baubet, Carole, Schmidt, Lothar
• Granted Patent: US 7,880,120 B2
• Time in Patent Office: Days
• US Class Current: 52/171.200
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10183 being not continuous, e.g. in edge regions
• CPC Class Codes: B32B 17/10385 for ohmic resistance heating
• CPC Class Codes: H05B 2203/008 with layout including a portion free of resistive material, e.g. communication window
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• 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

A transparent glazing unit including a resistive heating coating that extends over a substantial part of the glazing unit, in particular over a main viewing field, and is electrically connected to at least two busbars such that, when an electrical supply voltage is applied between the busbars, a current flows, which heats a heating field in the coating. The heating field includes at least one semiresistive region in direct contact with at least one busbar.

Claims

1-29. -29. (canceled)

30. A transparent glazing unit comprising:

a resistive heating coating that extends over a part of the glazing unit, or over a main viewing field, and that is electrically connected to at least two busbars such that, when an electrical supply voltage is applied between the busbars, a current flows, which heats a heating field in the coating,

wherein the heating field includes at least one semiresistive region in direct contact with at least one of the busbars.

31. The glazing unit as claimed in claim 30, wherein the main viewing field does not include a semiresistive region.

32. The glazing unit as claimed in claim 30, wherein at least one semiresistive region is in direct contact with at least one of the busbars at a positive potential.

33. The glazing unit as claimed in claim 32, wherein at least one semiresistive region is in direct contact with at least one of the busbars at a negative potential.

34. The glazing unit as claimed in claim 33, wherein the main viewing field lies between at least two semiresistive regions.

35. The glazing unit as claimed in claim 30, wherein at least one part of a peripheral edge of the glazing unit is concealed by an opaque colored layer, or a part in a region of the busbars, at least one semiresistive region lying in the main viewing field of the glazing, beyond an area covered by the colored layer.

36. The glazing unit as claimed in claim 30, wherein resistance of the heating coating in the semiresistive region is at least less than resistance of the heating coating outside any semiresistive region.

37. The glazing unit as claimed in claim 36, wherein the resistance of the heating coating in the semiresistive region is at least two times, five times, ten times less, or even less, than the resistance of the resistive coating outside any semiresistive region.

38. The glazing unit as claimed in claim 30, as a composite glazing unit that includes at least one adhesive layer in electrical contact with the heating coating, the adhesive layer including the at least one semiresistive region.

39. The glazing unit as claimed in claim 38, wherein the semiresistive region of the adhesive layer includes at least one band of the adhesive layer doped with conducting particles.

40. The glazing unit as claimed in claim 30, wherein the semiresistive region includes conducting strands formed from conducting printed lines and/or conducting wires.

41. The glazing unit as claimed in claim 40, wherein the strands start from at least one of the busbars, a length of the strands being greater than a width of the respective busbar, and the strands extending into the heating field in contact with the heating coating.

42. The glazing unit as claimed in claim 40, wherein the strands have a width and/or a thickness of 0.5 mm or less, or 0.3 mm or less, measured in projection on the surface of the glazing unit.

43. The glazing unit as claimed in claim 40, wherein the strands formed from conducting printed lines are printed on the heating coating.

44. The glazing unit as claimed in claim 40, wherein the strands formed from conducting wires are electrically connected to the heating coating and at least to the semiresistive region by soldering at least at discrete contact points.

45. The glazing unit as claimed in claim 40, wherein the current flows in the main viewing field in a direction approximately parallel to the longitudinal direction of the conducting strands.

46. The glazing unit as claimed in claim 40, wherein the strands are dark in color when viewed from an external face of the glazing unit.

47. The glazing unit as claimed in claim 40, wherein the strands are light in color when viewed from an internal face of the glazing unit.

48. The glazing unit as claimed in claim 40, wherein the strands are placed uniformly apart.

49. The glazing unit as claimed in claim 40, wherein the strands are all produced with a same length.

50. The glazing unit as claimed in claim 40, wherein the strands are produced in a form of straight lines, open or closed loops, portions of arcs, and/or meanders.

51. The glazing unit as claimed in claim 30, wherein the heating coating is divided by separating lines in the main viewing field, which lines divide up the heating coating into current paths.

52. The glazing unit as claimed in claim 51, wherein the separating lines collect current in the main viewing field.

53. The glazing unit as claimed in claim 30, wherein the busbars are produced by printing and/or from metal strips.

54. The glazing unit as claimed in claim 53, wherein the printed busbars are printed on the heating coating.

55. The glazing unit as claimed in claim 54, wherein the busbars produced from metal strips are electrically connected to the heating coating and to the semiresistive region by soldering at least at discrete contact points.

56. The glazing unit as claimed in claim 30, wherein the semiresistive region is placed only over part of the longitudinal extent of one or each busbar.

57. The glazing unit as claimed in claim 30 in a form of a vehicle windshield, wherein the semiresistive region extends at most as far as a boundary of a normalized viewing field of the windshield.

58. The glazing unit as claimed in claim 30, wherein a bluish band extends at least along its upper edge and at least partly conceals the semiresistive region positioned at an upper edge.