Abstract:
Described is a mobile device with a protective antenna cover. The mobile device comprises a housing, an antenna and an antenna cover. The housing encloses electronic components of the device including at least one of a transmitter and a receiver. The antenna is coupled to the one of a transmitter and a receiver. The antenna cover is ultrasonically welded to the housing. The antenna cover defines an interior space within which at least a part of the antenna is received. The interior space is sized so that the part of the antenna received therewithin is separated from an inner surface of the antenna cover around an entire circumference thereof.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to mobile devices with antennas. 
       BACKGROUND INFORMATION 
       [0002]    Mobile devices are subject to frequent handling by users and are consequently damaged by being dropped, struck by or against another object, or simply mishandled. One feature of many mobile devices is an antenna enabling these devices to transmit and/or receive signals. 
         [0003]    A conventional method of protecting the antenna is to cover the antenna with a protective layer such as a plastic coating. However, if sufficient force is applied thereto, the coating (and consequently the antenna) may bend or snap, damaging the device. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention relates to a mobile device with a protective antenna cover. The mobile device comprises a housing, an antenna and an antenna cover. The housing encloses electronic components of the device including at least one of a transmitter and a receiver. The antenna is coupled to the one of a transmitter and a receiver. The antenna cover is ultrasonically welded to the housing. The antenna cover defines an interior space within which at least a part of the antenna is received. The interior space is sized so that the part of the antenna received therewithin is separated from an inner surface of the antenna cover around an entire circumference thereof. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is an exemplary embodiment of a mobile device according to the present invention; 
           [0006]      FIG. 2  is a partial side view of the mobile device of  FIG. 1 ; 
           [0007]      FIG. 3  is a partial cross-sectional view of the mobile device of  FIG. 1  along line A-A; and 
           [0008]      FIG. 4  is a top view of an interior portion of the antenna cover of the device of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are provided with the same reference numerals. The present invention relates to mobile devices (e.g., mobile units, (“MUs”)) with antennas. An exemplary embodiment of the present invention is described with reference to an MU with a barcode scanner, however those skilled in the art will understand that the present invention may be implemented with any type of antenna-based MU such as, for example, an RFID reader, a cell phone, a PDA, a laptop, an image-/laser-based scanner, a network interface card, etc. 
         [0010]      FIG. 1  shows an exemplary embodiment of an MU  50  according to the present invention. The MU  50  includes a scanner (e.g., a barcode scanner  160 ) as well as one or more user input devices, such as a keypad, push buttons  150 , a stylus  155 , etc. The MU  50  may further include a display (e.g., an LCD) and computing components such as a processor, a memory, a hard drive, a wireless communications arrangement (e.g., a wireless transmitter and/or receiver), etc. 
         [0011]    The wireless communications arrangement includes an antenna  300  (shown in  FIG. 3 ) which transmits and/or receives radio frequency (“RF”) signals to/from another device (e.g., an access point). In the exemplary embodiment, the antenna  300  is substantially tubular in shape. However those skilled in the art will understand that the antenna  300  may have any other shape such as, for example, helical, “T”, parabolic, rectangular, etc. without departing from the scope of the invention. The antenna  300  may be any type of antenna including, but not limited to, a quarter wave, half-wave, co-linear and patch antenna. Furthermore, as would be understood by those skilled in the art, the antenna  300  may be formed of any material(s) suitable for transmitting and receiving radio waves, such as aluminum, steel, copper, fiberglass, etc. 
         [0012]    As shown in  FIG. 1 , the MU  50  includes a housing  100  and an antenna cover  200 . The housing  100  may be constructed of any number of materials, but is preferably formed of a durable plastic or rubber material using a conventional method such as, for example, injection or extrusion molding. The housing  100  may be formed integrally, or as a composite of two or more pieces. For example, the housing  100  may comprise two pieces held together using one or more screws  10 . Other attachment methods, such as snap fitting, adhesive bonding, etc. may also be used in conjunction with or as an alternative to screws. 
         [0013]    In an exemplary embodiment, the antenna cover  200  is formed using the same or similar materials and methods as the housing  100 . For example, the antenna cover  200  may be formed using a substantially rigid polymer that undergoes little or no deformation when subjected to temperatures consistent with an operating environment of the MU  50 . In other embodiments, the antenna cover  200  may be formed of a substantially different material from that of which the housing  100  is formed. For example, the material may be more or less rigid than that used for the housing  100 , the material may have different temperature response, different density, etc. 
         [0014]    Thicknesses of the antenna cover  200  and the housing  100  are preferably selected based on physical characteristics of the MU  50  (e.g., size, weight, etc.) and/or based on the operating environment (e.g., industrial environments may require greater thicknesses than home environments). As would be understood by those skilled in the art, larger thicknesses may increase rigidity and/or enhance shock absorption, while smaller thicknesses may decrease the size and/or weight of the MU  50 , making it easier to handle. 
