Abstract:
An electronic device comprises a housing, a touch pad disposed on a first surface of the housing, the touch pad being capable of outputting a signal when touched, a processor disposed on a second surface, the processor being capable of processing the signal, wherein the second surface and the first surface are non-coplanar. The electronic device further comprises a flexible printed circuit formed integrally with the touch pad and the processor and the flexible printed circuit is capable of electrically connecting the touch pad on the first surface to the processor on the second surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/824,006, filed Aug. 30, 2006, which is herein incorporated by reference in its entirety. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to an input device and, more particularly, to a touch-sensitive input device and a portable electronic device incorporating the touch-sensitive device. 
         [0003]    With the progress in semiconductor manufacturing processes and telecommunications techniques, interest in a compact, light-weight and low-profile input device for electronic devices such as personal digital assistants (“PDAs”) and mobile phones is growing. However, conventional input devices such as, for example, keyboards, mice, touch pads, touch screens and joysticks, are generally too large-sized relative to electronic devices, and therefore require additional spaces external to the electronic devices. To overcome the drawbacks, input devices integrable with electronic devices have been proposed. An embodiment of such an input device can be seen in U.S. Patent Application Publication No. 2003/0095096 by Robbin et al., entitled “Method and Apparatus for Use of Rotational User Inputs”. Robbin discloses a method and an apparatus for transforming a rotational user action supplied by a user at a user input device into a linear action. However, it may be optically and operationally more user-friendly to have a linear user input followed by a linear output than a rotational user input followed by a linear output. Furthermore, conventional input devices may be configured to be disposed on a surface of an electronic device where a display device is located, which may not help reduce the device size and lower the utility efficiency of an outer area of the device. 
         [0004]    It is thus desirable to have an input device that is able to be integrated with increasingly compact and low-profile electronic devices. It is also desirable to have an input device that allows a linear user input followed by a linear output. Furthermore, it is desirable to have an input device that provides flexibility in configuration and pattern to achieve area efficiency. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    Embodiments of the present invention may provide a touch-sensitive input device for use in a portable electronic device such as a PDA or a mobile phone. 
         [0006]    Embodiments of the present invention may provide an electronic device that comprises a housing, a touch pad disposed on a first surface of the housing, the touch pad being capable of outputting a signal when touched, a processor disposed on a second surface, the processor being capable of processing the signal, and a flexible printed circuit electrically connecting the touch pad on the first surface and the processor on the second surface, wherein the first surface and the second surface are non-coplanar. 
         [0007]    Embodiments of the present invention may also provide an electronic device that comprises a main circuit board having an electric contact formed on a first surface thereof, a touch pad disposed on a second surface over the main circuit board, the touch pad being capable of detecting motions of an object on the touch pad, a processor disposed on the second surface and connected to the touch pad, the processor being capable of processing an output of the touch pad, and a flexible printed circuit having one end integrally formed with the touch pad and the processor and the other end thereof electrically connected to the electronic contact, wherein the first surface and the second surface are non-coplanar. 
         [0008]    Some embodiments of the present invention may also provide an interface device for use in an electronic device that comprises a touch pad disposed on a first surface of the electronic device, the touch pad being capable of detecting motions of an object thereon, a processor disposed on a second surface of the electronic device, the processor being capable of processing an output of the touch pad, and a flexible printed circuit connected between the touch pad and the processor being integrally formed with the touch pad and the processor, wherein the first surface and the second surface are non-coplanar. 
