Patent ID: 8508184

Claim:
A coil unit that is provided in a vehicle or in a power supply device for a vehicle, and that performs at least one of transmission and reception of electric power using electromagnetic resonance between the coil unit and a primary resonance coil disposed to face the coil unit, the coil unit comprising a secondary resonance coil that electromagnetically resonates with the primary resonance coil, wherein: the secondary resonance coil includes a first coil and a second coil; the first coil and the second coil have a same number of turns, a same coil diameter, and a same shape, the first coil and the second coil are electrically connected in series, and the first coil and the second coil are disposed in a manner such that directions of generated magnetic fields are opposite to each other; and the first coil is disposed adjacent to the second coil on a plane perpendicular to the directions of the generated magnetic fields.