Abstract:
A method and apparatus for character entry and more particularly Chinese character entry. The method improves the ease of entry for Chinese characters on a device that has a keypad arrangement of at least a 3×3 matrix ( 106 ). For example wireless communication devices such as radiotelephones have a keypad ( 108 ) for dialing phone numbers. Arranging the Chinese characters on the device display in a 3×3 matrix to match the at least 3×3 matrix of the keypad allows the user to quickly select from the pinyin list ( 104 ) the key on the keypad that corresponds to the desired character in the matching matrix.

Description:
FIELD OF THE INVENTION  
         [0001]    The current invention relates generally to entering characters into an electronic device using a keypad, and more particularly to entering Chinese characters using a telephone keypad.  
         BACKGROUND OF THE INVENTION  
         [0002]    A portable handheld communication device, such as a cellular radiotelephone, generally has few keys available for the entry of information such as short messaging or email text. A typical keypad used with a handheld wireless communication device is a standard telephone keypad having ten number keys, a star (*) key, and a pound (#) key. For English and many other alphabet languages, the numeric keypad of the telephone is overlaid with an alphabet keypad where three or more letters of the alphabet are associated with each number key. For example, the five (5) key is associated with the letters j-k-l. In some reduced keypad electronic devices, upon entering an alphabet entry mode, a user employs multiple key presses to enter letters to make words and names for use by features such short messaging and address book.  
           [0003]    For example, once in alphabet entry mode, a user can employ one keypress to select the first letter associated with a depressed key, two keypresses of the same key to select the second letter associated with the key, three keypresses of the same key to select the third letter associated with the key, and so on.  
           [0004]    Chinese and other character-based languages such as Japanese kanji, however, do not have a manageable number of alphabet letters that can be overlaid onto a numeric keypad. For example, Chinese does not use an alphabet and instead has about 5000 to 7000 commonly used characters. Advantageously, many phonetic systems have been developed to standardize the pronunciation of, for example, Mandarin Chinese. Several of these phonetic systems use the roman alphabet as phonetic symbols, such as the Wade-Giles and the pinyin systems for Mandarin Chinese, and other phonetic systems use a unique phonetic symbol set, such as the zhuyin system for Mandarin Chinese which has a 37-symbol phonetic alphabet. Cantonese Chinese also has a phonetic system using the roman alphabet.  
           [0005]    Although there are over 5000 commonly used Chinese characters, there are only approximately 400 basic phonetic syllables in Mandarin Chinese speech. Thus, many different Chinese characters use the same Mandarin Chinese phonetic syllable. An extreme example is the Mandarin Chinese pinyin word “yi”; this phonetic syllable represents over 100 different Chinese characters, each with a different meaning.  
           [0006]    Additionally, Mandarin Chinese uses four standard tones to differentiate meanings. Thus, the same phonetic syllable, when pronounced using a different tone, has a different meaning. Using the phonetic word “yi” as an example, at least 20 characters use the first tone, at least 31 characters use the second tone, at least 16 characters use the third tone, and at least 63 characters use the fourth tone.  
           [0007]    Although there exist various methods of entering Chinese characters into a computer system using a full-sized keyboard having keys corresponding to all of the phonetic symbols of one of the various phonetic systems and the four tones, there is a need for a reduced keypad entry method for characters for use in a portable hand-held device such as a cellular radiotelephone.  
           [0008]    Accordingly, a system is needed to improve the esthetics and protect the user interface. Providing a means to allow the device functionality to increase yet maintain esthetically pleasing surface to the user and protect the interface form inadvertent subjection to the environment is needed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an exemplary view of a data entry device.  
         [0010]    [0010]FIG. 2 is an exemplary block diagram of the internal circuitry of a data entry device.  
         [0011]    [0011]FIG. 3 is an enlarged exemplary view of a display.  
         [0012]    [0012]FIG. 4 is an enlarged exemplary view of a display scrolling a pinyin list.  
         [0013]    [0013]FIG. 5 is an enlarged exemplary view of a display.  
         [0014]    [0014]FIG. 6 is a diagram of an exemplary mapping of an entry device to a matrix on the display.  
