Abstract:
A battery cover grounding device for a portable terminal including a metallic battery cover is provided. The grounding device includes a grounding member installed on the terminal to be connected to a grounding surface of the terminal and to be in contact with the battery cover. The grounding member has a cover protrusion formed on the battery cover and a grounding protrusion attached to the terminal to contact the cover protrusion. In this manner, the metallic battery cover is connected to the grounding surface of the terminal to minimize the possibility of current leakage, to improve the stability of the operation of the terminal, and to minimize potential malfunctions of the terminal due to static electricity.

Description:
PRIORITY 
       [0001]    This application claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Industrial Property Office on Oct. 30, 2006 and assigned Serial No. 2006-105690, the entire disclosure of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a portable terminal. More particularly, the present invention relates to a grounding device for a battery cover of a portable terminal. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, portable terminals are devices that provide users with mobile communication functions. In addition to being used for mobile communication functions, portable terminals are used as multi-functional devices, such as multimedia devices that reproduce music files, moving picture files and others, and financial service devices for micro payment, mobile banking, and the like. 
         [0006]    Portable terminals may be classified as bar-type, flip-type, and folder-type terminals according to their external shapes. Recently, slide-type terminals have emerged on the market and have garnered a large share of the market together with folder-type terminals. 
         [0007]    A bar-type terminal is a device in which an input unit (such as a keypad and a transmitter) and an output unit (such as a display and a receiver) are provided in a single housing. One advantage of bar-type terminals is that they have a simple construction with the installation of all components for mobile communication functions in a single housing. There is a limit to the miniaturization of bar-type terminals, however, because there must be a certain interval between the transmitter and the receiver for voice communication. 
         [0008]    A flip-type terminal is a device in which a flip cover is rotatably installed to a bar-type terminal. The flip cover prevents malfunctions by limiting access to the input unit (such as the keypad) when the terminal is in a call standby mode. Similar to bar-type terminals, there is a limit to the miniaturization of flip-type terminals due to the problem of securing a certain interval between the transmitter and the receiver. 
         [0009]    A folder-type terminal is a device in which a pair of housings are hingedly coupled to each other. For a long period, folder-type terminals have garnered most of the market for portable terminals because they may be miniaturized more easily because the input unit and output unit may be disposed on respective housings of the pair of housings to secure a sufficient interval between the transmitter and the receiver. 
         [0010]    A slide-type terminal has a pair of housings that are slidably coupled to each other such that the input unit and the output unit are separately disposed on respective housings of the pair of housings. In a slide-type terminal, in particular, the keypad in the input unit is opened or closed by relative sliding movement of the housings. This way, in a call standby mode, malfunctions are prevented, and in a calling mode, it is easy to secure an appropriate interval between the transmitter and the receiver. Thus, this makes it easier to miniaturize the slide-type terminal. This has allowed slide-type terminals to gather a large market share. 
         [0011]    These portable terminals include separate battery packs as power supplies. A typical installation space for a battery pack is configured such that the battery pack is installed by placing one end of the battery pack into the installation space, pivoting the battery pack into the installation space, and locking the battery pack into the installation space with a lock disposed on the other end of the battery pack. Another type of installation space is configured such that the battery pack is slidingly moved while being brought into contact with the terminal, is engaged with the terminal, and is then fixed thereto using a hook. 
         [0012]    Although efforts are being made to miniaturize portable terminals so that they are more portable, at the same time, portable terminals should have a display with a sufficient size to provide multimedia functions, such as watching broadcasting and reproducing moving pictures. Thus, in the case of a terminal with multimedia functions, the thickness of the terminal is reduced to make it light and compact while also providing a large size for the display. 
         [0013]    With a conventional installation structure for a battery pack (in which a battery fixing hole is provided at the terminal so as to detachably fix the battery pack), it is difficult to secure in a slim terminal sufficient space to form a protrusion, a hook, and the like to couple and fix the battery pack into the portable terminal. To address this, an installation space that receives a battery pack and protects it using a separate cover has been proposed. The battery cover for protecting the battery pack in the slim terminal is shaped like a flat plate and is made of a metallic material to provide impact resistance and secure engagement with the terminal. Such a metallic cover is conductive and may cause current to leak, causing inconvenience to a user. Further, the conductivity of the metallic material may affect the operation of the circuit devices therein or the radiation characteristics of an antenna in the portable terminal so that it is difficult to achieve stable operation of the terminal. 
