Abstract:
A portable communication apparatus which can atop the alert indicating the occurrence of an incoming call while holding the incoming call is disclosed. A silence function is assigned to at least one key for an alert operation mode. When starting an alert due to an incoming call, the alert is stopped while holding the incoming call when a key having the silence function assigned thereto is operated. A response function in assigned to at least one of the plurality of keys for an alert stopped mode. The response to the incoming call held is performed when a key having the response function assigned thereto is operated.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a portable communication apparatus such as a mobile telephone or the like, and more particularly, to a portable communication apparatus having a function of informing a user carrying the same of occurrence of an incoming call. 
     2. Description of Related Art 
     A portable telephone is a typical mobile communication apparatus. In general, the portable telephone is provided with an alert device for informing the user, by sound and/or silent vibration, of the occurrence of an incoming call. The user can select one or both of the audible alert and the vibration alert. 
     In the case where only the silent vibration alert has been selected, however, the user cannot be informed without having such a portable telephone on his/her person or making physical contact with it. Therefore, when the portable telephone is put in a bag or the like, the silent vibration alert is made in vain. To avoid such a case, many users select the audible alert. 
     In the case where the audible alert has been selected, however, a sounder sounds alert tone when an incoming call occurs, making a nuisance of itself. As a function of stopping the audible alert as soon as possible, an Any-key answer function has been proposed in Japanese Patent Application Laid-open Publication No. 10-107874. The Any-key answer function stops the sounder and start communication by the user depressing not only a start key but also any key of ten keys, 0-9, symbol keys (*, #) and other keys. Therefore, the user can stop the sounder without looking at the keypad provided in the portable telephone, resulting in rapid alert stop. 
     The portable telephone disclosed in the above Japanese Patent Application Laid-open Publication No. 10-107874 also provides another useful function called a response hold function. The response hold function is useful in the case where the user cannot respond to an incoming call immediately. More specifically, when an end key is depressed on incoming call, the sounder is stopped and the portable telephone sends a caller a message such that the called party cannot respond to this call immediately, and the caller is put on hold. When a start key is depressed, the telephone communication can be made. 
     However, according to the above-described conventional portable telephone, when the user depresses any key in the Any-key answer mode, the audible alert is stopped and, at the same time the portable telephone responds to the incoming call to be set to the communication mode. This would cause the calling party to start talking. If the calling party receives silence from the called party, the calling party may determine that some failure occurs and then is likely to disconnect the established line. To avoid such disconnection, the called party must start conversation, which will conversely make a nuisance of itself. 
     On the other hand, the response hold function provides transmission of a message that the called party cannot respond to this call immediately. Therefore, it is not necessary to start conversation immediately. However, there is a strong possibility that the calling party promptly disconnects the call because it is determined that it makes a nuisance of itself or partly because it cannot be determined how long the calling party is kept waiting. When the called party depresses the start key, the incoming call would be disconnected already. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a portable communication apparatus and a control method that can stop an alert indicating an incoming call so that the calling party does not disconnect the call. 
     According to an aspect of the present invention, a portable communication apparatus includes an alert device for producing an alert when an incoming call occurs and an input device having a plurality of keys. The alert device producing the alert is controlled to stop the alert while holding the incoming call depending on a first predetermined operation of the input device. 
     The portable communication apparatus is capable of responding to the incoming call held when a second predetermined operation of the input device is performed after the first predetermined operation. 
     According to another aspect of the invention, a portable communication apparatus further includes a key function changer for changing logical functions of the plurality of keys based on a predetermined rule depending on a change in operation mode of the portable communication apparatus. The alert device producing the alert is controlled to stop the alert while holding the incoming call when a key having a predetermined logical function is operated. 
     The key function changer preferably includes a memory storing a table of correspondence between the plurality of keys and a plurality of logical functions for an alert operation mode. Referring to the table, it is determined whether the key having the predetermined logical function is operated. 
     Preferably, a plurality of keys have the predetermined logical function assigned thereto. All the keys may have the predetermined logical function assigned thereto. All the keys other than a predetermined key may have the predetermined logical function assigned thereto and the predetermined key has a logical function of responding to the incoming call assigned thereto. Further, all the keys other than a plurality of predetermined keys may have the predetermined logical function assigned thereto and the respective predetermined keys have a logical function of responding to the incoming call assigned thereto. Alternatively, a single key may have the predetermined logical function assigned thereto. 
