Abstract:
A side key assembly ( 10 ) and a portable electronic device ( 200 ) using the side key assembly ( 10 ) is provided. The side key assembly ( 10 ) includes a key cover ( 12 ), a soft portion ( 142 ) and a hard portion ( 144 ) that can be firmly adhered to a housing of the portable electronic device □ 200 □. Using this structure, the opportunity for dust or water to enter the portable electronic device ( 200 ) is reduced.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to side key assemblies, particularly a side key assembly used in portable electronic devices. 
         [0003]    2. Description of Related Art 
         [0004]    Many electronic devices such as mobile phones have housings with an interior compartment for receiving a printed circuit board therein. The mobile phone usually forms a side key assembly on an outside sidewall of the housing, so that a user can operate the mobile phone with one finger. Typically, the side key assembly includes a key cover and a key cap adhered to the key cover. The key cap is elastic. The key cap is distorted when an external force is exerted thereon, and then is restored to its original state when the external force is removed. The key assembly is disposed in a hole defined in an outer shell of the portable electronic device, thus a slight gap is formed between the key assembly and the outer shell. If the key assembly becomes wet, water and/or vapor could penetrate through the gap into the portable electronic device, affecting the circuit board. In addition, dust entering into the portable electronic device can also degrade performance 
         [0005]    To avoid water or dust entering into the portable electronic device, a waterproof and/or dustproof structure is designed for the key assembly. Typically, the key assembly is wrapped by a waterproof and/or dustproof film. The wrapping process is complex and difficult to control. Moreover, the film can be easily damaged and then can no longer provide protection against water and dust. In addition, it is difficult to adhere the key cap of the keypad assembly to the outer shell. 
         [0006]    Therefore, a new key assembly in order to overcome the above-described shortcomings needs to be provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Many aspects of the present keypad assembly and portable electronic device 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 keypad assembly and portable electronic device. Moreover, in the drawings like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. 
           [0008]      FIG. 1  is an exploded view of a portion of a portable electronic device using a side key assembly according to an exemplary embodiment. 
           [0009]      FIG. 2  is an assembled view of the portable electronic device shown in  FIG. 1 . 
           [0010]      FIG. 3  is a partial cut-away view of the portable electronic device in  FIG. 2 . 
           [0011]      FIG. 4  is an isometric and exploded view of the side key assembly shown in  FIG. 1 , showing one aspect thereof. 
           [0012]      FIG. 5  is an isometric and exploded view of the side key assembly shown in  FIG. 1 , showing another aspect thereof. 
           [0013]      FIG. 6  is an assembled view of the side key assembly shown in  FIGS. 4 and 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0014]    Referring to  FIGS. 1 ,  2  and  3 , a portion of a portable electronic device  200  includes a side key assembly  10 , a housing  20 , and a circuit board  30 . The side key assembly  10  is assembled with the housing  20 . The circuit board  30  is also assembled with the housing  20 . 
         [0015]    The housing  20  includes a peripheral wall  22  and a bottom panel  24 . The peripheral wall  22  and the bottom panel  24  define a chamber  26 . The circuit board  30  is disposed (e.g., bolted or adhered) on the peripheral wall  22  in the chamber  26 . The peripheral wall  22  has a keyhole  28  defined therethrough. The side assembly  10 , as assembled with the housing  20 , is adhered to the peripheral wall  22  and partly accommodated in the keyhole  28 , ( FIGS. 2 and 3 ). Thus, the side key assembly  10  corresponds with the circuit board  30  for inputting information to the portable electronic device  200 . 
         [0016]    Referring to  FIG. 4 , the side key assembly  10  includes a key cover  12  and a key body  14 . 
         [0017]    Referring to  FIGS. 5 and 6 , the key cover  12  is configured (e.g., structured/arranged) for accommodating the key body  14  therein and is generally a semi-enclosed shell with a raised edge  122  and a planar surface  124 . The raised edge  122  and the planar surface  124  define a receiving space  126 . 
