Abstract:
When a radio unit incorporated in a facsimile device is made replaceable to make various radio units usable, a change in specification of communication between a facsimile body and a radio unit is made unnecessary. For this purpose, according to the present invention, a radio unit, which is united, for performing radio communication with another communication device, a controller for controlling the communication device, and an interface for performing communication of various control signals between the radio unit and the controller are arranged, the radio unit is replaced with another type of radio unit, and the interface and the control signal transmitting/receiving through the interface are shared regardless of the type of radio unit.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a communication device having a radio unit for performing radio communication.  
           [0003]    2. Description of the Related Art  
           [0004]    There is a conventional communication device in which radio communication is established between a transmitter/receiver for performing speech communication and a communication device.  
           [0005]    For example, there are facsimile devices similar to the above communication device. The facsimile device will be described below.  
           [0006]    This facsimile device has a radio unit for performing radio communication with a transmitter/receiver, and a controller of the facsimile device controls the facsimile device and the radio unit. The controller controls the radio unit by a signal system inherent in the controller.  
           [0007]    In a facsimile device in which radio communication is established between a transmitter/receiver and the facsimile device, when the transmitter/receiver receives an incoming notification to respond to the incoming notification, and the facsimile device performs an automatic receiving operation (so-called facsimile/telephone switching operation), a radio line between the transmitter/receiver and the facsimile device is suddenly cut off, or no notification is transmitted from the facsimile device to the transmitter/receiver even if the radio line is not cut off.  
           [0008]    When communication between the transmitter/receiver and the facsimile device cannot be established due to radio wave jamming between the transmitter/receiver and the facsimile device, the transmitter/receiver outputs an alarm tone by an alarming unit built in the transmitter/receiver.  
           [0009]    However, in such a conventional facsimile device, the controller of the facsimile device controls the radio unit by a radio system inherent in the controller. For this reason, the controller cannot control another type of radio unit.  
           [0010]    More specifically, a radio unit cannot be shared by this facsimile device and another facsimile device, and radio units must be formed for the types of facsimile devices, respectively.  
           [0011]    In a facsimile device in which radio communication between a transmitter/receiver and the facsimile device is established, when the transmitter/receiver receives an incoming notification to respond to the incoming notification, and the facsimile device performs an automatic receiving operation, a radio line between the transmitter/receiver and the facsimile device is suddenly cut off, or no notification is transmitted from the facsimile device to the transmitter/receiver even if the radio line is not cut off. For this reason, an operator who answers the notification with the transmitter/receiver suddenly hears noise.  
           [0012]    When communication between the transmitter/receiver and the facsimile device cannot be established, since an alarm tone is output by an alarm unit built in the transmitter/receiver, a signal from the facsimile device can be received by the transmitter/receiver. However, when the facsimile device cannot receive a signal from the transmitter/receiver, the transmitter/receiver cannot recognize that communication with the facsimile device cannot be established, and the transmitter/receiver cannot make an alarm tone indicating disable communication.  
         SUMMARY OF THE INVENTION  
         [0013]    It is an object of the present invention that a radio unit, included in a communication device, for performing radio communication can be replaced with another type of radio unit.  
           [0014]    It is another object of the present invention that an interface for exchanging a control signal between a radio unit for performing radio communication and a communication device performing communication through a communication line is shared by different types of radio units.  
           [0015]    It is still another object of the present invention that a control signal exchanged between a radio unit for performing radio communication and a communication device performing communication through a communication line is shared among different types of radio units.  
           [0016]    It is still another object of the present invention that when communication using a radio unit is switched to communication without a radio unit, the radio unit notifies a communication device which is performing radio communication that the communications are switched.  
           [0017]    Still another object of the present invention will be apparent from the following specification and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a view showing the arrangement of a facsimile device according to an embodiment of the present invention.  
         [0019]    [0019]FIG. 2 is a table showing control signals transmitted from a facsimile controller (FAX CPU) according to the embodiment of the present invention to a radio controller (CT CPU) of a radio unit of the facsimile device.  
         [0020]    [0020]FIG. 3 is a table showing control signals transmitted from the facsimile controller (FAX CPU) according to the embodiment of the present invention to the radio controller (CT CPU) of the radio unit of the facsimile device.  
