Bus bar arrangement for an electrically heated transparency

Abstract

An electrically heated transparency such as may be employed in a vehicle to provide defrosting, deicing, or defogging capability for the vehicle windows includes a transparent, electroconductive, heat-producing coating, e.g., a film including silver, on a major surface of a transparent sheet, e.g., a glass sheet. First and second bus bars contact the coating along first and second opposite edge portions of the transparency. A pair of electroconductive extensions extend from opposite ends of the second bus bar to a location near the first edge portion along third and fourth edge portions of the transparency, with the extensions being electrically insulated from the coating and the first bus bar. Terminal areas of the extensions and the first bus bar are connected to a power source. The extensions reduce the power losses in the bus bars, produce a more uniform heating pattern, and provide redundancy should one of the extensions fail.

Dependencies are inferred from the claim text.