Automatic dialling apparatus and method

Abstract: A dialling apparatus comprises a keypad ( 21 ) having digit keys for entering a digit corresponding to a set of characters and a function key ( SND ). Character strings and corresponding digit strings are stored in a memory ( 23 ). In response to a digit from the keypad, a controller ( 20 , 24 ) makes a search through the memory for detecting each one of characters of the set which corresponds to the digit and detecting character strings each containing the detected character. The detected character strings are then sequentially supplied to a display unit ( 22 ) from the memory so that they are displayed one at a time. When the command key is operated, the character string being displayed on the display unit is identified and the digits stored in the memory corresponding to the identified character string are dialed to a switched network.

Description: This invention relates to dialling apparatuses and to methods of operation of dialling apparatuses and is more particularly concerned with speed dialling. A conventional speed dialling procedure involves the use of combinations of digit keys assigned uniquely to different characters. By manually entering one of the key combinations, a memory is searched for detecting characters which are stored in the leftmost column of the memory and correspond to the entered key combination. If two or more characters are detected, the combination is entered to make a search for those characters stored in the next column. The process is repeated until there is only one remaining character string that contains the detected characters. The remaining character string is then put on display for confirmation by the user before corresponding digits are dialled. One disadvantage of this procedure is that if similar character strings are stored in the memory, the user must repeat key operations a substantial number of times. A first aspect the present invention is more specifically concerned with a dialling apparatus, comprising: a manually operable keypad having a plurality of data keys (such as keys for the numbers 1 to 9 and 0), each data key being associated with a respective digit and with a respective set of characters; a memory for storing a plurality of entries, each entry including a respective character string and a respective digit string constituting a subscriber number; a display unit for displaying a selected one of the character strings; a dialling circuit for transmitting digit strings to a switched network; and a controller which is operable: in response to operation of one of the data keys, to search through the memory to identify an entry therein whose character string begins with a character in the character set associated with the operated data key; in response to such an entry being so identified, to cause the character string of that identified entry to be displayed on the display unit; and, in a memory dialling mode, in response to operation of a first control key (such as a "send" or "dial" key) of the keypad, to cause the dialling circuit to transmit to the switched network the selected digit string associated with a currently displayed character string. Such an apparatus is known from patent document GB-A-2195867. That document describes, in an editing mode, that an entry in the memory can be accessed by pressing the data key associated with the first letter of the name for the entry to be edited, for example key "3" if the name begins with "D", "E" or "F". With successive operations of that key, names are displayed in alphabetical order, beginning those starting with "D", and proceeding all the way through the alphabet. With successive operations of a "back" key, the display scrolls through all of the entries in the memory in reverse order. In a data entry mode, the letter "E" can be entered by pressing the "3" key twice, or by pressing the "2" key five times. That document also explains that once an entry is displayed, operation of a "dial" key causes the telephone number for that entry to be dialled. In the apparatus of GB-A-2195867 therefore, at least in the editing mode, in response to operation of one of the data keys, one entry is identified and displayed. With repeated operation of the same key, the display scrolls through all of the entries stored in the memory, and with repeated operation of the "back" key, the display scrolls through all of the entries stored in the memory in reverse order. The dialling apparatus of the first aspect of the present invention is characterized in that the controller is operable, in the memory dialling mode: in response to such operation of one of the data keys, to search through the memory to identify any entry therein whose character string begins with any of the characters in the character set associated with the operated data key; and, in response to at least two such entries being so identified, to cause the character strings for the identified entries to be successively displayed on the display unit automatically or in response to operation of a second control key (such as a "*" key) of the keypad other than the data keys. Accordingly, with this aspect of the invention, the display does not scroll through all of the entries in the memory, but only those whose character string begins with a character in the character set associated with the operated data key. In one embodiment, the controller is so operable to cause the character strings for the identified entries to be successively