Patent ID: 7135995

Claim:
A method for automatic determination of validity or invalidity of key inputs made by operation of keys arranged next to each other in a keypad or keyboard, said method comprising the steps of: a) designating a plurality of the keys as principal keys and assigning each key neighboring each principal key as a nearest neighbor key or a next nearest neighbor key; b) testing each signal produced by operation of said keys; c) determining that the signal is valid during said testing of step b) if the signal is produced by operation of only one of the keys; d) determining that said signal is valid during said testing of step b) if said signal is produced by operation of at least two of the keys including one of the principal keys, and if said at least two keys are correlated in an unambiguous principal key-nearest neighbor key relationship; e) determining that said signal is valid during said testing of step b) if said signal is produced by operation of said at least two keys including one of the principal keys, and if said at least two keys are correlated in an unambiguous principal key-nearest neighbor key-next nearest neighbor key relationship; f) otherwise determining that said signal is invalid during said testing of step b) if said signal is not found to be valid during the determining of steps c), d) and e); g) performing the determining of steps c), d), e) and f) one after the other until said signal is found to be valid or not and ending said testing as soon as said signal is found to be valid.