摘要 |
An apparatus determines the position of a target part of a user's hand within a predetermined zone. It has a plurality of transducers for transmitting and/or receiving locating signals. The transducers are arranged such that, for any location of the target hand part within the predetermined zone there are at least two pairings of transmitting transducers and receiving transducers for which the total time-of- flight of said timing signals from the transmitter of the pairing to the receiver of the pairing via the target part of the user's hand is less than equivalent total times-of- flight to and from a set of points comprising all points in the predetermined zone which are beyond a minimum spacing from the target hand part but at least as far away from the nearest point of the apparatus as the location of the target hand part is. In some embodiments a selection is made between possible channels to determine which can be used for tracking without suffering from finger/hand confusion. |