displayed on the display unit automatically. In another embodiment, the controller is so operable to cause the character strings for the identified entries to be successively displayed on the display unit in response to operation of the second control key. In this case, the controller may be so operable to cause the successive display of the character strings for the identified entries to be in one order in response to operation of the second control key, and is operable to cause the character strings for the identified entries to be successively displayed on the display unit in the opposite order in response to operation of a third control key (such as a "#" key) other than the data keys. In accordance with a second aspect of the present invention, there is provided a corresponding method of operation of a dialling apparatus. In accordance with a third aspect of the present invention, there is provided telephone set incorporating a dialling apparatus according to the first aspect of the invention. Reference is also directed to patent document EP-A-206391, which discloses a microcomputer controlled dialler having both alphabetical and numerical keypads. Specific embodiments of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a flow chart of a prior art memory search dialling operation; Fig. 2 is a block diagram of an embodiment of telephone set according to the present invention; Fig. 3 is a flow chart representing operation of the embodiment of Fig. 2; and Fig. 4 is a flow chart representing operation of a modified embodiment of the invention. Prior to be description of the embodiments of the invention, it is appropriate to describe a prior art memory dialling procedure with reference to Fig. 1. During a memory search mode commenced by operation of a specially assigned key (block 1 ), control proceeds to block 2 to set variable "i" to 1. Combinations of two digit keys are uniquely assigned to the individual letters of the alphabet, and the user sees a list of such digit combinations and enters a string of digits corresponding to the first letter of the name of a desired destination party (block 3). Control proceeds to block 4 to search through a memory in which character strings are stored in a matrix of rows and columns. The search is made row by row along column "i" and the characters of this column which correspond to the entered digit string are identified and the rows to which they belong are treated as candidate character strings, or names. Control proceeds to block 5 to determine whether two or more of such candidate character strings exist. If the answer is affirmative, control branches at block 5 to block 6 to increment i by 1 and returns to block 3 to enter the next digit string and repeat the search through the next column. The column is incremented until there is only one candidate character string remaining. If this is the case, control branches out to block 7 to identify row "j" in which the remaining character string is stored. All characters of row "j" are then displayed (block 8 ) and the user is allowed to confirm the displayed name. If the displayed name is what is intended, the user operates a proceed-to-send key (block 9 ) and the digits of the displayed item are transmitted to the telephone network (block 10 ). Therefore, if similar names are stored in the memory, the user must perform a substantial number of key operations. In Fig. 2, a dialing circuit of the present invention is shown as being incorporated in a telephone set. The dialing circuit comprises a central processing unit 20 , a keypad 21 , a liquid-crystal display unit 22 , and an electrically programmable read-only memory (EPROM) 23 for storing character strings and corresponding telephone numbers in a matrix of N rows and M columns. The operating program of the CPU 20 is stored in a second EPROM 24 . The keypad 21 includes ten digit keys, function keys including asterisk (down scroll) and sharp (up scroll) keys, a proceed-to-send key SND and a memory read command key READ which is used to initiate a memory search mode. The display unit 22 has an upper area for displaying a telephone number and a lower area for displaying a destination user name corresponding to the telephone number. Since the number of items to be displayed is limited, only one item is displayed at a time by scrolling the display unit. Numeral digit keys "1" to "9" are labelled with letters of the alphabet as indicated so that digit "1" is assigned a set of two characters and each of the other keys is assigned a set of three characters as illustrated: During the memory search mode, one of these digit keys is used to address the first-column (leftmost column) characters stored in memory 23 . As shown in Fig. 3, CPU 20 performs a sequence of programmed instructions during a memory search mode, starting with decision block 30 which checks to see if the READ key is operated. At decision block 31 control determines whether one of digit keys 1 to 9 is depressed. If the answer is affirmative, control branches to block 32 to search through the memory 23 row by row for those of the first-column characters which correspond to the digit number of the key just operated, and determines the number "K" of rows "i" (where i = 1, 2, .... K) which contain the first-column characters detected as corresponding to the entered digit. These K rows are identified as candidate rows. Control exits to block 33 to set a variable i to 1 and proceeds to block 34 to read out the character string and digit