Patent Publication Number: US-2006005129-A1

Title: Method and apparatus for inputting ideographic characters into handheld devices

Description:
FIELD OF THE INVENTION  
      The present invention relates to handheld devices, and in particular to a method and apparatus for inputting ideographic characters into handheld devices.  
     BACKGROUND OF THE INVENTION  
      Ideographic characters are commonly used for Asian languages, such as Chinese and Japanese. Developers of handheld devices have struggled with designing method and apparatus for inputting ideographic characters into handheld devices.  
      A conventional device for inputting data into handheld devices is a keypad typically having only 12 to 24 keys of which 10 keys are used for entering numbers 1 through 9 and 0. The keypad is typically used on telephones, mobile phones and similar handheld devices. Scrollers, rotators, or wheels may also be used to input ideographic characters into handheld devices. Handwriting recognition technology may also be implemented in handheld devices for inputting ideographic characters.  
      In order to input ideographic characters into a handheld device via a keypad, the phonetic letters (e.g., pinyin or zhuyin letters for Chinese characters) or the strokes of the ideographic characters are first mapped by the manufacturer of the handheld device onto the 10 keys of the keypad, which are used for entering numbers. Then, for inputting an ideographic character into the handheld device via the keypad, a user may, in one input mode, enter the phonetic letters of the ideographic character by pressing the numeric keys of the keypad, and select one of the ideographic characters to be predicted and displayed by the handheld device based on the entered phonetic letters. Alternatively the user may, in another input mode, enter the strokes of the ideographic character by pressing the numeric keys of the keypad, and select one of the ideographic characters to be predicted and displayed by the handheld device based on the entered strokes. Hereinafter, the phonetic letters and strokes of ideographic characters are simply called symbols.  
      In order to speed up the process of inputting ideographic characters into handheld devices, inputting methods with phrase prediction capability have been developed. That is, after an ideographic character has been inputted, the handheld device predicts and displays several ideographic characters each of which may form a phrase with the ideographic character that has been previously inputted. In so doing, the user may simply select the predicted and displayed ideographic characters to finish the whole phrase, rather than to individually input the characters included in the phrase.  
      Take Chinese for example.   (today) is a Chinese phrase. After   has been inputted,   (day) may be automatically predicted and displayed by the handheld device. Thus, the user may simply select   to finish the input of   (today).   (eat a meal) is another Chinese phrase. After   (eat) has been inputted,   (a meal) may be automatically predicted and displayed by the handheld device. Thus, the user may simply select   to finish the input of   (eat a meal).  
      Only after the first character of a phrase has been inputted can the prior methods of inputting ideographic characters with phrase prediction capability work. However, sentences of ideographic languages are composed of not only phrases but also auxiliary characters. For example, in the Chinese sentence     (Have you eaten a meal today?),   (today) and   (eat a meal) are phrases, while other characters are not.  
      Apparently, the prior methods of inputting ideographic characters with phrase prediction capability is useful only for inputting less than half of characters in a sentence.  
      Besides, if phrases can be inputted directly via the inputting method, the phrase prediction capability is almost useless.  
      Also, it is burdensome to input a punctuation mark. Users usually have to select one punctuation mark from a plurality of punctuation marks.  
      Therefore, there is a need in the art to develop a method and apparatus by which ideographic characters and punctuation marks can be quickly inputted into handheld devices.  
     SUMMARY OF THE INVENTION  
      Embodiments of the present invention provide convenient methods and apparatuses for inputting ideographic characters and punctuation marks into handheld devices.  
      One embodiment of the invention provides a method of inputting ideographic characters into a handheld device, the method comprising: 
          predicting ideographic characters that correspond to symbols inputted by a user, for said user to select;     predicting, based on a previous ideographic character that has been selected by said user, ideographic characters that most likely follow said previous ideographic character but cannot form a phrase with said previous ideographic character, for said user to select; and     inputting ideographic characters that have been selected by said user into said handheld device.        