         [0015]    [0015]FIG. 7 is an enlarged exemplary view of a display.  
         [0016]    [0016]FIG. 8 is an enlarged exemplary view of a display.  
         [0017]    [0017]FIG. 9 is an enlarged exemplary view of a display with a character in a text field.  
         [0018]    [0018]FIG. 10 is an enlarged exemplary view of a display with Character Strokes. 
     
    
     DETAILED DESCRIPTION OF INVENTION  
       [0019]    The keypad entry method and apparatus to enter language notation for entry of words such as Chinese characters using a small number of keypresses on a reduced keypad is disclosed, where multiple characters are associated with a combination of alphanumeric symbols or character strokes. The user enters a symbol by pressing keys on a keypad the proper number of times to obtain the desired symbol on a screen. This symbol may be a stroke associated with a final desired character or an alphanumeric symbol or symbols associated with a set of symbols. A list of common sets of symbols associated with the Chinese language is called a pinyin list. As the user enters additional symbols to complete a word or character, the method and apparatus displays characters associated with the symbols in a three by three (3×3) matrix. The 3×3 matrix presented on the display corresponds or maps to the keypad on the device and allows the user to select the desired character by pressing the mapped key of the keypad that corresponds the quadrant of the matrix with the desired character. The keypad entry method and apparatus allows a Chinese character to be efficiently entered using a keypad.  
         [0020]    [0020]FIG. 1 shows a handheld data entry device  100  comprising a display  102 , a pinyin list  104 , a 3×3 character display matrix  106 , a keypad  108 , and a Text Display area  110 . The handheld data entry device  100 , may be a wireless communication device such as a cell phone or PDA with or with out wireless connectivity, so long as the device is used to entry Character type information and more particularly Chinese characters. This is particularly useful with limited keypads, or reduced entry keypads on smaller devices having limited data entry capability such as cell phones that are used to send SMS, EMS, or MMS messages.  
         [0021]    [0021]FIG. 2 shows a block diagram of the internal circuitry of a reduced keypad entry apparatus  200  according to a preferred embodiment. The reduced keypad entry apparatus shown is implemented in a cellular telephone, however, it may also be implemented in a standard wired telephone, a personal digital assistant, a facsimile machine, a pager, an electronic label maker, or other electronic devices with reduced keypads, which have fewer keys than alphabet symbols. A keypad  108  and a display  102  are coupled to a microprocessor  220 , which takes input from the keypad  108  and also transmits output to the display  102 . A memory  240 , such as a read-only memory (ROM) is also coupled to the microprocessor  220 . This memory  240  is preferably an electrically-erasable read-only memory (EEPROM) holding two separate blocks of information: validity rules  242  and a dictionary  244 . Another memory  250 , preferably a random-access memory (RAM) is coupled to the microprocessor  220  for storing letters as they are entered via the keypad, a temporary list of Chinese characters associated with an entered phonetic syllable, stored short messages, and address book information.  
         [0022]    [0022]FIG. 3 shows an enlarged view of the display  102  and a Chinese character pinyin list  104  according to a preferred embodiment. The Wade-Giles and pinyin phonetic systems both use the roman alphabet as phonetic symbols for the Mandarin Chinese language. Other language systems using the roman alphabet can also be implemented using the keypad  102 . In the embodiment shown, the pinyin system will be used for Chinese character entry.  
         [0023]    The keypad  108  has twelve standard keys  112 - 134  marked 0-9, *, and #. The keys  112 - 134  labeled 2-9 are also labeled with symbols corresponding to letters of the roman alphabet as dictated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) standard.  
         [0024]    Number keys  112 - 134  labeled 2-9 can be used to select one of three or four letters of the roman alphabet. In one, embodiment, the device data entry mode is a “pinyin entry” method. One option for letter selection during pinyin entry mode, is to select a roman letter by the number of times a single key is pressed in succession. For example, pressing the five (5) key  120  once, results in a letter j on the display  102 , pressing it twice results in a letter k on the display  102 , and pressing it three times results in a letter l on the display  102 . Pressing the five (5) key  120  additional times cycles through the j-k-l-1 letters again. Other methods of selecting a roman letters using the numeric keypad can be substituted for the method described. For example, another letter entry system uses the star (*) key  130  to scroll through the letters associated with a single number key: 5* produces a letter j on the screen, 5* * produces a letter k on the screen, and 5* * * produces a letter l on the screen.  
