Abstract:
A method and apparatus for text entry are provided. The method provides a keypad comprising four directional keys and a center selection key, and assigns a set of letters to each of the four directional keys. A representation of the set of letters assigned to each of the four directional keys is provided. A sequence of selected directional keys is received in accordance with a user input, and in accordance with the selected directional keys, the set of letters assigned to each of the selected directional keys are selectively passed to a parsing algorithm. The parsing algorithm determines a user intended text input based upon the passed sequence of letter groupings.

Description:
FIELD OF THE INVENTION 
     This application is related generally to the field of text input, and more particularly to a method and apparatus for easing a user experience when entering such text in accordance with an input device including a very limited number of input choices. 
     BACKGROUND OF THE INVENTION 
     Portable mobile devices, such as mobile telephones, MP3 players and the like are becoming smaller in size, yet being asked to perform far more sophisticated functions. Indeed many may be provided with an ability to access the Internet, or other communication ability, and with a browser or other user-friendly interface program for reviewing information. These devices allow web browsing and various interactive features including social networking features and yet these devices may not, on their face, be suitable for such interactions. Chat and instant text messaging have now become an integral part of mobile communications. There is therefore a need to enable interactive text entry using various consumer electronics devices that may not be provided with a full keyboard due to a reduced size of the device. 
     Therefore, it would be beneficial to provide an improved text input method and apparatus that overcomes the drawbacks of the prior art. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a rapid text entry system and method are provided that leverage advanced and innovative error tolerant predictive text algorithms. The user can easily enter text employing a text entry device including four directional keys, a center selection button and a menu button, or the like, by way of example. Each of the four directional keys represents a range of letters, numbers, or other characters to be selected by a user. When a user indicates one of the four directional keys, the set of letters, numbers, or other symbols represented by that directional key is selected. Upon the use of the directional keys again, a second set of indicated characters is selected by the user. In this manner, the user is able to consecutively select one of four sets of such letters, numbers or other symbols. The selected sequence of letters, numbers or other symbols are then input to a predictive algorithm that determines words, for example, most likely intended by the user. In accordance with the invention various menu selection elements allow a user to select between the set of characters represented by each of the directional keys. 
     Preferably, the invention further provides a method of selecting from among a number of the most likely selections generated by the predictive algorithm. Entry of such a selection mode allows the user to use the same directional keys to make an appropriate choice. Thus, in accordance with the invention a user may be able to use the same minimal number of directional keys to select characters, words, and make other indications that may be desirable in accordance with the invention. 
     The invention is also applicable to configurations of other numbers of directional, selection and menu indications, although it is most applicable when a minimal number of such selection indicators are available. 
     Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification and drawings. 
     The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combinations of elements and arrangement of parts that are adapted to affect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the invention, reference is made to the following description and accompanying drawings, in which: 
         FIG. 1  depicts a representative device including directional keys, selection and menu selection keys in accordance with the invention; 
         FIG. 2  depicts a menu selection provided to a user in accordance with the invention to allow the user to select between various available character sets; 
         FIG. 3  depicts a set of directional keys representing selection between various ranges of letters in accordance with the invention; 
         FIG. 4  depicts a set of directional keys representing selection between particular letters, numbers or symbols presented in one of the ranges of  FIGS. 3 ,  5  and  6 ; 
         FIG. 5  depicts a set of directional keys representing selection between various ranges of numbers in accordance with the invention; and 
         FIG. 6  depicts a set of directional keys representing selection between various ranges of symbols in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will now be described, making reference to the following figures in which like reference numbers refer to like elements. 