      An other embodiment of the invention can be an apparatus for inputting ideographic characters into a handheld device, the apparatus comprising: 
          means for predicting ideographic characters that correspond to symbols inputted by a user, for said user to select;     means for predicting, based on a previous ideographic character that has been selected by said user, ideographic characters that most likely follow said previous ideographic character but cannot form a phrase with said previous ideographic character, for said user to select; and     means for inputting ideographic characters that have been selected by said user into said handheld device.        

      Still another embodiment of the invention can be a handheld device, comprising: 
          a transition prediction database, for storing a plurality of ideographic character sequences, each of said plurality of ideographic character sequences comprising a previous ideographic character and at least one ideographic character that most likely follows said previous ideographic character but cannot form a phrase with said previous ideographic character; and     a controller, for referring to said transition prediction database for ideographic character sequences whose said previous ideographic character is identical to an ideographic character that has been inputted by a user.        

      According to embodiments of the present invention, phrases can be automatically predicted. Ideographic characters that most likely follow the previous character but cannot form a phrase with the previous character can also be automatically predicted. Additionally, punctuation marks can be automatically predicted. All of these can greatly increase the speed of inputting ideographic characters and punctuation marks into handheld devices.  
      Other features and advantages of the present invention should be apparent from the following description of various embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is the flowchart of one method of inputting ideographic characters into a handheld device according to one embodiment of the present invention;  
       FIG. 2  schematically shows the structure of one possible handheld device according to the present invention, which includes an apparatus for inputting ideographic characters according to one embodiment of the present invention;  
       FIG. 3  illustrates one sample process of inputting a Chinese sentence using various embodiments of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
      The embodiments of the present invention will be described in detail.  
       FIG. 1  is the flowchart of one sample method of inputting ideographic characters into a handheld device according to one embodiment of the present invention.  
      At step  101 , the process begins.  
      At step  102 , symbols can be received from an inputting device of a handheld device. The handheld device for example can be a mobile phone, a PDA, etc. The inputting device for example can be a keypad or a scroller mounted on a handheld device, or any other equivalent devices for inputting symbols into a handheld device.  
      At step  103 , a flag can be set to zero. The flag can be used to decide whether to initiate phrase prediction capability. (See steps  111  and  112 ). In one embodiment this flag is optional, and phrase prediction capability (step  112 ) may be valid all the time. If phrase prediction capability is only initiated under certain conditions, inputting ideographic characters into handheld devices may be sped up.  
      At step  104 , it can be determined whether “Cancel” has been pressed. If the result of step  104  is “Yes”, the process can go to step  105  where the process ends. If the result of step  104  is “No”, the process can go to step  106 .  
      At step  106 , ideographic characters (such as Chinese characters) and/or phrases can be predicted based on the symbols received at step  102 , and the predicted ideographic characters and/or phrases can be displayed for the user to select. Various conventional process of predicting ideographic characters and/or phrases based on symbols inputted by a user can be used.  
      At step  107 , it can be determined whether a selection has been made by the user. If the result of step  107  is “No”, the process can wait at step  107 . If the result of step  107  is “Yes”, the process can go on to step  108 .  
      At step  108 , can be determined whether “Cancel” has been pressed. If the result of step  108  is “Yes”, the process can go back to step  102 . If the result of step  108  is “No”, the process can go on to step  109 .  
      At step  109 , the ideographic characters and/or phrases that have been selected by the user at step  107  can be inputted into the handheld device. Then process can go on to step  110 .  
      At step  110 , ideographic characters (such as Chinese characters) can be predicted by means of transition prediction, based on the characters that have been inputted into the handheld device at step  109  (i.e., the characters that have been selected by the user at step  107 ), and the predicted ideographic characters can be displayed for the user to select. Transition prediction is described in detail as follows.  
