Patent ID: 6847833

Claim:
A hand free device commonly shared by multiple communication devices, comprising a micro processor, one or more than one Input/Output or I/O interfaces, a multiplexer control unit, one or more than one multiplexers, a voice processing unit, a speaker amplifying and control unit, a microphone amplifying circuit, a dialing unit, a charging and power supply unit and an artificial interface, working in combination with a speaker and a microphone; wherein said micro processor is used to coordinate the operation of an individual circuit of all units of said hand free device; said one or more than one I/O interfaces of communication devices is controlled by said micro processor to convert input signals from said communication devices of various types and brands into manageable signals for the use of rear terminals; said artificial interface enables a user to input operational settings; said one or more than one multiplexers have respectively at least one or more than one logic switch controlled by flagpole signals of said multiplexer control unit to judge that part or whole signals of said communication devices are able to be input or output via said logic switch; said multiplexer control unit is subject to the control of said microprocessor to control by means of flag poles the operation of said multiplexers; said voice processing unit subject to the control of said microprocessor is used to regulate the input and output of voice; said speaker amplifying and control unit under the control of said microprocessor receives and amplifies voice signals transmitted from said voice processing unit to control a speaker to broadcast the processed voice; said microphone amplifying circuit is used to amplify acoustic signals input from said microphone for the use of rear end; said charging and power supply unit subject to the control of the microprocessor supplies electrical power to said communication devices and charges batteries thereof; said dialing unit can cooperate with a matrix of press buttons, a voice controlled input device to permit a user to make direct dialing operation without use of original pressing buttons on said communication devices; whereby a single hand free device can be simultaneously coupled to more than one communication devices.