Patent Publication Number: US-2006018545-A1

Title: User interface and database structure for Chinese phrasal stroke and phonetic text input

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to U.S. provisional patent application Ser. No. 60/591,465 filed Jul. 26, 2004 and U.S. provisional patent application Ser. No. 60/590,713 filed Jul. 23, 2004, the contents of both of which are incorporated by reference here in their entirety by this reference. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Techical Field  
      The invention relates to data entry. More particularly, the invention relates to a user interface and database structure for Chinese phrasal stroke and phonetic text input.  
      2. Description of the Prior Art  
      Chinese stroke text input solutions for the handheld devices currently available on the market are predominantly character based. In such solutions, the user stroke sequence for entry of a character is typically delimited by the user entry of a terminator.  
      Single character input systems are known. See, for example, the T9 product (T9) offered by AOLITegic Communication Inc. (see http://www.tegic.com/).  
      A phrasal stroke input system is offered by Beijing d-Ear Technologies Co. (see http://www.d-ear.com/Frameset.htm). While the d-Ear product provides phrasal input, it greatly changes the manner in which users&#39; would otherwise enter single characters. Thus, the user is forced to enter exactly four strokes if the character has more than four strokes. This approach presents at least the following problems: 
          It does not allow shortcuts, for example the entry of one stroke for each character in the phrase if the phrase is frequently used; and     The user may want to enter more strokes for certain characters and fewer strokes for other characters, but the d-Ear input system does not support this feature.        

      It would be advantageous to provide a user interface and database structure for Chinese phrasal stroke and phonetic text input that overcomes the limitations of known devices.  
     SUMMARY OF THE INVENTION  
      The invention provides a stroke and phonetic text input entry system that has substantially the same definition of stroke match as that used in T9, where the input is a phrasal input rather than a character input. Phrasal stroke input can make the user&#39;s text input faster and more accurate compared to character stroke input. The invention solves the problem of Chinese phrasal stroke by allowing users to enter an arbitrary number of strokes for each character in a phrase, where each character is separated by a delimiter. This invention also allows stroke and phonetic phrasal input methods to share the same phrasal data. In this way, the invention provides a system that is easily learned and efficiently applied. Thus, the invention makes it possible for users to enter multiple characters while keeping their single character input habits.  
      Each Chinese character has a standard stroke sequence in Guo Biao (GB), which is the standard for mainland China (although some users may use non-standard stroke sequences), or multiple sequences for BIG5 Chinese Character Encoding for Traditional (Complex) Characters, which is the de facto standard in Taiwan but not used in mainland China. With the invention, users do not have to enter the complete sequence for a single character, but instead can stop at any point and enter a delimiter which indicates the end of the previous character and the start of the next character. The whole stroke sequence entered by the user can then be split into groups that are separated by zero or more delimiters. Phrases can then be identified by user entry of groups of characters. The presently preferred phrase matching criteria are as follows: 
          The first stroke group matches the leading stroke sequence of the first character of the phrase;     The second stroke group matches the leading stroke sequence of the second character of the phrase, etc;     The phrases that match the entered stroke sequence are presented to the user for selection.        

      A user interface design for Chinese phrasal stroke is also provided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  depicts a device for entering a Chinese phrase, showing a text area, a stroke area, and a selection area according to the invention; and  
       FIG. 2  is a block schematic diagram showing a system for phrasal stroke and phonetic text input according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Definitions, Acronyms, and Abbreviations  
      The terms listed on Table 1 below have the meaning in this document that is ascribed to them therein.  
               TABLE 1                          Definitions, Acronyms, and Abbreviations                     Term   Description               PTI   Phrasal text input, i.e. a way to input a           Chinese word/phrase instead of character by           character.       LDB   Linguistic database, i.e. where the character,           word, and phrase information is stored.       SID   Stroke ID, i.e. the index of Chinese characters           sorted by stroke.       PID   Phonetic ID, i.e. the index of Chinese           characters sorted by phonetic spelling.       Wild card   A key that the user enters to match any stroke           input.       Stroke   The most basic building blocks of Chinese           characters. 5-stroke and 8 stroke systems           are most popular.       Component   Defined as a part of a Chinese character in           the leading stroke position.       Fuzzy (“Mohu”)   A pair or multiple pairs of phonetic initials       phonetic spelling   (Shengmu in pinyin) or finals (Yunmu in           pinyin) that are not distinguishable to certain           groups of users       Phrase   One or more words                  
 
