Abstract:
A character input apparatus includes a key-in unit configured to input a character by a keystroke, a writing input unit to input a character by writing, a storage to store character strings, and a control unit to control the storage to store, in the storage, a first character input by the key-in unit and a second character input by the writing input unit in a form of a single character string including the first character and the second character.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-381379, filed Dec. 27, 2002, the entire contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a character input apparatus of, e.g., a mobile phone having as inputting means a tablet which directs a position by using a pen or a finger, a portable information device or an information household electric appliance which includes a function to input characters such as a PDA (Personal Digital Assistant), a barcode reader or a POS (Point Of Sales) terminal, and others.  
           [0004]    2. Description of the Related Art  
           [0005]    Conventional character input apparatuses are configured to include either a method of inputting characters by key operations or a method of inputting characters by drawing through a tablet. Since each of the methods has good points and bad points, the conventional character input apparatuses have a problem in convenience of inputting characters for users.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    In order to solve the above-described problem, it is an object of the present invention to provide a character input apparatus which can perform both character input by key operations and character input by drawing and has the high convenience.  
           [0007]    According to a first aspect of the invention, there is provided a character input apparatus which generates character string data, comprising: key-in means for inputting a character by a keystroke; writing input means for inputting a character by writing; means for storing character strings; and control means for controlling the storing means to store a first character input by the key-in means and a second character input by the writing input means in the storing means in a form of a single character string including the first character and the second character. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0008]    [0008]FIG. 1 is a view showing a structure of an external appearance of a mobile phone in an embodiment of a character input apparatus according to the present invention;  
         [0009]    [0009]FIG. 2 is a view showing a positional relationship between a main body device, display and coordinate detecting means of the mobile phone depicted in FIG. 1;  
         [0010]    [0010]FIG. 3 is a circuit block diagram showing an internal structure of the mobile phone depicted in FIG. 1;  
         [0011]    [0011]FIG. 4 is a view illustrating a character input operation of the mobile phone depicted in FIG. 1;  
         [0012]    [0012]FIG. 5 is a view illustrating a character input operation of the mobile phone depicted in FIG. 1;  
         [0013]    [0013]FIG. 6 is a view illustrating a character input operation of the mobile phone depicted in FIG. 1;  
         [0014]    [0014]FIG. 7 is a view illustrating the number of strokes required for character input by the mobile phone depicted in FIG. 1;  
         [0015]    [0015]FIG. 8 is a view illustrating the number of strokes required for character input by the mobile phone depicted in FIG. 1;  
         [0016]    [0016]FIG. 9 is a view illustrating the number of strokes required for character input by the mobile phone depicted in FIG. 1;  
         [0017]    [0017]FIG. 10 is a view illustrating the number of strokes required for character input by the mobile phone depicted in FIG. 1; and  
         [0018]    [0018]FIG. 11 is a view illustrating the number of strokes required for character input by the mobile phone depicted in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    An embodiment according to the present invention will now be described hereinafter with reference to the accompanying drawings. Here, a description will be given as to a mobile phone taken as an example including a character input apparatus according to the present invention.  
         [0020]    [0020]FIG. 1 is a view showing an exterior appearance of the mobile phone. As main constituent elements of the exterior appearance, this mobile phone as an apparatus main body  1  includes a display device  2  capable of displaying-sentences or handwritings, software keys and the like, a coordinate detecting unit  3  which is provided on a screen of the display device  2  and detects a position pressed by a user as a coordinate value, a key group  4  which includes a plurality of keys for inputting data by a keystroke and accepts instructions such as input of figures or characters, mode switching, deletion of inputted information, display of a menu or the like, and a multi-function key  5  which can accept instructions with the directionality such as movement of a cursor, selection or determination from a menu list and others.  
         [0021]    Further, the coordinate detecting unit  3  has been described as a unit to detect a coordinate of a position pressed by a user, but the present invention is not restricted thereto, and any units can be applied to the embodiment according to the present invention as long as it has a structure to detect a coordinate of a graphic written by a user.  