         [0009]    Embodiments of the present invention may also provide an interface device for use in an electronic device that comprises a touch pad disposed on a first surface of the electronic device, the touch pad being capable of detecting motions of an object thereon, a processor connected to the touch pad and disposed on the first surface of the electronic device, the processor being capable of processing an output of the touch pad, and a flexible printed circuit having one end electrically connected to the processor and the other end thereof being positioned on a second surface of electronic device, wherein the first surface and the second surface are non-coplanar. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
     
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0011]    The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments consistent with the invention. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
           [0012]    In the drawings: 
           [0013]      FIGS. 1A and 1B  are diagrams of an input device consistent with an embodiment of the present invention; 
           [0014]      FIG. 1C  is a schematic diagram of an input device consistent with another embodiment of the present invention; 
           [0015]      FIG. 2A  is an exploded view of an electronic device consistent with an embodiment of the present invention; 
           [0016]      FIG. 2B  is a perspective view of the electronic device illustrated in  FIG. 2A  when assembled; 
           [0017]      FIG. 2C  is a cross-sectional view of the electronic device illustrated in  FIG. 2A  when assembled; 
           [0018]      FIG. 2D  is a rear plan view of a main circuit board of the electronic device illustrated in  FIG. 2A ; 
           [0019]      FIG. 3  is a schematic diagram of an electronic device consistent with another embodiment of the present invention; 
           [0020]      FIG. 4  is a schematic diagram of an input device consistent with another embodiment of the present invention; 
           [0021]      FIG. 5A  is a schematic diagram of an electronic device consistent with another embodiment of the present invention; 
           [0022]      FIGS. 5B and 5C  are schematic diagrams of electronic devices consistent with still other embodiments of the present invention; and 
           [0023]      FIGS. 6A and 6B  are schematic diagrams of input devices consistent with still other embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Reference will now be made in detail to the present embodiments of the invention, embodiments of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like portions. It should be noted that the drawings are in greatly simplified form and are not to precise scale. In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms such as front, side and rear are used with respect to the accompanying drawings. Such directional terms used in conjunction with the following description of the drawings should not be construed to limit the scope of the invention in any manner not explicitly set forth in the appended claims. 
         [0025]      FIGS. 1A and 1B  are diagrams of an input device  10  consistent with an embodiment of the present invention. Referring to  FIG. 1A , the input device  10  includes a touch pad  11 , a flexible printed circuit (“FPC”)  12  and a processor  13 . The touch pad  11 , the FPC  12  and the processor  13  of the input device  10  are electrically connected and may be integrally formed in one piece. The input device  10  serves as an interface between a user and an electronic device such as, for example, a PDA, a mobile phone or a notebook computer. The touch pad  11  may be a touch-sensitive device capable of receiving a user input through, for example, the user&#39;s finger or a stylus. Specifically, with the touch pad  11 , the movement of a cursor on a display screen corresponds to the relative movements of the user&#39;s finger as the finger taps or moves along a surface of the touch pad  11 . The touch pad  11  facilitates a selection on the display screen when one or more taps are detected on the surface of the touch pad  11 . In one embodiment consistent with the present invention, a linear user input, i.e., a linear movement of the user&#39;s finger on the touch pad  11 , is transformed to a linear or sequential output, i.e., a linear or sequential movement of a cursor or pointer on a display screen. In another embodiment, a linear user input is transformed to a circular output. In still another embodiment, a circular user input is transformed to a linear output. The touch pad  11  in one embodiment is a capacitive-type touch pad such that taps or movements of the user&#39;s finger result in changed capacitance. Signals including information of the changed capacitance are transmitted to the processor  13  through the FPC  12  and then detected by the processor  13 . The processor  13 , configured in the form of an integrated circuit (“IC”), is electrically connectable to a main processor on a main circuit board through a connector  14 . In one embodiment, the connector  14  is configured in the form of a sheet on which conductive wires such as gold fingers  140  are formed. The connector  14  includes a male connector, to connect to a female connector disposed on a main circuit board, or vice versa. 
         [0026]    In one embodiment consistent with the present invention, the input device  10  further includes a ground pad  15 , integrally formed with the touch pad  11 , for the purpose of electrically grounding. The ground pad  15  includes, for example, a flexible conductive sheet. In another embodiment consistent with the present invention, the input device  10  further includes a metal shielding cover  16  to protect the processor  13  from electromagnetic interference (“EMI”). The metal shielding cover  16  is electrically connected to a ground layer  170  of a substrate  17  that supports the processor  13 . In one embodiment, one of the gold fingers  140  of the connector  14  is electrically connected to the ground layer  170 . 
         [0027]    Referring to  FIG. 1B , in operation, the FPC  12  may be flexibly bent to allow the touch pad  11  and the processor  13  to be positioned at different orientations or different surfaces of an electronic device (not shown). Thus the positions of the touch pad  11  and the processor  13  are non-coplanar, which facilitates the utility efficiency of the outer area of the electronic device. Furthermore, the ground pad  15  may be flexibly bent to also allow the touch pad  11  and the ground pad  15  to be positioned at different orientations or different surfaces of an electronic device. Thus the positions of the touch pad  11  and the ground pad  15  are non-coplanar. 
         [0028]      FIG. 1C  is a schematic diagram of an input device  10  consistent with an embodiment of the present invention. Referring to  FIG. 1C , the input device  10  includes the touch pad  11  further including a plurality of touch-sensitive areas  110  separated from each other and surrounded by a non-touch-sensitive area  112 . 
