Abstract:
A mobile communication device for receiving and transmitting wireless communication signals including a body having a border portion, a display supported by the body, a touch screen adjacent the display and defining an exterior surface of the mobile communication device such that the display is visible through the touch screen, the touch screen transferring an input signal through electrodes disposed at an edge portion of the touch screen, and an electrode covering layer located above the electrodes of the touch screen. The border portion of the body and the outermost portion of the touch screen are substantially coplanar.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority to Korean Application No. 10-2006-0089836, filed on Sep. 15, 2006, which is herein expressly incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to a mobile communication device, and more particularly, a mobile communication device having a touch screen. 
         [0004]    2. Description of Related Art 
         [0005]    A mobile communication device including a mobile phone or a PDA is one of many mobile terminals allowing a user to wirelessly transmit, receive, read, and/or process information. 
         [0006]    A touch screen is an input unit (i.e. user interface) installed at a display (screen) to allow various user inputs upon contact from the user&#39;s finger or stylus for writing characters, drawing figures, and the like. The touch screen is easy to use without the need for much training to understand its operation. By being integrated with the display, which requires minimal occupation space, such touch screen technology is receiving much attention in the field of display devices and is being increasingly implemented in mobile communication devices. 
         [0007]    Various principles are applied for touch screen operation, and there are two typical methods. One method is based on static electricity (i.e., a static electricity method) wherein electric charges are charged on the surface of the screen, and sensors are installed around the screen. When the surface of the screen is contacted by the user, such is recognized by detecting the electric charge loss at the touched portion. The other method is based on resistance (i.e., a resistive film method) wherein a contact portion is recognized by detecting changes in resistance corresponding to the contacted portion in reaction to user applied pressure on the surface of the screen. 
         [0008]    In the related art, the touch screen is formed in the mobile communication device such that edges of the mobile communication device case (i.e., body or housing) form an opening (or window) with an area that accommodates a display, and the touch screen and the display are mounted underneath the edges of the mobile communication device case. 
         [0009]    However, the mobile communication device case edges cause a height difference (i.e., a step) between the touch screen surface and the case surface. Such structure degrades the overall exterior appearance of the mobile communication device where a smooth clean appearance cannot be achieved. Also, such case edges undesirably increases the overall thickness of the mobile communication device, which runs counter to the trend of making the mobile communication device as thin or slim as possible. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    Therefore, in order to address the above matters the various features described herein have been conceived. One aspect of the exemplary embodiments is to provide a mobile communication device having a touch screen with an improved exterior that does not have a step between the body and the touch screen. 
         [0011]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a mobile communication device for receiving and transmitting wireless communication signals including a body having a border portion, a display supported by the body, a touch screen adjacent the display and defining an exterior surface of the mobile communication device such that the display is visible through the touch screen, the touch screen transferring an input signal through electrodes disposed at an edge portion of the touch screen, and an electrode covering layer located above the electrodes of the touch screen. The border portion of the body and the outermost portion of the touch screen are substantially coplanar. 
         [0012]    In another aspect, the outermost portion of the touch screen may have the same height as that of the border portion of the body. 
         [0013]    In yet another aspect, a mounting step with depth corresponding to the thickness of the touch screen may be provided on the body to allow the touch screen to be mounted therein. 
         [0014]    In a further aspect, the touch screen may include a transparent support plate, a touch sensing layer mounted on the transparent support plate and having edges with electrodes, and a protection film layer disposed at an upper portion of the electrode covering layer. 
         [0015]    In a still further aspect, the electrode covering layer may be disposed at an upper portion of the touch sensing layer. One of an upper and a lower surface of the electrode covering layer may include edges formed through an opaque printing. 
         [0016]    In another aspect, the touch sensing layer includes a first resistive film, a second resistive film disposed apart from the first resistive film with a gap therebetween, and the electrodes include first electrodes disposed at the edges of the first resistive film and second electrodes formed at the edges of the second resistive film. The second electrodes may be perpendicular to the first electrodes. 