         [0022]    The display device  2  and the coordinate detecting unit  3  have coordinate planes having substantially the same dimension. Furthermore, the coordinate detecting unit  3  is superposed on and integrated with the display device  2  on the apparatus main body  1  as shown in, e.g., FIG. 2. As a result, the display device  2  and the coordinate detecting unit  3  comprise a transparent tablet.  
         [0023]    The display device  2  can display information of, e.g., a handwriting  21 , a character input cursor  22 , cursor movement software keys  231  to  234 , software keys  241  to  244  and the like.  
         [0024]    When the cursor movement software keys  231  to  234  are operated by the control of a character input control unit  17  and a display control unit  18  which will be described later, the character input cursor  22  moves in upper, lower, right and left directions like a case when the multi-function key  5  is operated. As to the cursor movement software keys  231  to  234 , only those corresponding to the directions in which the input position cursor  22  can move are displayed by the control of the character input control unit  17  and the display control unit  18 .  
         [0025]    Moreover, the software keys  241  to  244  are displayed at predetermined positions in an outer peripheral portion of the screen so as not to overlap a screen central part which functions as both a character display area and a handwriting input area. Various functions used for dynamic sentence input such as insertion of a space, insertion of a line feed, deletion of characters, “kana” to “kanji” conversion and others can be assigned to these software keys  241  to  244 .  
         [0026]    [0026]FIG. 3 is a circuit block diagram of the mobile phone. It is to be noted that this drawing mainly shows a structure concerning a character input apparatus according to the present invention. Known structures such as a wireless unit which radio-communicates with a base station of a mobile phone system, an audio processing unit which controls audio signals, a control unit which collectively controls these units and realizes an audio communication, a microphone or a speaker are omitted for simplification of description.  
         [0027]    The apparatus main body  1  includes a coordinate determination unit  11 , a software key control unit  12 , a handwriting acquisition unit  13 , a character recognition unit  14 , a candidate selection unit  15 , a character key input control unit  16 , a character input control unit  17 , a display control unit  18  and a storage unit  20 .  
         [0028]    The coordinate determination unit  11  acquires a coordinate value from the coordinate detecting unit  3 , and determines a position pressed by a user on a display area of the display device  2  based on this value. Additionally, the coordinate determination unit  11  selectively outputs the coordinate value acquired from the coordinate detecting unit  3  to the software key control unit  12 , the handwriting acquisition unit  13  or the candidate selection unit  15  in accordance with the determined position.  
         [0029]    The software key control unit  12  controls display/erasure of the software keys on the display device  2 . Further, the software key control unit  12  determines which software key was pressed based on the coordinate value supplied from the coordinate determination unit  11 . Furthermore, the software key control unit  12  outputs data corresponding to the pressed software key to the character input control unit  17  as a user request.  
         [0030]    The handwriting acquisition unit  13  qualifies a track pressed and drawn by a user, i.e., information of continuous coordinate values as a scar of a handwritten character and detects it based on coordinate values supplied from the coordinate determination unit  11 . Moreover, the handwriting acquisition unit  13  outputs the detected handwriting, i.e., the information of continuous coordinate values to the character recognition unit  14  and the display control unit  18  as track information.  
         [0031]    The character recognition unit  14  analyzes the track information outputted from the handwriting acquisition unit  13 , and detects characters which can possibly correspond to this information from a later-described storage unit  20 . Then, the character recognition unit  14  outputs identification information of a character which can correspond to the information with the highest possibility among the detected characters to the character input control unit  17  as first candidate character information. Additionally, when a plurality of characters which may correspond to the information exist, the character recognition unit  14  outputs information used to respectively identify these characters to a candidate selection unit  15  as recognized candidate information.  
