COORDINATE READER

A coordinate reader includes a base member having a plurality of X-loop wires provided in a first surface of the base member, a plurality of Y-loop wires provided in a second surface of the base member, a first input plane provided over the plurality of X-coils and a second input plane provided over the plurality of Y-loop coils. When a coordinate input device generates an alternating magnetic field for inputting its coordinates into the coordinate reader, the coordinate reader detects signals generated on the X-loop wires and the Y-loop wires in response to the alternating magnetic field. Then, the coordinate reader determines, based on the detected signals, which of the first input plane or the second input plane the coordinate input device is placed on, and the coordinates of the coordinate input device on the first input plane or the second input plane.