Abstract:
A method and apparatus for minimizing the number of key pressings required for character input. When a key is initially pressed, a controller searches, in a storage unit, for characters corresponding to the keys pressed, and sequentially displays the characters in a current cursor position according to a predetermined time that the key is pressed. When pressing of the key is terminated, the character presently displayed in the current cursor position is maintained and the cursor moves to the next cursor position. Since the wanted character can be inputted by pressing only one key, there is a minimal amount of keys utilized to input a character. In particular, by utilizing a consecutive input, the same character can be inputted more effectively and conveniently.

Description:
PRIORITY 
     This application claims priority to an application entitled “METHOD AND APPARATUS FOR INPUTTING CHARACTERS IN A MOBILE TERMINAL” filed with the Korean Industrial Property Office on Sep. 27, 2000 and assigned Serial No. 2000-56726, the contents of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mobile terminal, and more particularly, to a method and apparatus for minimizing the number of keys pressed by a user when a key input unit is utilized to input characters. 
     2. Description of the Related Art 
     In general, mobile terminals are becoming more compact and lightweight, enabling it to be easily carried. As the size of the terminal becomes smaller, the area of a key input unit associated with the terminal also becomes smaller. Accordingly, most terminals have only basic function keys and a minimum amount of number keys. 
     Meanwhile, as the number of finctions included in the terminals increase, the number of keys associated with the number of functions needed also tends to increase. In order to solve such a problem, different operations are carried out according to the number of keys pressed so that one key can be utilized to input a number of characters. Therefore, in the case where a keypad in the mobile terminal is used to input a character, a user is required to repeatedly press the same key 1 to 5 times according to the order printed on the keypad. If the user repeatedly presses the same key in succession, the cursor can be displaced to the next character position only after a delay of a predetermined time or an artificial key operation. 
     In the mobile terminal of the related art as described hereinabove, a number of characters are allocated to one number key and the characters are inputted according to the number of times the key is pressed so that one key must be pressed repeatedly or a number of keys are pressed in order that the wanted character may be displayed. There is a problem that exists where the user waits for a certain time to displace the cursor, artificially, when the same key is repeatedly pressed. Therefore, there exists a need in the art for a device or method where a user is not required to wait a certain amount of time to artificially displace the cursor when the same key is repeatedly pressed. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a method for allowing a user of a mobile terminal to easily input characters. 
     It is another object of the invention to provide a method, which can minimize the number of keys pressed when the characters are inputted into the mobile terminal. 
     According to a preferred embodiment of the invention, there is provided a method for inputting characters in a mobile terminal which includes a key input unit and a storage unit for storing a number of characters in mutual association which are arranged in predetermined order, the method comprising: confirming if a key input signal is generated from the key input unit; if the key input signal is generated, searching a number of characters corresponding to the inputted key from the storage unit and displaying the characters in a current cursor position in sequence according to a predetermined time interval; when generation of the key input signal is terminated, maintaining the characters displayed at the point of time when the key input signal is terminated; and displacing the current cursor position to the next cursor position after maintaining the displayed characters. 
     According to another preferred embodiment of the invention, there is provided a method for inputting characters in a mobile terminal, comprising: sequentially displaying characters corresponding to pressing a key from a number of keys in a key input unit; and when the pressing of the key is terminated, maintaining a character displayed in a current cursor position and displacing the current cursor position to a next cursor position. 
     According to another preferred embodiment of the invention, there is provided a method for inputting characters in a mobile terminal, the method comprising: storing a number of characters in mutual association with respect to each of a number of keys in a key input unit; and when one of the keys is pressed, displaying one character corresponding with a maintained time of the key pressed from the characters stored in association with the pressed key of the key input unit. 
     According to a further preferred embodiment of the invention, there is provided an apparatus for inputting characters in a mobile terminal, comprising: a key input unit having a number of keys; a storage unit for a number of characters in mutual association which are arranged in predetermined order with respect to each of the keys; a display unit for displaying a character associated with the key inputted by the key input unit; a controller, for searching corresponding characters from the storage unit and sequentially displaying the searched characters in a current cursor position of the display unit according to a time interval when a key is pressed, and maintaining the characters displayed in the display unit and displacing the current cursor position to the next cursor position when pressing of the key being pressed is terminated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Hereinafter a preferred embodiment of the present invention will be described in reference to the appended drawings, wherein: 
     FIG. 1 shows the internal structure of a mobile terminal according to an embodiment of the invention; 
     FIG. 2 shows the structure of a key input unit according to the embodiment of the invention; and 
     FIG. 3 shows a flow chart for inputting characters according to the embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Detailed specific matters are presented in the following description. However, it should be understood that these are provided only for helping the general understanding of the present invention and it will be apparent to those skilled in the art that the invention can be performed even without these specific matters. Also, in describing the invention, detailed description about related known functions or structures will be omitted if the detailed description thereof may unnecessarily obscure the substance of the invention. 
     FIG. 1 shows the internal structure of a mobile terminal according to an embodiment of the invention. 
     Referring to FIG. 1, a mobile terminal  10  acts as a transceiver in a mobile telephone system which includes a base station, a mobile switching center and a message center. Mobile terminal  10  is comprised of a transmitter  11 , a receiver  12 , a controller  13 , a speaker  14 , a microphone  15 , a display unit  16 , a key input unit and a storage unit  18 . Those of ordinary skill in the art will recognize that a mobile terminal may be comprised of more elements than those described by this invention. Transmitter  11  includes a modulator and a transmitting amplifier. Receiver  12  includes a receiving amplifier and a demodulator. 
