Abstract:
A structure of a keyboard is combinable with an electronic device, and includes a keyboard body and a frame. The frame is of a U-shape having two limbs that has end portions slidably fit in elongate slots defined in two side walls of the keyboard body to be movable along the slots and rotatable with respect thereto. When the keyboard body and the frame are assembled together, the keyboard structure defines in a top thereof a receptacle for receiving and retaining the electronic device. The keyboard body includes a signal output structure engageable with a signal transmission interface of the electronic device. When combined together for operation, the electronic device is movable with the frame to expose keys of the keyboard. The electronic device is detachable from the keyboard structure for independent operation thereby reducing the overall size for easy carrying.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention generally relates to a structure of keyboard that is combinable with an electronic device, and particularly to a keyboard structure that is readily combined with and/or detached from a portable electronic device to form a unitary device, wherein the portable electronic device is a device that comprises a touch panel for receiving input operations, such as a mobile phone, a palmtop computer, a game device, a personal digital assistant (PDA), an MP4 device, or other similar devices or other devices having multiple functions, so that after the combination of the keyboard of the present invention with the electronic device, the keyboard that is additionally mounted can be used for operation and further, the keyboard, when not in use, can be detached from the electronic device to allow the electronic device to be operated in an independent manner with the touch panel. 
     DESCRIPTION OF THE PRIOR ART 
     A known electronic device, such as a mobile phone, a palmtop computer, a game device, a PDA, an MP4 device, or other electronic device having similar functions, is provided in such a form that the input and operation thereof are realized in two ways, one being a keyboard or a keypad, and the other being a liquid crystal touch panel. Both ways of input and operations for electronic devices have advantages and disadvantages. 
     Input with a keyboard is disadvantageous in that the keyboard occupies a substantial surface area and space of the electronic device, so that the area of a display screen is made small. For a given size of an electronic device, to make a display screen large, the keyboard and the display screen are often manufactured as separate enclosures, which are jointed in a movable manner, such as a flap cover arrangement, a foldable arrangement, or a retractable arrangement. This, however, increases the volume and weight of the whole electronic device, making it inconvenient to carry. 
     The solution of input through a touch panel, although effectively overcoming the problem of size and weight (for an electronic device of the same dimensions), is disadvantageous in that in performing an operation or entering an input, the image of a keyboard is shown on the display screen and is put to overlap or locate next to an image displayed on the screen, whereby the image to be observed by a user is interfered with or reduced. This problem does not occur in the device that uses a keyboard as an input device. 
     Thus, the present invention aims to provide a solution to overcome the problems observed in the above discussed two types of input of electronic devices. 
     SUMMARY OF THE INVENTION 
     The primary purpose of the present invention is to provide a structure of a keyboard that is combinable with an electronic device so as to be integrated with the electronic device to allow the electronic device to perform input or operation control with the keyboard and that is detachable from the electronic device to allow the electronic device to be operated with a touch panel originally provided on the electronic device. 
     To achieve the above purpose, the present invention provides a keyboard structure that comprises a keyboard body and a frame. The keyboard body has two opposite side walls, which define a pair of symmetric elongate slots. The keyboard body has a top surface forming stop flanges along portions of a circumference thereof. The keyboard body contains therein a keyboard circuit that comprises a signal output structure extending therefrom for engagement with a corresponding signal transmission interface of an electronic device. The frame comprises two slide blocks, two extension arms, two hinge devices, and an outer frame member. The two slide blocks are respectively fit into the elongate slots defined in the side walls of the keyboard body to be movable frontward and backward along the elongate slots. The two extension arms are respectively and pivotally jointed to rear ends of the slide blocks by the hinge devices and extend rearward to be rotatable upward and downward with the hinge devices serving as rotation centers. The outer frame member is in the form of a U-shaped tubular member and has two limbs each having a front end forming an opening telescopically fit over the respective extension arm. The outer frame member has a top surface forming in a potion thereof a stop flange. The stop flange forms a plurality of retention hooks on an inside face of a rear wall thereof. 
     According to the structure described above, when the keyboard body and the frame are assembled together and set in a collapsed condition, the stop flanges formed on the top surfaces of the keyboard body and the frame define a receptacle corresponding to a bottom of a circumference of the electronic device for receiving the electronic device therein in such a way that the retention hooks are engageable with the electronic device and he signal output structure that extends from the keyboard body is engageable with the signal transmission interface of the electronic device to establish transmission and connection therebetween. When the electronic device is moved rearward with the extension of the frame, keys of the keyboard body are exposed outside to allow for operation and use. When the keyboard is not in use, the keyboard structure can be completely separated from the electronic device to reduce the overall size for easy carrying. 