         [0017]    In a further aspect, the touch sensing layer may be connected with a circuitry supporting substrate installed within the body by a flexible circuitry supporting substrate. The flexible circuitry supporting substrate may be connected with a terminal formed perpendicular to the electrodes of the touch sensing layer. The terminal penetrates the touch screen so as to extend to a lower surface of the touch screen or through the transparent support plate. 
         [0018]    In still a further aspect, one end of the flexible circuitry supporting substrate may be connected with the electrodes of the touch sensing layer in a horizontal direction and the other end thereof may be bent in a vertical direction and may penetrate the body so as to be connected with the circuitry supporting substrate. 
         [0019]    In another aspect, the touch screen may have a size corresponding to an entire upper surface of the body. 
         [0020]    In yet another aspect, the touch screen includes a through hole, and at least one external key exposed through the through hole. 
         [0021]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
           [0023]    In the drawings: 
           [0024]      FIG. 1  is a perspective view of a mobile communication device having a touch screen according to one exemplary embodiment of the present invention; 
           [0025]      FIG. 2  is an exploded perspective view of the mobile communication device in  FIG. 1 ; 
           [0026]      FIG. 3  is a cross-sectional view of the mobile communication device in  FIG. 1 , and  FIG. 3I  is a detail of the touch screen shown in  FIG. 3 ; 
           [0027]      FIG. 4  is a sectional view showing a flexible circuitry supporting substrate that connects the touch screen and its peripheral parts according to one exemplary embodiment of the present invention; and 
           [0028]      FIG. 5  is a sectional view showing the flexible circuitry supporting substrate that connects the touch screen and its peripheral parts according to another exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    A mobile communication device having a display and touch screen will now be described in detail with reference to the accompanying drawings. 
         [0030]    With reference to  FIG. 1 , a mobile communication device  10  includes upper and lower cases  20 ,  30 , respectively. A touch screen  40  is formed on the upper case  20  and defines an exterior surface of the mobile communication device  10 . 
         [0031]    An image display portion  11  of the mobile communication device  10  is located substantially at the middle portion of the touch screen  40  as indicated by a dotted line. A speaker unit  12  that outputs a voice and external keys  13  are provided at both upper and lower ends of the touch screen  40 , respectively. Preferably, they are located outside the image display portion  11  at non-image display portions. 
         [0032]      FIG. 2  is an exploded perspective view of the mobile communication device in  FIG. 1 . As shown in  FIG. 2 , a display  50  is installed at a certain depth with respect to the upper case  20  and the touch screen  40  is provided above the display  50 . The touch screen  40  includes a speaker hole  41  and an external key hole  42  corresponding to the speaker unit  12  and the external keys  13 , respectively. 
         [0033]    A resistive film method is applied to the touch screen  40  so that the touch screen  40  discriminates a resistance value corresponding to a touched portion and transfers a corresponding input signal through the electrodes  43  positioned at the edges thereof. The electrodes  43  can receive power, transmit data, and/or receive data through a flexible circuitry supporting substrate  60  connected with a lower surface of the touch screen  40 . 
         [0034]    A window  22  is formed at a lower portion of the touch screen  40  to allow light of the display  50  to pass therethrough, and a mounting step  21  with depth corresponding to thickness of the touch screen  40  is formed around the window  22 . Accordingly, when the touch screen  40  is mounted on the mounting step  21 , an outer layer portion (outer surface) of the touch screen  40  can have the same height as a border portion  25  of the upper case  20  (See  FIG. 3 ). 
         [0035]    An flexible circuitry supporting substrate through hole  23  is formed on the mounting step  21  of the upper case  20  to allow the flexible circuitry supporting substrate  60  to pass therethrough, and the external keys  13  can be supported by the mounting step  21 . A speaker hole  24  corresponding to the speaker unit  12  is formed in the mounting step  21 . 