         [0021]    [0021]FIG. 4 is a table showing control signals transmitted from the radio controller (CT CPU) of the radio unit of the facsimile device according to the embodiment of the present invention to the facsimile controller (FAX CPU).  
         [0022]    [0022]FIG. 5 is a table showing control signals transmitted from the radio controller (CT CPU) of the radio unit of the facsimile device according to the embodiment of the present invention to the facsimile controller (FAX CPU).  
         [0023]    [0023]FIG. 6 is a table showing the bit patterns of the control signals transmitted from the facsimile controller (FAX CPU) according to the embodiment of the present invention to the radio controller (CT CPU) of the radio unit of the facsimile device.  
         [0024]    [0024]FIG. 7 is a table showing the bit patterns of control signals transmitted from the radio controller (CT CPU) of the radio unit of the facsimile device according to the embodiment of the present invention to the facsimile controller (FAX CPU).  
         [0025]    [0025]FIG. 8 is a sequence chart showing an operation performed in outside line outgoing from an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0026]    [0026]FIG. 9 is a sequence chart showing incoming from an outside line to the facsimile device according to the embodiment of the present invention.  
         [0027]    [0027]FIG. 10 is a sequence chart showing call cutting in the facsimile device according to the embodiment of the present invention.  
         [0028]    [0028]FIG. 11 is a sequence chart showing hold and hold cancellation in the facsimile device according to the embodiment of the present invention.  
         [0029]    [0029]FIG. 12 is a sequence chart showing hold and hold cancellation in the facsimile device according to the embodiment of the present invention.  
         [0030]    [0030]FIG. 13 is a sequence chart showing hold and hold cancellation in the facsimile device according to the embodiment of the present invention.  
         [0031]    [0031]FIG. 14 is a sequence chart showing hold and hold cancellation in the facsimile device according to the embodiment of the present invention.  
         [0032]    [0032]FIG. 15 is a sequence chart showing extension line speech communication in the facsimile device according to the embodiment of the present invention.  
         [0033]    [0033]FIG. 16 is a sequence chart showing stop of extension line speech communication in the facsimile device according to the embodiment of the present invention.  
         [0034]    [0034]FIG. 17 is a sequence chart showing extension line speech communication in the facsimile device according to the embodiment of the present invention.  
         [0035]    [0035]FIG. 18 is a sequence chart showing stop of extension line speech communication in the facsimile device according to the embodiment of the present invention.  
         [0036]    [0036]FIG. 19 is a sequence chart showing hold transfer in the facsimile device according to the embodiment of the present invention.  
         [0037]    [0037]FIG. 20 is a sequence chart showing stop of hold transfer in the facsimile device according to the embodiment of the present invention.  
         [0038]    [0038]FIG. 21 is a sequence chart showing hold transfer in the facsimile device according to the embodiment of the present invention.  
         [0039]    [0039]FIG. 22 is a sequence chart showing stop of hold transfer in the facsimile device according to the embodiment of the present invention.  
         [0040]    [0040]FIG. 23 is a sequence chart showing three-person speech communication in the facsimile device according to the embodiment of the present invention.  
         [0041]    [0041]FIG. 24 is a sequence chart showing stop of three-person speech communication in the facsimile device according to the embodiment of the present invention.  
         [0042]    [0042]FIG. 25 is a sequence chart showing three-person speech communication in the facsimile device according to the embodiment of the present invention.  
         [0043]    [0043]FIG. 26 is a sequence chart showing stop of three-person speech communication in the facsimile device according to the embodiment of the present invention.  
         [0044]    [0044]FIG. 27 is a sequence chart showing automatic recording set/canceled by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0045]    [0045]FIG. 28 is a sequence chart showing recording/reproducing of an automatic answer telephone by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0046]    [0046]FIG. 29 is a sequence chart showing recording/reproducing of an automatic answer telephone by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0047]    [0047]FIG. 30 is a sequence chart showing facsimile communication switching by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0048]    [0048]FIG. 31 is a flow chart showing an operation of a facsimile controller (FAC CPU) when facsimile communication is switched by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0049]    [0049]FIG. 32 is a flow chart showing an operation of a radio controller (CT CPU) of a radio unit when facsimile communication is switched by remote control of an extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0050]    [0050]FIG. 33 is a flow chart showing an operation of a controller of an extension telephone when facsimile communication is switched by remote control of the extension telephone of the facsimile device according to the embodiment of the present invention.  
