Data Entry Device for Entering Characters by a Finger with Haptic Feedback

A data entry device for entering predetermined characters by the finger of a user and converting the characters into a sequence of electronic signals representing the entered characters, said device comprises a touch sensitive zone (2) on an outer surface thereof that can be touched by a finger of the user, a processor (58) coupled to said touch sensitive zone (2) for sensing when the touch sensitive zone (2) is touched and interpreting the electronic signals generated by the touch sensitive zone (2), the processor (58) is programmed to recognize predetermined elementary finger movements and predetermined combinations of said elementary movements and to associate each of said predetermined combinations with a character, and after having sensed the entry of a predetermined combination to deliver the electronic signals of the character associated with the recognized combination, characterized in that a closed boundary (10) is defined on the surface of the device above a portion of the touch sensitive zone (2), said boundary (10) has at least one haptic property differing from the haptic properties of the surrounding area whereby the finger can definitely sense when the boundary (10) is touched, and the boundary (10) has an interior area constituting a data entry field (11), said data entry field (11) has a centre region (16) which has at least one haptic property differing from the haptic properties of the portion of the data entry field (11) beyond the centre region (16), whereby the finger when touching the centre region (16) can recognize being on the centre region (16) by means of a haptic feedback based on said differing haptic property, and the processor (58) is programmed so as to recognize when the centre region (16) is touched for a predetermined duration by the finger and interprets this event as the beginning of the entry of a character and from that moment starts observing and analyzing the combination of elementary finger movements as long as the finger touches the data entry field (11), and when the finger has finished touching the data entry field (11) this is interpreted by the processor (58) as the end of the entry of the character, wherein the elementary finger movements can be radial movements between the centre zone (16) and one of a plurality of predetermined discrete special positions along the boundary (10) in any direction and arced movements along the boundary (10) from one special position to a neigbouring special position, and each character that can be entered is associated with a continuously sensed finger movement along the predetermined combination of consecutive elementary finger movements.