Input device and input method

摘要: A device for obtaining user input includes i)a source (11) for emitting acoustic waves, ii) a receiver (12) for detecting such as transducer, adapted to produce signal (SIG) responsive to an wave detected, iii) modulation means (13) user input, modulate waves emitted, and iv) converting (14) produce (INPUT) in response the (SIG). Acoustic may be emitted in bursts, cause reflection of wave or it change frequency of the acoustic wave.