TOUCHLESS INTERACTION

摘要

A portable electronic device comprises means (4) for transmitting ultrasonic signals (8), means (6) for receiving ultrasonic signals (12) reflected from an input object, and means for processing received ultrasonic signals to determine an input to the device. The device is configured to reduce the transmission power of the ultrasonic signals transmitted by the transmitting means in the event that: the device determines that a reflection (16) from an object (14) other than the input object meets a predetermined criterion; or if an event is detected which indicates that the (10) user is or will be using a function of the device which does not support touchless interaction. Also disclosed is an electronic device comprising transmission means (4) for transmitting ultrasonic signals (8), means (6) for receiving ultrasonic signals (12) reflected from an input object (10) and means for processing received ultrasonic signals to determine an input to the device, the device further comprising user operable control means for allowing a user to turn a touchless interaction mode on and off, the device being configured to execute an additional operation when the touchless interaction mode is turned off.