string of candidate row "i" from the memory 23 and supply them to the display unit 22 . The user is thus allowed to confirm the name of the displayed item. If the displayed item is what is desired, the user operates the proceed-to-send key SND , otherwise he operates the scroll-down key*. If the scroll-down key is operated (block 35 ), control branches at block 35 to block 36 to increment variable "i" by one. Variable "i" is then checked against the integer "K" (block 37 ). If variable i is smaller than K, control branches at block 37 to block 34 to read out the item of the next row from the memory 23 and put them on display. If i = K, control branches out at block 37 to block 39 to decrement variable i by one and proceeds to block 40 to check if i = 1. If the answer is negative, control returns to block 34 to repeat the process for the decremented candidate row. The function keys are then checked (block 35 ) to see if the scroll-up key # is operated. If this is the case, control repeats blocks 39 and 40 to continue the down-scroll operation until variable i becomes equal to 1. When this occurs control branches at block 40 and ends the program execution. In this way, stored names having the same characters in the first column are successively displayed each time one of the scroll keys is operated. Alternatively, the program cap be modified to automatically scroll down or up without manual key operation as shown in a flowchart of Fig. 4. In this modification, blocks 30 to 33 are identical to those of Fig. 3. Following the initialization of variable i to 1 (block 33 ), a flag F is initialized to 0 (block 50 ). Exit then is to block 51 to display the character and digit strings of row "i" and control proceeds to block 52 to check to see if the proceed-to-send key SND is operated. If the answer is negative, control branches to block 53 to determine whether flag F is set to 1. Initially, the answer affirmative, and control branches at block 53 to block 54 and goes to block 52 after executing a timeout check step (block 54 ). Within the timeout period, block 52 is repeatedly checked while the contents of row "i" are being displayed. If the timeout period expires, control branches at block 54 to block 55 to increment i by 1 and checks to see if i ≥ K. If the answer is negative, blocks 51 through 56 are repeated until variable i is equal to K. When i = K, control branches at block 56 out to block 58 to set flag F to 1 and decrement variable i by 1 (block 58 ) and makes a check for i = 1 in block 59 . If the answer is negative, control branches at block 59 to block 51 to display the contents of the decremented candidate row. The proceed-to-send key SND is again checked (block 52 ). If this key is not operated, control exits to block 53 . Since F = 1, control branches at block 53 to block 60 to provide a timeout check to allow time for the user to examine the displayed item of the decremented candidate row by repeatedly executing blocks 52 , 53 and 60 . Upon expiry of the timeout period, control exits block 60 to block 58 to decrement i by 1 and makes a check for i = 1 in block 59 . The down-scroll process is thus continued until i = 1, whereupon control exits block 59 and end the program execution. If the user wants to place a call to a destination, say; "CGSPQR " which is stored in the sixth row of memory 23 , the user operates digit key "2". The memory 23 is searched for (block 32 ) and the character strings having the letters "A " , "B" and "C" in the first column of the memory 23 are detected. Thus, the character and digit strings stored in the first to sixth rows of the memory 23 are read and successively put on display. When i = 6, a character string " CGSPQR" will appear on the lower area of display unit 22 and the corresponding digit string "014532427 " appears on the upper area. The user confirms that the displayed item is what is desired and operates the proceed-to-send key SND to select the displayed item. When this occurs, control branches at block 52 to block 57 to transmit the digits of the selected telephone number "014532427" to the telephone network. Returning to Fig. 2, the displayed digits are supplied from CPU 20 to a dialing circuit 25 where the digits are converted to a sequence of multi-frequency tone signals in cases where they are to be sent to an analog telephone network or converted to a sequence of AMI (alternate mark inversion) line codes in cases where the signals are to be sent to a digital network. The output of the dialing circuit 25 is then transmitted via a speech circuit 26 to the telephone network. Thus the preferred embodiment of the present invention can be summarised as follows. A dialling apparatus comprises a keypad (21) having digit keys for entering a digit corresponding to a set of characters and a function key (SND). Character strings and corresponding digit strings are stored in a memory (23). In response to a digit from the keypad, a controller (20,24) makes a search through the memory for detecting each one of characters of the set which corresponds to the digit and detecting character strings each containing the detected character. The detected character strings are then sequentially supplied to a display unit (22) from the memory so that they are displayed one at a time. When the command key is operated, the character string being displayed on the display unit is identified and the digits stored in the memory corresponding to the identified character string are dialled to a switched network.