       SUMMARY OF THE INVENTION 
       [0014]    Accordingly, the present invention has been made to address the above-mentioned problems and/or disadvantages, and an aspect of the present invention is to provide a grounding device for a battery cover for a slim terminal that contributes to the protection of a battery pack and the stable operation of the terminal. 
         [0015]    Another aspect of the invention is to provide a grounding device for a metallic battery cover for a slim terminal that prevents the metallic battery cover from interfering with the operation of the circuit devices (including an antenna unit), thereby improving performance of the portable terminal. 
         [0016]    In accordance with an aspect of the present invention, a battery cover grounding device for a portable terminal is provided. The battery cover grounding device includes a metallic battery cover and a grounding member disposed on the terminal to be connected to a grounding surface of the terminal and to be in contact with the battery cover. The grounding member includes a cover protrusion on the battery cover and a grounding protrusion on the terminal to contact the cover protrusion. 
         [0017]    In accordance with another aspect of the present invention, a portable terminal includes a housing having a battery opening, a metallic battery cover for closing the battery opening, and a grounding member for grounding the metallic battery cover to a grounding surface of the portable terminal. 
         [0018]    In accordance with another aspect of the present invention, a portable terminal includes a housing having an opening for receiving a battery pack, the housing having a grounding surface and a grounding protrusion, and a metallic battery cover for closing the opening in the housing, the cover having a cover protrusion. The grounding protrusion of the housing contacts the cover protrusion to form an electrically conductive path between the grounding surface and the metallic cover when the cover is closed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
           [0020]      FIG. 1  is a perspective view of a portable terminal having a battery cover grounding device according to an exemplary embodiment of the present invention; 
           [0021]      FIG. 2  is a perspective view of the portable terminal illustrated in  FIG. 1  in an opened state; 
           [0022]      FIG. 3  is an exploded perspective view of the battery cover grounding device illustrated in  FIG. 1 ; 
           [0023]      FIG. 4  is an assembled perspective view of the battery cover grounding device illustrated in  FIG. 3 ; 
           [0024]      FIG. 5  is a perspective view of the battery cover grounding device illustrated in  FIG. 4 , as viewed from the exterior of the portable terminal; and 
           [0025]      FIG. 6  is a plan view illustrating the portable terminal illustrated in  FIG. 3 . 
       
    
    
       [0026]    Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0027]    The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness. 
         [0028]    Referring to  FIGS. 1 and 2 , a portable terminal  100  having a battery cover  201  ( FIG. 3 ) grounding device according to an exemplary embodiment of the invention includes a first housing  101  and a second housing  102  slidably coupled to the first housing  101 . In the illustrated embodiment, the battery cover  201  is installed on the back face of the first housing  101 . 
         [0029]    In the following description, the battery cover  201  grounding device is described in conjunction with a sliding-type portable terminal  100 . It should be noted that the battery cover grounding device is not limited to sliding-type portable terminals and can be applied to any portable terminal that receives a battery pack and includes a separate cover for opening and closing the battery pack. 
         [0030]    The first housing  101  has a keypad  111  and a transmitter  113  disposed on one side of the housing. The keypad  111  is opened and closed by the sliding movement of the second housing  102 . The transmitter  113  is installed on a protrusion  115  protruding from one surface of the first housing  101 . The second housing  102  is slidably coupled to the first housing  101  while being opposed thereto, thereby opening and closing the keypad  111 . The second housing  102  is provided at one surface thereof with a display  121 , a receiver  123 , and a function keypad  125 . 
         [0031]    Since the display  121 , the receiver  123 , and the function keypad  125  are always exposed irrespective of whether or not the second housing  102  has been slid, they can provide functions such as watching moving picture files, watching broadcasting, and the like, even when the first housing is closed. When the keypad  111  of the first housing  101  is open, a user can use communication functions, such as calling a recipient or writing short messages/mail messages and the like, play games and perform other functions. 