         [0029]      FIG. 2A  is an exploded view of an electronic device  20  consistent with an embodiment of the present invention. Referring to  FIG. 2A , the electronic device  20  such as, for example, a PDA or a mobile phone, includes a housing further comprising a front cover  21  and a back cover  22 , a main circuit board  23  disposed within the housing, a display device  24  disposed in an opening of the front cover  21 , a keypad  25  disposed on the front cover  21  and an input device  10 . The input device  10  includes a touch pad  11 , an FPC  12 , a processor  13 , a connector  14  and a ground pad  15 . When assembled, the touch pad  11  is located on a surface in a recess region  211  in a sidewall  210  of the front cover  21 . A cover  111  such as, for example, a plastic sheet, is configured with the housing to protect the touch pad  11  from physical damage, contamination or moisture attack. Skilled persons in the art will understand that the touch pad  11  may be disposed on the sidewall  210  without any recess region or protection by the cover  111 . The FPC  12  and the flexible ground pad  15  extend through a slot  212  adjacent to the recess region  211  into an inner space defined by the front cover  21  and the back cover  22 . The slot  212  is formed as the front cover  21  and the back cover  22  are assembled. The connector  14  is electrically coupled to a connector  234  disposed on the main circuit board  23 . The main circuit board  23  further includes a ground area  236  to facilitate grounding. 
         [0030]      FIG. 2B  is a perspective view of the electronic device  20  illustrated in  FIG. 2A  when assembled. Referring to  FIG. 2B , the touch pad  11  is disposed on the sidewall  210  near the display  24 . The sidewall  210  includes an inclined surface with respect to the display  24 . 
         [0031]      FIG. 2C  is a cross-sectional view of the electronic device  20  illustrated in  FIG. 2A  when assembled. Referring to  FIG. 2C , the touch pad  11  is disposed on a surface in the recess region  211  on the sidewall  210 . The ground pad  15  is electrically connected to a display module casing  240  which receives an LCD display  24 . Specifically, a portion of the ground pad  15  is electrically connected to a surface  241  of the conductive casing  240  for grounding. The FPC  12  bent into the inner space extends across the main circuit board  23  to electrically connect the processor  13  positioned on a back surface  231  of the main circuit board  23 , wherein the surface in the recess region  211  and the back surface  231  of the main circuit board  23  are non-coplanar. The processor  13  is held on a substrate  17  and enclosed by a metal shielding cover  16 . In the present embodiment, a resilient biasing member  221  (also referring to  FIG. 2A ) such as a sponge, immobile relative to the back cover  22 , abuts against the substrate  17  to allow the processor  13  to be positioned on a back surface  231  of the main circuit board  23 , and to allow the metal shielding cover  16  to contact the ground area  236  formed on the back surface  231 . 
         [0032]      FIG. 2D  is a rear plan view of the main circuit board  23  of the electronic device  20  illustrated in  FIG. 2A . Referring to  FIG. 2D , the connector  14  of the input device  10  is electrically coupled to the connector  234  disposed on the surface  231  of the main circuit board  23 . Both of the display module casing  240  and the ground pad  15 , illustrated in dotted lines, are disposed above the front surface (not numbered) of the main circuit board  23 . Also referring to  FIG. 2C , the touch pad  11 , the ground pad  15  and a package (not numbered) including the processor  13 , the substrate  17  and the metal shielding cover  16  are disposed on different surfaces of the electronic device  20 , and those surfaces are non-coplanar. 
         [0033]    Skilled persons in the art understand that an “antenna effect” may occur to an electronic device if an input device of the electronic device includes only one grounded end. In the example of an input device of an electronic device including a touch pad, a processor and a flexible printed circuit (FPC) electrically connecting the touch pad and the processor, if the FPC is grounded with a main circuit board only by a ground layer or by one of gold fingers of a connector formed on the FPC and when the electronic device such as a mobile phone emanates a radio frequency (RF) signal, the RF signal may cause noise signals in the touch pad and the noise signals may in turn disturb the cursor action on a display because the input device has only one grounded end. Such a phenomenon is called the “antenna effect”. 