     The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a keyboard constructed in accordance with the present invention set in an expanded condition with respect to a frame; 
         FIG. 2  is an exploded view of  FIG. 1 . 
         FIG. 3  is a perspective view showing a combination of the present invention and an electronic device. 
         FIG. 4  is a perspective view showing the present invention in an operation condition. 
         FIG. 5  is a side elevational view of  FIG. 5 . 
         FIG. 6  is a perspective view showing a combination of a keyboard structure of another embodiment of the present invention with an electronic device. 
         FIG. 7  is a perspective view showing a combination of a keyboard structure of a further embodiment of the present invention with an electronic device. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
     As shown in  FIGS. 1 to 3 , a keyboard constructed in accordance with the present invention, generally designated at  10 , is combinable with an electronic device, designated at  30 . The keyboard  10  comprises a keyboard body  100  and a frame  200 . The keyboard body  100  has two opposite side walls, which define a pair of symmetric elongate slots  101 . The keyboard body  100  has a top surface forming first stop flanges  102  along portions of a circumference thereof. The keyboard body  100  contains therein a keyboard circuit that comprises a signal output structure  104  extending therefrom for engagement with a corresponding signal transmission interface  302  of the electronic device  30 . The frame  200  comprises two slide blocks  210 , two extension arms  220 , two hinge devices  230 , a retention hook  243 , and an outer frame member  240 . The two slide blocks  210  are respectively fit into the elongate slots  101  defined in the side walls of the keyboard body  100  to be movable frontward and backward along the elongate slots  101 . The two extension arms  220  are respectively and pivotally jointed to rear ends of the slide blocks  210  by the hinge devices  230  and extend rearward to be rotatable upward and downward with the hinge devices  230  serving as rotation centers. The outer frame member  240  is in the form of a U-shaped tubular member and has two limbs each having a front end forming an opening  241  telescopically fit over the respective extension arm  220 . The outer frame member  240  has a top surface forming a second stop flange  242 . The second stop flange  242  forms a plurality of elongate openings  244  on an inside face of a rear wall thereof. 
     According to what discussed above, when the keyboard body  100  and the frame  200  are assembled together and set in a collapsed condition, the first stop flanges  102  formed on the top surfaces of the keyboard body  100  and the second stop flanges  242  formed on the top surfaces of the frame  200  define a receptacle  201  corresponding to a bottom of a circumference of an electronic device  30  (as shown in  FIG. 3 ) for receiving the electronic device  30  therein in such a way that the retention hook  243  is engageable with retention holes  301  defined in a rear surface of the bottom of the electronic device  30  to provide a unitary device. The signal output structure  104  that projects outward from the keyboard body  100  is made engaging the corresponding signal transmission interface  302  to establish transmission of power and data between the keyboard  10  and the electronic device  30 . The signal output structure  104  as discussed above is made in the form of a connector in the embodiment illustrated in  FIGS. 1 and 2 , comprising a flexible cable  103  that extends through hollow portions of the hinge device  230  and the extension arm  220  to penetrate into and fix inside the outer frame member  240  with conductor terminals  1041  of the signal output structure  104  exposed on the top surface of the outer frame member  240  to allow for engagement of the conductor terminals  1041  with contacts of the signal transmission interface  302  of the electronic device  30  exposed outside, whereby when the electronic device  30  and the keyboard  10  are combined together, electrical connection can be simultaneously established. 
     Further, to practice the present invention, the signal output structure  104  can be alternatively constructed to comprise a flexible cable  103  that extends outside the keyboard body  100  (as shown in  FIG. 6 ) and has a free end forming a signal output structure  104  (such as a plug connector) that mates a signal transmission interface  302  (signal output/input connection port) of the electronic device  30 . In combination, the signal output structure  104  is plugged into the signal transmission interface  302  of the electronic device  30  to similarly realize signal connection therebetween. Alternatively, the present invention may adopt a connection cable (not shown) having opposite free ends that are both provided with plug connectors, or as shown in  FIG. 7 , the signal output structure  104  and the signal transmission interface  302  are formed as mated infrared or Bluetooth wireless communication modules. 
