Abstract:
The present invention provides an apparatus and method, for a terminal equipment such as a facsimile device, wherein a character or symbol to be entered and/or displayed is read from a memory according to an index value generated in response to the sequential input of two numeric keys.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C §119 from an application entitled Method Of Inputting Characters Through Combination Of Numeric Keys earlier filed in the Korean Industrial Property Office on 12 Jun. 1995, which was duly assigned Ser. No. 15384/1995 by that Office. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of using a combination of keys for inputting a character, and more particularly, an apparatus and method for entering characters and symbols using a combination of numeric keys on a key pad of an image formation device. 
     2. Background Art 
     In general, terminal telecommunications equipment such as that used in a telephone system or a facsimile system may be programmed to input characters by using the numeric keys of the key pad. In one contemporary system, in order to input different characters, symbols and numbers, respective ones of the numeric keys, asterisk (*) key and pound (#) key of the key pad have to be pressed a set number of times as shown in the following Table 1: 
     
                       TABLE 1______________________________________0      1        2     3   4   5   6   7   8   9   *   #______________________________________once ,     Q        A   D   G   J   M   P   T   W   (                       twice                        Z B E H K N R U X ) !                       three / BLANK C F I L O S V Y ? |                       times                       four 0 1 2 3 4 5 6 7 8 9 * #                       times______________________________________ 
    
     As shown in Table 1, numbers, symbols and characters are entered into a resident memory according to the number of times a corresponding key is pressed. For example, when the numeric key &#34;0&#34; is pressed once, the symbol &#34;,&#34; is entered, when it is pressed twice, the symbol &#34;-&#34; is entered, when it is pressed three times, the symbol &#34;/&#34; is entered, and when it is pressed four times, the numeral &#34;0&#34; is entered. Similarly, when the numeric key &#34;2&#34; is pressed once, the character &#34;A&#34; is entered, when, it is pressed twice, the character &#34;B&#34; is input, when it is pressed three times, the character &#34;C&#34; is entered, and when it is pressed four times, the numeral &#34;2&#34; is entered. 
     In the conventional system as described above, since the symbol and character are entered into a resident memory according to the number of times each numeric key is manually depressed by a user, I have found that there is a disadvantage however, because in order to input several of the symbols, characters or numbers, a numeric key may have to be manually depressed three or four times in quick sequence by the user. 
     Also, it is thought from the text of a Canon® Laser Class 7000/7500 facsimile instruction book that characters can be entered by pressing a set key twice to start the letter entry mode, and then by pressing the corresponding numeric key one to three times. Additionally, in order to enter a symbol, while in the letter entry mode, the pound (#) key is repeatedly pressed until the desired symbol is displayed. To switch from the letter entry mode to a number entry mode the asterisk (*) key is pressed. Furthermore, corrections can be made using a &#34;space&#34; key or a &#34;clear&#34; key. Accordingly, I have noticed that the Canon® Laser Class 7000/7500 facsimile also has a disadvantage in that the numeric keys have to be pressed three times in order to enter several of the corresponding characters. Also, there is a disadvantage wherein a &#34;&#34; key must be pressed in order to input each succeeding character or symbol. 
     It is further thought from the text of a Canon® FAX-L770 facsimile user&#39;s instruction book that characters can be entered by selecting one of four &#34;lists&#34; of characters, symbols and numbers, by pressing the number &#34;5&#34; key. Then, one can scroll through the selected list using numeric keys &#34;2&#34;, &#34;4&#34;, &#34;6&#34;, and &#34;8&#34;, and once the desired letter appears on a display, the user pressesd a &#34;cursor&#34; key to enable entry of a next character, symbol or number. For example, when desiring to enter the letter &#34;x&#34;, one would press the &#34;5&#34; key twice, then press the &#34;8&#34; key four times and then depress the &#34;6&#34; key three times. I have found that the Canon® FAX-L770 facsimile device has a disadvantage in that in order to display most of the characters and symbols the user must use a combination of three or four keys and must press several of these keys a plurality of times. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved character entry circuit and process. 
     It is another object to provide a circuit and process for entry of symbols and characters into a resident memory by combining two numeric keys without repeatedly pressing a numeric key a plurality of times. 
