Abstract:
There is provided a portable communication device for minimizing the SAR of electromagnetic waves. In the portable communication device, a slim upper housing has an FBC on which a keypad is mounted, a lower housing is vertically spaced from the slim upper housing by a predetermined distance and includes a PCB assembly, and a middle housing is positioned between the slim upper housing and the lower housing, spatially isolated from the lower housing by a separation plate to minimize the adverse effects of electromagnetic waves generated from the PCB assembly, and has a slot opened from the front end to hold an object in the lengthwise direction. A sliding battery pack is insertable to and detachable from the middle housing in the lengthwise direction.

Description:
PRIORITY  
         [0001]    This application claims priority to an application entitled “Portable Communication Device for Minimizing Specific Absorption Rate (SAR) Value of Electromagnetic Waves” filed in the Korean Industrial Property Office on Jun. 7, 2001 and assigned Serial No. 2001-31614, the contents of which are hereby incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to a portable communication device such as a cellular phone or a PDA (Personal Digital Assistant), and in particular, to a portable communication device for minimizing the SAR of electromagnetic waves.  
           [0004]    2. Description of the Related Art  
           [0005]    A portable communication device generally refers to a portable device like a cellular phone, a PDA, a laptop computer, etc. A mobile station like a cellular phone is a portable terminal that can provide wireless communication services to a user by wirelessly communicating with a base station.  
           [0006]    Electronic parts for the portable terminal become smaller and more lightweight along with the present trend of the portable terminal toward high sensitivity and miniaturization. Such portable terminals are classified into a bar type, a flip type, and a folder type according to appearances, or a neck-wearing type and a wrist type according to where they are carried.  
           [0007]    Among popular portable terminals, a cellular phone will be taken as an example. FIG. 1 is a perspective view of a conventional cellular phone and FIG. 2 is a partial cut-out sectional view of the interior stack structure of the conventional cellular phone.  
           [0008]    Referring to FIG. 1, the cellular phone includes a data input device  104 , a data output device  103 , an antenna  101 , a transmitter  105 , a receiver  102 , and a battery pack  20 , all of which are contained in a body housing  10 . A keypad is usually used as the data input device  104  and an LCD (Liquid Crystal Display) module as the data output device  103 . A microphone is used as the transmitter  105  and an earpiece including a speaker is used as the receiver  102 . The battery pack  20  is composed of a plurality of battery cells (not shown) and generally detachable from the body housing  10  to be recharged when power is used up.  
           [0009]    The data input and output devices  104  and  103 , the transmitter  105 , the receiver  102 , and the antenna  101  are installed at appropriate positions of the body housing  10  and the battery pack  20  is detachably installed under the body housing  10 .  
           [0010]    Referring to FIG. 2, the interior structure of the body housing  10  will be described. Along a vertical direction, the keypad  104  and the LCD module, and the transmitter/receiver are disposed on the top end of the body housing  10  and the battery pack is detachably installed on the bottom end of the body housing  10 . A PCB (Printed Circuit Board) assembly PBA 1  having circuit parts is located between the keypad  104  and the battery pack  20 .  
           [0011]    The keypad  104  has a plurality of silicon rubber keys  104   a  with key tops  104   c  exposed outward from the body housing  10  to be pressed by a user for data entry. Located on PBA 1  are a plurality of button switches  104   b  that correspond to the plurality of rubber keys  104   a.    
           [0012]    This keypad  104  is connected to the PCB assembly PBA 1  to input data a user presses on a key top  104   c , which depresses rubber key  104   a  into switch  104   b . The battery pack  20  is detachable from the bottom end of the body housing  10 . Connection ports (not shown) are separately provided on the bottom end of the body housing  10  and the top end of the battery pack  20 . When the battery pack  20  is mounted to the body housing  10 , the connection between the connection ports establish a path for supplying power to the body housing  10 , particularly the PCB assembly PBA 1 .  
           [0013]    A key frame for the body housing  10  has a plurality of holes for holding the key tops  104   c  of the keypad  104 . This layout results in the emission of electromagnetic waves from the PCB assembly PBA 1  through the holes as shown by the arrows on FIG. 2. The electromagnetic waves of the portable terminal eminate from its PCB assembly with a multitude of circuit parts and chips. Those electromagnetic waves have adverse effects on the human body.  
           [0014]    In addition, as the portable communication devices become miniaturized by making them thinner, heat emitted from a PCB assembly in a housing is transferred to the head, ear, mouth, or hand of the user, making it inconvenient to converse on the phone.  
         SUMMARY OF THE INVENTION  
         [0015]    It is, therefore, an object of the present invention to provide a portable communication device with a battery pack located between a keypad and a PCB assembly and removable therefrom.  
           [0016]    It is another object of the present invention to provide a portable communication device for minimizing the electromagnetic waves emitted from a PCB.  
           [0017]    It is a further object of the present invention to provide a portable communication device with a PCB assembly at a maximum distance from the head of a user during a call, as compared to a conventional portable communication device.  
