Abstract:
A switching control device for transmitting calls received by a cellular phone to a fixed-network telephone enables people to receive calls transmitted to a cellular phone by way of a fixed network telephone particularly equipped with a plurality of extension lines via conversion operations. It operates with a cellular phone/fixed network telephone switching device in cooperation with an on/off device. When a cellular phone receives an incoming call, the switching device will first detect the main telephone set and its extension lines of their individual status of use; and the on/off device is selectively actuated of its on and off states and also its vibration ring operation according to the detection. Thereby a user can pick up a nearest extension line without rushing back to a main telephone set when an incoming call is transmitted to a cellular phone.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a switching control device for transmitting calls received by a cellular phone to a fixed network telephone. Such a device enables people to receive calls transmitted to a cellular phone via a fixed network telephone particularly equipped with a plurality of extension lines by conversion operations. The present invention operates with a cellular phone/fixed network telephone switching device in cooperation with an on/off device. When a cellular phone receives an incoming call, the switching device will first detect the main telephone set and its extension lines of their individual status of use; and the on/off device is selectively actuated of its on and off states and vibration ring operation according to the detection. Thereby a user can pick up a nearest extension line without rushing back to a main telephone set when an incoming call is transmitted to a cellular phone. 
     Cellular phones have been widely and popularly used by people in modern cities all over the world because they make instant communication possible at any places and any time, facilitating people in everyday life. However, the frequent use of cellular phones do cause bad effect on people&#39;s health, especially microwaves can cause people&#39;s brains damaged without notice. So, the use of cellular phones brings crisis to people&#39;s health. In such a situation, people aware of the danger of using cellular phones try to reduce the frequency of use of cellular phones indoors, they will use cellular phones only outdoors. But many important personal contacts are generally made via cellular phones at homes or in offices, and turning off cellular phones can cause personal communication inconvenient. In that case, people are forced to make use of cellular phones all the time even inside houses with common telephones. To make cellular phones adapted to be operable on an indoor fixed-network telephone, such as at homes and in offices, has been a major concern by people. Such a fixed-network telephone can transform cellular phone calls into communication via the fixed-network telephone. 
     The conventional device for effecting such a communication transformation is illustrated in FIG.  1 . It mainly includes a switching device  11  to which a cellular phone T is to be in inserting connection. Then the switching device  11  is coupled to a fixed network telephone  12  so that incoming calls of the cellular phone T can be transmitted via transformation operations of the switching device  11  to the fixed network telephone  12 . When such a switching device  11  is applied to a fixed network telephone with extension lines, there are several problems found in practical use. Referring first to FIG. 2 which shows the wire arrangement of a fixed network telephone with a number of extension lines. The fixed network wiring  3  mainly comprises a main line  30  branched into a main telephone set  32  and several extension lines  33 ,  34 ,  35 ; and only the main telephone set  32  is equipped with a cellular phone/fixed network telephone switching device  31 . Once an incoming call is transmitted to the cellular phone T, a person can only receive the call by way of the main telephone set  32 . The remaining extension lines will not receive any vibration ring signals at all. Thus, the extension lines become useless in such a situation. This will force a person to rush to the place where the main telephone set  32  is located. Such a problem makes the prior switching device a major disadvantage in use. 
     SUMMARY OF THE INVENTION 
     Therefore, the primary object of the present invention is to provide a switching control device for transmitting a cellular phone call to a fixed-network telephone particularly equipped with extension lines in such a manner that people can get a transformed call at the nearest extension line without rushing back and forth in an office or at home. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective diagram showing a conventional cellular phone/fixed network telephone switching device; 
     FIG. 2 shows the conventional switching device applied to a fixed network telephone with a plurality of extension lines; 
     FIG. 3 shows the switching control device of the present invention applied to a fixed network telephone with a plurality of extension lines; 
     FIG. 4 is the block diagram of the electric circuit of the cellular phone/fixed network telephone switching control device of the present invention; 
     FIG. 5 is the block diagram of the electric circuit of the on/off device of the present invention; 
     FIG. 6 is a first control flow chart of the switching device of the present invention; 
     FIG. 7 is a second control flow chart of the present invention; 
     FIG. 8 is a control flow chart of the on/off device of the present invention; 
     FIG. 9 is a diagram showing the circuit of the present invention in combination with a fixed network telephone; 
     FIG. 10 is a diagram showing the second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 3-5, the present invention mainly has a cellular phone/fixed network telephone switching device  5  which operates in combination with an on/off device  6 . The cellular phone/fixed network telephone switching device mainly includes a cellular phone mount  50 , an acoustic frequency signal amplifying unit  51 , a fixed network telephone signal transformation unit  52 , a fixed network telephone/cellular phone switching unit  53 , an incoming call detecting unit  54 , a charger unit  55 , a central control unit  56 , an on state signal generating unit for on/off device  57 , an on state/off-hook state detecting unit  58  and an on/off state control unit  59 . 
