CPC F24C 7/062 (2013.01) [A47J 36/2483 (2013.01); F24C 7/088 (2013.01); H05B 3/03 (2013.01); H05B 3/20 (2013.01); H05B 3/26 (2013.01); H05B 3/265 (2013.01); H05B 3/68 (2013.01); H05B 3/748 (2013.01); H05B 2203/007 (2013.01); H05B 2203/016 (2013.01); H05B 2203/03 (2013.01)] | 19 Claims |
1. An electric heater comprising:
a substrate;
a first plane heating element located at a surface of the substrate; and
a second plane heating element located at the surface of the substrate,
wherein the first plane heating element comprises:
a first pattern portion that is located in a first annular zone, the first pattern portion being symmetrical with respect to a reference line that passes through a center of the first annular zone,
a pair of first electrodes located outside the first annular zone, and
a pair of first connectors that connect the first pattern portion to the pair of first electrodes, the pair of first connectors being symmetrical with respect to the reference line,
wherein the second plane heating element comprises a second pattern portion located in a second annular zone surrounding the first annular zone, the second plane heating element being located outside the first plane heating element in a radial direction of the first annular zone with respect to the center of the first annular zone,
wherein at least a portion of the pair of first connectors is located in the second annular zone, and
wherein the first pattern portion and the pair of first connectors define a first heating portion configured to generate heat based on a flow of electric current through the pair of first electrodes.
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