BACKLIGHT FOR A PORTABLE DEVICE

摘要

A handportable device is disclosed which comprises a user interface (1), a light detector (21) for detecting the light incident on at least part of the user interface, a comparator for comparing the light detected with a given threshold and control means for controlling an illuminator for illuminating the user interface in dependence upon the output of the comparator. Preferably the light detector is positioned to detect light incident on the device, which light is the sum of ambient light and the light from the illuminator.