         [0032]    The candidate selection unit  15  outputs to the display control unit  18  the recognized candidate information outputted from the character recognition unit  14 . Further, the candidate selection unit  15  determines which one of the characters as the recognized candidates displayed on the display device  2  is one that a user is going to input based on a determined result of the coordinate determination unit  11 . Then, the candidate selection unit  15  outputs to the character input control unit  17  information used to identify a character the user is going to input as character information based on this determined result.  
         [0033]    A character key input control unit  16  determines an input request from the user through the key group  4 , and accepts a setting for switching a character type to be inputted or character information according to this setting. Then, the character key input control unit  16  outputs the accepted character information to the character input control unit  17 .  
         [0034]    The character input control unit  17  performs controls concerning edition of various sentences such as conversion of an inputted character string in accordance with the character information outputted from the character recognition unit  14 , the candidate selection unit  15  or the character key input control unit  16  or the user request accepted in the software key control unit  12  or the character key input control unit  16 .  
         [0035]    The display control unit  18  displays on the display device  2  a sentence or a characters edited by the character input control unit  17 , a handwriting acquired from the handwriting acquisition unit  13 , a software key drawn by the software key control unit  12 , and characters based on the identification information outputted from the candidate selection unit  15  in accordance with an instruction from the character input control unit  17 .  
         [0036]    The storage unit  20  includes a storage area which stores drawing data such as characters or software keys and various control data or sentences created by the character input control unit  17 , or a working area which temporarily stores information in order to execute controls concerning editing of sentences by the character input control unit  17 .  
         [0037]    An operation of the mobile phone having the above-described structure will now be described. Here, the explanation about essential operations of the mobile phone such as an operation concerning the wireless communication performed with a base station device of a mobile phone system is eliminated, and an operation concerning character input will be described.  
         [0038]    An example of an operation to input Japanese characters by handwriting input will be explained with reference to FIG. 4. The character input control unit  17  supplies a command to the display control unit  18 . As a result, as shown at a step al, the display control unit  18  displays an input position cursor  22  on the display device  2 , additionally displays characters at a position of the input position cursor  22  when characters are inputted, and moves the input position cursor  22  to the right-hand side by an amount corresponding to one character.  
         [0039]    Further, when a command instructing a movement in one of the upward, downward, right and left directions is supplied from a user through the multi-function key  5 , the character input control unit  17  supplies the command to the display control unit  18  and causes it to move and display a position of the character input cursor  22  in a direction corresponding to the command. As a result, it is possible to specify a position where characters are inputted, deletion, a target to be copied and others.  
         [0040]    Here, as shown at a step a 2 , when a user starts writing by pressing the display means  2  through a pen or fingers, the coordinate detecting unit  3  superposed on the display device  2  detects a pressed coordinate. The coordinate determination unit  11  is notified of this detected coordinate.  
         [0041]    The coordinate determination unit  11  determines the position pressed by the user from the coordinate notified from the coordinate detecting unit  3 . Then, the coordinate determination unit  11  outputs a value of the coordinate to the software key control unit  12 , the handwriting acquisition unit  13  or the candidate selection unit  15  in accordance with the determined position.  
         [0042]    Here, if the determined position is not a coordinate of a software key, the coordinate value supplied from the coordinate detecting unit  3  is outputted to the handwriting acquisition unit  13 . On the other hand, the handwriting acquisition unit  13  detects a handwriting of a user based on the coordinate value supplied from the coordinate determination unit  11 .  
         [0043]    For example, as shown at a step a 3 , when the pen moves on the display device  2  being pressed, the coordinate determination unit  11  sequentially outputs pressed coordinates to the handwriting acquisition unit  13 , and the handwriting acquisition unit  13  detects a handwriting  21  of a user from the pressed coordinates.  
         [0044]    In this manner, the handwriting acquisition unit  13  receives information of the pressed coordinates from the coordinate determination unit  11 , and stores the handwriting inputted by a user as a stroke coordinate string. Furthermore, this coordinate string is fed to the display control unit  18 , and the display control unit  18  displays it as a handwriting on the screen of the display device  2  based on this.  