      The invention provides a stroke text input entry system that has substantially the same definition of stroke match as that used in T9, where the input is a phrasal input rather than a character input. The invention solves the problem of Chinese phrasal stroke text input by allowing users to enter an arbitrary number of strokes wild cards or a component for each character in a phrase, where each character is separated by a delimiter. In this way, the invention provides a system that is easily learned and efficiently applied. Thus, the invention makes it possible for users to enter multiple characters while keeping their single character input habits.  
      Each Chinese character has a standard stroke sequence in Guo Biao (GB), which is the standard for mainland China, or multiple sequences for BIG5 Chinese Character Encoding for Traditional (Complex) Characters, which is the de facto standard in Taiwan but not used in mainland China. With the invention, users do not have to enter the complete sequence for a single character, but instead can stop at any point and enter a delimiter which indicates the end of the previous character and the start of the next character. The whole stroke sequence entered by the user can then be split into a few groups that are separated by zero or more delimiters. Phrases can then be identified by user entry of groups of characters.  
      The presently preferred phrase matching criteria are as follows: 
          The first stroke group matches the leading stroke sequence of the first character of the phrase;     The second stroke group matches the leading stroke sequence of the second character of the phrase, etc;     The phrases that match the entered stroke sequence are presented to the user for selection.        

      A user interface design for Chinese phrasal stroke and phonetic text input is shown in  FIG. 1 , which depicts a device for entering a Chinese phrase, showing a text area  10 , a stroke area  14 , and a selection area  12  according to the invention. The device comprises a data entry keypad  18  in which the 1-5 keys bear an indication of the stroke that is input when the key is pressed. Key  8  bears a delimiter symbol; key  8  is pressed to indicate the end of a character and the start of a next character during phrasal input and selection. In  FIG. 1 , a word  11  has been entered into the text area. The stroke area  14  shows the stroke sequence entered by the user, where the diamond symbol indicates that the user has entered a delimiter. There are four words in the selection area (1-4). The next word  13  is the third selection (3) in the selection area. In a T9 embodiment of the invention, the user press-holds a key (1-4 in the example shown in  FIG. 1 ) to select a corresponding phrase. The delimiters divide the user input into a few stroke sequences. All the words in the selection area (1-4) should have characters that match the stroke sequences, respectively. In this example, the user entered key  1 , key  5 , key  8  as a delimiter, key  3 , and key  4 . All the phrases in the selection area (1-4) have the first characters that have stroke sequences starting with “15” and second characters with stroke sequence of “34 . . . ”. Those skilled in the art will appreciate that the device shown in  FIG. 1  is provided for purposes of illustration and example only, and that many different input devices may be employed to implement the invention herein disclosed.  
      Data Structure  
       FIG. 2  is a block schematic diagram showing an apparatus for phrasal stroke and phonetic text input according to the invention. The data structure  20  of the invention comprises two kinds of internal IDs for the Chinese character set: stroke ID  21  and phonetic ID  22 . 
          Stroke ID is defined as the index of stroke sorted Chinese characters.     Phonetic ID is defined as the index of phonetic-sorted Chinese characters or the index of key-sorted, then phonetically sorted Chinese characters. The phonetic sort may be further sorted by the tone of the character to support tone options in phrases.        
      The data structure also includes a word list structure  25  and two ID range lookup structures for the Chinese character set: one for stroke  23  and one for phonetic  24 . The data structure also includes lookup tables which can translate between phonetic ID and stroke ID  28 , and from either phonetic ID or stroke ID to Chinese characters  29 , for example encoded in Unicode.  
      A Chinese input system can have either a phonetic or a stroke ID range lookup structure or both for single character input. With the provision of a word list, the input system supports phrasal text input. If a system supports only stroke or phonetic input, the lookup tables translating between PID and SID are not necessary.  
      The core finds the stroke or phonetic ID range for the given stroke or phonetic input based on the ID range structure. The word list is scanned to find out the words whose character IDs fall into the ranges. The words are then sent to a word buffer  26  sorted by frequency or other criteria, for example by whether a key input matches the word exactly or partially.  
      Lookup Tables  
      The lookup tables must support one-to-many mapping due to the fact that one Chinese character may have different phonetic pronunciations and multiple stroke sequences. The database may contain the frequency information about the different pronunciations and different stroke sequences. The lookup tables in the presently preferred embodiment of the invention comprise: stroke ID to phonetic ID  31 , phonetic ID to stroke ID  28 , and phonetic ID (or stroke ID) to Unicode  29 ,  30 .  
      Stroke ID to phonetic ID and phonetic ID to stroke ID tables have the same format. There are two tables: the main table and the multiple value table.  
      The main table is: 
          0xxx xxxx xxxx xxxx: if there are no multiple lookup values. X is the lookup value.     1nnn xxx xxx xxxx: if there are multiple values. X points to the address in the multiple value table and n+2 is the number of multiple values. The multiple values, n+2 words, can be read from the address. Each multiple value table has an adjustment table in case the number of total multiple values exceeds 4 k.        