      Transition prediction can be used to predict ideographic characters and punctuation marks based on at least one ideographic character (called “previous character” here) . Based on the previous character, ideographic characters that most likely follow the previous character but cannot form a phrase with the previous character can be predicted. Also, punctuation marks that most likely follow the previous character can be predicted.  
      For example, if the previous character is   the characters that may be predicted by transition prediction may include   etc. The character sequences   are not phrases in Chinese language, but they frequently appear in sentences.  
      If the previous character is   the punctuation marks that may be predicted by transition prediction may include question mark “?”. In Chinese,   generally appears at the end of a question.  
      At step  111 , it can be determined whether the flag is zero. If the result of step  111  is “No”, the process can go on to step  113 . If the result of step  111  is “Yes”, the process can go on to step  112 .  
      At step  112 , ideographic characters (such as Chinese characters) can be predicted by means of phrase prediction, based on the characters that have been inputted into the handheld device at step  109  (i.e., the characters that have been selected by the user at step  107 ), and the predicted ideographic characters can be displayed for the user to select.  
      Conventional phrase prediction technology can be used to predict ideographic characters based on at least one ideographic character (called “previous character” here). Based on the previous character, ideographic characters that may form a phrase with the previous character can be predicted.  
      For example, if the previous character is   the characters that may be predicted by phrase prediction may include   etc.   are phrases in Chinese language.  
      The order of steps  110  and  112  are not important and constitutes no restriction to the present invention. That is, steps  111  and  112  may be performed ahead of step  110 .  
      At step  113 , it can be determined whether a selection has been made by the user. If the result of step  113  is “No”, the process can wait at step  113 . If the result of step  113  is “Yes”, the process can go on to step  114 .  
      At step  114 , it can be determined whether “Cancel” has been pressed. If the result of step  114  is “Yes”, the process can go on back to step  102 . If the result of step  114  is “No”, the process can go on to step  115 .  
      At step  115 , it can be determined whether the ideographic character that has been selected by the user at step  113  is predicted by phrase prediction (i.e., at step  112 ). If the result of step  115  is “No”, the process can go on to step  116 . If the result of step  115  is “Yes”, the process can go on to step  117 .  
      At step  116 , the flag can be set to zero. At step  117 , the flag can be set to one.  
      At step  118 , the ideographic characters that have been selected by the user at step  113  can be inputted into the handheld device. Then the process can go back to step  110 .  
      Of course, if a punctuation mark has been selected by the user at step  113 , the selected punctuation mark can be inputted into the handheld device at step  118 , and the process can go back to step  102 .  
       FIG. 2  schematically shows the structure of one embodiment of a handheld device according to the present invention, which can include apparatus for inputting ideographic characters according to one embodiment of the present invention. While a handheld device is discussed herein, the concepts and principles of the invention can be applied and used in non-handheld devices as well.  
      In  FIG. 2 , reference numeral  201  denotes a controller,  202  character prediction database,  203  phrase prediction database,  204  transition prediction database,  205  inputting device such as a keypad or a scroller,  206  display, and  207  outputting device.  
      Controller  201  can initially receive symbols, inputted by the user, from inputting device  205 . Inputting device  205  for example can be a keypad, a scroller, or any other equivalent devices for inputting symbols into a handheld device.  
      Controller  201  can then refer to character prediction database  202  for ideographic characters that match the symbols received from inputting device  205 , and can display the matched ideographic characters on display  206  for the user to select.  
      If the user selects one of the plurality of ideographic characters displayed on display  206 , controller  201  can receive the selection (for example, a digit associated with the selected ideographic character) from inputting device  205 , and operate outputting device  207  to output the selected ideographic character to the component of the handheld device for which the method of inputting ideographic characters has been initiated. For instance, such a component may be a short message composer, a notepad, a telephone directory, a dictionary, etc.  
      In one embodiment, character prediction database  202  car store symbol strings and corresponding characters in a table. A conventional character prediction database  202  and conventional operations of predicting characters based on symbols can be used.  