     With the structure discussed above, the power that the keyboard circuit needs for the operation thereof can be transmitted in a wired manner through the flexible cable  103  and the signal output structure  104  for connection with and being supplied from an internally built up power source unit inside the electronic device  30 . Or alternatively the keyboard body  100  contains therein a separate power source unit  110  (as indicated by phantom lines of  FIG. 7 , which can be a rechargeable cell, a lithium cell, or a carbon-zinc cell) for self powering. 
     To combine the keyboard  10  as described above with an electronic device  30  for operation, the frame  200  is pulled rearward to the condition illustrated in  FIG. 1  or  4  to expose the keys of the keyboard body  100  by which the operation can be carried out. As described above, to facilitate visual observation of a display screen of the electronic device  30 , the present invention is made so that the frame  200  (with the electronic device carried thereon) is tilted upward by a given inclination angle, as shown in  FIGS. 4 and 5 . When the keyboard is not used, the retention hook  243  of the keyboard  10  is released to allow separation of the keyboard  10  from the electronic device  30  and then the electronic device can be separately carried and operated individually. 
     Referring to  FIGS. 1 and 2 , as described above, the frame  200  is provided with the retention hook  243 , which comprises an elongate metal bar having opposite ends each forming a raised barb  2431  projecting outside through a corresponding elongate opening  244  defined in the outer frame member  240  and movable along the elongate opening  244 . The retention hook  243  forms, on an intermediate section thereof, a coupling section  2432  and a mounting section  2433 , which project sideways in opposite directions. The coupling section  2432  extends outside the outer frame member  240  (projecting beyond a rear wall thereof) to couple to an operation knob  2434 . The mounting section  2433  is bent laterally for fixing a spring  2435  that has an end fixed inside the outer frame member  240  for biasing the retention hook  243  at a locked position. To unlock, the operation knob  2434  is manipulated to move in a direction opposite to biasing force of the spring  2435  so as to disengage the barbs  2431  out of the retention holes  301  of the electronic device  30  by which unlocking is realized and the electronic device  30  can be removed for separate use. 
     Further, each extension arm  220  of the frame  200  forms an inward projecting stop block  221  at an end thereof jointing to the respective slide block  210 , whereby when the frame  200  is tilted upward by rotation about a center defined by the hinge devices  230 , the stop block  221  is brought into engagement with and abutting a top surface of the slide block  210  to limit further inclination of the frame  200  and thus set the inclination angle of the frame  200  at a position that is most suitable for visual observation. 
     In the embodiment shown in  FIG. 1 , the keyboard body  100  forms a plurality of hooks  105  in an inside surface of the first stop flange  102  thereof for mating slots  303  defined in a front edge of the bottom of the electronic device  30 . To combine the keyboard  10  and the electronic device  30 , the frame  200  is first pulled rearward and after the retention hook  243  of the frame  200  engage and hold the electronic device  30 , the frame  200  is pushed forward to position (as shown in  FIG. 3 ) to have the electronic device  30  overlapping the keyboard  10 . By then, the hooks  105  of the keyboard body  100  are just fit into the slots  303  on the front edge of the electronic device  30  to prevent the electronic device  30  from separating. 
     Referring to the embodiment shown in  FIGS. 1 and 2 , the keyboard body  100  has a bottom that defines a recess  106 . The recess  106  forms a cutoff  107  in a rear surface of the keyboard body  100 . A support board  108  is arranged inside the recess  106 . The support board  108  is pivotally mounted, at an end thereof, inside the recess  106  by a pivot pin  109 , and has an opposite free end rotatable outward through the cutoff  107  to the rear side of the keyboard body  100 , or rotatable in a reversed direction back into and thus stowed inside the recess  106 . Thus, when set in the condition of  FIGS. 4 and 5  for operation, the support board  108  can be rotated outward to extend rearward from the keyboard body  100  to enhance stability for supporting the product on for example a desktop. Further, the support board  108  (as shown in  FIG. 2 ) is selectively provided at an outer edge thereof with a push tab  1081  extending upward. A V-shaped spring  1082  (or springs of the same function) is arranged between the support board  108  and an internal side face of the recess  106  to provide an outward-rotating biasing force so that when the frame  200  is expanded by being pulled rearward, the support board  108  is automatically sprung out for use. On the other hand, when the frame  200  is collapsed into the keyboard body  100 , an inside face of the frame  200  engages and forces the push tab  1081  of the support board  108  inward for storage into the recess  106 . This provides further enhancement of the efficacy of the product. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.