US Patent 7427933 Data entry device

A self-service terminal alphanumeric data entry device comprises a multi-button input device and processing circuitry comprising a letter selector. At least one of the buttons is associated with a number and with at least two alphabetic letters. The input device is arranged to operate in a number entry mode wherein actuation of a button inputs the number associated therewith and a text entry mode. In the text entry mode, actuation of a button causes the letter selector to chose, from the letters associated with that button, the letter which has the highest probability of forming a word.