         [0018]    The key body  14  includes a soft portion  142  and a hard portion  144 . The soft portion  142  is mounted to the hard portion  144 . 
         [0019]    The soft portion  142  is made of an elastic material (e.g., an elastic rubber material) so soft portion  142  can be distorted under an external force exerted thereon and restored to its original state upon release of the external force. 
         [0020]    The soft portion  142  has a front surface  1421  and a rear surface  1422 . The rear surface  1422  includes a projection  1423  thereon. The front surface  1421  defines a recess  1424  that corresponds to the projection  1423 . The soft portion  142  further has a flange  1425  formed surrounding the projection  1423 . Correspondingly, the flange  1425  surrounds the recess  1424  therein. The projection  1423  is disposed in the receiving space  126  of the key cover  12  to form an integral assembly. 
         [0021]    The soft portion  1423  has a plurality of contacts  1426  protruding from the bottom surface (not labeled) of the recess  1424 . The number of the contacts  1426  can be modified according to actual needs. The contacts  1426  correspond to conventional signal sensing points (not shown) of the circuit board  30 . The contacts  1426  facilitate pressing the signal sensing points. 
         [0022]    The flange  1425  has a plurality of mating holes  1427  defined therethrough. The mating holes  1427  are located around the projection  1423 . 
         [0023]    The hard portion  144  is made of a hard material (e.g., a hard plastic material) and has a first surface  1441  and a second surface  1442 . The second surface  1442  is an attaching surface for attaching the hard portion  144  to the soft portion  142 . The hard portion  144  has an aperture  1443  corresponding to the projection  1423 . The aperture  1443  is substantially the same size and shape as the projection  1423 . Correspondingly, the contacts  1426  can respectively penetrate through the aperture  144 . 
         [0024]    The hard portion  144  has a slot  1444  defined in the second surface  1442 . The slot  1444  has substantially the same size and shape as the flange  1425 . The slot  1444  accommodates the flange  1425 . 
         [0025]    A plurality of protrusions  1445  protrude from the bottom surface (not labeled) of the slot  1444 . The protrusions  1445  of the hard portion  144  correspond with the mating holes  1427  so the mating holes  1427  can accommodate the protrusions  1445  therein. 
         [0026]    Referring to  FIGS. 4-6 , during assembly of the side key assembly  10 , the flange  1425  is adhered in the slot  1444 . Then the protrusions  1445  are accommodated in the mating holes  1427 . In this case, the soft portion  142  can be assembled integrally with the hard portion  144 . Thus, water and dust cannot penetrate through the engaging surface between the soft portion  142  and the hard portion  144 . After that, the projection  1423  is adhered into the receiving space  126 . In use, because the hard portion  144  is made of a hard material, it can be firmly adhered to the housing  20 . 
         [0027]    Referring back to  FIGS. 1 through 3 , as the side key assembly  10  is assembled to the housing  20  of the portable electronic device  200 , the key cover  12  and the soft portion  142  of the side key assembly  10  are partly disposed in the key hole  28  of the housing  20 . The hard portion  144  of the side key assembly  10  is then adhered to the housing  20  of the portable electronic device  200  with glue  40 . The glue  40  can be a waterproof glue to prevent water and dust from entering into the portable electronic device  200 . In use, the side key assembly  10  is accommodated in the housing  20  of the portable electronic device  200  by the glue  40 . More specifically, the hard portion  144  is made of a hard material, so the hard portion  144  can be firmly adhered to the housing  20  of the portable electronic device  200 . Thus, the portable electronic device  200  has no gaps between the housing  20  and the side key assembly  10 , thereby preventing water and dust from entering into the portable electronic device  200 . As a result, the portable electronic device  200  has advantageous effects such as being waterproof and dustproof. 
         [0028]    It is to be understood that the integrating means between the key cover  12  and the soft portion  142 , and between the soft portion  142  and the hard portion  144  is not confined to glue. For example, the key cover  12 , the soft portion  142  may be integrally molded onto the hard portion  144 . 
         [0029]    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 parts 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.