Claims: A dialling apparatus, comprising: a manually operable keypad (21) having a plurality of data keys (1-9,0), each data key being associated with a respective digit and with a respective set of characters; a memory (23) for storing a plurality of entries, each entry including a respective character string and a respective digit string constituting a subscriber number; a display unit (22) for displaying a selected one of the character strings; a dialling circuit (25) for transmitting digit strings to a switched network; and a controller (20,24) which is operable: in response to operation of one of the data keys, to search through the memory to identify an entry therein whose character string begins with a character in the character set associated with the operated data key; in response to such an entry being so identified, to cause the character string of that identified entry to be displayed on the display unit; and in a memory dialling mode, in response to operation of a first control key (SND) of the keypad, to cause the dialling circuit to transmit to the switched network the selected digit string associated with a currently displayed character string; said apparatus being characterized in that the controller is so operable, in the memory dialling mode: in response to such operation of one of the data keys, to search through the memory to identify any entry therein whose character string begins with any of the characters in the character set associated with the operated data key; and in response to at least two such entries being so identified, to cause the character strings for the identified entries to be successively displayed on the display unit automatically or in response to operation of a second control key (*) of the keypad other than the data keys. An apparatus as claimed in claim 1, wherein the controller is so operable to cause the character stings for the identified entries to be successively displayed on the display unit automatically. An apparatus as claimed in claim 1, wherein the controller is so operable to cause the character strings for the identified entries to be successively displayed on the display unit in response to operation of the second control key. An apparatus as claimed in claim 3, wherein the controller is so operable to cause the successive display of the character strings for the identified entries to be in one order in response to operation of the second control key, and is operable to cause the character strings for the identified entries to be successively displayed on the display unit in the opposite order in response to operation of a third control key (#) other than the data keys. A method of operation of a dialling apparatus, the apparatus comprising: a manually operable keypad (21) having a plurality of data keys (1-9,0), each data key being associated with a respective digit and with a respective set of characters; a memory (23) for storing a plurality of entries, each entry including a respective character string and a respective digit string constituting a subscriber number; a display unit (22) for displaying a selected one of the character strings; and a dialling circuit (25) for transmitting digit strings to a switched network; the method including the steps of: (a) in response to operation of one of the data keys, searching through the memory to identify an entry therein whose character string begins with a character in the character set associated with the operated data key; (b) in response to such an entry being so identified, causing the character string of that identified entry to be displayed on the display unit; and (c) in a memory dialing mode, in response to operation of a first control key (SND) of the keypad, causing the dialing circuit to transmit to the switched network the selected digit string associated with a currently displayed character string; said method being characterized by the steps, in the memory dialing mode, of: (d) in response to such operation of one of the data keys, searching through the memory to identify any entry therein whose character string begins with any of the characters in the character set associated with the operated data key; and (e) in response to at least two such entries being so identified, causing the character strings for the identified entries to be successively displayed on the display unit automatically or in response to operation of a second control key (*) of the keypad other than the data keys. A method as claimed in claim 5, wherein, in step (e) the character stings for the identified entries are successively displayed on the display unit automatically. A method as claimed in claim 5, wherein, in step (e) the character strings for the identified entries are successively displayed on the display unit in response to operation of the second control key. An method as claimed in claim 7, wherein the successive display of the character strings for the identified entries is in one order in response to operation of the second control key, and the character strings for the identified entries are successively displayed on the display unit in the opposite order in response to operation of a third control key (#) other than the data keys. A telephone set incorporating a dialling apparatus as claimed in any of claims 1 to 4.

Inventors: NORIMATSU NORIKO, NORIMATSU, NORIKO
Applicants: NIPPON ELECTRIC CO, NEC CORPORATION
Application year: 1993
Main classification: H04M1
IPC codes: H04M1