         [0045]    Then, as shown at a step a 4 , when writing is performed by repeating pressing and interruption of pressing with respect to the display device  2 , the coordinate determination unit  11  detects the interruption of pressing, and the coordinate determination unit  11  notifies it to the handwriting acquisition unit  13 . The handwriting acquisition unit  13  judges end of one stroke of writing input from this notification, and activates a timer.  
         [0046]    When the next pressing is carried out before the time-out of the timer, the handwriting acquisition unit  13  assumes that input of one character is yet to be finished, and continuously accepts input. When the time-out of the timer occurs, the hand writing acquisition unit  13  assumes that the inputted handwriting is one character, and supplies it to the character recognition unit  14  as one set of handwriting data. On the other hand, the character recognition unit  14  starts recognition of the written and inputted character based on the handwriting data.  
         [0047]    It is to be noted that using “Online Character Recognition Apparatus and Method, Computer-readable Storage Medium, and Online Character Recognition Program” disclosed in Japanese patent application KOKAI publication No. 2002-203208 can automatically judge input of each character without using a timer and sequentially recognize characters.  
         [0048]    Moreover, the character recognition unit  14  analyzes the acquired handwriting data, and detects a plurality of characters which may possibly correspond to this data from information stored in the storage unit  20 . Identification information of the detected characters is outputted to the candidate selection unit  15  as recognized candidate information, and a character with a highest matching degree among these candidates is outputted to the character input control unit  17  as character information of a first candidate (step a 5 ).  
         [0049]    It is to be noted that recognition of characters performed in the character recognition unit  14  can be realized by using conventionally known various techniques such as a method of performing matching in units of stroke or a method of performing matching with a reference pattern as an image.  
         [0050]    The candidate selection unit  15  outputs the recognition candidate information outputted from the character recognition unit  14  to the display control unit  18 . On the other hand, as shown at a step a 5  in FIG. 4, the display control unit  18  displays the recognized candidates in recognized candidate areas  25  in a screen peripheral portion so as not to overlap the character display area which also functions as the handwriting input area at the screen center and any other software keys.  
         [0051]    When these recognized candidate areas  25  are pressed by the pen or fingers (step a 6 ), the coordinate determination unit  11  detects and notifies it to the candidate selection unit  15 , and the candidate selection unit  15  notifies the touched selected candidate to the character input control unit  17 .  
         [0052]    As a result, the character input control unit  17  controls the display control unit  18 , and displays the selected candidate newly notified from the candidate selection unit  15  in place of the presciently supplied first candidate, and eliminates the display of the recognized candidate areas  25  (step a 7 ).  
         [0053]    Thereafter, when the software key  244  indicative of “conversion” is touched by the pen or fingers (step a 7 ), the coordinate determination unit  11  detects and notifies it to the software key control unit  12 .  
         [0054]    On the other hand, the software key control unit  12  instructs the character input control unit  17  to execute the function “conversion” assigned to the touched software key  244 . In response to this, the character input control unit  17  converts the undetermined character string from “kana” to “kanji”. Then, the character input control unit  17  displays a result of this conversion as a conversion candidate  26  by controlling the display control unit  18  (step a 8 ).  
         [0055]    Thereafter, in execution of such a handwriting input mode (step b 1  in FIG. 5), i.e., when there is an undetermined character string and any one in the key group  4  is pressed, the character input control unit  17  determines the conversion candidate  26  upon detecting the pressing, and displays it as a determined character string  27  by controlling the display control unit  18  (step b 2 ).  
         [0056]    Furthermore, the character input control unit  17  displays a character  28  corresponding to the pressed key in the key group  4  by controlling the display control unit  18  (step b 2 ). When any one in the key group  4  is pressed in the handwriting input mode in this manner, the character input control unit  17  detects this state and switches the input mode from the handwriting input mode to the key input mode.  