     The cellular phone mount  50  is used to house a cellular phone T which is coupled by wire to the switching device  5  and is connected to an antenna  501 . 
     The acoustic frequency signal amplifying unit  51  is used to properly amplify the output or input acoustic frequency signals of a cellular phone. If the level of the acoustic input and output of the cellular phone is close to that of the fixed network telephone, then the amplifying rate of the acoustic frequency signal amplifying unit  51  is equal to one. 
     The fixed network telephone signal transformation unit  52  is used to converting input and output acoustic frequency signals of a cellular phone into acoustic frequency signals compatible with specifications of a fixed network telephone. 
     The fixed network telephone/cellular phone switching unit  53  is responsible for selective switching connection between a fixed network communication or cellular phone communication to a fixed-network telephone  4  and is subject to the control of the incoming call detecting unit  54 . 
     The incoming call detecting unit  54  is used to detect if an incoming call is transmitted to a cellular phone; and if the cellular phone is being in communication so as to control the operational connection position of the fixed network telephone/cellular phone switching unit  53 . 
     The charger unit  55  is used to supply electrical power to a battery of the cellular phone T when it is put in a stand-by state. 
     The central control unit  56  operates according to the results of detection of the incoming call detecting unit  54  and the on state/off-hook state detecting unit  58  to control the actions of the on state signal generating unit for on/off device  57 , the on/off state control unit  59  and the fixed network telephone signal transformation unit  52 . 
     The on state signal generating unit for on/off device  57  is simplified in the present invention to be a grounding short circuit switch which serves as a short circuit signal generating device. It is controlled by the central control unit  56  to output the on state actuation signal of the on/off device  6 . 
     The on state/off-hook state detecting unit  58  is responsible for detecting the on and off state of the on/off device  6  and the off-hook state of the receiver of a telephone. 
     The on/off state control unit  59  receives control signals transmitted from the central control unit  56  to control the switching selection of the fixed network telephone/cellular phone switching unit  53 . 
     The on/off device  6  operates in collaboration with the cellular phone/fixed network telephone switching device  5  comprises an on/off command signal detecting unit for on/off device  61 , a vibration ring echo signal generating unit  62 , a central control and on/off control unit  63 , a vibration ring high voltage signal detecting unit  64  and a switching unit  65 . 
     The on/off command signal detecting unit for on/off device  61  is employed to detect the on/off state of the on/off device  6  for the use of the central control and on/off control unit  63 . 
     The vibration ring echo signal generating unit  62  is subject to the control of the central control and on/off control unit  63  to produce vibration ring echo signals. 
     The central control and on/off control unit  63  controls the on/off switching operation of the switching unit and controls the vibration ring echo signal generating unit  62  to produce vibration ring echo signals according to the detected signals of the vibration ring high voltage signal detecting unit  64  and the on/off command signal detecting unit for on/off device  61 . 
     The vibration ring high voltage signal detecting unit  64  is responsible for detecting the high voltage signals of the vibration ring. 
     The switching unit  65  is controlled by the central control and on/off control unit  63  to switch between on and off states of the on/off device. 
     By way of the assembly of the above components, when the cellular phone T is receiving an incoming call, the cellular phone/fixed network telephone switching device  5  will operate according to the following procedures, as shown in FIGS. 6,  7 . 
     1. The Detection of the Incoming Call of a Cellular Phone 
     When a cellular phone is receiving an incoming call, the incoming call detecting unit  54  will detect the incoming call and actuate the central control unit  56  to control over the on/off state control unit  59  and the fixed network telephone/cellular phone switching unit  53  to switch to the circuit of the fixed-network telephone  4 . At this moment, the connection A 1 , B 1 , C 1  and A 2 , B 2 , C 2  of the fixed-network telephone/cellular phone switching unit  53  is put in an OFF state. 
     2. Detecting an OFF-HOOK State 
     (1) When the on state/off-hook state detecting unit  58  detects that any one of the fixed network telephones  4  including the main telephone set  41  or the extension lines  42 ,  43 ,  44 ,  45  is put in an OFF-HOOK state, the central control unit  56  controls the on/off state control unit  59  to actuate the fixed network telephone/cellular phone switching unit  53  so as to switch the connection of B 1 , C 1  and B 2 , C 2  to an ON state. 