         [0051]    [0051]FIG. 34 is a sequence chart obtained when the radio controller (CT CRT) of the radio unit of the facsimile device according to the embodiment of the present invention detects an out-of-range state of an extension telephone.  
         [0052]    [0052]FIG. 35 is a sequence chart obtained when the radio controller (CT CRT) of the radio unit of the facsimile device according to the embodiment of the present invention detects an out-of-range state of an extension telephone.  
         [0053]    [0053]FIG. 36 is a sequence chart obtained when the controller of an extension telephone of the facsimile device according to the embodiment of the present invention detects an out-of-range state of the extension telephone.  
         [0054]    [0054]FIG. 37 is a sequence chart obtained when the controller of an extension telephone of the facsimile device according to the embodiment of the present invention detects an out-of-range state of the extension telephone.  
         [0055]    [0055]FIG. 38 is a flow chart showing an operation of the facsimile controller (FAX CPU) when an extension telephone of the facsimile device according to the embodiment of the present invention is in an out-of-range state.  
         [0056]    [0056]FIG. 39 is a flow chart showing an operation of the radio controller (CT CPU) of the radio unit when an extension telephone of the facsimile device according to the embodiment of the present invention is in an out-of-range state.  
         [0057]    [0057]FIG. 40 is a flow chart showing an operation of the controller of an extension telephone when the extension telephone of the facsimile device according to the embodiment of the present invention is in an out-of-range state. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0058]    An embodiment of the present invention will be described below with reference to the accompanying drawings.  
         [0059]    In the following embodiment, a facsimile device will be exemplified as a communication device.  
         [0060]    [0060]FIG. 1 is a block diagram showing a facsimile device according to this embodiment.  
         [0061]    Referring to FIG. 1, reference numeral  1  denotes a facsimile device, and reference numeral  2  denotes an extension telephone which performs radio communication with the facsimile device  1 . A telephone line  3  is connected to a facsimile device  1 .  
         [0062]    The facsimile device  1  is constituted by a radio unit  11  and a facsimile unit  12 , and the facsimile device  1  and the facsimile unit  12  are connected to each other by an interface  113 .  
         [0063]    The radio unit  11  comprises: an RF unit  111  which converts a signal from the telephone line  3  or a signal from a handset  124  arranged in the facsimile device  1  into a radio signal when radio communication is performed between the facsimile device  1  and the extension telephone  2  to transmit the signal from an antenna, transmits the radio signal received from the extension telephone  2  to the telephone line  3 , or which converts a radio signal received from the extension telephone  2  into a signal to be transmitted to the telephone line  3  or a signal to be transmitted to the handset  124  arranged in the facsimile device  1 ; an EEPROM  112  in which a control program for controlling the radio unit  11  is stored; and a radio controller  114  (to be referred to as a CT CPU hereinafter) for controlling the radio unit  11  according to the program in the EEPROM  112  to perform communication with the extension telephone  2 .  
         [0064]    The CT CPU  114  controls the radio unit  11  on the basis of a control signal from a facsimile controller  121  (to be referred to as a FAX CPU hereinafter) of the facsimile unit  12 .  
         [0065]    The facsimile unit  12  comprises: an EEPROM  122  in which a control program for controlling the facsimile unit  12  is stored; a facsimile controller  121  for controlling the facsimile unit  12  according to the control program in the EEPROM  122 ; and an audio storage unit  123  for storing a voice guidance output when the speech communication state of the extension telephone  2  is shifted to a facsimile communication state by remote control of the extension telephone  2 , a response message used when the function of an automatic answer telephone is used, or a voice message output from a communication destination. The handset  124  for performing speech communication through the telephone line  3  or speech communication with the extension telephone  2  is connected to the facsimile unit  12 .  