     The key function changer preferably includes a first memory for storing function setting data Including a quick-silence function flag and a second memory storing a table of correspondence between the plurality of keys and a plurality of logical functions for each of an alert operation and alert stopped modes in a case where the quick-silence function flag is set. Referring to the function setting data and the table, it is determined whether the key having the predetermined logical function is operated. 
     According to further another aspect of the present invention, a control method for a portable communication apparatus including an input device having a plurality of keys, includes the steps of: assigning a silence function to at least one of the plurality of keys for an alert mode; producing an alert when an Incoming call occurs; and stopping the alert while holding the incoming call when a key having the silence function assigned thereto is operated. 
     Further, the method preferably includes the step of: assigning a response function to at least one of the plurality of keys for an alert stopped mode; and responding to the incoming call hold when a key having the response function assigned thereto is operated. 
     As described above, according to the present invention, the alert indicating the occurrence of an incoming call can be stopped while holding the incoming call. Since the incoming call is maintained, the calling party continues to hear a ringing tone when the alert has been stopped at the called party, resulting in a reduced possibility that the calling party disconnects the call. 
     Further, in the case where a silence function is assigned to a plurality of keys, the alert can be stopped while holding the incoming call by depressing any of the silence keys, resulting in rapid alert stop. 
     Furthermore, in the case where a response (off-hook) function is assigned to a plurality of keys after the alert has been stopped, the response to the incoming call can be rapidly performed by depressing one of the plurality of response keys. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic block diagram showing an internal circuit structure of a portable telephone as an embodiment of a portable communication apparatus according to the present invention; 
     FIG. 2 is a perspective view of the portable telephone according to the present embodiment of FIG. 1; 
     FIG. 3 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a first embodiment of the present invention: 
     FIG. 4 is a format diagram showing a function setting area of an BEPROM included in the portable telephone as shown in FIG. 1; 
     FIG. 5 is a diagram showing examples of display according to a Quick-silence setting operation; 
     FIG. 6 is a flow chart showing a control operation when an incoming call occurs according to the present invention; 
     FIG. 7 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a second embodiment of the present invention; 
     FIG. 8 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a third embodiment of the present invention; 
     FIG. 9 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a fourth embodiment of the present invention; 
     FIG. 10 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a fifth embodiment of the present invention; and 
     FIG. 11 is a diagram showing an example of a table for the correspondence of physical keys and logical keys according to a sixth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, inside a portable telephone according to an embodiment of the present Invention, there are built an antenna  101 , a radio system  102 , a control unit  103 , and other circuits as described below. 
     The antenna  101  is connected to the radio system  102 , which performs transmission/reception of a radio signal under the control of the control unit  103  including a channel controller, a speech processor, and a microprocessor (CPU). The control unit  103  controls the operations of the portable telephone using a read-only memory (ROM)  104 , a random access memory (RAM)  105  and a non-volatile memory  106 . The ROM  104  stores control programs, which run on the microprocessor of the control unit  103 , and other necessary control data including a physical-logical key correspondence table as described later. The RAM  105  temporarily stores various kinds of data. The non-volatile memory  106  may be an electrically erasable programmable ROM (EEPROM), which stores function setting data and an identification number (here, the telephone number of its own). 
     A user&#39;s instruction is input by a user operating an input device  107  composed of a plurality of keys including numerical and symbol keys and other function keys (see FIG.  2 ). The portable telephone is provided with an alert device composed of a sounder and/or a silent vibrator. In this embodiment, the control unit  103  controls a sounder driver  108  to drive a sounder  109  so that an audible alert indicating occurrence of an incoming call is produced. Alternatively, the control unit  103  can be set to control a vibrator driver  112  to drive a vibrator  113  so that a silent alert indicating occurrence of an incoming call is produced. Both the sounder  109  and the vibrator  113  can be also driven to produce the audible and silent alerts when an incoming call occurs. The control unit  103  controls a speaker driver  110  to drive a speaker  111  so that the voice of the opposite party is produced. The control unit  103  receives the voice signal of the user from a microphone  115  through an amplifier  114 . Further, the control unit  103  controls a display driver  116  to drive a display device  117  such as a liquid crystal display (LCD) and an incoming call Indicating lamp  118  such as a light-emitting diode. The incoming call indicating lamp  118  blinks as a visible alert when an incoming call occurs. It should be noted that a power supply circuit including a battery is not shown in this figure for simplicity. 