      The unicode table  32  can be accessed either from the phonetic ID or stroke ID tables.  
      Phonetic Structure  
      From the users&#39; point of view, the phonetic system is designed to convert the key sequence to spellings first, then to Chinese characters. Internally, the second step contains two parts: first to convert from spellings to phonetic IDs, then to Chinese characters.  
      Interpretation from Keys to Spellings  
      A phonetic tree is built for all the possible phonetic spellings for the words using T9 alpha techniques, which are covered by U.S. Pat. No. 5,818,437, U.S. Pat. No. 5,953,541, U.S. Pat. No. 6,011,554, U.S. Pat. No. 6,307,548, U.S. Pat. No. 6,286,064, U.S. Pat. No. 6,307,549, U.S. Pat. No. 5,945,928, U.S. Pat. No. 5,187,480, U.S. Pat. No. 6,646,573 and U.S. Pat. No. 6,636,162 and other U.S. and foreign pending patents. The input key sequence is fed into the T9 alpha core to generate the valid spellings. The spellings are presented to the user as spelling choices.  
      Interpretation from Spellings to Phonetic IDs  
      A list of all possible syllables is stored, sorted alphabetically. A spelling is compared with all the possible spellings and, if matched, the index of the spelling is used to look up the phonetic ID range. The phonetic ID range table is a list of starting phonetic IDs for each spelling.  
      The spellings of the syllables are saved for lookup purpose. Each syllable can have up to six letters. For a given syllable, the invention first searches the syllable table to try to match the spellings. If a match is found, the invention then uses the index to find the starting PID in the PID range table. The next entry in the PID range table is the ending PID. All the PIDs in the range have the same spelling.  
      In the phrasal input case, the spelling can be divided into a few syllables. Each syllable can have a corresponding PID range. The word data are searched to match the PIDs in a phrase to the PID ranges and find the matching phrases.  
      Tones  
      If the phonetic ID does not contain tone information or the PID is not sorted by tone, the tone information table 33 is needed to support tone input.  
      Each PID should have its own tone information in the format of: 
          pppx xxxx 
 
 where p indicates the primary tone for the character of the spelling and X is a bit mask indicating the available tones for the character of the spelling. 
 
 Mohu Phonetic Spelling Consideration 
       

      Mohu phonetic spelling concerns a phenomenon in which some phonetic users cannot distinguish a pair or multiple pair of phonetic initials or finals. For example, “hu” and “w”, “z” and “zh” or “an” and “ang.” These users cannot tell the difference among “zan,” “zhan,” “zang,” and “zhang.” 
      Mohu phonetic spelling is implemented based on the syllable tree. The core, also referred to herein as the engine, (see  FIG. 2 ) scans the input key sequence. For each possible key combination that has an active mohu pair, the core applies the mohu pair and checks against the phonetic tree whether the new key sequence is valid. If it is, the instructions are further checked to make sure that the mohu pair shows up. If the mohu pair shows up, a spelling match is found. The process can be repeated recursively to get all the possible mohu phonetic spelling.  
      The Word Data  
      The word information, independent of input method, is stored separately. It should contain the information of a frequently used word set encoded in phonetic ID. The data structure is sorted by the phonetic IDs of the leading characters.  
      Stroke Design  
      The database includes a single character stroke tree. Each node in the tree is a key and the path to the node can form a key sequence. If the key sequence matches the stroke sequence of a character, the character is an exact match to the key sequence or the node. The numbers of exact matches and partial matches are saved in the node. Stroke ID is defined as the index in the character set sorted by stroke. Some Chinese characters, especially in traditional Chinese, can be written with more than one stroke sequences. The stroke sequences that are not most frequently used or not standard are called alternative stroke sequences of the character. A character with an alternative stroke sequence is treated as a different SID entry.  
      From this structure, the user entered key sequence in the tree can be followed to find a corresponding node. It is then possible to calculate the exact match stroke ID range and the partial match stroke ID range.  
      In single character input, the stroke ID ranges can be converted to a list of Chinese characters with the help of an SID to PID lookup table and a PID to Unicode lookup table, or a SID to Unicode lookup table.  
      In a phrasal input system, if the user enters a key sequence that can be split into mutiple sub-sequences, the stroke ID ranges can be found for each sub-sequence. The stroke ID ranges can be used as match criteria to search the matching phrases in the word data structure.  
      Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the Claims included below.