         [0066]    The extension telephone  2  comprises: an RF unit  21  for converting a radio signal received from the facsimile device  1  into a signal to be controlled by a controller  26  or a signal to be output by an audio control  24  or converting a signal from the controller  26  or the audio control  24  into a radio signal to transmit the radio signal from an antenna; a key matrix  22  for performing various key operations; a display  23  for performing various display operations; the audio control  24  for inputting/outputting an audio signal; an EEPROM  25  in which a control program for controlling the extension telephone  2  is stored; and a controller  26  for controlling the extension telephone  2 .  
         [0067]    A control signal transmitted/received between the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  and the controller  26  of the extension telephone  2 , a method of transmitting/receiving the control signal, and a radio communication scheme (e.g., analog radio communication or digital radio communication) vary depending on the type of facsimile device like a conventional control signal transmitted/received by a facsimile device which establishes radio communication between an extension telephone and the facsimile device, a conventional method of transmitting/receiving the control signal, and a conventional radio communication scheme. However, a control signal transmitted/received by the interface  113  between the facsimile controller (FAX CPU)  121  and the radio controller (CT CPU)  114 , a method of transmitting/receiving the control signal, and the interface  113  are commonly used independently of the type facsimile device or the type of radio unit.  
         [0068]    [0068]FIGS. 2 and 3 show a control signal transmitted from the facsimile controller (FAX CPU)  121  to the radio controller (CT CPU)  114 , and FIGS. 4 and 5 show a control signal transmitted from the radio controller (CT CPU)  114  to the facsimile controller (FAX CPU)  121 .  
         [0069]    [0069]FIG. 6 shows the bit pattern of the control signal transmitted from the facsimile controller (FAX CPU)  121  to the radio controller (CT CPU)  114 , and FIG. 7 shows the bit pattern of a control signal transmitted from the radio controller (CT CPU)  114  to the facsimile controller (FAX CPU)  121 .  
         [0070]    [0070]FIG. 8 shows an operation sequence performed when outside line outgoing is performed from the extension telephone  2  through the facsimile device  1 .  
         [0071]    Referring to FIG. 8, when an off-hook button is pressed by the key matrix  22  of the extension telephone  2 , the controller  26  of the extension telephone  2  transmits a connection request signal to the facsimile device  1  through the RF unit  21 . The radio controller (CT CPU)  114  of the radio unit  11  which receives the connection request signal finds an empty speech communication channel, and transmits a speech communication channel designation signal for designating the speech communication channel to the extension telephone  2 . The radio controller (CT CPU)  114  shifts from the control channel to the speech communication channel.  
         [0072]    The controller  26  of the extension telephone  2  which receives the speech communication channel designation signal shifts to a designated speech communication channel, and transmits the speech communication request signal to the facsimile device  1  through the speech communication channel. The radio controller (CT CPU)  114  of the radio unit  11  which receives the speech communication request signal transmits the speech communication confirmation signal to the extension telephone  2 , and transmits an outside speech communication command to the facsimile controller  121  (FAX CPU). The facsimile controller (FAX CPU)  121  sends an ACK back to the radio controller (CT CPU)  114  of the radio unit  11  when the facsimile controller (FAX CPU)  121  receives the outside speech communication command from the radio controller (CT CPU)  114  of the radio unit  11 , and transmits a signal for closing a line to an exchanger to close a DC loop, thereby setting a speech communication state.  
         [0073]    When the controller  26  of the extension telephone  2  transmits a dial signal to the facsimile device  1  when a dial button is pressed by the operation of the key matrix  22 . When the radio controller (CT CPU)  114  of the radio unit  11  receives the dial signal, the radio controller (CT CPU)  114  transmits the code of the dial signal to the facsimile controller (FAX CPU)  121 .  
         [0074]    When the facsimile controller (FAX CPU)  121  receives the code of the dial signal, the facsimile controller (FAX CPU)  121  transmits an ACK to the radio controller (CT CPU)  114  of the radio unit  11  to notify the radio controller (CT CPU)  114  that the facsimile controller (FAX CPU)  121  receives the code of the dial signal. The radio controller (CT CPU)  114  of the radio unit  11  which receives the ACK transmits a dial confirmation signal to the extension telephone  2  to notify the extension telephone  2  that the dial signal is normally received.  