         [0015]    A shown in  FIG. 2 , the antenna cover  200  which is mated to the housing  100 , includes an optional collar portion  210  which is attached to a receiving shoulder  110  of the housing  100 . The collar  210  may be permanently attached to the shoulder  110  via ultrasonic welding. For example, an ultrasonic signal may be applied to the shoulder  110  and/or the collar  210 , thereby heating a surface thereof and causing the surface to bond to a mating surface of an opposing piece. After the ultrasonic signal is removed, the piece(s) rapidly cools and a permanent bond is formed. The permanent bond may form a tight seal around the pieces  110 ,  210  that is substantially gas and/or liquid impermeable. In other embodiments, alternative bonding methods such as adhesives (e.g., glue) may be used to perform the attaching. 
         [0016]    As shown in  FIG. 3 , the antenna  300  is enclosed within a hollow portion of the antenna cover  200  and extends into interior portion of the housing  100 . In an exemplary embodiment, the antenna cover  200  completely surrounds the antenna  300  without contacting any portion thereof. For example, a space  290  around the antenna  300  comprises a buffer zone or sway space which in an exemplary embodiment of the invention, is filled with air. However in other embodiments, the space  290  may be partially or entirely filled with any radio-conductive complaint material (e.g., a shock-absorbing polymer, an inflatable membrane, etc.). Thus, if the antenna cover  200  is subjected to an external force (e.g., an impact) the space  290  allows the antenna cover  200  to be deformed without transferring the force to the antenna  300 . In addition, if the external force is sufficient to separate the antenna cover  200  from the housing  100 , the space  290  allows the antenna cover  200  to be partially or entirely displaced without contacting the antenna  300 . 
         [0017]    As shown in  FIG. 3 , the antenna cover  200  includes an inner end  220  which extends into a hole in the shoulder  110  to, for example, contact and/or mate with the shoulder  110  to which it may be ultrasonically welded. In an exemplary embodiment a shown in  FIG. 3 , the inner end  220  does not extend past an end of the shoulder  110 , and the inner end  220  terminates with a small gap between an innermost surface of the inner end  220  and an innermost surface of the shoulder  110 . However, in other embodiments the inner end  220  may extend past the shoulder  110  into the interior portion of the housing  100 . 
         [0018]    As shown in  FIG. 4 , the antenna cover  200  may mate with the shoulder  110  without any spacing there between and with the antenna cover  200  completely surrounding the antenna  300  while separated there from around its entire circumference by the space  290 . One or more ridges  120  of the housing  100  may extend laterally into the inner end  220  towards the antenna  300  so long as a minimum desired clearance of the space  290  is maintained. 
         [0019]    As shown, the ridge  120  extends only partially into the inner end  220 , terminating before the sway space  290 . In other embodiments, the ridge  120  may extend into the sway space  290  without contacting the antenna  300 . The ridge  120  may provide additional structural support for the antenna cover  220  by, for example, resisting inwardly directed compressive forces while providing stability by restricting longitudinal displacement of the antenna cover  200 . Although in the exemplary embodiment only one ridge  120  is utilized, in other embodiments a plurality of ridges  120  may be placed along a perimeter of the innermost surface of the inner end  220 . For example, at each corner of the innermost surface of the inner end  220 , along a middle of each side of the innermost surface of the inner end  220 , etc. 
         [0020]    As previously discussed, the antenna cover  200  may be ultrasonically welded to the housing  100  to form a permanent bond between any surface (e.g., an inner surface of the collar  210 , a lateral surface of the inner portion  220 , etc.) of the antenna cover  200  and the shoulder  110  and/or the ridge  120 . This provides an extremely strong bond which is stable and resists external forces. For example, if the force is a pulling force directed outward against the antenna cover  200 , the force may be transferred to part or all of the housing  100  and dispersed, since the antenna cover  200  and the housing  100  act as a single structure. If the force is a compressive force, it may also be transferred to the housing  100  and dispersed. 
         [0021]    Dispersal of the force may cause a portion of the housing  100  which is weaker relative to the antenna cover  200  and/or the shoulder  110  (e.g., which has been intentionally weakened) to yield. For example, the force may cause the weaker portion to break (e.g., crack, deform, snap, etc.) and dispose the force before the antenna cover  200  is damaged, thereby preventing damage to the antenna  300 . Thus, the housing  100  may be designed to include one or more weaker portions in non-critical areas of the MU  50 , where breakage would not cause permanent damage and/or impairment of functionality. 
         [0022]    Alternatively, according to an exemplary embodiment the designer may choose to make the housing  100  stronger than the antenna cover  200 , allowing the cover  200  to yield before the housing  100 . So long as the space  290  prevents damage to the antenna  300 , the antenna cover  200  may be replaced. In other embodiments, the antenna cover  200  and the housing  100  may be equally strong so that external forces applies to the antenna cover  200 , cause the ultrasonic weld to yield separating the antenna cover  200  from the housing  100  to disperse the force. 
         [0023]    The present invention has been described with reference to the above exemplary embodiments. One skilled in the art would understand that the present invention may also be successfully implemented if modified. Accordingly, various modifications and changes may be made to the embodiments without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings, accordingly, should be regarded in an illustrative rather than restrictive sense.