Abstract:
The object of the present invention is to improve convenience of a telephone equipped with a speaker. In order to attain this object, the telephone equipped with a speaker in accordance with the present invention comprises a telephone body and a speakerphone functional unit comprising a microphone and a speaker and capable of being detachably mounted on the telephone body. The speakerphone functional unit comprises a wireless unit, and exchange of voice signals and control signals with the telephone body is conducted via the wireless circuit. As a result, the speakerphone functional unit can be freely used anywhere, without selecting a special location therefor.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a telephone equipped with a speaker, more particularly to improved technology for increasing the convenience of speakerphone functions.  
           [0003]    2. Description of the Related Art  
           [0004]    Cordless telephones for indoor communications are known in which a base set and/or a handset are provided with a speakerphone function. Providing a speakerphone function makes it possible to have a conversation without holding a handset. The speakerphone function in cordless telephones has been implemented by equipping a base set and/or handset with a microphone and a speaker.  
           [0005]    However, because the base set has to be connected to a subscriber line and an external power source line, limitation is placed on the base set location. Therefore, positional limitation is placed on conversations using a speakerphone mounted on the base set. On the other hand, the size of a speaker in the handset is limited because of size and weight requirements, and a speaker sound volume identical to that of the base set is difficult to provide. Moreover, because the charge capacity of the handset is limited, temporal limitations were placed on the communication using the speakerphone.  
         SUMMARY OF THE INVENTION  
         [0006]    Accordingly, it is an object of the present invention to resolve the above-described problems and to improve the convenience of a telephone equipped with a speaker.  
           [0007]    In order to attain this object the telephone equipped with a speaker in accordance with the present invention comprises a telephone body and a speakerphone functional unit comprising a microphone and a speaker and capable of being detachably mounted on the telephone body. Employing the configuration with detachable telephone body and speakerphone functional unit makes it possible to communicate using a speakerphone function, without placing limitation on a telephone installation site.  
           [0008]    Preferably, each of the telephone body and the speakerphone functional unit is provided with a wireless unit for opening a wireless circuit there between when the two are detached from each other and conducting transmission and reception of voice signals and control signals. With such a configuration, communication can be conducted by moving the speakerphone functional unit freely from one place to another.  
           [0009]    Preferably, wireless units installed in each of the telephone body and the speakerphone functional unit maintains a communication circuit by automatically opening a wireless circuit and conducting transmission and reception of voice signals and control signals when the telephone body and the speakerphone functional unit are detached during communication via the telephone equipped with a speaker. With such a configuration, conversation can be maintained without breaking the communication circuit, even when the speakerphone functional unit is detached during the conversation.  
           [0010]    Preferably, the speakerphone functional unit conducts transmission and reception of voice signals and control signals in a state in which it is attached to the telephone body, via connection units of the speakerphone functional unit and the telephone body. With such a configuration, when the speakerphone functional unit is attached to the telephone body, the function thereof as a speakerphone is realized by conducting transmission and reception of voice signals and control signals between the speakerphone functional unit and the telephone body, without using the wireless circuit.  
           [0011]    Preferably, the speakerphone functional unit comprises a secondary battery for supplying electric power to the microphone and the speaker. With such a configuration, an independent battery drive of the speakerphone functional unit is possible.  
           [0012]    Preferably, the telephone body comprises a power unit for charging the secondary battery. Such a configuration provides for excellent convenience because the speakerphone functional unit is automatically charged when attached to the telephone body. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a functional block diagram of the cordless telephone of the present embodiment;  
         [0014]    [0014]FIG. 2 is a plan view of a speakerphone functional unit; and  
         [0015]    [0015]FIG. 3 is a side view of the speakerphone functional unit. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    The preferred embodiments of the present invention will be described below with reference to the drawings.  
         [0017]    [0017]FIG. 1 is a functional block diagram of the cordless telephone of the present embodiment.  
         [0018]    As shown in the figure, a cordless telephone  10  is composed of a base set  20  and a handset  30 . The handset  30  is composed of an audio unit  31  comprising a microphone and a speaker to function as a speakerphone, a wireless unit  32  for wireless communication with the base set  20 , a display unit  33  for displaying dial numbers and the like, operation keys  34  for inputting telephone number or the like, and a power source unit  35  comprising, for example, a secondary battery. The wireless unit  32  comprises a receiving unit and a transmitting unit comprising a synthesizer and a digital modem (not shown in the figure).  
         [0019]    On the other hand, the base set  20  is a telephone equipped with a speaker, which is composed of a speakerphone functional unit  200  and a base set body (telephone body)  210 . The speakerphone functional unit  200  is a functional unit comprising a microphone  202  and a speaker  203  as the main components and can be freely attached to and detached from the base set body  210  via a connection unit  40 , for example, a connector. The speakerphone functional unit  200  is composed of a microphone  202  for inputting the caller&#39;s voice, a speaker  203  for amplifying the received voice and producing a loud-speaker output, a control unit  204  for conducting exchange of control signals with a control unit  214  of the base set body  210  via a control channel, a wireless unit  201  for conducting wireless communication with the base set body  210 , operation keys  207  for conducting key input, a power source unit  205  comprising a battery such as a secondary battery, and an attachment detector  206  for detecting the attachment of the speakerphone functional unit  200  to the base set body  210 . The wireless unit  201  comprises a receiving unit and a transmitting unit comprising a synthesizer and a digital modem.  