         [0075]    When the facsimile controller (FAX CPU)  121  receives the code of the dial signal, dial signals represented by the code is transmitted to the exchanger through the telephone line  3 . When a communication destination represented by the dial signals responds to the dial signals, a speech communication state between the extension telephone  2  and the communication destination is established.  
         [0076]    [0076]FIG. 9 shows a sequence chart obtained when incoming is received from an outside line.  
         [0077]    Referring to FIG. 9, when a calling signal is received from the exchanger such that outside line incoming occurs in the facsimile device  1 , the facsimile controller (FAX CPU)  121  transmits a command representing the presence of outside line incoming to the radio controller (CT CPU)  114  of the radio unit  11 , and calling is performed on the facsimile device  1  side to notify that incoming is present. When the radio controller (CT CPU)  114  of the radio unit  11  which receives the command representing the presence of outside line incoming sends an ACK back to the facsimile controller (FAX CPU)  121 , and transmits a connection request signal and a speech communication designation signal for designating a speech communication channel to be used to the extension telephone  2  through a control channel.  
         [0078]    When the extension telephone  2  receives the connection request signal and the speech communication channel designation signal, the extension telephone  2  transmits a connection confirmation signal to the facsimile device  1 .  
         [0079]    The radio controller (CT CPU)  114  of the radio unit  11  which receives the connection confirmation signal transmits a speech communication channel shift designation signal to the extension telephone  2  to shift to the channel. The extension telephone  2  which receives the speech communication channel shift designation signal also shifts to the speech communication channel.  
         [0080]    When the radio controller (CT CPU)  114  of the radio unit  11  transmits an incoming signal to the extension telephone  2  to notify the extension telephone  2  of the presence of incoming. The extension telephone  2  which receives the incoming signal performs a calling operation to notify that incoming occurs, and transmits an incoming confirmation signal to the facsimile device  1 .  
         [0081]    When an off-hook operation is performed by the of-hook button of the key matrix  22  of the extension telephone  2 , the controller  26  of the extension telephone  2  transmits a speech communication request signal to the facsimile device  1 . When the radio controller (CT CPU)  114  of the radio unit  11  receives the speech communication request signal, the radio controller (CT CPU)  114  transmits the speech communication confirmation signal to the extension telephone  2  and transmits an outside line speech communication command to the facsimile controller (FAX CPU)  121 . When the facsimile controller (FAX CPU)  121  receives the outside line speech communication command, the facsimile controller (FAX CPU)  121  sends the ACK back to the radio controller (CT CPU)  114  of the radio unit  11  and transmits a line closing state signal to the exchanger. Speech communication between the communication destination and the extension telephone is established.  
         [0082]    [0082]FIG. 10 shows a sequence chart obtained when a call between the extension telephone  2  and a communication destination which are connected through the telephone line  3  is cut off.  
         [0083]    FIGS.  11  to  14  show sequence charts obtained when a holding operation and a hold canceling operation.  
         [0084]    FIGS.  15  to  18  show sequence charts obtained when extension line speech communication is performed between the facsimile device  1  and the extension telephone  2  and sequence charts obtained when the extension line speech communication is stopped.  
         [0085]    FIGS.  19  to  22  show sequence charts obtained when hold transfer is performed between the facsimile device  1  and the extension telephone  2  and sequence charts obtained when the hold transfer is stopped.  
         [0086]    FIGS.  23  to  26  show sequence charts obtained when three-person speech communication is performed and sequence charts obtained when the three-person speech communication is stopped.  
         [0087]    [0087]FIG. 27 shows a sequence chart obtained when an automatic answer telephone is set and canceled by remote control of the extension telephone  2 , and FIGS. 28 and 29 show sequence charts obtained when a message recorded on the automatic answer telephone is reproduced by remote control of the extension telephone  2 .  
         [0088]    Referring to FIGS.  10  to  29 , the control signal shown in these drawings is transmitted/received between the facsimile controller (FAX CPU)  121  and the radio controller (CT CPU)  114  of the facsimile device  1  and the controller  26  of the extension telephone  2 .  
