System and method for continuous stroke word-based text input
First Claim
1. A method of inputting alphabetic text to an electronic device having a virtual keyboard on a touch-sensitive screen, said virtual keyboard comprising a set of keys wherein each letter of the alphabet is associated with at least one key, by contacting the screen on or near the key associated with the first letter of a desired word, and moving the point of contact along a path that passes in succession through or near the keys associated with each letter of the desired word in sequence, and removing the point of contact from the screen at a position that is on or near the key associated with the last letter of said desired word, forming an input stroke pattern, comparing said input stroke pattern with a set of words stored in a database, determining a set of one or more words determined to most closely match the input stroke pattern, and offering one or more words of said determined set of words to the user for selection.
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Abstract
Many portable electronic devices are designed to utilize only a touch-screen for text input, generally using some form of stylus to contact the screen. Such devices generally input text using some form of handwriting recognition, which is slow and often inaccurate, or an on-screen keyboard, which essentially requires the user to perform “one-finger” typing, often on a reduced-size keyboard. The Continuous Stroke Word-Based Text Input System allows someone to use a small on-screen keyboard to quickly enter words by drawing a continuous line that passes through or near the keys of each letter in a word in sequence without lifting the stylus (similar to a children'"'"'s connect-the-dots drawing). The user traces an input pattern for a word by contacting the keyboard on or near the key of the first letter of the word, then tracing through each letter in sequence, lifting the stylus from the screen upon reaching the last letter. In one preferred embodiment, the user traces a small circle around each double letter that occurs in the word to reduce ambiguity. In another preferred embodiment, a database of words is organized according to the first and last letters so that only a small number of words need to be explicitly scored for each input pattern. In another preferred embodiment, the expected path length corresponding to each word is stored in the database and is compared to the actual input path length entered to further limit the number of words to be explicitly scored. The input pattern is analyzed to identify inflection points of various types, each of which has a greater or lesser probability of corresponding to a letter of the word being input. Words are scored according to the average distance from each letter to the nearest inflection point (or to the nearest point of the traced line if there are more letters in the word than detected inflection points in the input pattern), where each such distance is weighted according to the probability associated with the type of the inflection point from which the distance is measured. In one preferred embodiment, the average weighted distance for a word is further weighted by the frequency of use associated with the word. The method of the present invention enables the system to analyze each input stroke pattern and present one or more corresponding words for selection by the user, wherein the default word match (deemed the most probable match by the system) is automatically output by the system unless the user explicitly selects an alternate word choice.
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Citations
7 Claims
- 1. A method of inputting alphabetic text to an electronic device having a virtual keyboard on a touch-sensitive screen, said virtual keyboard comprising a set of keys wherein each letter of the alphabet is associated with at least one key, by contacting the screen on or near the key associated with the first letter of a desired word, and moving the point of contact along a path that passes in succession through or near the keys associated with each letter of the desired word in sequence, and removing the point of contact from the screen at a position that is on or near the key associated with the last letter of said desired word, forming an input stroke pattern, comparing said input stroke pattern with a set of words stored in a database, determining a set of one or more words determined to most closely match the input stroke pattern, and offering one or more words of said determined set of words to the user for selection.
Specification