     Referring to FIG. 2, the portable telephone  100  has the antenna  101  and the incoming call indicating lamp  118  on the top thereof. The speaker  111 , the microphone  115 , the display  117  and the input device  107  are provided in the main surface of a housing of the portable telephone  100 . The input device  107  has a layout of various keys  201 - 211 . The sounder  109  is provided on the back side of the housing and an earphone-microphone jack  119  is provided in the side wall of the housing. 
     In this embodiment, the input device  107  is composed of a display operation keys: a left-arrow key  201 , center key  202 , right-arrow key  203 , and backtrack key  204 . The input device  107  is further composed of a ten-key pad  205  consisting of numerical keys  0 - 9  and symbol keys * and #, voice key  206 , power key  207 , manner key  208 , start key  209 , redial key  210  and end key  211 . A total of 22 keys are provided in a predetermined layout. 
     When a physical key is depressed, the input device  107  outputs a key code identifying the depressed key to the control unit  103 . The control unit  103  determines a logical key corresponding to the depressed physical key by referring to the physical-logical key correspondence table previously stored in the ROM  104 . As described hereafter, a physical key serves as a logical key depending on the current operation mode. 
     Referring to FIG. 3, a physical-logical key function correspondence table is previously stored In the ROM  104 . Each of the physical keys  201 - 205  provided in the input device  107  as shown in FIG. 2 changes its operation role depending on an operation mode of the portable telephone. In this embodiment, the operation mode has standby state and incoming call state, the incoming call state having quick-silence function ON mode and any key answer function ON mode, and the quick-silence function ON mode having two states: audible-alert state and alert stop state. As shown in this figure, in the case where the audible alert is being produced by the sounder  109  in the quick-silence function ON state when an incoming call occurs, the control unit  103  logically sets the left-arrow key  201 , the right-arrow key  203 , the backtrack key  204 , the voice key  206 , the redial key  210 , and the ten-key pad  205  for a silence key. Therefore, when the user depresses one of these keys  201 ,  203 - 206 , and  210  in this audible alert state, the audible alert is stopped while holding the incoming call. The details of respective keys will be described hereinafter. 
     As shown in FIG. 3, the power key  207  functions as a power on/off key in any of the operation modes. More specifically, when the power key  207  is depressed for a duratlon of, for example, one second in the power-off state, the portable telephone is powered on and its operation mode becomes the standby state. On the contrary, when the power key  207  is depressed for a duration of, for example, two second in the power-on state, the portable telephone is powered off. 
     In the case of the standby state, the left-arrow key  201 , the right-arrow key  203 , the backtrack key  204  and the end key  211  do not function, which is referenced by “-” in FIG.  3 . The other keys  202  and  205 - 210  function as logical keys, respectively. The ten-key pad  205  including numerical keys  0 - 9  and symbol keys * and # function as logical keys for inputting numerals  0 - 9  and the symbols * and # and the start key  209  functions as a calling key. Therefore, when the user operates the ten-key pad  205  to input a destination telephone number, the destination phone number is displayed on the display  117 . After checking the displayed phone number, the user depresses the start key  209  to dial. The radial key  210 , which is a well-known function key, is used to read the previously dialed phone number to display it on the display  117 . Then, when depressing the start key  209 , the previously dialed phone number is redialed. 
     The voice key  206  is used to activate a voice-search function, which is a voice-activated function for stored phone numbers or various functions. The manner key  208  is used to set the telephone for manner mode which is a silent operation mode such that a confirmation sound is not made when a key is depressed, a silent vibration alert indicating the occurrence of an incoming call is produced instead of the audible alert. The center key  202  functions as a menu key in any of the operation states. In the case of menu mode, menu items are displayed on the display  117  and one of the menu items can be selected by operating the left-arrow and right-arrow keys  201  and  202 . 
     In the incoming call state, the center key  202  and the power key  207  function respectively as the menu key and the power on/off key without changing in logical role among the standby state, the quick-silence function ON state, and the any key answer function ON state. The manner key  208  changes in logical function from the manner mode key to a manner mode and message key when the operation mode changes from the standby state to the incoming call state. In the incoming call state, the logical function of the manner key  208  is kept at the manner mode and message key regardless of whether the operation mode is in the quick-silence function ON state or the any key answer function ON state. The manner mode and message key functions such that a message of the caller is recorded in the manner mode. The start key  209  changes in logical function from the calling key to a response key, or an off-hook key, when the operation mode changes from the standby state to the incoming call state. In the incoming call state the logical function of the start key  209  is kept at the response key regardless of whether the operation mode is in the quick-silence function ON state or the any key answer function ON state. The end key  211  changes in logical function from a nonfunctioning key to a response hold key for activating a repose holding function when the operation mode changes from the standby state to the incoming call state. In the incoming call state, the logical function of the end key  211  is kept at the response hold key regardless of whether the operation mode is in the quick-silence function ON state or the any key answer function ON state. 