      If controller  201  receives a selection from inputting device  205 , controller  201  can refer to phrase prediction database  203  for ideographic characters each of which may form a phrase with the ideographic character selected by the user, and display the predicted ideographic characters on display  206  for the user to select.  
      In one embodiment, phrase prediction database  203  can store a plurality of phrases in a table. Phrase prediction database  203  and operations of predicting phrases based on initial characters can be used.  
      Preferably, controller  201  controls phrase prediction database  203  in such a way that phrase prediction database  203  works only after the user selects an ideographic character that has been predicted by character prediction database  202  or by transition prediction database  204 . That is to say, if the user selects an ideographic character that has been predicted by phrase prediction database  203 , controller  201  does not refer to phrase prediction database  203  again for ideographic characters.  
      Take Chinese phrase   (today) for example. If the user selects   phrase prediction database  203  predicts   and other Chinese characters. If the user further selects   to finish inputting the phrase   controller  201  does not refer to phrase prediction database  203  until the user selects an ideographic characters which is either predicted by character prediction database  202  or by transition prediction database  204 .  
      If controller  201  receives a selection from inputting device  205 , controller  201  can also refer to transition prediction database  204  for ideographic characters that most likely follow the previous character but cannot form a phrase with the previous character, and for punctuation marks that most likely follow the previous character, and display the predicted ideographic characters and punctuation marks on display  206  for the user to select.  
      In one embodiment, transition prediction database  204  can store in a table a plurality of character sequences and character-punctuation mark combinations that are frequently used in sentences. Each character sequence can be composed of a previous character and at least one character that most likely follows the previous character but cannot form a phrase with the previous character. Each character-punctuation mark combination can be composed of a previous character and at least one punctuation mark that most likely follows the previous character.  
       FIG. 3  depicts a process of inputting a Chinese sentence using the method and apparatus according to the present invention.  
      In  FIG. 3 , suppose character sequences that are frequently used in Chinese sentences include     etc. and phrases include     etc. The above character sequences can be stored in transition prediction database  204 , and the above phrases can be stored in phrase prediction database  203 .  
      In order to input a sentence     the user initially inputs symbols (for example, pinyin or zhuyin symbols) for   and symbols for    
      Then   and other possible characters can be predicted by controller  201  by referring to phrase prediction database  203 , and displayed on display  206 . The user may simply select   from display  206  via inputting device  205 .  
      After   is selected,   and other possible characters can be predicted by controller  201  by referring to transition prediction database  204 , and displayed on display  206 . The user may simply select   from display  206  via inputting device  205 .  
      After   is selected,   and other possible characters are predicted by controller  201  by referring to phrase prediction database  203 , and are displayed on display  206 . The user may simply select   from display  206  via inputting device  205 .  
      After   is selected,   and other possible characters can be predicted by controller  201  by referring to transition prediction database  204 , and displayed on display  206 . The user may simply select   from display  206  via inputting device  205 .  
      After   is selected,   and other possible characters are predicted by controller  201  by referring to transition prediction database  204 , and are displayed on display  206 .   and other possible characters can be predicted by controller  201  by referring to phrase prediction database  203 , and displayed on display  206 .   are Chinese phrases.) The user may simply select   rather than   and   from display  206  via inputting device  205 .  
      After   is selected, “?” and other possible punctuation marks or ideographic characters can be predicted by controller  201  by referring to transition prediction database  204 , and displayed on display  206 . The user may simply select “?” from display  206  via inputting device  205 .  
      Thus, the whole sentence     can be inputted into the handheld device.  
      Apparently from the above example, if there were no transition prediction database  204 , the user would have to input symbols for   and input question mark “?”. The function of transition prediction database  204  can be used to assist the user in inputting symbols for   and inputting question mark “?”. This can greatly speed up the process of inputting the sentence    
      While the foregoing has been with reference to specific embodiments of the invention, it will be appreciated by those skilled in the art that these are illustrations only and that changes in these embodiments can be made without departing from the principles of the invention, the scope of which is defined by the appended claims.