Abstract: A goggle (11) that includes an electrical defogging system includes a frame (13) and a transparent lens (15). The transparent lens includes an outside layer(51 or 61) and inside layer(53 or 63) spaced from the outside layer by a peripheral gasket (55 or 65). The inside layer has an indium tin oxide (ITO) coating. The ITO coating includes an interior heating zone (33) that is electrically isolated from the edge of the inside layer. Silver bus bars (45, 47) are printed atop the ITO coating along the opposing edges of the interior heating zone adjacent the top and bottom of the goggle lens. The edge isolation regions and the bus bars are positioned and oriented such that the region (48) where the bus bars cross the nose area(41) of the goggle lens is isolated from the interior heating zone(33). Further, the bus bar that passes along the bottom of the goggle lens extends upwardly along one side of the lens. The side section of this bar is electrically isolated (39 ) from the interior heating zone.

Abstract: A window defogging system that comprises a power supply and an optically clear overlay includes a sheet of heat-stabilized polyester (13) having a hard coat layer (15) on one surface and an indium tin oxide (ITO) layer (17) on the other surface. The ITO layer (17) is scored around its periphery (19) to create a groove that electrically isolates the edge of the ITO layer from an interior heating zone (23). Additional grooves create electrically isolated regions (26a, 26b, 28a and 28b). Multiple layers of silver are printed atop the ITO layer (17), along opposing edges of the interior (heater) zone (23), to create bus bars (25a, 25b). The bus bars end at terminal regions (29a, 29b) that are connected directly to the power supply. The housing (61) of the power supply is supported by connectors mounted in the optically clear overlay. In some versions of the invention, a dielectric layer (33a, 33b) is located along a portion of the bus bars, between the multiple layers of silver.