           [0018]    The above and other objects can be achieved by providing a portable communication device. The portable communication device has a body housing and a sliding battery pack. The body housing includes a slim upper housing with an FBC (Flexible Printed Board Circuit) on which a keypad is mounted, a lower housing vertically spaced from the slim upper housing by a predetermined distance and including a PCB assembly, and a middle housing between the slim upper housing and the lower housing, spatially isolated from the lower housing by a separation plate to minimize the adverse effects of electromagnetic waves generated from the PCB assembly, and having a slot opened from the front end to hold an object in the lengthwise direction. The sliding battery pack is insertable to and detachable from the middle housing in the lengthwise direction. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:  
         [0020]    [0020]FIG. 1 is a perspective view illustrating the exterior of a conventional cellular phone;  
         [0021]    [0021]FIG. 2 is a partial cut-out sectional view illustrating the interior stack structure of the conventional cellular phone;  
         [0022]    [0022]FIG. 3 is a perspective view of a portable communication device with a sliding battery pack according to an embodiment of the present invention;  
         [0023]    [0023]FIG. 4 is a partial cut-out sectional view illustrating the interior stack structure of the portable communication device according to an embodiment of the present invention;  
         [0024]    [0024]FIG. 5 is a perspective view of an embodiment of a sliding battery pack with a connection port at the front end thereof, insertable/detachable into/from the portable communication device according to an embodiment of the present invention;  
         [0025]    [0025]FIG. 6A is a frontal view of the battery pack shown in FIG. 5;  
         [0026]    [0026]FIG. 6B is a rear view of the battery pack shown in FIG. 5;  
         [0027]    [0027]FIG. 7 is a schematic view of a locking device for the sliding battery pack according to an embodiment of the present invention;  
         [0028]    [0028]FIG. 8 is a sectional view illustrating a first connection mechanism for the sliding battery pack according to an embodiment of the present invention;  
         [0029]    [0029]FIG. 9 is a plan view of the sliding battery pack with a connection port positioned at a bottom corner thereof according to a second embodiment of the present invention; and  
         [0030]    [0030]FIG. 10 is a sectional view illustrating a second connection mechanism for the sliding battery pack shown in FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    Preferred embodiments of the present invention will be described hereinbelow with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.  
         [0032]    [0032]FIG. 3 is a perspective view of a portable communication device according to the present invention.  
         [0033]    Referring to FIG. 3, the portable communication device includes a body housing  30  and a sliding battery pack  40  detachable in a lengthwise direction as indicated by the bi-directional arrow charging port  410  is shown located on the front end of battery pack  40 .  
         [0034]    The body housing  30  has top and bottom ends  30   a  and  30   b , front and rear ends  30   c  and  30   d , and two side ends  30   e  and  30   g . The sliding battery pack  40  is mounted or detached in the lengthwise direction indicated by the bi-directional arrow.  
         [0035]    Referring to FIG. 4, the body housing  30  is divided into an upper housing  300   a , a lower housing  300   c , and a middle housing  300   b  between the upper and lower housings  300   a  and  300   c , which are separated from one another by separation plates P 1  and P 2 . Especially, the middle housing  300   b  is entirely isolated from the lower housing  300   c  by the separation plate P 2 .  
         [0036]    Referring again to FIG. 3 and FIG. 4, an earpiece  301 , an LCD module  302 , a keypad  303 , and a microphone  304  are mounted on the top end  30   a  of the upper housing  300   a , a PCB assembly PBA 2  with chips is included in the lower housing  300   c , and the middle housing  300   b  has space for holding the sliding battery pack  40 .  
         [0037]    The upper housing  300   a  and the lower housing  300   c  are formed with a plastic casing frame and the middle housing  300   b  has an open space, that is, a slot S.  
         [0038]    As described before, the keypad  303  is mounted on the upper housing  300   a . The keypad  303  includes silicon rubber keys  303   a  with key tops  303   b  exposed outward from the top end  30   a  of the housing  30  and metal domes D which are brought into contact with an FBC (Flexible printed Board Circuit) when the silicon rubber keys  303   a  are pressed. The silicon rubber keys  303   a  and the metal domes D are well known to those skilled in the art.  
         [0039]    Since the separated upper, middle, and lower housings  300   a ,  300   b , and  300   c  are integrally formed and especially the middle housing  300   b  and the lower housing  300   c  are entirely separated by the separation plate P 2 , electromagnetic waves adverse to the human body generated from the PCB assembly PBA 2  are grounded in the lower housing  300   c  without penetrating into the middle housing  300   b  or the upper housing  300   a.    
         [0040]    Now there will be given a description of the structure of the sliding battery pack detachable from the body housing according to the present invention referring to FIGS. 5, 6A, and  6 B. FIG. 5 is a perspective view illustrating the exterior of the sliding battery pack according to the embodiment of the present invention and FIGS. 6A and 6B are frontal and rear views of the sliding battery pack shown in FIG. 5.  