         [0057]    When the input mode is switched to the key input mode, the character input control unit  17  erases the software keys  241  to  244  and  231  to  234  for the handwriting input mode from the screen by controlling the display control unit  18 , thereby assuring a large display area for character input (step b 2 ).  
         [0058]    Then, when key input is performed through the key group  4 , the character input control unit  17  sequentially accepts input of a character string through the key group  4  (step b 3 ). For example, when a command “determine” is supplied from the multi-function key  5 , an undetermined character string is determined (step b 4 ).  
         [0059]    Thereafter, when a user presses the display device  2  and inputs a coordinate, the character input control unit  17  again switches the input mode from the key input mode to the handwriting input mode. Moreover, as described above in connection with FIG. 4, the character input control unit  17  causes the coordinate detecting unit  3  to detect an inputted coordinate and notify it to the coordinate determination unit  11 . Additionally, the coordinate determination unit  11  determines the coordinate, and outputs a value of the coordinate to the software key control unit  12 , the handwriting acquisition unit  13  or the candidate selection unit  15  in accordance with a result of this judgment.  
         [0060]    As described above, in the mobile phone having the above-described structure, when a user presses the display device  2  and a coordinate is inputted, the input mode is switched from the key input mode to the handwriting input mode, and input of characters or a request of editing is accepted by the handwriting input. Further, then, when any one in the key group  4  is pressed, the input mode is switched from the handwriting input mode to the key input mode, and input of characters or a request of editing is accepted. The thus inputted characters or edited sentences are stored in the storage unit  20  by the character input control unit  17 .  
         [0061]    It is to be noted that the character key input control unit  16  holds settings of character types inputted through the key group  4  even if the input mode is switched from the key input mode to the handwriting input mode. When the input mode is again switched from the handwriting input mode to the key input mode, input of keys is accepted with the held settings of character types unless a further request to switch a character type is issued from a user.  
         [0062]    A description will now be given as to an operation when creating a sentence in which a plurality of types of characters are used while switching between the handwriting input mode and the key input mode. Inputting a sentence in which both Japanese language and Arabic numerals are used is taken as an example with reference to FIG. 6.  
         [0063]    At a step c 1  in FIG. 6, a Japanese character string including three characters has been already inputted by key input and it is displayed in the display device  2  in the determined state. In such a key input mode, when writing is started by using the pen or fingers, the input mode is switched to the handwriting input mode as described above, and the handwriting is acquired by the coordinate determination unit  11  and the handwriting acquisition unit  13  (step c 2 ).  
         [0064]    When the input mode is switched to the handwriting input mode in this manner, the character input control unit  17  displays the software keys  241  to  244  and  231  to  234  by controlling the display control unit  18 . Then, when “2” is written and inputted (step c 3 ), the character recognition unit  14  performs character recognition with respect to an inputted track, thereby accepting the character input (step c 4 ).  
         [0065]    When the key input is again performed here, the character input control unit  17  accepts this input, the input mode returns to the key input mode (step c 5 ), an undetermined character is determined, input of “2” is completed, and the character input is accepted by the key input.  
         [0066]    When the input mode is switched to the key input mode in this manner, the character input control unit  17  erases the software keys  241  to  244  and  231  to  234  for the handwriting input mode from the screen by controlling the display control unit  18 , thereby assuring a large display area during the character input.  
         [0067]    Furthermore, when writing is restarted (step c 6 ), the character input control unit  17  accepts this, the input mode returns to the handwriting input mode, and the handwriting is acquired by the coordinate determination unit  11  and the handwriting acquisition unit  13 . When the input mode returns to the handwriting input mode, the character input control unit  17  displays the software keys  241  to  244  and  231  to  234  by controlling the display control unit  18 .  
