Abstract:
A hand-free device equipped with expansion function modules allows a basic hand-free handset to attach expansion function modules depending on users&#39; requirements so that the existing hand-free handset can be upgraded to equip additional or new function without obsolete. The invention consists of a hand-free main body and externally connected expansion function modules of various function desired. The function may be selected based on users&#39; requirements such as GPS, PDA enabling, or audio control dialing, etc.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a hand-free device that equips with expansion function modules and particularly a hand-free handset that has basic hand-free capability and is allowed to add expansion function modules to include additional function based on users&#39; requirements to avoid mobile phones or m hand-free handsets from obsolete because of lack of certain function.  
           [0003]    2. Description of the Prior Art  
           [0004]    Mobile phones have become very popular in many countries around the world nowadays. Hand-free handset is a widely used peripheral device for mobile phones and in many countries also becomes an essential gadget in the cars under government regulations. In recent years, mobile phones and hand-free handsets have also become fashionable products. New function and enhancements have been added and updated at a very fast pace. As a result, mobile phones or hand-free handsets tend to become obsolete whenever there is new function or feature introduced and marketed. As the inherent function of the mobile phone or hand-free handset are set and built-in in the plant, once shipped, they cannot be altered or upgraded. For instance, there are new function of adding mobile phone extension, PDA, electronic telephone directory, access the Internet, audio control, etc. When consumers want to enjoy these new function, they often have to throw away the old mobile phones or hand-free handsets. It is a huge waste of resources.  
         SUMMARY OF THE INVENTION  
         [0005]    In view of aforesaid disadvantages, it is therefore a primary object of the invention to provide a hand-free handset that includes a hand-free main body which may attach optional and selected expansion function modules (such as GPS function, PDA function or audio dialing function or the like) so that users can add various expansion function modules whenever desired without replacing the existing mobile phones or hand-free handsets.  
           [0006]    By means of the invention, users can add additional expansion function modules on the hand-free handsets depending on their different requirements so that users can enjoy new and expanded function on the old or existing hand-free handsets.  
           [0007]    The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a structural block diagram of an embodiment of the invention.  
         [0009]    [0009]FIG. 2 is a schematic block diagram of an embodiment of the invention.  
         [0010]    [0010]FIG. 3 is a block diagram of an embodiment of the invention for upgrading to equip car phone function.  
         [0011]    [0011]FIG. 4 is a block diagram of an expansion function module of the invention.  
         [0012]    [0012]FIG. 5 is a schematic block diagram of an expansion function module of the invention for upgrading to equip car phone function. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    Referring to FIG. 1 for an embodiment of the invention that has a hand-free main body  10  externally attached to an expansion function module  20  of various function, the hand-free main body  10  consists of a central processing unit  101 , a power supply management unit  102 , a power supply input muting control unit  103 , a power amplifier  104 , an audio frequency amplifier  105 , a digital signal processing unit  106 , a module detection and control unit  107 , a charging unit  108 , a relay switch  109 , a front amplification unit  110 , a signal switch unit  111 , and a connection unit  112 .  
         [0014]    The central processing unit  101  controls operations of all units in the device.  
         [0015]    The power supply management unit  102  is controlled by the central processing unit  101  for selecting different power supply (such as battery or car electric power).  
         [0016]    The power supply input muting control unit  103  is controlled by the central processing unit  101  for controlling car audio device to cut off power supply or switch to a muting condition.  
         [0017]    The power amplifier  104  is controlled by the central processing unit  101  for processing and amplifying signals output by the digital signal processing unit  106 .  
         [0018]    The audio frequency amplifier  105  is controlled by the central processing unit  101  for amplifying audio signals output by the digital signal processing unit  106  and delivering to an earphone S for output.  
         [0019]    The digital signal processing unit  106  processes input audio source (such as eliminate echo voice, noise processing, etc.)  
         [0020]    The module detection and control unit  107  detects and controls external variations of the expansion function modules, and provides the signals to the central processing unit  101 .  
         [0021]    The charging unit  108  provides desired charge voltage and current output to mobile phones of different brands.  
         [0022]    The relay switch  109  links to car audio device output and car audio device speakers, and switches circuits of different audio outputs.  
         [0023]    The front amplification unit  110  processes audio input from the microphone (such as amplifying the sound).  
         [0024]    The signal switch unit  111  switches signals depending on different linking expansion function modules.  
         [0025]    The connection unit  112  has at least one set to link a mobile phone rear end signal line to an output unit  24  of the expansion function module.  