     On the other hand, the respective logical functions of the left-arrow key  201 , the right-arrow key  203 , the backtrack key  204 , the voice key  206 , the redial key  210 , the ten-key pad  205  change depending on whether the operation mode is in the quick-silence function ON state or in the any key answer function ON state. In the any key answer function ON state, these keys  201 ,  203 - 206 , and  210  function as the response key as in the case of the start key  209 . In the quick-silence function ON state, however, when the audible alert is being generated, these keys  201 ,  203 - 206 , and  210  function as the silence key and, after stopping the audible alert, these keys  201 ,  203 - 206 , and  210  do not function. 
     Referring to FIG. 4, the EEPROM  106  stores the function setting data of the quick-silence/any-key function, the audible alert, and the silent vibration alert, which are used by the control unit  103  to control the respective functions. 
     As shown in FIG. 4, the function setting area includes a quick-silence function flag  401 , an audible alert flag  402 , and a silent vibration flag  403 . In the case where the quick-silence function flag  401  is set, the quick-silence function is set to “ON” and the any key answer function to “OFF”. Contrarily, in the case where the quick-silence function flag  401  is reset, the quick-silence function is set to “OFF” and the any key answer function to “ON”. In the case where the audible alert flag  402  is set, alert is by the sounder  109  when an incoming call occurs. In the case where the audible alert flag  402  is reset, the sounder  109  does not function even when an incoming call occurs. In the case where the silent vibration flag  403  is set, the vibrator  113  is activated when an incoming call occurs. In the case where the silent vibration flag  403  is reset, the vibrator  113  does not function even when an incoming call occurs. 
     As shown in FIG. 5, the quick-silence function flag  401  is set by the user operating the keys  201 - 203  and  211 . In the standby screen as shown in FIG.  5 ( a ), for example, date and the time of day are displayed on the display  117 . In this standby screen, the user inputs a predetermined menu number by depressing the center key  202  followed by the corresponding numeral key of the ten-key pad  205 . This causes the control unit  103  to start a quick-silence function setting program to display an operation screen on the display  117 , as shown in FIG.  5 ( b ). Here, since “OFF” is positioned by a highlight bar, the quick-silence function flag  401  is reset. 
     When the user depresses the left key  201  in such a state, the highlight bar is moved in the left direction and positions “ON” as shown in FIG.  5 ( c ), which means that the quick-silence function flag  401  changes in setting state from Reset to Set. When the user depresses the right key  203  in such a state, the highlight bar is moved in the right direction back to “OFF” as shown in FIG.  5 ( b ), which means that the quick-silence function flag  401  changes in setting state from Set to Reset. 
     In the state of the quick-silence function flag  401  setting as shown in FIG.  5 ( c ), when the user depresses the end key  211 , the quick-silence function is set to “ON” and the screen of the display  117  returns to the standby screen as shown in FIG.  5 ( d ). Similarly, the other audible alert flag  402  and the silent vibration flag  403  can be set. 
     Referring to FIG. 6, when an incoming call occurs, the control unit  103  changes its operation mode from the standby state to an incoming-call state and starts the mode control according to the physical-logical key correspondence table as shown in FIG.  3 . 
     In the case of the incoming-call state, the control unit  103  controls the driver  116  so that a predetermined mark indicating the occurrence of the incoming call is displayed on the display  117  and the lamp  118  blinks and, further selectively controls the sounder driver  108  and the vibrator drover  112  depending on the audible alert flag  402  and the silent vibration flag  403  of the EEPROM  106  (step S 601 ). 
     Subsequently, the control unit  103  cheaks whether the quick-silence function flag  401  is in the set state (step S 602 ). In other words, it is determined by checking the quick-silence function flag  401  whether the quick-silence function is set to “ON” and the any key answer function to “OFF”. 