         [0025]    The validity rules  242  in memory  240  shown in FIG. 2 stores in a table which roman letters can be a first letter of a pinyin word and the frequency of each valid first letter. When a key is pressed, the microprocessor  220  orders the presentation of valid first letters on the display  102  according to the validity rules  242 . For example, the two (2) key  312  is associated with the roman letters a, b, and c. There are 5 pinyin words that start with the letter a, 16 pinyin words that start with the letter b, and 35 pinyin words that start with the letter c. Because the letter c is the most common first letter associated with the two (2) key  312 , the letter c is presented on the display  102  when a user presses the two (2) key  312  once. Pressing the two (2) key  312  a second time presents a letter b on the display  102 , and pressing it a third time presents a letter a on the display  102 . Pressing the two (2) key  312  additional times scrolls through the letters c-b-a.  
         [0026]    The presentation of other roman letters associated with a single key may also be reordered in light of their frequency of occurrence as a first letter of a pinyin word. In the preferred embodiment, the letters associated with the seven (7) key  124  are presented in the order s-p-q-r and the letters associated with the nine (9) key  128  are presented in the order z-y-w-x while the letters associated with the remainder of the number keys are presented in their standard alphabetical order. Also, certain roman letters never begin a pinyin word in Mandarin Chinese. For example, the letters i, u, and v do not begin any pinyin words and thus are not displayed by the microprocessor  220  when a first letter of a word is being entered. This validity and presentation order information is preferably stored in the ROM  240  shown in FIG. 2 in the validity rules  242  memory.  
         [0027]    Once a first letter is selected and exhibited on the display  102 , the user presses a different key to start cycling through next letters, or the user presses the pound (#) key  134  to indicate that the desired letter has been entered and then enters an additional letter. Pressing the pound (#) key  134  is necessary in situations where consecutive letters in a pinyin word are both associated with the same number key. For example, the consecutive letters c-a in the phonetic syllable “can” are both associated with the two (2) key  114 . Thus, after the letter “c” is displayed on the display  102 , the user presses the pound (#) key  134  to confirm the entry of the letter c and then returns to the two (2) key  114  to enter the letter a. In situations apart from the one described above, the use of the pound (#) key  134  between letters in a word is optional. For example, once the “a” in “can” is entered, the user can immediately press the six (6) key  122  to obtain an “n” without first pressing the pound (#) key  134 .  
         [0028]    The microprocessor  220  presents on the display  102  letters associated with a selected number key depending on its frequency of occurrence following the first letter. For example, if the letter j is the first letter of a pinyin word, a valid second letter can only be a letter i or a letter u. Thus, if a user presses the five (5) key  315  and then the four (4) key  314 , the display  102  will show the phonetic word “ji” in only two keystrokes. In the preferred embodiment, when only one letter associated with a keypress is valid, the microprocessor  220  will automatically cause the display  102  to show the valid letter continuously. If more than one letter associated with a single keypress is valid, the microprocessor  220  will cause the presently displayed letter to blink on the display  102  thus indicating that other valid options exist. Because the ROM  240  stores information regarding the occurrence of each letter depending on its position in a word, it can be used to direct the continuous display or blinking display of the letter.  
