Abstract: In a power transmission system for transmitting electric power from the primary side power feeding coil to the secondary side power receiving coil without their mutual contact and using electromagnetic induction, the power coils on each of the primary and secondary sides include a pair of planar spiral coils which are shaped in the form of a figure 8 and connected differentially to power supply, and each of the spiral coils is D-shaped having a semicircular portion and a linear portion combined together, the two spiral coils having their linear portions laid one on the other to form a planar figure-8 coil. Plates of soft magnetic material 4 and 41 are disposed each on a side of the power coil on one of the primary and secondary sides which is opposite to the side that faces the power coil on the other of the primary and secondary sides.

Abstract: A parking assist system for a vehicle includes a target position setting unit setting a vehicle target parking position on the basis of a coil type and position of a power transmitting unit. When the coil type is a composite coil having a configuration such that an annular coil wound to surround a first axis and a solenoid coil wound to surround a second axis intersecting with the first axis are serially connected, the target position setting unit sets the target parking position such that a center of a power receiving unit mounted on the vehicle is located at a predetermined distance from the first axis along the second axis. The solenoid coil is set at a position with respect to the annular coil such that the first axis extends through a side face center portion of the solenoid coil.

Abstract: A power transmitting device includes: a power transmitting unit being able to contactlessly transmit electric power to a power receiving unit of a power receiving device; and a guide unit changing a guide position of the power receiving device at power reception of the power receiving device on the basis of a type of the power receiving unit. The guide unit may when the types of the power receiving and transmitting units are the same, set a position of the power receiving unit, at which center positions of the power receiving and transmitting units coincide with each other, for the guide position, and, when the types of the power receiving and transmitting units are different, set a position of the power receiving unit, at which the center positions of the power receiving and transmitting units deviate from each other, for the guide position.

Abstract: A parking assist system for a vehicle includes a target position setting unit setting a vehicle target parking position on the basis of a coil type and position of a power transmitting unit. When the coil type is a composite coil having a configuration such that an annular coil wound to surround a first axis and a solenoid coil wound to surround a second axis intersecting with the first axis are serially connected, the target position setting unit sets the target parking position such that a center of a power receiving unit mounted on the vehicle is located at a predetermined distance from the first axis along the second axis. The solenoid coil is set at a position with respect to the annular coil such that the first axis extends through a side face center portion of the solenoid coil.

Abstract: A coil unit of a power reception device includes a coil through which electric power output from a power transmission device is received in a contactless manner; and a core around which the coil is wound, The core includes a plate-shaped first core, and a plate-shaped second core disposed so as to face the first core at a distance from the first core. The coil is wound around the first core and the second core so as to extend over the first core and the second core. Consequently, the power reception device and the power transmission device each can be reduced in physical size while an electrical device can be less influenced by an electromagnetic field generated during power transfer.

Abstract: A power transmitting device includes: a power transmitting unit being able to contactlessly transmit electric power to a power receiving unit of a power receiving device; and a guide unit changing a guide position of the power receiving device at power reception of the power receiving device on the basis of a type of the power receiving unit. The guide unit may when the types of the power receiving and transmitting units are the same, set a position of the power receiving unit, at which center positions of the power receiving and transmitting units coincide with each other, for the guide position, and, when the types of the power receiving and transmitting units are different, set a position of the power receiving unit, at which the center positions of the power receiving and transmitting units deviate from each other, for the guide position.