         [0020]    The base set body  210  is composed of an audio unit  213  for digitally processing the transmitted voice that was input in the microphone  202 , amplifying the received voice, and loud-speaker outputting the amplified voice from the speaker  203 , the control unit  214  for conducting exchange of control signals with the speakerphone functional unit  200  via a control channel, the wireless unit  212  for conducting wireless communication with the handset  30  or the speakerphone functional unit  200 , operation keys  218  for conducting key input, a display  211  for displaying the dial number or the like, a power source unit  215  for distributing the powder supplied from an AC power source to each circuit, an interface circuit  216  connected to a subscriber line, and an attachment detector  217  for detecting the attachment of the speakerphone functional unit  200  and the base set body  210 .  
         [0021]    When the speakerphone functional unit is attached to the base set body  210 , it functions as a usual speakerphone, and a person can speak over the phone, without holding the handset. At this time, transmission and reception of various signals (voice signals, controls signals) between the speakerphone functional unit  200  and the base set body  210  and power supply from the base set body  210  to the speakerphone functional unit  200  are conducted via the connection unit  40 . More specifically, the microphone  202  and the speaker  203  and connected with the audio unit  213  to receive and transmit voice signals, and the control unit  204  is connected to the control unit  214  to receive and transmit control signals. The power source unit  205  receives power supply from the power supply unit  215  and accumulates power supplied to each circuit (wireless unit  201 , microphone  202 , and the like).  
         [0022]    On the other hand, when the speakerphone functional unit  200  is detached from the base set body  210 , the speakerphone functional unit  200  conducts transmission and reception of voice signals to and from the base set body  210  via a wireless circuit. More specifically, the transmission voice that was input in the microphone  202  is transmitted into the audio unit  213  via the wireless circuit, digitally processed and thereafter transmitted to the telephone receiver of the call receiving party. Furthermore, voice generated by the other party is transmitted from the audio unit  213  via the wireless circuit to the speakerphone functional unit  200  and loud-speaker output from the speaker  203 . With such a configuration, communication becomes possible in any location, without any specific limitation, provided that the location of the speakerphone functional unit  200  allows for wireless communication with the base set body  210 .  
         [0023]    The speakerphone functional unit  200  and the base set body  210  are provided with respective attachment detectors  206 ,  217  for detecting the attachment state thereof. If the attachment detectors  206 ,  217  detect that the speakerphone functional unit  200  is detached from the base set body  210 , the speakerphone functional unit  200  automatically opens the wireless circuit between itself and the base set body  210 , and communication between the speakerphone functional unit  200  and the base set body  210  is established. As a result, even when the speakerphone functional unit  200  is detached during communication via the base set  20 , the communication can be maintained using the speakerphone functional unit  200 , without breaking the communication circuit. Obviously, when the speakerphone functional unit  200  is attached to the base set body  210 , a wireless circuit between the speakerphone functional unit  200  and the base set body  210  is disconnected, and the voice signals and control signals are transmitted and received directly via the connection unit  40 .  
         [0024]    A microphone and a speaker identical in size to those that have been installed in the conventional base sets can be directly used as the microphone  202  and the speaker  203 . Therefore, the speaker sound volume of the speakerphone functional unit  200  detached from the base set body  210  is identical to the speaker sound volume obtained when the speakerphone functional unit is arranged on the base set body  210 . Furthermore, because the power source unit  205  is charged to a capacity sufficient to conduct wireless communication over a sufficiently long time, an independent battery drive is possible and communication performance identical to that of the speakerphone of the conventional base set is ensured.  
         [0025]    [0025]FIG. 2 is a plan view of the speakerphone functional unit  200 . FIG. 3 is a side view of the speakerphone functional unit. As shown in FIG. 2, a body unit  208  constituting the main part of the speakerphone functional unit  200  has the microphone  202 , the speaker  203 , and the operation keys  207  provided therein. Further, as shown in FIG. 3, the body unit  208  is rotatably supported on a rotary shaft  209   a  with respect to a base  209 , thereby allowing the orientation of the microphone  202  and the speaker  203  to be varied freely. With such a configuration, even when the directional microphone  202  and speaker  203  are used, for example, conversation can be conducted with good sensitivity if a large number of people change appropriately the orientation of the microphone  202  and speaker  203  in a conference room or the like.  
         [0026]    As described hereinabove, in accordance with the present embodiment, the speakerphone functional unit  200  is constructed to be detachable from the base set body  210  and wireless communication with the base set body  210  is enabled, while allowing for an independent battery drive. As a result, the speakerphone functional unit  200  can be used without placing limitation on the lay-out location of the subscriber line. Furthermore, the telephone is very convenient because the base set  20  can be used as the usual speakerphone when the speakerphone functional unit  200  is attached to the base set body  210 . Moreover, if detachment of the speakerphone functional unit  200  and the base set body  210  is detected with the attachment detectors  206 ,  217 , even during the conversation via the base set  20 , a wireless circuit is automatically opened therebetween and transmission and reception of voice signals can be conducted, thereby providing for excellent convenience.