     Referring first to  FIG. 1 , a first embodiment in accordance with the invention is shown. In  FIG. 1 , a device  100  employing a directional key design  110  is shown. In particular, such directional key design  110  further comprises individual directional keys  120 ,  122 ,  124  and  126 , and a selection button  128 . Further provided are a menu selection key  130 , a power button  140 , and a display  150 . While such keys are shown as being dedicated hardware elements of the device  100 , it is contemplated in accordance with the invention that such keys may be displayed on a portion of a touch screen device, thus providing a version of such a device allowing for the ease of use described herein, but also flexibility for choosing modes of display and the like. Upon selection of menu key  130 , a user is provided with a menu allowing for selection between various character sets to be represented by the directional keys  120 ,  122 ,  124  and  126 . Such a menu  200  is viewed by a user on display  150  of device  100 , and is shown in  FIG. 2 . Once menu  200  is displayed, the user may use directional keys  120  and  124  to move through the menu, and select a menu choice by the activation of selection key  128 . As is shown in  FIG. 2 , the menu preferably includes a selection for “Multitap” representing the ability to select from groups of letter, “Numbers” to select from groups of numbers, “Symbols” to select from groups of symbols, and “Clear” to remove one or more previous entries. Upon selection of a menu choice from menu  200 , display  150  changes to display alternatives in accordance with the selection. 
     Thus, by way of example, upon selection of “Multitap” from menu  200 , display  150  preferably displays an image such as that shown in  FIG. 3 . This image preferably mimics the shape of directional key design  110 , and in this case indicates that upon activation of directional key  120 , letters A-G located at portion  320  of display  150  are selected, upon activation of directional key  122 , letters N-S located at portion  322  of display  150  are selected, upon activation of directional key  124 , letters T-Z located at portion  324  of display  150  are selected, and upon activation of directional key  126 , letters H-M located at portion of  326  of display  150  are selected. When activated sequentially, the user is able to select groups of letters that encompass sequential letters from words the user is attempting to spell. In all modes, long activation of directional key  126  results in a backspace, as noted at portion  350  of display  150 , and a long activation of directional key  122  results in a space. 
     A predictive algorithm is used to determine user intended words, these words being displayed on display  150  at portion  340  thereof. Preferably, the most likely word is shown first and may be selected by the user by depressing middle selection button  128  for a short period of time. Upon depression of the middle selection button for a long period of time, the displayed word choices may populate the display  150  as shown in  FIG. 4 . Thus, in display portion  420 , the first choice is shown, the second at portion  426 , and the third at portion  424 . By depressing the corresponding directional key, the displayed choice can be selected. If the user wishes to view additional choices from which to choose, the user can activate the directional key corresponding to display portion  422 , thus displaying a next three suggestions. 
     As can be recognized by a user, each directional key represents a set of letters. Thus, any time a user is interested in selecting any one of the letters indicated by a particular directional key, the user activates the corresponding directional key and all of the letters associated with the particular directional key are selected. 
     As can be understood from this description, a user experience is eased as a user need not select each desired letter form a traditional keyboard, and similarly need not scroll to each letter in a displayed keyboard employing directional keys, but rather need only choose from one of four letter sets. Of course, when employing a predictive parsing algorithm that only has four inputs, determining user intent may be assumed to be a bit more difficult in that the algorithm must choose a suggested word or words only knowing consecutive groups of letters selected, and not the actual letters selected. This assumption, however, may not be correct. Indeed, when selecting among 26 keys, any determination algorithm must consider the fact that the user may make a large number of input errors. While any algorithm must parse words, and having fewer input selections would tend to make this parsing more difficult, this may be counterbalanced with the fact that a user is less likely to make errors when entering information in a system employing the directional key entry method and system in accordance with the invention. 
     In an alternative embodiment, rather than having four sets of letter, eight sets of letters may be provided, four requiring only one activation of the directional keys, and four requiring two activations, either in sequence or simultaneously. Thus display  150  might show four letter groups corresponding as shown in  FIG. 3 , and four additional letter groups displayed between the positions shown in  FIG. 4 . 