         [0032]    Referring to  FIGS. 3 to 5 , the other surface of the first housing  101  has a battery opening  119  which is opened and closed by a separate battery cover  201 . When the battery pack is installed into the battery opening  119 , it is fixed thereto while being surrounded by a rib  198  extending inward from the first housing  101 . When the battery pack (not shown) has been installed into the battery opening  119 , the battery cover  201  is attached to the first housing  101  of the terminal  100  to close the battery opening  119  and protect the battery pack. 
         [0033]    The battery cover  201  is made of a metallic material such as stainless steel. This is because the thickness of the battery cover  201  is limited in a slim terminal, and a metallic material provides adequate mechanical properties, such as impact resistance. An insulation material is applied to the battery cover  201 , and a portion of the insulation material is removed to expose the metallic material therein. The insulating material on the metallic battery cover  201  prevents a user from receiving an electric shock even when current leaks through the battery cover  201 . The battery cover  201  includes a cover protrusion  221  that protrudes through the portion where the insulation material is removed. 
         [0034]    To fix the battery cover  201  to the first housing  101 , the battery cover  201  includes a first engaging rib  211  at a first end thereof and a second engaging rib  213  at an opposite second end thereof. The first engaging rib  211  includes a pair of ribs that protrude outward from the first end and are substantially parallel to each other. The second engaging rib  213  protrudes upward from the second end of the battery cover  201  and has a through-hole  215 . 
         [0035]    To fix the battery cover  201  to the first housing  101 , the first housing  101  includes an engaging hole  217  and a hook (not shown). The engaging hole  217  is formed at one side of the battery opening  119 . The hook is installed on the other side of the battery opening  119  to move into and out of the battery opening. To install the hook, an operating recess  218  is formed at the other side of the battery opening  119 , so that the hook is linearly moved while being installed in the operating recess  218 , thereby moving into and out of the battery opening  119 . The operating recess  218  may be provided with a coil spring (not shown) to provide elastic force on the hook to press against the battery opening  119 . The construction of the hook and the coil spring will be easily understood by persons skilled in the art. 
         [0036]    The battery cover  201  is brought into contact with the first housing  101  by pivoting about the first engaging rib  211  while the first rib is engaged with the engaging hole  217 . When the battery cover  201  is brought into contact with the first housing  101 , the second engaging rib  213  is moved into the battery opening  119 . At this time, the through-hole  215  of the second engaging rib  213  faces the hook, and the hook protrudes into the battery opening  119  due to the elastic force of the coil spring, thereby being engaged with the second engaging rib  213 , specifically, the through-hole  215 . Then, the battery cover  201  is fixed to the first housing  101 , closing the battery opening  119 . 
         [0037]    To prevent the battery cover  201  from protruding outward from the outer periphery of the first housing  101  when it is attached to the first housing  101 , the first housing  101  is provided with a cover recess  117 . The cover recess  117  is formed along an edge of the battery opening  119 , and has a depth that corresponds to the thickness of the battery cover  201  from the outer periphery of the first housing  101 . Thus, when the battery cover  201  is mounted onto the first housing  101 , it is positioned inside the cover recess  117 , and the outer surface thereof has the same level as that of the first housing  101 . 
         [0038]    Meanwhile, to facilitate replacing the battery pack received in the battery opening  119 , a release hole  219  is formed at one end wall of the battery opening  119 . The release hole  219  exposes a portion of one side of the battery pack mounted into the battery opening  119  to outside, and a user can release the battery pack from the battery opening  119  by contacting the exposed portion of the battery pack through the release hole  219  and drawing out the battery pack. 
         [0039]    To prevent the metallic battery cover  201  from affecting the operations of an antenna or circuit devices of the terminal  100 , the battery cover  201  is grounded to a grounding surface  189  ( FIG. 6 ) formed in the terminal  100 . To ground the battery cover  201  to the grounding surface  189 , the terminal  100  includes a ground member that consists of a cover protrusion  221  and a grounding protrusion  223  attached to the first housing  101 . 
         [0040]    Referring to  FIG. 6 , the grounding surface  189  is formed by applying at least a portion of the inner surface of the first housing  101  with an electromagnetic interference (EMI) paint, thereby providing a ground to the terminal  100 . Further, in addition to preventing electromagnetic waves generated from the operations of the internal circuit devices of the terminal  100  from radiating outside, the grounding surface  189  prevents static electricity generated from outside from interfering with the internal circuit devices. 