     To achieve these and other objects, the present invention provides an apparatus and method, for terminal telecommunications equipment such as a facsimile device, wherein a character or symbol to be entered and/or displayed is read from a memory according to an index value generated in response to the sequential input of two numeric keys. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detail description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
     FIG. 1 is a block diagram illustrating a structure of an apparatus constructed according to the principles of the present invention; and 
     FIGS. 2A and 2B illustrate, by way of a flowchart, several steps of a process for controlling the generation of characters and symbols in response to the sequential input of two numeric keys according to the principles of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now to the drawings, FIG. 1 shows a key entry unit 10 having a plurality of keys for generating a combined key signal for entry by a user of characters and symbols into a resident memory 30, and a numeric key signal. A control unit (CPU) 20 outputs character data and symbol data in response to inputs of the combined key signal and the numeric key signal from the key entry unit 10. Resident memory 30 stores character data and symbol data, and a program for generating characters and symbols under the control of control unit 20. A variable visual display unit 40 displays information about various kinds of numerals, characters and symbols under the control of control unit 20. FIGS. 2A and 2B illustrate a flowchart, with further reference to FIG. 1, for the control operations to be followed in order to generate characters and symbols in response to the sequential entry of a combination of numeric keys in accordance with the principles of the present invention. 
     In FIG. 2A, &#34;START&#34; represents when a user initiates the mode for generating characters and symbols. Accordingly, the following description concerns the character/symbol generating mode and not a mode for dialing a telephone number. In step 101, a FLAG register (not shown) and a BUFFER INDEX register (not shown) are cleared by setting the values of these registers to &#34;0&#34;. These registers will be further explained below. In step 102, the control unit 20 checks for an input key signal in response to activation any one of a plurality of keys on the key inputting unit 10. Control unit 20 then determines, steps 103-114 whether the input key signal from key inputting unit 10 is one of the numeric keys (0-9), an asterisk (*) key or a pound (#) key and then, if the inputted key is one of the numeric keys (0-9), an asterisk (*) key or a pound (#) key, proceeds to step 119. 
     In step 119, control unit 20 checks the value of the FLAG register in order to determine whether the FLAG register is in a cleared state. When the FLAG register is in a cleared state, control unit 20 multiplies the value of the key by 4 and stores the result in an INDEX register (not shown), and then, in step 121, changes the FLAG register to a set state. Control unit 20 then returns to step 102. 
     Note here that the characters and symbols are generated through a two key combination of the numeric keys, the asterisk (*) key and the pound (#) key as shown in the following Table 2: 
     
                       TABLE 2______________________________________0      1        2     3   4   5   6   7   8   9   *   #______________________________________0    0     1        2   3   4   5   6   7   8   9   *                       #                       1 , Q A D G J M P T W (                       2                        Z B E H K N R U X ) !                       3 / BLANK C F I L O S V Y ? |______________________________________ 
    
     Accordingly, when the FLAG register is in the cleared state the value of the key represented by the first horizontal row in Table 2, i.e., numeric keys (0-9), the asterisk (*) key and the pound (#) key, is multiplied by 4 in step 120. The numeric keys (0-9) will have their corresponding values 0-9, the asterisk (*) key will have a value 10 and the pound (#) key will have a value 11. 
     Following the return to step 102 after the FLAG register has been set, control unit 20 again checks for an input key signal in response to a subsequent activation any one of the plurality of keys on the key inputting unit 10. Control unit 20 then determines, steps 103-114 whether the input key signal is one of the numeric keys (0-9), an asterisk (*) key or a pound (#) key and then, if the inputted key is one of the numeric keys (0-9), an asterisk (*) key or a pound (#) key, proceeds to step 119. 
     During step 119, control unit 20 checks the value of the FLAG register in order to determine whether the FLAG register is in a cleared state. When the FLAG register is not in a cleared state, control unit 20 proceeds to step 122. Accordingly, when the FLAG register is in the set state, the value of the key is checked to determine whether it is greater than 3. This step is represented by the first vertical column in Table 2, i.e., numeric keys (0-3). Control unit 20 returns to step 102 when step 122 determines that the activated key is greater than 3. 
     Control unit 20 proceeds to step 123 when the step 122 determines that the value of the activated key not greater than 3. In step 123, the value of the INDEX register is changed by increasing the value of the activated key by one, and adding this value to the value stored in the INDEX register during step 120. For example, if control unit 20 determines that the first activated key was the &#34;1&#34; key in step 104, and the FLAG register was determined to be in a clear state in step 119, then the value stored in the INDEX register in step 120 will be 1×4=4. Then, following, a return to step 102, if control unit 20 determines that the subsequent activated key was the &#34;1&#34; key in step 104, and that the FLAG register was not in a clear state in step 119, then the value of the &#34;1&#34; key will be increased by one, i.e., 1+1=2, and added to the value 4 stored in the INDEX register in step 120, i.e., 2+4=6, thus resulting in a value of 6 being stored in the INDEX register in step 123. Note here that the value 6 corresponds to the character Q stored in memory 30. Similarly, if the user desired to input the character U, then the first key to be activated would be the &#34;8&#34; key, resulting in a value of 32 being stored in the INDEX register in step 120, and the subsequent key to be activated would be the &#34;2&#34; key resulting in a value of 35, i.e., (2+1)+32, being stored in the INDEX register in step 123. 