         [0029]    Another method for selecting the pinyin is a predictive selection method. This method utilizes a list of pinyins. This allows for easier data entry as the user need only execute a single key press to obtain all the letters associated with that key. For example, when the nine (9) key is pressed, a vertically oriented list of the letters, w x y z is displayed in ascending order with the bottom letter field highlighted. The user then proceeds to execute a second key press to add a second letter to the pinyin. Any valid letters, conforming to the validity rules associated with the first letter presented, is displayed. In this case if the two (2) key was selected, the vertically oriented list would display a two-letter pinyin list with wa, xa, ya, za. The validity rules would eliminate the potential combination of letters from the list. The same process applies when the third letter is selected. A three-letter pinyin is formed and all valid combinations are presented in the vertically displayed pinyin list with the most commonly used pinyin displayed in the highlighted filed at the bottom of the list. For example if the third keypress is a six (6), the following pinyin list  104  in accordance with the validity rules would be wan  302 , yan  304 , yao  306 , zan  308 , zao  310 . The wan pinyin  302  being highlighted  312  at the bottom of the pinyin list  104  as it is the most commonly selected pinyin from the resulting pinyin list  104 .  
         [0030]    Also shown in FIG. 3 are the characters associated with the highlighted pinyin  302  of the pinyin list  104 . In FIG. 3, the highlighted area highlights the pinyin wan  302 . The Chinese characters associated with wan are displayed in the matrix located below the pinyin list. The relation of the pinyin list to the matrix can be in any orientation. The current arrangement allows for use on all display and even smaller displays where only a portion of either the pinyin list or the matrix can be displayed. It may be that only one pinyin and the top row of the matrix may be displayed in the given display. Positioning the most frequently chosen pinyin at the bottom of the pinyin list and more particularly nearest the matrix allows for both the current pinyin and the characters associated with that pinyin to be displayed at the same time. As the display size increases more and more of each may be shown. For example, two pinyins may be presented along with two rows from the matrix and so on.  
         [0031]    Continuing to FIG. 4, as the user scrolls through the pinyin list  104 , the list appears to move while the highlight remains stationary. This keeps the pinyin and the associated or corresponding characters visible. The arrow  402  indicates the progression of scrolling from a first pinyin  302 , positioned in the highlight area  310 , to FIG. 4 where the pinyin yan  304  is now positioned in the highlight area  310 . The characters in the matrix  106  have also changed. The characters presented in the matrix  106  of FIG. 3 correspond to the wan pinyin  302 , and the characters presented in the matrix  106  in FIG. 4 correspond to the yan pinyin  304 .  
         [0032]    Once a pinyin is displayed in the highlight are  310 , characters corresponding to the highlighted pinyin are displayed in a 3×3 matrix  106  of the preferred embodiment. The 3×3 matrix  106  may be filled with nine characters or if less, if less than nine characters correspond with the given pinyin. Only those characters are displayed in the matrix and some of the space in the 3×3 matrix  106  are left blank. If more than nine characters correspond to the given pinyin, than a second page to the 3×3 matrix (not shown) will be necessary. The user will use a navigation key to move to the second page of the 3×3 matrix.  
         [0033]    Once the user enters and or scrolls to the desire pinyin, the desired character associated with the chosen pinyin can be selected. The user can use navigation keys on the keypad  108  or a joystick to move from the pinyin list to the matrix. In either case the user will need to exit pinyin entry mode and enter character selection mode because the same keys are used to select the pinyin and the characters. Because the 1 key  112  is not used it may be used to toggle between pinyin entry mode and character selection mode. Another soft key or menu key may also be used. Once in character selection mode, the user can manipulate arrow keys or a joystick to move around the matrix. FIG. 5 shows the character  518  highlighted in the matrix. The characters are highlighted as the user navigates around the matrix. When the desired character is highlighted, a selection key is depressed to select the character.  
         [0034]    The preferred embodiment of the present invention maps the character matrix  106  to the keys of the keypad  108  as shown in FIG. 6. Here each key on the keypad has a corresponding position in the character matrix  106 . For example, position  402  maps to the 1 key  602  on the keypad. Once the user toggles to character entry mode, it is only necessary to press the corresponding key on the keypad  108  to select the desired character. For example, if the user desires to select the character in position number  518 , the nine (9) key  610  is pressed. The character, as shown in FIG. 9, is then displayed on the text lines  110 .  
