Abstract: A position detection system includes a position pointer and a position detector. The “blind” area in which a position pointed to by a position pointer is undetectable is minimized. A transmission coil selector selects one of a plurality of transmission coils. A signal is generated by a transmission signal generator and supplied to a selected transmission coil. The selected transmission coil transmits the signal to the position pointer. A reception sensor coil selector selects a plurality of sensor coils. A position-indicating signal transmitted from the position pointer is received by each selected sensor coil, and a position pointed to by the position pointer is calculated from the received position-indicating signals. The position detection system loop coils are part of a resonant LC transmission circuit and are excited with a pulsed carrier signal to maximize the strength of the transmission signal, while dissipating relatively little power.

Abstract: A three-dimensional information sensor device is disclosed in which sensor coils thereof are sequentially selected by a control section. Signals are communicated between indicating coils of a three-dimensional information indicating device and sensor coils by electromagnetic coupling. The signals received by each of the selected coils are detected by detecting means. The position and the direction of the indicating device in a three-dimensional apace are calculated by control means based on the detected signals.