     Display unit  16  can be constructed as an LCD(Liquid Crystal Display) for example and outputs various display data generated in mobile terminal  10 . Key input unit  17  can be constructed as a keypad for example and comprises a plurality of number keys, function keys for interface with a user, and keys for conversation. If the user presses one of the keys, the key input unit  17  generates a key input signal corresponding thereto. 
     Storage unit  18  is comprised of a ROM(Read Only Memory) for storing a number of programs and data, a RAM(Random Access Memory), an audio memory, etc. Storage unit  18  also stores a number of characters in mutual association, which are arranged in a predetermined order with respect to each of the keys of the key input unit  17  according to the embodiment of the invention. 
     Controller  13  includes a DSP(Digital Signal Processor), a microprocessor and other circuits, and controls the transmitter  11  and the receiver  12 , so that the mobile telephone user can perform a conversation with another user by using a speaker  14  and a microphone  15 . In particular, the controller  13  controls the display unit  16  and the key input unit  17  to perform a character input operation according to the embodiment of the invention. 
     FIG. 2 shows the structure of a key input unit according to the embodiment of the invention. 
     Referring to FIG. 2, the key input unit  17  has a number of keys, which are mutually associated with a number of characters that are arranged in the predetermined order according to a character input mode. For example, the number key “2” is associated with “A”, “B”, “C”, and “2” in a capital letter input mode, and “a”, “b”, “c”, and “2” in a small letter input mode in sequence. 
     FIG. 3 shows a flow chart for inputting characters according to the embodiment of the invention. 
     The embodiment of the invention will be described hereinafter with reference to FIG. 1 to FIG. 3 as follows: 
     In step S 110  of FIG. 3, the controller  13  confirms if the user starts to press one of the keys. When the user presses one of the keys in the key input unit  17 , the key input unit  17  generates a key input signal. The key input unit  17  consecutively generates the key input signal while the user keeps pressing the key. The key input signal is inputted into the controller  13 . 
     If pressing of a key is started by the user, namely, generation of the key input signal is started, the controller  13  searches for characters corresponding to the inputted key from the storage unit  18  and displays the searched characters in sequence, according to a predetermined time interval in the current cursor position of the display unit  16 , in step S 120 . The display of the characters like this is consecutively repeated while the key input signal is being generated. Also, the characters can be flickered in display unit  16  to show that the input is not completed. 
     For example, when the “2” key is inputted, “A”, “B”, “C” and “2” will be repeatedly flickered in sequence in the current cursor position (in the capital letter input mode). Here, the time interval for displaying the characters can be designated while manufacturing the mobile terminal or adjusted by the user, for example in increments of 0.2, 0.3 or 0.4 second. The user removes his/her finger from the key when a wanted character is displayed and terminates the key pressing. 
     In step S 130 , the controller  13  confirms if generation of the key input signal is terminated, namely, once pressing the key by the user is terminated. If the pressing of the key is terminated, then controller  13  maintains the character displayed in the display unit at that point of time in step S 140 . For example, when the time interval for displaying characters is set at 0.2 second and the “2” key is pressed by the user, the character “A” will be displayed, if pressing of the key is terminated between 0.2 and 0.4 seconds, and the character “B” will be displayed if pressing of the key is terminated between 0.4 and 0.6 seconds. If pressing is not terminated, the process returns to step S 120 . 
     After the character wanted by the user is inputted along the foregoing steps, the controller  13  displaces the current cursor position to a next cursor position even without any key input and waits for an input of the next character in step S 150 . The process then returns to step S 110 . 
     This embodiment can be briefly described as follows: 
     When the user waits while pressing the key of the mobile terminal until the wanted character is displayed, and then releases the pressed key, the wanted character is directly inputted. When the wanted character is inputted, the mobile terminal advances into an input standby state of the next character. 
     This embodiment can be described in comparison with the related art as follows: 
     When an input, a word or a string of letters “LEE” is wanted in the related art, the user presses the “5” button three times to display “L”, and then waits for a while or presses “#” button to move to the next position. After that, the user presses the “3” button twice to display the “E” character, and then waits for a while or presses “#” button to move to the next position. Then, the user presses the “3” button twice to display the second “E” character. 
     In the present invention, four characters of “J”, “K”, “L” and “5” are repeatedly displayed in sequence while the user just keeps pressing the “5” button. When the user takes his/her finger off the “5” button, when the wanted character “L” is displayed, then the display of “L” is maintained. At the same time, the cursor is automatically displaced to the next cursor position. Then, the user presses the “3” button for a while and takes the finger off when “E” is displayed, and then presses the “3” button for a while without waiting so that “E” can be displayed. 
     According to the present invention, since various characters are displayed according to the maintained time the key is pressed rather than the number of times the key is pressed, the number of key pressings by the user can be minimized, and in particular, the standby time or the number of times the key is pressed can be minimized in inputting the same character consecutively. 
     According to the embodiment as described hereinabove, the number of times a key is pressed for a wanted character can be minimized because the wanted character can be inputted with only one key being pressed from a key input in the mobile terminal. In particular, the same character can be inputted more effectively and conveniently in a consecutive input. 
     Also, if the order or arrangement of the characters are changed the characters corresponding to the inputted key are displayed in the display unit in sequence, so that the characters can be easily inputted even if the order or arrangement of the characters is changed. 
     While the detailed embodiment has been described, above, it should be understood that various modifications or variations can be made without departing from the scope of the invention. For example, while it has been described above for inputting English characters only, the invention can be applied to characters of other languages such as Korean. Therefore, the scope of the invention should be not restricted by the above described embodiment, but should be defined by the following claims or equivalents thereof.