         [0089]    [0089]FIG. 30 shows a sequence chart obtained when the state is switched to a facsimile communication state by remote control of the extension telephone  2  in a state wherein speech communication between the extension telephone  2  and a communication destination of the outside line is established. FIG. 31 is a flow chart showing an operation of the facsimile controller (FAX CPU)  121  of the facsimile device  1  in the sequence in FIG. 30, FIG. 32 is a flow chart showing an operation of the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  in the sequence in FIG. 30, and FIG. 33 is a flow chart showing an operation of the controller  26  of the extension telephone  2  in the sequence in FIG. 30.  
         [0090]    Referring to FIG. 33, when a remote button for performing remote control is pressed by the key matrix  22  (S 3301 ) when speech communication state between the extension telephone  2  and a speech communication destination of the outside line is established, a remote button signal is transmitted to the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  (S 3302 ). When the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  receives the remote button signal (S 3201  in FIG. 32), the radio controller (CT CPU)  114  transmits an extension telephone remote command to the facsimile controller (FAX CPU)  121  (S 3201 ). When the facsimile controller (FAX CPU)  121  receives the extension telephone remote command (S 3101  in FIG. 31), the facsimile controller (FAX CPU)  121  sends an ACK back to the radio controller (CT CPU)  114  of the radio unit  11  (S 3102 ).  
         [0091]    When a remote reception button for causing speech communication by the extension telephone  2  to shift to facsimile communication is pressed by the key matrix  22  (S 3303 ), the controller  26  of the extension telephone  2  transmits a FAX reception switching signal to the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  (S 3304 ).  
         [0092]    In FIG. 30, a dial button  3  is used as the FAX reception switching signal.  
         [0093]    When the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  receives the ACK from the facsimile controller (FAX CPU)  121  (S 3203 ) and then receives the FAX reception switching signal (S 3204 ), the radio controller (CT CPU)  114  transmits the FAX reception switching command, i.e., a dial code  3 , to the facsimile controller (FAX CPU)  121  (S 3205 ).  
         [0094]    When the facsimile controller (FAX CPU)  121  receives the FAX reception switching command (dial code  3 ) (S 3103 ), the facsimile controller (FAX CPU)  121  sends the ACK back to the radio controller (CT CPU)  114  of the radio unit  11  (S 3104 ) and transmits a voice guidance stored in the audio storage unit  123  to the radio unit  11  (S 3105 ). Therefore, the facsimile controller (FAX CPU)  121  transmits a remote end command to the radio controller (CT CPU)  114  of the radio unit  11  (S 3106 ).  
         [0095]    When the radio controller (CT CPU)  114  of the radio unit  11  receives the ACK from the facsimile controller (FAX CPU)  121  (S 3206 ), the radio controller (CT CPU)  114  transmits the voice guidance (to be supplied later) to the extension telephone  2  on an audio line through the speech communication channel (S 3207 ). When the radio controller (CT CPU)  114  receives the remote end command which is supplied subsequent to the voice guidance (S 3208 ), the radio controller (CT CPU)  114  transmits the ACK to the facsimile controller (FAX CPU)  121  (S 3209 ), designates the extension telephone  2  to shift to a wait state (S 3201 ), and cuts a radio line connected to the extension telephone  2  (S 3211 ).  
         [0096]    The controller  26  of the extension telephone  2  outputs the received voice guidance by the audio control  24  (S 3305 ). When the controller  26  receives a designation for shifting to a wait state from the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  (S 3306 ), a radio line to the facsimile device  1  is cut off (S 3307 ), and the controller  26  shifts to the wait state (S 3308 ).  
         [0097]    The facsimile controller (FAX CPU)  121  which receives the ACK from the radio controller (CT CPU)  114  of the radio unit  11  (S 3107 ) starts facsimile communication through the telephone line  3  (S 3108 ).  
         [0098]    When the facsimile controller (FAX CPU)  121  receives a signal other than an extension telephone remote signal in S 3101  (S 3109 ), the facsimile controller (FAX CPU)  121  performs another process based on the signal (S 3110 ).  
         [0099]    When the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  receives a signal other than a remote signal in S 3201  (S 3212 ), the radio controller (CT CPU)  114  performs another process based on the signal (S 3213 ).  
