Patent Publication Number: US-2010127897-A1

Title: Multi-status key assembly

Description:
BACKGROUND 
     1. Field of the invention 
     The present invention relates to key assemblies and, particularly, to a multi-status key assembly used in a portable electronic device. 
     2. Description of related art 
     A portable electronic device (e.g., mobile phone or personal digital assistant, PDA) usually has a key assembly including four direction keys and an enter key. The enter key is typically arranged among the four direction keys. 
     However, in use of such key assembly, a user usually has to move his/her fingers from one key to another, thus reducing the input efficiency. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of a multi-status key assembly can be better understood with reference to the following drawings. These drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present multi-status key assembly. Moreover, in the drawings like reference numerals designate corresponding sections throughout the several views. 
         FIG. 1  is an exploded, isometric view of a multi-status key assembly, according to an exemplary embodiment. 
         FIG. 2  is similar to  FIG. 1 , but viewed from another aspect. 
         FIG. 3  is an assembled view of the multi-status key assembly shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional view of  FIG. 3  showing one state of the use of the multi-status key assembly shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional view of  FIG. 3  showing another state of the use of the multi-status key assembly shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT 
       FIGS. 1 through 3  show an exemplary embodiment of a multi-status key assembly  10 . The key assembly  10  includes a pressing cover  11 , a support member  12 , a pressing body  13  and a printed circuit board  14 . The support member  12  is disposed between the pressing cover  11  and the pressing body  13 . The pressing body  13  is positioned on the printed circuit board  14 . 
     The pressing cover  11  has a T-shaped cross-section, including an operating portion  111  and a connecting portion  112  connected to the operating portion  111 . The operating portion  111  includes an operating surface  1111  and a tapered brim  1112 . The tapered brim  1112  is connected to a periphery of the operating surface  1111 . The operating surface  1111  and the tapered brim  1112  are configured to be pressed by a user&#39;s finger. The connecting portion  112  is a hollow column, defining a cavity  1121  therein. 
     The support member  12  generally includes a through hole  121  defined at a central area thereof and several fastening blocks  122  protruding from a peripheral wall of the support member  12 . The fastening blocks  122  are fixed to a body section of a portable electronic device. The through hole  121  is configured to receive the connecting portion  112  of the pressing cover  11 . 
     The pressing body  13  includes a top surface  131  and an opposite bottom surface  132 . A connecting post  133  protrudes from the top surface  131 , corresponding to the connecting portion  112 . An outer diameter of the connecting post  133  is substantially equal to an inner diameter of the cavity  1121 . The bottom surface  123  has a pressing pole  135  protruding from a center. Four direction pressing poles  134  also protrude from the bottom surface  132 , surrounding the pressing pole  135 . A height of the pressing pole  135  is bigger than each direction pressing pole  134 . 
     The printed circuit board  14  forms five electrical contacts  141  corresponding to the pressing pole  135  and the four direction pressing poles  134 . Each electrical contact  141  has an arcuate surface with a good resilience. 
     Referring to  FIG. 3 , in assembly, the connecting portion  112  is inserted into the through hole  121  from one side of the support member  12 . The connecting post  133  of the pressing body  13  is inserted into the cavity  1121  and combined with the connecting portion  112  on the other side of the support member  12 . The printed circuit board  14  is placed adjacent to the pressing body  13 , with the pressing pole  135  and the four direction pressing poles  134  being aligned with the corresponding electrical contacts  141 . At this time, the four direction pressing poles  134  are spaced from their corresponding electrical contacts  141 , while the pressing pole  135  slightly contacts its corresponding electrical contacts  141 , thus supporting the pressing body  13 . 
     Referring to  FIG. 4 , when an external force F is applied on the operating surface  1111  towards the printed circuit board  14 , the pressing cover  11  and the pressing body  13  move towards the printed circuit board  14 . Since the pressing pole  135  is higher than the direction pressing poles  134 , the pressing pole  135  presses its corresponding electrical contact  141  to input a corresponding signal, while the four direction pressing poles  134  are still spaced from their corresponding electrical contacts  141 . When the external force F is removed, the electrical contact  141  returns/restores the pressing pole  135  to the previous position. 
     Referring to  FIG. 5 , when an external force F is applied on the tapered brim  1112  towards one direction pressing pole  134 , the pressing cover  11  and the pressing body  13  swing about the support member  12 . At this time, the above-mentioned direction pressing pole  134  advances more than the other three direction pressing poles  134 . Thus the direction pressing pole  134  presses its corresponding electrical contact  141  and inputs a corresponding signal, while the other three direction pressing poles  134  are spaced from the printed circuit board  14  and the pressing pole  135  still slightly contacts its corresponding electrical contact  141 . Once the external force F is removed, the electrical contact  141  returns/restores the direction pressing pole  134  to the previous position. 
     Users can operate the pressing pole  135  and the four direction pressing poles  134  via the pressing body  13 , thus avoiding frequent jumps of fingers between different keys and improving the input efficiency of the multi-status key assembly  11 . 
     It is to be understood, however, that even through numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of sections within the principles of the invention to the full extent indicated by the broad general meaning of the terms, in which the appended claims are expressed.