         [0036]      FIG. 3  is a cross-sectional view of the mobile communication device in  FIG. 1 , and  FIG. 4  is a sectional view showing a flexible circuitry supporting substrate that connects the touch screen and its peripheral parts according to one exemplary embodiment of the present invention. 
         [0037]    As shown in  FIGS. 3 and 4 , the outer layer portion of the touch screen  40  has the same height as the border portion  25  of the upper case  20 , resulting in a smooth overall exterior surface of the mobile communication device. 
         [0038]    The touch screen  40  includes a transparent support plate  71  mounted on the mounting step  21 , a touch sensing layer  72  mounted on the transparent support plate  71  and having electrodes  43   a ,  43   b  disposed at its edges (seen in  FIG. 4 ), an electrode covering layer  76  disposed on the touch sensing layer  72 , and a protection film layer  75  disposed on the electrode covering layer  76 , which are formed in a stacking manner. 
         [0039]    Upper or lower surfaces of the edges of the electrode covering layer  76  may be formed through opaque printing, or an opaque pigment may be mixed with a base material so that the electrodes  43   a ,  43   b  positioned at the lower portion of the electrode covering layer  76  are not visible. The electrode covering layer  76  provides a boundary line of the display  50  in order to discriminate an image display part  11  and a non-image display part. As such, the electrode covering layer  76  may be larger or smaller that the display  50 . 
         [0040]    As seen in  FIG. 4 , the touch sensing layer  72  includes a first resistive film  74 A with first electrodes  43   a  disposed on the edges, and a second resistive film  74 B disposed at a certain gap by a spacer  73  from the first resistive film  74 A and having second electrodes  43   b  disposed at the edges and being perpendicular to the first electrodes  43   a . Herein, the first and second electrodes  43   a  and  43   b  can be disposed by a 4-line resistive film method or 5-line resistive film method. 
         [0041]    Accordingly, when an arbitrary portion of the touch screen  40  is touched, the first resistive film  74 A and the second resistive film  74 B contact to be electrically connected with each other at the arbitrary portion. Then, the contact portion of the first and second resistive films  74 A and  74 B can be detected through an electric current signal that flows at the first and second electrodes  43   a  and  43   b  and the mobile communication device  10  inputs the corresponding input value. 
         [0042]    With reference to  FIG. 4 , the touch sensing layer  72  is connected to the flexible circuitry supporting substrate  60 , and the flexible circuitry supporting substrate  60  is connected with a circuitry supporting substrate  15  (See  FIG. 3 ) installed within the mobile communication device  10 . The flexible circuitry supporting substrate  60  is connected with terminals  81  and  82  formed to be perpendicular from the electrodes  43   a  and  43   b  of the touch sensing layer  72 . 
         [0043]    In a different exemplary embodiment of the present invention, as shown in  FIG. 5 , the flexible circuitry supporting substrate  60  can be formed such that one end thereof is connected in a horizontal direction from the electrodes  43   a  and  43   b  of the touch sensing layer  72  and the other end thereof is bent in a vertical direction and penetrates through a mounting step  21  so as to be connected with the circuitry supporting substrate  15 . 
         [0044]    With such a structure, the touch screen  40  can have the electrode covering layer  76  that can cover the electrodes  43   a  and  43   b  while reflecting content displayed on the display  50 . 
         [0045]    Preferably, the touch screen  40  has an integrated form that covers the entire upper surface of the mobile communication device  10  (or a substantial portion thereof). As such, portions that are too wide (or large in size), too complicated, and/or having undesirable bends or curves are not employed, thus improving the exterior appearance of the mobile communication device. In particular, the upper case  20  does not need to have a portion to wrap over the edge(s) of the touch screen  40 , so the outer surface of the touch screen  40  can have the same height as (i.e., is flush with) the border portion  25  of the upper case  20 . As a result, the overall thickness of the mobile communication device  10  can be minimized (i.e., a slim profile can be provided). 
         [0046]    As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims. 
         [0047]    The invention thus being described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.