         [0100]    When the controller  26  of the extension telephone  2  detects an operation other than a pressing operation of the remote button in S 3301  (S 3309 ), the controller  26  performs a process based on the operation (S 3310 ).  
         [0101]    [0101]FIG. 34 is a sequence chart obtained in a case wherein the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  cannot receive a signal from the extension telephone  2 , the extension telephone  2  is set out of a radio area, and the line is opened. FIG. 35 is a sequence chart obtained when speech communication is restarted.  
         [0102]    [0102]FIG. 36 is a sequence chart obtained in a case wherein the controller  26  of the extension telephone  2  cannot receive a signal from the facsimile device  1 , and the line is opened. FIG. 37 is a sequence chart obtained when speech communication is restarted.  
         [0103]    [0103]FIG. 38 is a flow chart showing an operation of the facsimile controller (FAX CPU)  121  in the cases shown in FIGS.  34  to  37 . FIG. 39 is a flow chart showing an operation of the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1 . FIG. 40 is a flow chart showing an operation of the controller  26  of the extension telephone  2 .  
         [0104]    A case wherein the extension telephone  2  is set out of a radio area will be described below with reference to FIGS.  38  to  40 .  
         [0105]    Referring to FIG. 39, when it is determined that the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  cannot receive a signal from the extension telephone  2  to set the extension telephone  2  out of a speech communication range because a radio wave environment is degraded or the distance between the extension telephone  2  and the facsimile device  1  becomes longer than the distance that a radio wave reaches (S 3901 ), the radio controller (CT CPU)  114  of the radio unit  11  transmits a primary out-of-range detection command to the facsimile controller (FAX CPU)  121  (S 3902 ). When the facsimile controller (FAX CPU)  121  receives this primary out-of-range detection command (S 3801  in FIG. 38), the facsimile controller (FAX CPU)  121  transmits an ACK to the radio controller (CT CPU)  114  of the radio unit  11  (S 3802 ), and transmits an out-of-range alarm tone for notifying the extension telephone  2  of an out-of-area state to the radio unit  11  (S 3803 ). The radio controller (CT CPU)  114  of the radio unit  11  receives the ACK from the facsimile controller (FAX CPU)  121  (S 3903 ), and then transmits an area out-of-range alarm tone transmitted to the facsimile controller (FAX CPU) through the speech communication channel to put the area out-of-range alarm tone on the audio line (S 3904 ). When the extension telephone  2  receives the area out-of-range alarm tone, the area out-of-range alarm tone is output by using the audio control  24 . Since the area out-of-range alarm tone is put on the audio line to be transmitted to the extension telephone  2  as described above, a signal from the extension telephone  2  does not reach the facsimile device  1 . However, when a signal from the facsimile device  1  reaches the extension telephone  2 , it is recognized that the operation of the extension telephone  2  is out of a speech communication range.  
         [0106]    When the extension telephone  2  is continuously set out of the speech communication range for a predetermined period of time (20 seconds in this embodiment) (S 3905 ), an out-of-range command to the facsimile controller (FAX CPU)  121  (S 3906 ). When the facsimile controller (FAX CPU)  121  receives the out-of-range command (S 3804 ), the facsimile controller (FAX CPU)  121  sends the ACK back to the radio controller (CT CPU)  114  (S 3805 ), and a line to a communication destination (S 3806 ). When the radio controller (CT CPU)  114  of the radio unit  11  receives the ACK from the facsimile controller (FAX CPU)  121  (S 3907 ), a radio line to the extension telephone  2  is cut off (S 3908 ), and the extension telephone  2  is set in a wait state (S 3909 ).  
         [0107]    When the radio controller (CT CPU)  114  of the radio unit  11  can receive the signal from the extension telephone  2  before 20 seconds has passed in S 3905  in FIG. 39 to cause the extension telephone  2  to be out of the speech communication range (S 3910 ), the radio controller (CT CPU)  114  transmits an out-of-range detection canceling command to the facsimile controller (FAX CPU)  121  (S 3911 ). When the facsimile controller (FAX CPU)  121  receives the out-of-range detection canceling command from the radio controller (CT CPU)  114  of the radio unit  11  (S 3808 ), transmission of the area out-of-range alarm tone is stopped (S 3809 ), and the facsimile controller (FAX CPU)  121  returns to a speech communication state.  