         [0026]    By means of the architecture and construction set forth above, the hand-free main body  10  can attach at least one expansion function module  20  (as shown in FIG. 4). Each expansion function module  20  includes at least a control unit  21 , a coding/decoding unit  22 , an input unit  23 , an output unit  24  and an expansion function unit  25 .  
         [0027]    The control unit  21  controls and coordinates operations of the expansion function module  20  and outputs signals, and coordinates operations of the hand-free main body  10 .  
         [0028]    The coding/decoding unit  22  coordinates operations of the signal switch unit  111  of the hand-free main body  10  (generally conforms to RS232 communication protocol).  
         [0029]    The input unit  23  is an input end linking to the connection unit  112  of the main body  10  to function as a human machine interface.  
         [0030]    The output unit  24  is an output end to output information of the expansion function module (such as displaying data, sound, etc.), and may be a display device, LCD, signal line, etc.  
         [0031]    The expansion function unit  25  contains preset expansion function data, such as GPS, audio control dialing, PDA, infrared light transmission, car phone, etc.  
         [0032]    By means of aforesaid construction, the hand-free main body  10  can connect respectively through the connection unit  112  to a mobile phone P and the input unit  23  of the expansion function module  20 . Then the hand-free handset can equip additional function provided by the expansion function module  20  (such as upgrade the mobile phone P to equip GPS function when the expansion function module  20  is a GPS device; or equip the mobile phone P with audio control dialing capability when the expansion function module  20  has audio control dialing function thereby to overcome the deficiency of no audio control dialing function of the original hand-free).  
         [0033]    Referring to FIG. 2 for an embodiment of the invention linking to a mobile phone without the expansion function module, and with the mobile phone receiving incoming telephone calls and delivering audio output through the speaker of the car audio device. When in use, one end of the mobile phone signal line is plugged in the mobile phone P and another end of the signal line is plugged in the connection unit  112  of the invention  10 . The central processing unit  101  outputs control signals to the charging unit  108  for outputting desired voltage to the mobile phone P for operation and charging. When the mobile phone P receives an incoming phone call, through the signal line and the linked connection unit  112 , the central processing unit  101  is notified. Then through the power supply input muting control unit  103 , the car audio device is turned off or switched to a silence state. And through the relay switch  109 , the input of the speaker SP of the car audio device is switched to the invention so that user&#39;s conversation may be output through the speaker SP, and the microphone M may be used for entering input voice to do conversation.  
         [0034]    Thus by means of the invention users may base on their requirements to add at least one expansion function module of various function to upgrade the original hand-free main body or mobile phone to equip additional function not available originally.  
         [0035]    [0035]FIGS. 3 and 5 illustrate another embodiment of the invention for linking a car phone expansion function module  40  to equip the hand-free main body  10  with car phone function. The car phone expansion function module  40  consists of a control unit  41 , a coding/decoding unit  42 , an input unit  43 , an output unit  44  and an expansion function unit  45 .  
         [0036]    The control unit  41  controls and coordinates operations of the car phone expansion function module  40  and outputs signals, and coordinates operations with the hand-free main body  10 .  
         [0037]    The coding/decoding unit  42  matches operations and coordination of the signal switch unit  111  of the hand-free main body  10 .  
         [0038]    The input unit  43  is an input end linking to the connection unit  112  of the main body  10 .  
         [0039]    The output unit  44  is an output end to output dialing and conversation information for the expansion function module  40 .  
         [0040]    The expansion function unit  45  has car phone expansion function and includes:  
         [0041]    a power supply processing unit  451  for controlling power supply of the expansion function module  40 ,  
         [0042]    a GSM module unit  452  which is a communication module matching mobile phone chips; and  
         [0043]    a DTMF unit  453  to allow the expansion function unit  45  dialing telephone through audio frequency.  
         [0044]    When attaching the car phone expansion function module  40  to the hand-free main body  10 , users may insert the mobile phone chips supplied by the mobile phone service providers in the GSM module  452 , then the hand-free hand set of the invention can equip car phone function, and can avoid the mobile phone connection line matching specification problem that might otherwise happen. When in use, the module detection and control unit  107  may detect output signals from the output unit  44  of the car phone expansion function module  40 , and notify the central processing unit  101  to output control (or matching) signals so that users may use the input unit  43  to activate dialing or receiving the incoming call. And the expansion function module  40  can communicate with the hand-free main body  10  through the output unit  44 , input unit  43  and connection unit  112  (including output/input voice, control signals, etc.).  
         [0045]    By means of the hand-free device equipped with expansion function modules of the invention set forth above, users may freely configure expansion function modules of different function depending on their requirements to allow communication products constantly upgrade and function as desired without obsolete because of fashion changes.  
         [0046]    While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.