     An exemplary predictive text algorithm is depicted in, for example, co-assigned U.S. patent application Ser. No. 12/186,425 to Matthew Cecil, el al., filed Aug. 5, 2008, entitled “A PROBABILITY-BASED APPROACH TO RECOGNITION OF USER-ENTERED DATA”, the entire contents thereof being incorporated herein by reference. This application describes a system that associates a probability distribution to each key on the key board, and employs predetermined probabilities of the user striking a key among the plurality of keys, given the intended key. The system described in the application further provides a number associated to each pair of keys (α,β) indicating the probability that key β will be pressed when key α is intended. Thus given a user entered string, one is able to associate to every dictionary word a number indicating the likelihood that the entered string would occur given the dictionary word was intended. Such an algorithm utilized in accordance with the present invention addresses the predictive text requirements of the invention. The user interface will pass the algorithm a character (or string of characters associated with a particular jumper point and zone) and the algorithm will interpret that character (or characters) and return a result to the user interface in the form of one or more suggested word selections, or may return an indication of an inability to properly parse out a word selection, indicating that the user has not yet entered enough letters as of yet. Other algorithms, in addition to that described in the &#39;425 application may also be applied. 
     Of course, user context, history or the like may be employed to aid in such suggested word selection. Additionally, while the described predictive text algorithm may be employed, the present invention may be used with any appropriate text parsing or predictive text algorithm. As long as jump points can be associated with a number of different inputs, and these inputs can be differentiated from each other and used to select an intended input by a user, the invention may be employed. Furthermore, if the user is selecting from among a limited number of entries, as in a list of songs stored on an mp3 player, a list of contacts in a device, a list of stations in a satellite radio receiver, or the like, the predictive text algorithm relying on such a limited number of inputs can be made even more robust as the number of choices is greatly reduced from a general dictionary. In such a situation, the inventive text entry method of the invention may be preferable to that of a full qwerty keyboard in that a user can enter text more quickly, and because of the limited dictionary, time until recognition of user intent may not be greatly increased. 
     Thus, using a matrix of probabilities the algorithm knows that for each directional key pressed the user entered all letters represented by the activated directional key. Once the algorithm knows the selected characters the algorithm then runs a search against a dictionary, as is more completely described in the &#39;425 application referenced above. Any words that match the string of selected characters are designated and then preferably scored based on distance between characters, frequency, probability, and any number of other characteristics that may be indicative of a user intention. The system can also adopt over time to give a higher probability of selection to frequently used patterns of a particular user. Thus, the prediction mechanism may be personalized for a particular user. Furthermore, in order to additionally aid in determining user intention, in accordance with the invention the predictive algorithm of the proposed system may, in addition to relying upon a traditional dictionary, attempt to further determine user intention by determining the context of a particular text input, such as determining whether the input is for an email, chat, search, or the like, or whether the text input is taking place during a particular television show, or while a music application is playing a song. To the extent a user is likely to use different words and/or other language differences, such context determination may aid in the accuracy of the predictive text algorithm. The algorithm may also receive information about information from stored content, the content of one or more databases, such as a user&#39;s contact list or the like, to improve the reliability of the prediction. Such context may be stored within a device being used for text entry, or may be stored remotely in a database accessible over the Internet, or other available network. The list of words is then sorted based on that score and returned to the user interface. Thus, the invention uses the redundancy in the input language or the possible input functionalities to map approximate input into non-ambiguous input per the user intention. Additionally, device features and functionality may be considered when determining user input, thus perhaps taking into account device limitations when determining such input. 
     Referring once again to  FIG. 2 , when one of the other selections is made from menu  200 , display  150  displays corresponding information to the selection. Thus, upon selection of “Numbers” from menu  200 , display  150  preferably displays information such as that shown in  FIG. 5 . Functioning of selecting the groups of numbers is similar to that of selecting numbers in  FIG. 3 . Upon selection of one group of letters, a display such as that shown in  FIG. 4 , each of the group of numbers being selectable by use of the corresponding directional keys. Upon selection of the “Symbols” choice from menu  200 , the display as shown in  FIG. 6  is employed. Selection of the symbols in accordance with the sequences noted above and with respect to  FIG. 4  are employed. 
     It is also contemplated that a user may enter a direct letter selection mode in which a user is shown a sequence of letters, and can employ the directional keys to highlight one of the letters, and select the letter by use of the center selection key  128 . Such entry may be desirable when entering a name or uncommon word. When such direct letter entry is employed, the predictive algorithm may or may not be employed. 
     While the invention has been described making reference to a four directional key implementation, any number of directional keys may be employed, including as few as two. 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, because certain changes may be made in carrying out the above method and in the construction(s) set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.