Patent attributes
A small-sized and lightweight pointing device and receiving unit reduce power consumption. The receiving unit transmits UWB (Ultra Wide Band) signals simultaneously from an antenna thereof. The pointing device receives the transmitted UWB signals with three antennas thereof. The respective timings when the transmitted UWB signals are received with the three antennas depend on the distances between the transmitting antenna and the three receiving antennas. With this principle, propagation distances from the transmitting antenna to the three receiving antennas are real distances between the transmitting antenna and the three receiving antennas. By applying the principle of triangular surveying to the distances, position coordinates of the pointing device to the receiving unit can be specified. Amount of movement made by the pointing device is calculated based on a change in the position coordinates.