     (2) The main telephone set being in a communication state 
     As the main telephone set  41  is detected in a communication state, a call interruption signal is being issued to warn the user till the FLASH button (it functions identically to hang up a receiver and then pick it up again) is pressed for receiving. As a receiving action is completed with the receiver set in an ON-HOOK state or an incoming call detecting signal disappears and the on/off device  6  is set in an off state (if the on/off device  6  is in an on state, an on/off command signal for the on/off device is sent and received by the on/off command signal detecting unit for on/off device  61  so as to activate the central control and on/off control unit  63  to switch the connections D 1 , E 1 , D 2 , E 2  of the switching unit  65  to an OFF state), a stand-by state is resumed. 
     (3) An extension line is being used for communication (it means an extension line being taken up) 
     The on/off device  6  issues a high voltage signal to actuate the vibration ring of the main telephone set  41  to produce a ringing sound. As a receiver is detected to be picked up (in an OFF-HOOK state), the vibration ring stops. When a call action is completed (the receiver being put in an ON-HOOK state), or an incoming call detecting signal disappears and the on/off device is in an off state (if the on/off device  6  is in an on state, an on/off command signal for the on/off device is sent and received by the on/off command signal detecting unit for on/off device  61  so as to activate the central control and on/off control unit  63  to switch the connections D 1 , E 1 , D 2 , E 2  of the switching unit  65  to an OFF state), a stand-by state is resumed. 
     3. A non-communication State Being Detected 
     (1) When the on/off device  6  is detected in an on state (if the on/off device  6  is in an off state, the central control unit  56  actuates the on state signal generating unit for on/off device  57  to transmit a signal which is detected by the on/off command signal detecting unit for on/off device  61  so as to activate the central control and on/off control unit  63  to switch the connections D 1 , E 1 , D 2 , E 2  of the switching unit  65  to an OFF state), the on/off device  6  generates vibration ring high voltage signals to get the main telephone set  41  and the extension lines  42 ,  43 ,  44 ,  45  . . . to ring together. 
     (2) If an OFF-HOOK state is detected, then the vibration ring stops to operate; at this time, the connection lines between B 1 , C 1  and B 2 , C 2  of the fixed network telephone/cellular phone switching unit  53  are set in an ON state: 
     (A) if the main telephone set  41  is engaging in a receiving operation and the on/off device is in an off state (if it is in an on state, the on/off device  6  will be set in an off state by the on/off command signal generating unit of the on/off device), the internal circuit of the cellular phone/fixed network telephone main switching unit  5  is cut off if connection to the fixed network and the other extension lines are still in connection to the fixed network. 
     (B) If a phone call is received via the extension lines  42 ,  43 ,  44 ,  45  . . .  . . . , then the connection lines A 1 , B 1 , C 1  and A 2 , B 2 , C 2  of the fixed network telephone/cellular phone switching unit  53  are set in an off state and are connected to other extension lines network telephone/cellular phone switching unit  53 ; and D 1 , D 2 , E 1 , E 2  of the on/off device are put in an on state so as to make the main set and each extension line separated from the fixed network. 
     (3) After the completion of a communication, the receiver is put in an ON-HOOK state or the disappearance of a detection signal, and the on/off device is set in an off state (if it is in an on state, the on/off device  6  will be set in an off state by a on/off command signal generating unit), a stand-by state is resumed. 
     As to the on/off device  6 , it operates in the following procedures, as illustrated in FIG.  8 : 
     1. When an on/off command signal is detected and if the on/off device  6  is originally set in an off state, then the on/off device  6  is switched to an on state; and if the on/off device  6  is originally set in an on state, then it is switched to an off state. 
     2. If no on/off command signal is detected and a vibration ring signal is detected (indicating the fixed network is being used for communication), then a communication interrupting signal is issued to warn the user of a cellular phone that an incoming call is being received. 
     The proceeding practical embodiment shows application of the devices of the present invention combined with a general fixed network telephone. On the same theoretical ground, the devices  5 ′ of the present invention can be directly housed in a fixed network telephone P, as shown in FIGS. 9,  10 , so as to permit people already having a fixed network telephone not to replace the old fixed network telephone. 
     If a user is not equipped with a fixed network telephone at first, a new fixed network telephone can be purchased according with the following recommended embodiment. It is made up of a cellular phone mount  50 ′, an acoustic frequency signal amplifying unit  51 ′, a fixed network telephone signal switching unit  52 ′, a fixed network telephone/cellular phone switching unit  53 ′, an incoming call detecting unit  54 ′, a charger unit  55 ′, a central control unit  56 ′, an open circuit signal generating unit for on/off device  57 ′, an on state/off-hook detecting unit  58 ′, an on/off state control unit  59 ′. It is combined with a conventional fixed network telephone circuit to form a fixed network telephone P. All these components similar to those cited in the first embodiment are not repeatedly described. Thereby it provides a fixed network telephone P that can meet all the requirements of the present invention. 
     In summary, the present invention enables a cellular phone to receive calls via a fixed network telephone, and is particularly suitable for a fixed network telephone system having a plurality of extension lines.