Abstract:
A housing for an electronic device is disclosed and comprises a unitary tubular body ( 1 ) having an open end ( 2 ) for insertion of electronic componentry therein. Preferably, the housing is for a mobile telecommunications device.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a housing for an electronic device and, particularly but not exclusively, to a housing for a mobile telecommunications device such as a mobile telephone. 
   BACKGROUND OF THE INVENTION 
   A housing for a mobile telephone generally comprises a front and a rear casing. The electronic circuitry and other components of the telephone are mounted on one casing and the other casing part fits over it in a back-to-back relationship to form an enclosure around the circuitry and components. The two casing halves ate attached to each other and are separable to enable access to the interior of the telephone for maintenance and other requirements such as insertion or removal of a SIM card. Additionally, design conscious consumers often prefer to personalise their telephone by replacing one or both parts of the casing with another of a different colour so it is important that a consumer can separate the casing portions without difficulty. Screws or clips may be used to attach the two casing halves together. 
   A disadvantage with a conventional housing such as that described above is that the join between the two housing portions extends all the way around the assembled telephone housing and is clearly visible. This compromises the design and appearance of the telephone thereby reducing the overall quality and feel of the product to consumers. Furthermore, the housing of a mobile telephone is subject to considerable wear and must not break too readily when inadvertently dropped. As the conventional housing is formed in two back-to-back parts releasably joined together, the overall strength and rigidity of the housing is reduced thereby increasing the likelihood that one or both parts will break on impact. It is possible to increase the strength and rigidity of a conventional housing by increasing the thickness of the materials from which the casing is made. However, this results in an increase in overall weight which also needs to be kept to a minimum. 
   SUMMARY OF THE INVENTION 
   It is one object of the present invention to overcome or alleviate the aforementioned disadvantages associated with a conventional housing for an electronic device. 
   According to the present invention, there is provided a housing for an electronic device comprising a unitary tubular body having an open end for insertion of electronic components therein. 
   The housing preferably includes a member for closing the open end of the tubular body. 
   The member is advantageously configured to support electronic components thereon. The electronic components may include a printed circuit board. 
   In a preferred embodiment, a portion of the inner peripheral wall of the member includes a recess to receive a transducer module. 
   A guide is formed on the body to receive and support electronic components mounted on the member. In one embodiment, the guide means is a rail. 
   Preferably, the body includes a plurality of apertures in one face to receive the keys of a keymat mounted on an inner wall of the body, and an opening in the other face opposite the apertures to receive a battery pack. 
   The body preferably also includes means to releasably secure a keymat retaining plate over the keymat. 
   In a preferred arrangement, a portion of the body overlaps the member, said body and member including co-operating means to mount the member on the body. 
   The co-operating means conveniently includes a flange on the member that forms an interference fit with the body. 
   Preferably, a lock is provided for releasably securing the member mounted to the body. The lock can include an aperture in the member and a boss in the body, fastening means being insertable through the aperture for engagement in the boss. 
   The present invention also relates to an electronic device incorporating the housing of the invention. Most preferably, the electronic device is a mobile telecommunications device. 
   The electronic device preferably includes a keymat, a keymat retaining plate and a battery pack, the retaining plate being configured such that the keymat is biased against the housing by the retaining plate when the battery pack is mounted in the housing. 
   In a preferred embodiment, the retaining plate includes resiliently deformable regions raised out of the plane of the plate, said regions being deflected back towards the plane of the plate by the battery pack when mounted in the housing, thereby biasing the keymat against the housing. 
   The resiliently deformable regions are preferably a plurality of spaced parallel ribs. 
   The present invention also relates to a method of forming a housing according to the invention for an electronic device according to the invention by permanently attaching at least two housing portions together. 
   The housing portions may be attached to each other by welding. 
   Alternatively, the housing portions may be attached by adhesive bonding. 
   The present invention also relates to a method of forming a housing for an electronic device both according to the invention, including the step of forming the housing in one piece. 
   In one embodiment, the housing is formed by extrusion. 
   In another embodiment, the housing is formed from sheet metal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a perspective view of the housing of a mobile telephone of the invention together with a module shown removed from the open end of the housing, the module carrying the electronic componentry of the telephone; 
       FIG. 2  illustrates a perspective view of the underside of the housing shown in  FIG. 1  together with the keymat, keymat retaining plate before insertion into the housing; 
       FIG. 3  illustrates a perspective view of the underside of the module shown in  FIG. 1 ; 
       FIG. 4  illustrates a perspective view of the transducer module for fitting to the module illustrated in  FIG. 3 ; and 
       FIG. 5  illustrates a partial cross-section through the housing with the keymat, retaining plate and battery fitted thereto. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings. 
   Referring now to the drawings, there is shown in  FIGS. 1 and 2  a housing for a mobile telephone comprising a rigid unitary tubular body  1  open at one end  2 . The front face  3  extends forward of the rear face  4  to form an overhang  5 . The front face includes an aperture  6  for attachment of a transparent window  7  by laser welding (part of the window is shown fitted in the aperture  6 , in  FIG. 2 ). Beneath the aperture  6  on the front face  3  is an array of smaller openings  8  through which the keys  9  of a keymat  10  may protrude. The rear face  4  has a rectangular aperture  11  therein opposite the array of smaller openings  8  in the front face  3  for insertion of a keymat  10 , a keymat retaining plate  12  and a battery pack  13  in the order and direction shown by arrow A in  FIG. 2 . These components will be explained in more detail hereinafter. 