         [0108]    Referring to FIG. 40, when the controller  26  of the extension telephone  2  cannot receive a signal from the facsimile device  1  and determines that speech communication with the facsimile device  1  cannot be established (S 4001 ), the area out-of-range alarm tone is made from the loudspeaker of the audio control  24  (S 4002 ). The area out-of-range alarm tone may be made from the loudspeaker of a transmitter/receiver for performing speech communication, or may be made from a loudspeaker other than the loudspeaker of the transmitter/receiver.  
         [0109]    When this state continues for a predetermined period of time (20 seconds in this embodiment), the controller  26  cuts a radio line to the facsimile device  1  (S 4004 ), and a wait state is set (S 4005 ). When the controller  26  can receive a signal from the facsimile device  1  within 20 seconds (S 4006 ), the area out-of-range alarm tone is stopped (S 4007 ), and the extension telephone  2  returns to the wait state. When the extension telephone  2  cuts radio line in S 4004 , the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  detects that the radio line is cut (S 3912 ), the radio controller (CT CPU)  114  transmits the out-of-range command to the facsimile controller (FAX CPU)  121  in S 3906  to perform operations in S 3908  and S 3909 . When the facsimile controller (FAX CPU)  121  does not receive the primary out-of-range command in S 3801  in FIG. 38, but receives the out-of-range command (S 3810 ), the facsimile controller (FAX CPU)  121  sends the ACK back to the radio controller (CT CPU)  114  of the radio unit  11  in S 3805  to open the line to a communication destination.  
         [0110]    In the above description, when the radio controller (CT CPU)  114  of the radio unit  11  detects that the extension telephone  2  is out of the area, the facsimile controller (FAX CPU)  121  transmits the area out-of-range alarm tone to the radio unit, and the radio controller (CT CPU)  114  puts the area out-of-range alarm tone on the audio line to transmit it to the extension telephone  2 . However, when the radio controller (CT CPU)  114  detects that the extension telephone  2  is out of the range, the radio controller (CT CPU)  114  transmits a control signal for notification of the out-of-range state to the extension telephone  2 . When the extension telephone  2  receives the control signal, the radio controller (CT CPU)  114  may perform a display for notification of the out-of-range state.  
         [0111]    In this embodiment, as described above, a control signal transmitted/received between the radio controller (CT CPU)  114  of the radio unit  11  of the facsimile device  1  and the controller  26  of the extension telephone  2 , a method of transmitting/receiving the control signal, and a radio communication scheme vary depending on the type of the facsimile device like a control signal transmitted/received by a facsimile device which establishes radio communication between an extension telephone and the facsimile device, a method of transmitting/receiving the control signal, and a radio communication scheme for the control signal. However, a control signal transmitted/received through the interface  113  between the facsimile controller (FAX CPU)  121  of the facsimile device  1  and the radio controller (CT CPU)  114  and a method of transmitting/receiving the control signal can be replaced with those of another type of radio unit regardless of the type of facsimile device or radio unit by transmitting/receiving the signals shown in FIGS.  2  to  5  in the same manner (a control signal and a communication method are shared).  
         [0112]    As has been described above, according to the present invention, in a radio communication device for performing radio communication and a communication device having a radio unit for performing radio communication with the radio communication device, a control signal exchanged between the radio unit and a controller of the communication device and a method of transmitting/receiving the control signal are shared. For this reason, the radio unit of another communication device can be controlled by the controller of the above communication device. More specifically, even if radio units are not formed for the types of communication devices, respectively, a radio unit can be shared by the communication device and another communication device.  
         [0113]    When a transmitter/receiver is used as a radio communication device, even if a switching operation from speech communication using the transmitter/receiver to communication of a communication device which does not use a transmitter/receiver is performed, harsh grating noise is not suddenly output from the transmitter/receiver.  
         [0114]    Even if it cannot be awarded that a radio communication device cannot communicate with a communication device, information representing that communication cannot be performed is transmitted from the communication device to the radio communication device. For this reason, an alarm tone can be output.