Virtual keyboard system with automatic correction
View Patent ↗There is disclosed an enhanced text entry system which uses word-level analysis to automatically correct inaccuracies in user keystroke entries on reduced keyboards such as those implemented on a touch-sensitive panel or display screen, or on mechanical keyboard systems. A method and system are defined which determine one or more alternate textual interpretations of each sequence of inputs detected within a designated auto-correcting keyboard region.
1. A text entry system comprising:
a user input device comprising a touch sensitive surface including an auto-correcting keyboard region comprising a plurality of the characters of an alphabet,
a nontransitory memory containing a plurality of objects, wherein each object is a string of one or a plurality of characters forming a word or a part of a word, the nontransitory memory further comprising:
a word stem module comprising a logical organization of uninflected word stem objects; and
a suffix module comprising a logical organization of suffixes which can be appended to word stems to form inflected words,
a processor coupled to the user input device and memory, said processor comprising:
a word evaluation component which, for each generated input sequence, identifies one or a plurality of candidate objects in memory, and for each of the one or a plurality of identified candidate objects, evaluates each identified candidate object by calculating a matching metric;
wherein when the word evaluation component calculates a matching metric value for a given word stem in a given word stem module with respect to an initial sequence of contacts within an input sequence such that the calculated matching metric value ranks higher than a predetermined threshold, the word evaluation component evaluates the remaining contacts of the input sequence with respect to the associated suffix modules, and
wherein when the word evaluation component calculates a matching metric value for a given suffix in one of said associated suffix modules that ranks higher than a second predetermined threshold, said suffix is appended to said word stem to form a completed word corresponding to a matching metric value that is a function of said determined word stem matching metric value and said determined suffix matching metric value.
2. The system of claim 1 , wherein the characters of the alphabet are arranged on the auto-correcting keyboard region in approximately a standard “QWERTY” layout.
3. The system of claim 1 , wherein the word evaluation component calculates the matching metric for each candidate object by summing distance values calculated from each contact location in the input sequence to the location assigned to the character in the corresponding position of the candidate object, and applying a weighting function according to the frequency of use associated with the object.
4. The system of claim 3 , wherein each character of the alphabet associated with the auto-correcting keyboard region is assigned a Cartesian coordinate and wherein the distance value calculation component calculates the distance between the contact location and the location corresponding to a character according to standard Cartesian coordinate distance analysis.
5. The system of claim 3 , wherein the frequency of use associated with each candidate object in memory comprises the ordinal ranking of the object with respect to other objects in memory, wherein an object associated with a higher relative frequency corresponds to a numerically lower ordinal ranking.
6. The system of claim 5 , wherein the frequency weighting function applied by the word evaluation component to the summed distance values for a candidate object comprises multiplying the sum of the distance values by the base 2logarithm of the ordinal ranking of the object.
7. The system of claim 3 , wherein the word evaluation component adds an increment value to the sum of the distance values prior to applying a weighting function according to the frequency of use associated with the candidate object.
8. The system of claim 7 , wherein the increment value is a fixed value that is approximately twice the average distance between adjacent locations on the auto-correcting keyboard region corresponding to characters.
9. The system of claim 1 , wherein each character corresponds to a known location in the auto-correcting keyboard region, a region is predefined around one or a plurality of said known locations wherein the distance between an input contact location falling within said predefined region and the known character location within said predefined region is calculated as a distance of zero, wherein the relative sizes of said predefined regions correspond to the relative frequencies of occurrence of the characters associated with the known locations within said predefined regions.
10. The system of claim 1 , further comprising a word choice list component configured to display a word choice list comprising one or more typing objects corresponding to characters of the completed word.