         [0034]    To prevent the antenna effect, in an embodiment consistent with the present invention, referring to  FIG. 1A , an input device  10  of an electronic device includes a touch pad  11 , a processor  13  and a flexible printed circuit (FPC)  12  electrically connecting the touch pad  11  and the processor  13 , a ground layer  170  or a connector  14  electrically connected to the FPC  12  for grounding purpose, and a ground pad  15  extending from one end of the touch pad  11  for grounding. As a result, the input device  10  includes two grounded ends. The antenna effect that may otherwise occur in the electronic device due to interaction between the RF signal and the input device may be greatly alleviated. 
         [0035]      FIG. 3  is a schematic diagram of an electronic device  30  consistent with another embodiment of the present invention. Referring to  FIG. 3 , the electronic device  30  is similar in structure to the electronic device  20  illustrated in  FIG. 2B  except it includes a vertical sidewall  310  instead of the inclined sidewall  210 . In this embodiment, the input device  10  is also located on the sidewall  310  of the electronic device  30 , which is vertical with respect to the display  34  disposed on the front cover  31 . 
         [0036]      FIG. 4  is a schematic diagram of an input device  40  consistent with another embodiment of the present invention. Referring to  FIG. 4 , the input device  40  used in an electronic device (not shown) includes a touch pad  41 , a processor  43  directly connected to one end of the touch pad  41 , and one end of an FPC  42  connected to the processor  43 , wherein the touch pad  41  is used to be positioned on a sidewall of the electronic device. The input device  40  further includes a connector  44  extending from the other end of the FPC  42  and a ground pad  45  extending from the other end of the touch pad  41 . As previously discussed, the connector  44  formed on the other end of the FPC  42  is electrically connectable to an electric contact including an connector formed on a surface or a position on a main circuit board (not shown) of the electronic device, and the ground pad  45  is electrically connectable to a conductive module casing (not shown), for example. Thus two ends of the FPC  42  are positioned on different surfaces which are non-coplanar. 
         [0037]      FIG. 5A  is a schematic diagram of an electronic device  50  consistent with another embodiment of the present invention. Referring to  FIG. 5A , the electronic device  50  includes a main circuit board  53 , a display  54 , a keypad  55  and the input device  40  as illustrated in  FIG. 4 , in which the housing of the electronic device  50  is omitted for clearer illustration. The display  54  and the keypad are both disposed over the main circuit board  53 . The touch pad  41  and the processor  43  are both disposed over the main circuit board  53 , wherein the processor  43  is used to be hidden inside the housing of the electronic device  50  and the touch pad  41  is used to be exposed and disposed on a sidewall of the housing of the electronic device  50 . The other end of FPC  42  extends across a side  530  of the main circuit board  53  to electrically connect an electric contact including a connector (not shown) formed on the rear surface of the main circuit board  53 , and the ground pad  45  is bent to electrically connect, for example, a ground area (not shown) formed on the main circuit board  53 . 
         [0038]      FIGS. 5B and 5C  are schematic diagrams of electronic devices  501  and  502  consistent with still other embodiments of the present invention. Referring to  FIG. 5B , the electronic device  501  is similar in structure to the electronic device  50  illustrated in  FIG. 5A  except that an notch  512  is formed at the side  530  of the main circuit board  53 , which facilitates extension of the FPC  42  across the main circuit board  53 . Referring to  FIG. 5C , the electronic device  502  is similar in structure to the electronic device  50  illustrated in  FIG. 5A  except that an opening  513  is formed through the main circuit board to facilitate extension of the FPC  42  across the main circuit board  53 . In the embodiments illustrated in  FIGS. 5A ,  5 B and  5 C, they reveal that different surfaces on which two ends of the FPC  42  are positioned are non-coplanar. 
         [0039]      FIGS. 6A and 6B  are schematic diagrams of input devices  60  and  70  used in electronic devices (not shown) consistent with still other embodiments of the present invention. Referring to  FIG. 6A , the input device  60  includes a touch pad  61 , a processor  63 , an FPC  62  connecting the touch pad  61  and the processor  63 , and a connector  64  connected to the processor  63 , wherein the touch pad  61  is used to be positioned on a sidewall of the electronic device. The touch pad  61  includes a streamlined shape and the connector  64  is integrated with the processor  63 . Referring to  FIG. 6B , the input device  70  includes a touch pad  71  with a rectangular shape, a processor  73  connected to the touch pad  71 , an FPC  72  connected to the processor  73 , and a connector  74  integrated with the FPC  72 . 
         [0040]    It will be appreciated by those skilled in the art that changes could be made to one or more of the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the scope of the present invention as defined by the appended claims.