         [0041]    As shown in FIGS. 5, 6A, and  6 B, the sliding battery pack  40  has top and bottom ends  40   a  and  40   b , front and rear ends  40   c  and  40   d , and two side ends  40   e  and  40   g . Charging port  410  is disposed on the front end  40   c  to recharge the battery and a female interface connector  414  is under the charging port  410  for charging by use of a male interface connector (not shown). A connection port  412  is disposed on the rear end  40   d  for electrically connecting to the PCB when the sliding battery pack  40  is locked in the slot of the body housing. The connection structure of the connection port  412  will be described later.  
         [0042]    Locking grooves  40   f  are formed on both side ends  40   e  and  40   g  of the sliding battery pack  40  to maintain its mounted/connection state when the sliding battery pack  40  is completely inserted into the slot.  
         [0043]    The locking device of the sliding battery pack according to the preferred embodiment of the present invention will be described with reference to FIG. 7. As shown in FIG. 7, the locking device functions to mount the sliding battery pack  40  in the middle housing  300   b  and retain the battery pack  40  within the middle housing  300   b . The sliding battery pack  40  has the locking grooves  40   f  on both ends and lockers  306  in the vicinity of the rear end of the middle housing  300   b  to lock the sliding battery pack  40  in the middle housing  300   b  in cooperation with the locking grooves  40   f.    
         [0044]    Each of the lockers  306  has a hinge shaft H. One end  306   a  of the locker  306  is exposed from an end  30   e  of the body housing  30 , and the other end  306   b  thereof is shaped into a hook to be inserted into or removed from a locking groove  40   f . An identical configuration is on end  30   g . Therefore, a predetermined opening  30   f  is formed at the body housing end  30   e  and  30   g  to hold the end  306   a  of the locker  306 .  
         [0045]    When the sliding battery pack  40  is pushed into slots, the rear end  40   d  of the sliding battery pack  40  advances against the ends  306   b  of the lockers  306  which rotate slightly in the counterclockwise direction about the hinge shafts H. The ends  306   b  of the lockers  306  are slanted to allow ease of insertion of battery pack  40  and rotation of lockers  306  about hinge shafts H. By further pushing the sliding battery pack  40 , the ends  306   b  of the lockers  306  rotate in the clockwise direction and insert into the locking grooves  40   f . A spring  307  provides restoring force to the ends  306   b  of the lockers  306 . The ends  306   b  of the lockers  306  have inclined portions to slide against the rear end of the sliding battery pack  40 .  
         [0046]    To detach the sliding battery pack  40 , the ends  306   a  of the lockers  306  are pressed in the direction of the arrow shown in FIG. 7. The lockers  306  slightly rotate in the counterclockwise direction around the hinge shafts H and the ends  306   b  of the lockers  306  are completely removed from the locking grooves  40   f . In this state, a user pulls the sliding battery pack  40  from the slot in the lengthwise direction.  
         [0047]    Referring to FIG. 8, the electrical connection between the sliding battery pack and the FBC and the PCB will be described. In FIG. 8, the LCD module  302  and a speaker SPK are mounted on the FBC and the sliding battery pack  40  is inserted into the middle housing  300   b.    
         [0048]    If the sliding battery pack  40  is maintained in a locked state in the slot by the lockers  306 , the connection port  412  (not shown) of the sliding battery pack  40  is connected to a connection port c at the rear portion of the middle housing  300   b . The connection port c is connected to a connector C 3  of the PCB assembly PBA 2  through connectors C 1  and C 2 . Connector C 2  connects to the FBC.  
         [0049]    In this connection mechanism, the connector C 2  connected to an end of the FBC in the upper housing  300   a  is connected to the connector C 3  of the PCB assembly PBA 2 .  
         [0050]    [0050]FIG. 9 is a plan view of a sliding battery pack  50  with the connection port c 2  positioned in the vicinity of a corner of the bottom end  50   d  according to a second embodiment of the present invention and FIG. 10 is a sectional view illustrating a second connection mechanism for the sliding battery pack shown in FIG. 9.  
         [0051]    As shown in FIGS. 9 and 10, when the sliding battery pack  50  is inserted into the slot, the connection port c 2  is connected to a protruding connection port c 3  so that the sliding battery pack  50  is connected to a PCB assembly PBA 3 . Many variations of connecting the battery pack to the main unit are contemplated.  
         [0052]    Consequently, heat and electromagnetic waves are blocked during a call by positioning the PCB assembly remotely from a human body.  
         [0053]    In accordance with the present invention as described above, a battery pack for power supply is held between an upper housing and a lower housing and a PCB assembly generating electromagnetic waves is mounted on the lower housing. Therefore, the adverse effects of the electromagnetic waves are minimized. Remote position of the PCB assembly from the head of a user during a call adds to the minimization of adverse effects of the electromagnetic waves on the human body and makes it more convenient to talk on the phone.  
         [0054]    While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.