Abstract:
A key button structure ( 10 ) for using in a portable electronic device ( 100 ) is provided. The key button structure ( 10 ) include a housing ( 14 ) having a joining portion ( 1428 ) formed on the outer wall ( 1422 ) of the housing ( 14 ) and a key body ( 124 ) have a mating portion ( 1245 ) formed thereon corresponding with the joining portion ( 1428 ).

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to key button structures, particularly to key button structures used in a portable electronic device. 
         [0003]    2. Description of related art 
         [0004]    Many portable electronic devices such as mobile phones, each has a housing with an interior compartment for receiving a printed circuit board (PCB) therein. The mobile phone usually includes a side key assembly on an outer sidewall of the housing, so that user can operate the mobile phone merely by one finger. Typically, the side key assembly includes a key cover and a key cap adhered with the key cover. The key cap is elastic. The key cap can be distorted once an external force exerted thereon, and then restored to its original state by eliminating the external force. The key assembly is disposed in a hole defined on an outer shell of portable electronic device, and a slight gap is defined between the key assembly and the outer shell. If the key assembly is wetted, water and/or vapor may penetrate through the gap into the portable electronic device, thus affecting circuit board of the portable electronic device. In addition, if the dust in the air enters into the portable electronic device through the gap, the performance of the portable electronic device would also be deteriorated 
         [0005]    Therefore, a new key button structure for use in a portable electronic device in order to overcome the above-described shortcomings needs to be provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is an exploded view of a portion of a portable electronic device using a key button structure in accordance with an exemplary embodiment. 
           [0007]      FIG. 2  is an assembled view of the portable electronic device shown in  FIG. 1 . 
           [0008]      FIG. 3  is an isometric and exploded view of the portable electronic device shown in  FIG. 1 , showing another aspect thereof. 
           [0009]      FIG. 4  is partially enlarged view of the portable electronic device shown in  FIG. 3 . 
           [0010]      FIG. 5  is an isometric and assembled view of the portable electronic device shown in  FIG. 3 . 
           [0011]      FIG. 6  is a cross sectional view of the portable electronic device shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0012]      FIG. 1  shows a portable electronic device  100  (only a portion of which is shown) having a housing  14  and a key button structure  10 . The housing  14  includes a peripheral wall  142  and a bottom panel  144 . The peripheral wall  142  and the bottom panel  144  define/enclose a chamber  146  where a circuit board  16  is positioned. 
         [0013]    As shown in  FIGS. 5 and 6 , the circuit board  16  is associated with the key button structure  10 . The key button structure  10  is configured for being pressed to contact the circuit board  16 , e.g., to generate an electrical signal. 
         [0014]    The key button structure  10  includes a key cap  122  and a key body  124 . 
         [0015]    The key cap  122  is made of an elastic material (e.g., an elastic rubber material) and can be distorted by an external force. The key cap  122  returns to its original state by releasing the force. 
         [0016]    Referring to  FIG. 2 , the key cap  122  has a front surface  1222  and a rear surface  1224 . The front surface  1222  is an operating surface of the key button structure  10 . Accordingly, a push portion  1223  is formed (e.g., mounted) on the front surface  1222 . The key cap  122  has at least one contact  1226  protruding from rear surface  1224 . The contact(s)  1226  correspond to and contact signal sensing points  162  of the circuit board  16 . The key body  124  is made of a hard material (e.g., a hard plastic material). 
         [0017]    The key body  124  has a first wall  1241  and a second wall  1242 . The first wall  1241  faces the key cap  122  and is for attaching the key cap  122  to the key body  124 . In particular, the key body  124  has a first groove  1244  defined in the first wall  1241 . The first groove  1244  surrounds a through aperture  1243 . The first groove  1244  has substantially the same size and shape as that of the key cap  122 . Accordingly, key cap  122  is press fit into groove  1244 . 
         [0018]    The second wall  1242  is for attaching the key body  124  to the housing  14 . Referring to  FIG. 3 , the key body  124  has a mating portion  1245  in the form of a mating slot formed on the second wall  1242  and surrounding the through aperture  1243 . The mating portion  1245  is exemplified by a mating slot in the present embodiment, and the cross section of the mating slot is triangle in shape. The peripheral wall  142  of housing  14  has a key hole  1423  defined therethrough. The contact(s)  1226  can enter the housing through the key hole  1423 . Referring to  FIG. 4 , the housing  14  has a second groove  1424  defined in the outside wall  1422  and having a bottom surface  1426  formed on the housing  14 . The second groove  1424  surrounds the key hole  1423 . The second groove  1424  has substantially the same size and shape as that of the key body  124  for receiving the key body  124  therein. A joining portion  1428  protrudes from the bottom surface  1426 . The joining portion  1428  is a rib surrounding the key hole  1423 . The joining portion  1428  has substantially the same size and shape as that of the mating portion  1425 , and the joining portion  1428  mates with the mating portion  1245 . 
         [0019]    Referring to  FIGS. 5 and 6 , during assembling the key button structure  10 , the key cap  122  is adhered (e.g., by a glue) within the first groove  1244  of the key body  124 , and the contact  1226  of the key cap  122  penetrate through the through aperture  1243  of the key body  124 . Then the key body  124  is received in the second groove  1424 , and the joining portion  1428  mates with the mating portion  1425 . The joining portion  1428  is welded with the mating portion  1425  via ultrasound welding, thus the key body  124  is assembled with the housing  14  (i.e., the key button structure  10  is assembled with the housing.) In use, since the key button structure  10  is welded with the housing  14 , the housing  14  and the key button structure  10  are tightly sealed together without a gap, thereby preventing water and/or dust from entering into the interior space of the portable electronic device  100 . As a result, the portable electronic device  100  of the present embodiment is waterproof and dustproof. 
         [0020]    It is to be understood that the key cap  122  may be integrally molded with the key body  124 . 
         [0021]    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.