         [0041]    To connect the battery cover  201  to the grounding surface  189 , the terminal  100  is provided with the grounding protrusion  223 . Referring again to  FIG. 3 , the grounding protrusion  223  is shaped like a cap that is coupled to a head portion of the screw  225 , and is connected to the grounding surface  189  through the screw  225 . 
         [0042]    When the screw  225  is coupled to the first housing  101  of the terminal  100 , the head portion thereof is positioned inside a screw hole  229  of the first housing  101 , and a portion of the grounding protrusion  223  is positioned in the screw hole  229 . 
         [0043]    When the battery cover  201  is coupled to the first housing  101 , the grounding protrusion  223  comes into contact with the cover protrusion  221 . The grounding protrusion  223  may be made of a resilient material, so that upon contact with the cover protrusion  221 , it is deformed corresponding to the shape of the cover protrusion  221 . Thus, even when the cover protrusion  221  and the grounding protrusion  223  are brought into contact with each other, the battery cover is neither applied with external force nor deformed, so that the battery cover  201  is stably kept engaged with the terminal  100 . 
         [0044]    In the present exemplary embodiment, the screw  225  is fastened to the first housing  101  so as to be connected to the grounding surface  189  of the inner surface of the housing, and to connect the cover protrusion  221  to the grounding surface  189 . Alternatively, the terminal  100  may be provided with other types of grounding surfaces or grounds. For example, the first housing  101  may house a main board (not shown) of the terminal  100 , and the main board may be fixed to the first housing  101  by the screw  225 . Typically, a printed circuit board has a ground pattern, and persons skilled in the art will appreciate that the main board of a portable terminal has a ground pattern. By fastening the screw  225  to the ground pattern of the main board, the grounding protrusion  223  can be connected to the ground pattern of the printed circuit board installed inside the terminal  100 . 
         [0045]    Moreover, if the grounding surface is also formed on the cover recess  117 , the grounding protrusion  223  can be attached to the cover recess  117 . That is, if the battery cover  201  can be connected to the grounding surface provided to the terminal  100 , the grounding protrusion  223  can be directly attached and connected to the grounding surface provided to the cover recess  117  without passing through the screw  225 . In the present exemplary embodiment, the grounding surface  189  is formed on an inner surface of the terminal  100 , so that the grounding protrusion  223  comes to be connected to the grounding surface  189  through the screw  225 . 
         [0046]    As a result, the battery cover  201  is grounded to the grounding surface  189  provided to the terminal  100 , or the ground pattern formed on the printed circuit board, through the cover protrusion  221  and the grounding protrusion  223 . Alternatively, the grounding protrusion  223  may be connected to the grounding surface  189  and the like through the screw  225 . 
         [0047]    As set forth above, according to the battery cover grounding device for a portable terminal of the exemplary embodiment of the present invention, the metallic battery cover is connected to the grounding surface provided to the terminal while closing the battery opening to thereby prevent current leakage and to produce stable operation of the terminal. That is, by preventing the metallic battery cover from having an electrical property using high frequency generated from the circuit devices of the terminal, or transmission signal of the antenna unit, stable operation of the terminal is realized, and performance of the antenna unit and the like is secured. Further, the metallic cover diminishes malfunctions of the terminal by grounding external static electricity. 
         [0048]    It will be understood by those skilled in the art that the embodiment illustrated and described above is merely exemplary, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, in the illustrated embodiment, the grounding protrusion  223  is connected to the ground surface  189  through the screw  225 . However, if the grounding protrusion  223  is made of a flexible conductive tape, it can be exposed outside the first housing  101  through the screw hole  229 , to which the screw is not fastened, when attached to the inner surface of the first housing  101  that has the grounding surface  189  thereon. Since the cover protrusion  221  of the battery cover  201  protrudes from the battery cover  201 , it can contact the grounding protrusion of conductive tape, which is attached to the inner surface of the first housing  101 , through the screw hole  229 . 
         [0049]    While the invention has been shown and described with reference to certain exemplary 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 and their equivalents.