MACHINE INTERFACES

摘要

Apparatus for determining the movement of an object comprises a plurality of ultrasonic transducers (1, 4; 16) arranged to enable the location of the object to be determined by transmission and reflection of signals between the transducers (1, 4; 16). A yielding surface (2; 12) is arranged in proximity to the transducers such that movement of the object into the surface upon application of a yielding pressure to the yielding surface (2; 12) can be detected.