     In step 124, control unit 20 reads out the character/symbol data stored in memory 30 corresponding to the value of the INDEX register obtained in step 123, and stores this character/symbol data in a buffer (not shown) according to the value of the BUFFER INDEX register. Since the BUFFER INDEX register was set to &#34;0&#34; in step 101 when the character/symbol generating mode was started, then the first character/symbol read from memory 30 will be stored in the initial, or first, position of the buffer. Control unit 20 then clears the FLAG register in step 125 and increases the value of the BUFFER INDEX register by one in step in step 126. Accordingly, the BUFFER INDEX register points to a position in the buffer where the character/symbol data, read from memory 30 in response to the value of the INDEX register, is to be stored. 
     Key inputting unit 10 also incorporates a &#34;NO&#34; key and a &#34;YES&#34; key, and when control unit 20 determines that the input key signal, step 102, is not one of the numeric (0-9) keys, the asterisk (*) key and the pound (#) key, control unit determines in step 115 whether it is the &#34;NO&#34; key. The &#34;NO&#34; key is a backup, or erase, key. When control unit 20 detects the &#34;NO&#34; key in step 115, the BUFFER INDEX register is checked in step 116 to determine whether it has a value of &#34;0&#34;. If the BUFFER INDEX register is set to &#34;0&#34; then control unit 20 performs step 118. In step 118, control unit 20 clears the FLAG register. If the BUFFER INDEX register has a value greater than &#34;0&#34; then the value in the BUFFER INDEX register is decreased by one in step 117 so that the character/symbol data next read from memory 30 will overwrite the last character/symbol data stored in the buffer and then step 118 is performed. Accordngly, the user can re-enter the last character/symbol or, by repeatedly entering the &#34;NO&#34; key, re-enter all the character/symbol data. In step 118, control unit 20 clears the FLAG register. 
     Control unit 20 determines in step 127 whether the input key signal of step 102 corresponds to the &#34;YES&#34; key when it is determined that the input key signal, step 102, is not one of the numeric (0-9) keys, the asterisk (*) key, the pound (#) key and the &#34;NO&#34; key. When it is determined in step 127 that the &#34;YES&#34; key has not been activated, control unit 20 returns to step 102. When it is determined in step 127 that the &#34;YES&#34; key has been activated, control unit 20 reads out the character/symbol data stored in the buffer and displays the characters/symbols on display unit 40. 
     As shown in Table 2, and as described above, when two numeric keys are pressed or one numeric key and either one of the asterisk (*) key and the pound (#) key are pressed, the corresponding character or symbol is generated to be displayed. For example, if the numeric keys &#34;00&#34; are pressed, the numeral 0 is displayed, if the numeric keys &#34;01&#34; are pressed, the symbol, is displayed, if the numeric keys &#34;02&#34; are pressed, the symbol - is displayed, and if the numeric keys &#34;03&#34; are pressed, the symbol / is displayed. Similarly, if the keys &#34;#0&#34; are pressed, the symbol # is displayed, if the keys &#34;#1&#34; are pressed, the symbol  is displayed, if the keys &#34;#2&#34; are pressed, the symbol ! is displayed, and if the numeric keys &#34;#3&#34; are pressed, the symbol | is displayed. 
     For instance, when the user desires to input the characters &#34;TELEPHONE NUMBER&#34;, the combined numeric keys &#34;81&#34;, &#34;32&#34;, &#34;53&#34;, &#34;32&#34;, &#34;71&#34;, &#34;42&#34;, &#34;63&#34;, &#34;62&#34;, &#34;32&#34;, &#34;31&#34;, &#34;62&#34;, &#34;82&#34;, &#34;61&#34;, &#34;22&#34;, &#34;32&#34;, &#34;72&#34; are input and the character/symbol data corresponding to the characters/symbols T, E, L, E, P, H, 0, N, E, BLANK, N, U, M, B, E, R are stored in the buffer. Then, when the &#34;YES&#34; key is input, the characters &#34;TELEPHONE NUMBER&#34; are displayed. 
     As discussed previously, in the system contemplated by the principles of the present invention, characters and symbols can be input by combining any one of numeric keys (0-9) asterisk (*) key and the pound (#) key with any one of numeric keys 0-3. Accordingly, the only keys which may have to be input more than once but not more than twice, of the numeric keys (0-9), the asterisk (*) key or the pound (#) key, would be numeric keys 0-3. Accordingly, there is an advantage in that the fewer key manipulations are required in order to enter alphanumeric characters and other symbols.