     In the case where the quick-silence function is set to “ON”, and the any key answer function to “OFF” (YES In step S 602 ), the control unit  103  waits for key input (steps S 603 -S 605 ). When receiving a key code from the input device  107 , the control unit  103  determines the logical function of the depressed physical key by referring to the physical-logical key correspondence table as shown in FIG.  3  and then performs the corresponding operation. 
     More specifically, in the incoming-call state and the audible alert state, as shown in FIG. 3, the respective logical functions of the left-arrow key  201 , the right-arrow key  203 , the backtrack key  204 , the voice key  206 , the redial key  210 , the ten-key pad  205  function as the silence key. Therefore, when the user depresses any of these keys  201 ,  202 - 206  and  210  (YES in step S 603 ), the control unit  103  stops the sounder  109  in the case of the audible alert and stops the vibrator  113  in the case of the silent vibration alert while maintaining the incoming call (step S 606 ). At this time, the display alert is still displayed on the display  117 . Since the incoming call is held, from the view of the base station calling this telephone, the calling operation continues. 
     After having stopped the alert, the control unit  103  waits for key input (steps S 607  and  610 ). When receiving a key code from the input device  107 , the control unit  103  determines the logical function of the depressed physical key by referring to the physical-logical key correspondence table as shown in FIG.  3 . When the response key is depressed (YES in step S 607 ), the display alert is stopped (step S 608 ) and the control goes to the communication mode allowing conversation between the calling and called parties (step S 609 ), since the alert is stopped in the quick-silence function ON state, only the start key  209  functions as the response key as shown in FIG.  3 . When another key is depressed (YES in step S 610 ), the operation mode is changed to the corresponding mode according to the physical-logical key correspondence table as shown in FIG. 3 (step S 611 ). For example, when the end key  211  which now functions as the response hold key is depressed, the control unit  103  changes its operation mode to the response hold mode. 
     On the other hand, after the quick-silence function has been set to “ON” (YES in step S 602 ), when the response key (here, the start key  209 ) is depressed (YES in step S 604 ), the control unit  103  stops the display alert as well as the audible/vibration alert as in the case of the step S 606  (step S 612 ) and then changes its operation mode to the communication mode (step S 609 ). When any key other than the response key and nonfunctioning keys is depressed (YES in step S 605 ), the operation mode is changed to the corresponding mode (step S 613 ). For example, when the end key  211  which now functions as the response hold key is depressed, the control unit  103  changes its operation mode to the response hold mode. 
     In the case where the quick-silence function is set to “OFF” and the any key answer function to “ON” (NO in step S 602 ), the control unit  103  waits for key input (steps S 614  and S 617 ). When receiving a key code from the input device  107 , the control unit  103  determines the logical function of the depressed physical key by ref erring to the physical-logical key correspondence table as shown in FIG.  3 . When the response key is depressed (YES in step S 614 ), the control unit  103  stops the display alert as well as the audible/vibration alert as in the case of the step S 612  (step S 615 ) and then changes its operation mode to the communication mode (step S 616 ). As shown in FIG. 3, in this case, the physical keys  201 ,  203 - 206  and  210  function as the response key. 
     When a key other than the response keys is depressed (YES in step S 617 ), the operation mode is changed to the corresponding mode (step S 618 ). For example, when the end key  211  which now functions as the response hold key is depressed, the control unit  103  changes its operation mode to the response hold mode. 
     As described above, in the quick-silence function ON state and the any key answer function OFF state, when an incoming call occurs and the audible/vibration alert Is by the sounder/vibrator, the user can stop the alert by depressing a silence key while maintaining the incoming call. Since any of the keys  201 ,  203 - 206  and  210  functions as the silence key as shown in FIG. 3, the user can easily and rapidly stop the audible/vibration alert. 
     On the other hand, when the quick-silence function is set to “OFF” as shown in FIG. 5, the any key answer function is automatically set to “ON”. In the any-key answer function ON state, any of the keys  201 ,  203 - 206  and  210  functions as the response key as shown in FIG. 3, allowing prompt off-hook operation. It should be noted that the line is disconnected when the calling party performs an on-hook operation before the response key is depressed and the control program shown in FIG. 6 is terminated. 
     A different assignment of the logical functions to the physical keys can be implemented by modifying the physical-logical key correspondence table as shown in FIGS. 7-11. 
     As shown in FIG. 7, in the case of the audible-alert state in the quick-silence function ON state, the silence key is assigned to only the left-arrow key  201  and other keys  203 - 205  and  210  do not function. The remaining operations are the same as the case of FIG.  3  and the control flow for the table of FIG. 7 is the same as FIG.  6 . 
