Portable device with text entry

摘要

A portable electronic device (1) has a keypad for entering alphanumeric characters. Some of the keys include a fingerprint sensor (2) and for each of these keys a different character may be selected for entry by using a different finger. The device is provided with a reference set of fingerprints of the authorised user or users, so unauthorised users cannot enter characters. A high resolution fingerprint sensor may be used for validating a user for secure transactions, while a lower resolution sensor may be used for differentiating between a small number of fingerprints. Size and interconnection complexity can be minimised by providing fingerprint sensors that are smaller than a fingerprint, and entering a fingerprint by wiping a finger across the sensor.