Wireless charging systems have been developed that charge batteries installed in vehicles such as electric vehicles and hybrid vehicles via a wireless connection without the use of plugs. Accurate positioning of power receiving devices on the vehicle side and power transmission devices on the ground side is important to implement efficient charging in such wireless charging systems. Japanese Patent Application No. 2011-015549 describes a positioning assistance system that uses weak excitation to determine a distance between a power receiving device on the vehicle side and a power transmission device on the ground side and displays the result thus obtained.
The system described in Japanese Patent Application Publication No. 2011-015549 displays the power receiving device on the vehicle side and the power transmission device on the ground side as virtual images. This may prevent a driver from instinctively figuring out which direction the vehicle should be moved, even when the distance between the devices is determined.