     As shown in FIG. 8, all the keys other than the start key  209  may function as the silence key in the case of the audible-alert state in the quick-silence function ON state. In this case, it is necessary to modify the control flow as follows. 
     Since only the start key  209  function as the response key after the quick-silence function has been set to “ON” (YES in step S 602 ), the steps S 605  and S 613  are deleted from FIG. 6 and, when the response key is not depressed (NO in step S 604 ), the control goes back to the step S 603 . Therefore, in the case where the quick-silence function is set to “ON” and the any key answer function to “OPP” (YES in step S 602 ), the control unit  103  waits for key input (steps S 603  and S 604 ) and, as shown in FIG. 8, the respective logical functions of all the keys other than the start key  209  function as the silence key. When the user depresses the silence key (YES in step S 603 ), the control unit  103  stops the sounder  109  in the case of the audible alert and stops the vibrator  113  in the case of the silent vibration alert while maintaining the incoming call (step S 606 ). After having stopped the alert, the control unit  103  waits for key input (steps S 607  and  610 ). When the response key (here, only the start key  209  as shown in FIG. 8) is depressed (YES In step S 607 ), the display alert is stopped (step S 608 ) and the control goes to the communication mode allowing conversation between the calling and called parties (step S 609 ). When another key is depressed (YES in step S 610 ), the operation mode is changed to the corresponding mode according to the physical-logical key correspondence table as shown in FIG. 3 (step S 611 ). The following control operation is the same as in the case of FIG.  3 . 
     As shown In FIG. 9, all the keys  210 - 211  may function as the silence key in the case of the audible-alert state in the quick-silence function ON state. In this case, it is necessary to modify the control flow as follows. 
     Since no key functions as the response key after the quick-silence function has been set to “ON” (YES in step S 602 ), the steps S 604 , S 605 , S 612  and S 613  are deleted from FIG. 6 and, the control unit  103  waits for the silence key to be depressed. In other words, the control unit  103  waits for any of the keys  210 - 211  to be depressed. When any of the keys  210 - 211  is depressed (YES in the step S 603 ), the control unit  103  stops the audible/vibration alert (step S 606 ) and changes its operation mode to the alert stopped state. The following control operation is the same as in the case of FIG.  3 . Therefore, if the user wants to respond to the incoming call, then the user depresses any key followed by the start key  209 . 
     After having stopped the audible/vibration alert, the response key may be assigned to a plurality of physical keys. 
     As shown in FIG. 10, in the case of the audible-alert state in the quick-silence function ON state, the silence key is assigned to the physical keys  201 ,  203 - 206  and  210  as in the case of FIG.  3 . After having stopped the audible/vibration alert by depressing the silence key, however, these keys  201 ,  203 - 206  and  210  function as the response key. The remaining assignments are the same as the case of FIG.  3  and the control flow for the table of FIG. 10 is the same as FIG.  6 . 
     As shown in FIG. 11, in the case of the audible-alert state in the quick-silence function ON state, the silence key is assigned to the physical keys  201 ,  203 - 206  and  210  as in the case of FIG.  3 . After having stopped the audible/vibration alert by depressing the silence key, however, all the keys  201 - 211  function as the response key. Although the remaining assignments are the same as the case of FIG. 3, the control flow for the table of FIG. 10 is modified as follows. Namely, in the control flow of FIG. 6, the steps S 610  and S 611  are deleted. 
     In the above embodiments, the present invention is applied to the portable telephone which is provided with the input device  107  having the physical keys  201 - 211 . Alternatively, as the input device  107 , a touch-sensitive panel on the LCD may be employed. More specifically, the display  117  having the touch-sensitive panel thereon displays a layout of keys respectively corresponding to the physical keys  201 - 211  as a screen. The user touches a position corresponding to a desired function/numeral/symbol key to input desired data or instruction. 
     In the case where the portable telephone has a key invalidating function to avoid undesired key operations which may occur, for example, in a bag, when the key invalidating function is set, all the keys other than the start key  209  and the end key  211  are invalid. In other words, the key invalidating function is given priority over the quick-silence function and the any key answer function. 
     Further, the present invention can be also applied to a mobile communication device such as an automobile telephone, a cellular telephone, a digital cordless telephone such as PHS (personal handy-phone system).