USER INTERFACES FOR ELECTRONIC DEVICES

摘要

An electronic device comprises a transmitter (6) for transmitting ultrasonic signals, a receiver (8) for receiving reflections (20) of said ultrasonic signals, wherein the device is adapted to control a function thereof in dependence on said received reflections, the device further comprising means for providing to a user an indication (14) of the presence of signals or noise which could interfere with said reflections.