         [0035]    When the phonetic syllable has been fully entered, the user has the option of selecting a tone value to indicate the tone of the syllable. Tone values can be selected using the zero (0) key  134 . An alternate to the zero (0) key is the one (1) key  112 , because it also does not have letters associated with it. Pressing the zero (0) key  134  once results in a first tone marker on the screen (1 or “-” depending on the implementation), pressing the zero (0) key  134  again results in a second tone marker (2 or “/”) on the screen, and so on for the third tone (3 or {square root}) and fourth tone (4 or \). Pressing the zero (0) key  134  five times removes the tone marker, and pressing it more than five times in succession cycles through the tones again. Preferably, the microprocessor  220  automatically skips invalid tone markers like it automatically skips invalid letters based on the information stored in the ROM  240 . Thus, the number of keystrokes needed to enter a phonetic syllable and an associated tone marker can be reduced.  
         [0036]    At any point during the phonetic syllable entry, a user can erase a roman letter or tone marker using the clear (C) key  384 . After a user presses the OK key  386  to indicate that the word is completely entered, the microprocessor  220  shown in FIG. 2 initiates a search through the dictionary  244  in ROM  240  for all possible Chinese characters associated with the entered phonetic syllable. If no tone marker is entered, the microprocessor  220  will present on the display  102  all of the characters associated with the phonetic syllable alone ordered by frequency of use. If a tone marker is entered, only the characters associated with the entered phonetic syllable and tone marker are presented, again ordered by frequency of use. The eligible Chinese characters are loaded into the RAM  250  for display. In this embodiment, five Chinese characters appear on the display  102  at a time, and the user can select one of the five displayed characters using the 1-5 number keys  311 - 315  or scroll forward to the next set of five character alternatives using the pound (#) key  322 . The star (*) key  321  also allows a user to scroll backwards through the character alternatives five at a time.  
         [0037]    There are various validity rules depending on whether the keypress is a first letter of a word, a next letter of a word, or a tone marker. The microprocessor  220  uses the proper validity rule to determine in step  435  if a valid key has been pressed. If a valid key has not been pressed, the microprocessor  220  returns to step  410  without displaying a roman letter on the display  102  shown in FIG. 2. If a valid key was pressed, in step  440  the microprocessor  220  displays the most frequently encountered valid letter associated with the keypress on the display  102  and returns to step  410 . If subsequent keypresses are presses of the same key, the microprocessor  220  will scroll through all of the valid letters associated with the key in order of priority according to the validity rules. If subsequent keypresses are different keys, the microprocessor will add roman letters or a tone marker to the word being built on the display  102 .  
         [0038]    Since more than nine characters may be associated with a given pinyin, the microprocessor  220  displays the first nine most frequently used Chinese characters in the character matrix  106 . A scrolling key, such as the star (*) or pound (#) key  321 ,  322 , or a joystick may be used to causes the next or previous nine frequently-used characters to be shown in the character matrix  106 .  
         [0039]    This reduced keypad entry apparatus and method can be used not only for pinyin word entry but also stroke entry for Chinese characters. FIG. 10 shows a Chinese character corresponding to a stroke sequence  1002  entered with the keypad in the same manner as the pinyin list  104 . As the strokes are entered the possible characters associated with the stroke sequence combination are presented in the character matrix  106 . The user may then toggle to the character selection mode and press the corresponding key on the keypad  108 . The character is then presented on the text line  110 .  
         [0040]    Thus, the keypad entry method and apparatus provides a method and apparatus for entry of words using a small number of keypresses on a reduced keypad. The method and apparatus uses priority rules to rearrange the order of presentation of the multiple alphabet symbols associated with a single key on the keypad, automatically eliminates the presentation of invalid alphabet symbols, and allows the entry of additional information such as a tone value. The mapping of the individual keys of the keypad to the character matrix on the display allow for faster an more intuitive selection of character. While specific components and functions of the reduced keypad entry method and apparatus are described above, fewer or additional functions could be employed by one skilled in the art within the true spirit and scope of the present invention. While the invention has been described in detail above, the invention is not intended to be limited to the specific embodiments as described. It is evident that those skilled in the art may now make numerous uses, modifications of, and departures from the specific embodiments described herein without departing from the inventive concepts.