         [0068]    In the handwriting character input, the same character type as that in the key input mode and different character types can be arbitrarily inputted irrespective of a character type set at the time of key input as described above. Therefore, a character type does not have to be switched at the time of key input, and hence the efficient input can be performed.  
         [0069]    Now, the number of key strokes and the number of writing strokes will be compared with each other based on various input techniques in case of performing input while switching between the handwriting input mode and the key input mode.  
         [0070]    First, FIG. 7 shows a user operation when Arabic numerals are inputted by handwriting recognition and any other Japanese characters are inputted by using keys.  
         [0071]    In this case, the total number of strokes including both the key strokes and the writing stokes is  38 . That is, in the mobile phone having the above-described structure, as compared with 52 strokes when all characters are inputted by using keys, the burden on the operation can be reduced by 14 strokes corresponding to the character type switching operation.  
         [0072]    On the other hand, FIG. 8 shows a user operation when Arabic numerals are inputted by using keys and any other Japanese characters are inputted by handwriting.  
         [0073]    In this case, a part of a sentence is inputted in “hiragana” by handwriting character input, and then converted into “kanji”. In such a case, the total number of strokes including both the key strokes and the writing strokes is 32, and hence the number of strokes can be further reduced.  
         [0074]    Additionally, as shown in FIG. 9, when “kanji” parts are inputted by handwriting character input and Arabic numerals are inputted by using keys, the total number of strokes including the key strokes and the writing strokes is 26. That is, the number of strokes is reduced to ½ as compared with the case that the characters are inputted by using only keys.  
         [0075]    A description will now be given as to a case that alphabetic characters are inputted. It is to be noted that the display of the software key  244  is changed from “conversion” to “SPACE” which is used to input a space in this case.  
         [0076]    First, FIG. 10 shows a user operation when alphabetic characters are inputted by handwriting and Arabic numerals are inputted by using keys. In this case, the total number of strokes including the writing strokes and the key strokes is 25.  
         [0077]    On the other hand, FIG. 11 shows a user operation when alphabetic characters are inputted by using keys and Arabic numerals are inputted by handwriting. In this case, the total number of strokes including the key strokes and the writing strokes is 45.  
         [0078]    As mentioned above, in the mobile phone having the above-described structure, a user can arbitrarily carry out the key input mode and the handwriting input mode, switching of the input mode can be automatically performed by effecting the key operation or the handwriting input, and an action for the mode switching is unnecessary.  
         [0079]    Therefore, according to the mobile phone having the above-described structure, the character input based on the key operation and the character input based on drawing through the tablet can be both performed without switching them, and the convenience is very high, thereby greatly reducing the burden on a user at the time of character input.  
         [0080]    Furthermore, since a user can input characters by using both the handwriting input and the key input according to needs, it is possible to change the input mode according to a purpose. For example, a complicated “kanji” character with many strokes is inputted in hiragana, and then it is converted into a “kanji” character.  
         [0081]    Therefore, characters can be inputted by using both the handwriting character recognition and the keys according to needs without deteriorating advantages of both the character input based on the handwriting character recognition and the character input using the keys, thereby greatly improving the operability.  
         [0082]    It is to be noted that the present invention is not restricted to the foregoing embodiment.  
         [0083]    Although the description has been given as to the mobile phone as an example in the foregoing embodiment, the present invention can be applied to a portable information device or an information household electric appliance including a function to input characters such as a PDA (Personal Digital Assistant), a barcode reader, a POS (Point Of Sales) terminal and others.  
         [0084]    Additionally, in regard to, e.g., the recognition mode when inputting characters, the character input mode using keys and the character data holding and processing mode, adopting conventionally proposed modes according to specifications can suffice.  
         [0085]    Further, a light emitting diode, a cold cathode tube or a plasma tube may be used as the display device  2 , and a moving body detection mode using an electrostatic type tablet or ultrasonic waves can be employed for the coordinate detecting unit  3 .  
         [0086]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.