   The body  1  includes integrally moulded guide rails  14  formed along each inside edge between the front and tear faces  3 , 4  to support a printed circuit board  15  and other electronic components  16  such as a liquid crystal display within the body  1 . These components are mounted to a module  17  that fits over the open end  2  of the body  1  and interfaces with the edge of the open end  2  to close the body  1 . The module  17  has an integrally moulded “U”-shaped clip  18  to receive and support the edge of the printed circuit board  15  and a spigot  16  to support its underside. Other electronic components are mounted to the PCB  15 . 
   The module  17  includes an integrally formed boss  18  therein through which the antenna of the mobile telephone may extend. A portion  19  of the inner peripheral wall  20  of the module  17  is recessed to receive a transducer module  21  illustrated in  FIG. 4 , and has a first elongate port  22  to allow for the transmission of infra red waves through the module  17  from an emitter (not shown) mounted to the rear face  23  of the transducer module  21  that has a corresponding opening  24 . Two further circular openings  25 , 26  are provided in the recess to receive an on/off key (not shown) and to allow for transmission of sound through the module  17  from a transducer (not shown). The transducer and on/off key are both mounted to the rear face  23  of the transducer module  21  which is provided with openings  25   a,    26   a  that correspond to the openings in the module  17 . 
   The transducer module  21  is “L” shaped to fit the recess  19  in the peripheral wall  20  of the module  17  and has a reinforcing web  21   a  to increase its rigidity. A flexible electrical connector  27  extends from the transducer module  21  which connects to an interface on the printed circuit board  15 . 
   The edge  28  of the printed circuit board  15  mounted to the module  17  locates on the top surface of the guide rails  14  and is slideably received within the body  1 . When fully inserted into the body  1 , the overhang  5  covers the electronic components and PCB  15  on the module  17  and closes the open end  2  of the body  1 . The liquid crystal display is visible through the window  7  in the aperture  6  when the module  17  is located on the body  1 . The module  17  includes a pair of apertures  29  therein and the body I has a pair of corresponding bosses  30  that are in alignment when the module  17  is fitted to the body  1 . Conventional screws  31  (not shown) extend through the apertures  29  and are threadingly engaged in the bosses  30  to releasably secure the module  17  to the body  1 . 
   Referring now to  FIG. 2  and  FIG. 5 , the keymat  10  is disposed within the body  1  such that the keys  9  protrude through the apertures  8  in the front face  3 . The keymat  10  is maintained in position using a layer of adhesive  32  interspersed between the body  1  and the keymat  10 . The keymat  10  is positioned within the body  1  by inserting it through the rectangular aperture  11  in the rear face  4 . To further retain the keymat  10  in position, the retaining plate  12  is positioned above the keymat  10  and locates under tabs  34  integrally formed on the body  1  between the front and rear faces  3 , 4 . The retaining plate  12  is made from a resilient plastics material such as polyurethane and is a snap-fit under tabs  34 . 
   The retaining plate  12  comprises an end portion  35  bent at right angles to the plane of the plate  12 . A support block  36  is mounted to end portion  35  and co-operates with the closed end of the casing to further hold the retaining plate  12  in position in the body  1 . Three ribs  40  are deformed out of the plane of the plate  12  directly above the keys  9 . As is clearly shown in  FIG. 5 , when the battery pack  13  is inserted into the aperture  11 , the ribs  40  are compressed (see rib  40   a  in  FIG. 5 ) by the underside  41  of the battery pack  13  to urge the plate  12  against the keymat  10 , and the keymat  10  against the body  1 . When the battery pack  13  is removed, the resilient nature of the material from which the plate  12  is made causes the ribs  40  to spring back into their original shape, as shown by rib  40  in  FIG. 5 . 
   The retaining plate  12  includes an arm  45  that extends laterally from the other end of the plate  12 . The printed circuit board  15  contacts the arm  45  when inserted into the body  1  to provide additional support for the printed circuit board  15  and the retaining plate  12 . 
   The battery pack  13  is inserted into the body  1  through the aperture  11  from above (in the direction shown by arrow A in  FIG. 2 ) and the outer cover  46  of the back of the battery pack  13  locates within the edges of the aperture  11 . A moulded lip  47  on the cover  46  engages beneath the rear face  4  of the body  1  to retain the battery pack  13  in position. 
   The body  1  of the housing may be formed using a number of different methods. For example, it may be made in two parts which are subsequently permanently attached together by laser or ultrasonic welding, MIG or TIG welding or by using adhesive along their interface. Alternatively, the body  1  can be formed in one piece by extrusion, by injection moulding or by sheet metal forming. The body  1  can be made from either plastics material or metal. 
   Many modifications and variations of the invention falling within the terms of the following claims will be apparent to those skilled in the art and the foregoing description should be regarded as a description of the preferred embodiments only.