Abstract:
A keyboard assembly includes a keyboard body and an interface pivotally arranged on a pivotal axis of the keyboard body and being able to rotate laterally. The pivotal axis has an inclined angle with respect to a vertical line of the interface. The keyboard body is composed of a first panel and a second panel pivotally connected to the first panel. Each of the first panel and the second panel has a receiving space in a symmetrical arrangement to accommodate the interface.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a keyboard assembly with a positioning function, especially to a compact keyboard assembly for portable electronic devices such as PDAs (personal digital assistants) or cellular phones. 
     BACKGROUND OF THE INVENTION 
     Compact and portable electronic devices such as PDAs (personal digital assistants) or cellular phones are essential for mobile communication. The compact and portable electronic devices generally rely on a keyboard for inputting data. 
     However, there is often a connection problem between the compact keyboard and the portable electronic device. For example, the compact keyboard may be electrically connected to the cellular phone by a cable and mechanically connected to the cellular phone by a clamping device. 
     FIG. 1 shows a sectional view of a prior art keyboard  1   a  for a cellular phone  11   a.  The keyboard  1   a  is electrically connected to the cellular phone  11   a  by an interface  10   a.  Moreover, the keyboard  1   a  is collinear with the cellulous phone  11   a.  Therefore, it is a problem for a user to view a display panel  12   a  on the cellular phone  11   a  while inputting data through the keyboard  1   a.    
     The PDA generally has a foldable keyboard and the keyboard can be expanded to an inclined angle with respect to the PDA to facilitate viewing. However, the clamping of the keyboard to an inclined angle with respect to the 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a keyboard assembly with a positioning function, whereby the keyboard can be advantageously positioned. 
     In a first aspect of the invention, the keyboard assembly has an interface with its vertical line inclined to its pivotal axis. The inclined angle is increased when the interface is rotated with respect to the inclined pivotal axis. 
     In a second aspect of the invention, the keyboard assembly has an interface with its vertical line inclined to its pivotal axis. When the interface is rotated with respect to the inclined pivotal axis, the keyboard can be advantageously positioned to expanded state. 
     According to the first aspect of the invention, the keyboard assembly comprises a keyboard body and an interface pivotally arranged on a pivotal axis of the keyboard body and being able to rotate laterally. The pivotal axis has an inclined angle with respect to a vertical line of the interface. After the interface is rotated to a clamping position with respect to the keyboard body, there is an included angle between the interface and the keyboard body, wherein the included angle is two times of the inclined angle. 
     According to the second aspect of the invention, the keyboard assembly comprises a keyboard body composed of a first panel and a second panel pivotally connected to the first panel. Each of the first panel and the second panel has a receiving space in symmetrical arrangement to accommodate the interface. The interface is rotated to the receiving space and the two panels of the keyboard body are prohibited from folding due to the interface. 
     The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: 
    
    
     BRIEF DESCRIPTION OF DRAWING 
     FIG. 1 shows a sectional view of a prior art keyboard for cellular phone; 
     FIG. 2 demonstrates the basic principle of the present invention; 
     FIG. 3 shows a perspective view of the preferred embodiment of the present invention; 
     FIG. 4 shows a top view of the preferred embodiment of the present invention; 
     FIG. 5 shows a perspective view for demonstrating the usage of the preferred embodiment of the present invention; 
     FIG. 6 shows a top view for demonstrating the usage of the preferred embodiment of the present invention; 
     FIG. 7 shows a sectional view of the preferred embodiment of the present invention; and 
     FIG. 8 shows a top view of another preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 2 demonstrates the basic principle of the present invention. As shown in this figure, an object M has an axis O of rotation. The axis O has an included angle θ with respect to the Z-axis of a reference coordinate. The object M initially lies on the X-Y plane of the reference coordinate. The object M has a distance D with respect to the axis O of rotation. If the object M is rotated in a clockwise direction with respect to the axis O by 90°, the object M will have an included angle θ with respect to the Z-axis. If the object M is further rotated in clockwise direction with respect to the axis O by 90°, the object M will have an included angle 2θ with respect to the Z-axis. 
     As can be seen from above description, if an object is rotated by 180° about an axis that slants with respect to the Z-axis of a reference coordinate system for the object, the object will have an included angle equal to two times of slanting angle with respect to the X-Y plane of the reference coordinate system. 
     FIGS. 3 and 4 show a perspective view and a top view of the preferred embodiment of the present invention. The keyboard assembly according to the preferred embodiment of the present invention comprises a keyboard body  1  and an interface  2 . The keyboard body  1  has a plurality of keyswitches  10  thereon and is composed of a first panel  11  and a second panel  12 . The first panel  11  has an adjacent side and the second panel  12  has an adjacent side pivotally connected to the adjacent side of the first panel  11 , thus forming a foldable keyboard. The keyboard body  1  can be folded or expanded along the adjacent sides of the first panel  11  and the second panel  12 . However, this is well-known art and a detailed description is not stated here. 
     The first panel  11  and the second panel  12  have a first receiving space  13  and a second receiving space  14 , respectively. The first receiving space  13  and the second receiving space  14  are symmetrically arranged on a top portion of the keyboard body  1 . The interface  2  is received in the first receiving space  13  and the second receiving space  14  when the first panel  11  and the second panel  12  are closed. 
     The first panel  11  has a pivotal section  15  near the first receiving space  13 . More particularly, the first receiving space  13  is placed on one side of the pivotal section  15  and a positioning groove or recess  16  is formed on another side of the pivotal section  15 . The positioning recess  16  is formed at the junction of the first panel  11  and the second panel  12  and is composed of two dents or concave portions  160 ,  161 . The interface  2  is received in the positioning recess  16  when the first panel  11  and the second panel  12  are opened. 
     The second panel  12  has a clamping means  17  near the second receiving space  14 . The clamping means  17  comprises a knob  170 , a fastener  171  and an elastic section  172 . The knob  170  is connected to the fastener  171  and the fastener  171  has a hook  173  extending beyond one side of the positioning recess  16 . The knob  17  can be moved laterally by the elasticity of the elastic section  172 , whereby the hook  173  can be locked on or detached from one side of the positioning recess  16 . 
     The interface  2  is electrically connected to a cellular phone  3  as shown in FIG. 7 or a PDA (not shown) and the commands or data input by the keyboard body  1  are sent to the cellular phone  3  or the PDA through the interface  2 . 
     The interface  2  is arranged in the first receiving space  13  and pivotally connected to the pivotal section  15  of the first panel  11  such that the interface  2  can be rotated leftward or rightward. The interface  2  can be rotated to the positioning recess  16  as shown in FIG.  6 . The axis of the pivotal section  15  has an inclined angle  22  with respect to a perpendicular or vertical line  21  of the interface  2 , wherein the inclined angle  22  is about 10 degrees. After the interface  2  is rotated to the positioning groove  16 , the clamping means  17  is engaged with a clip  23  on one side of the interface  2  to clamp the interface  2 . 
     FIGS. 5 and 6 show the perspective view and top view for demonstrating the usage of the preferred embodiment of the present invention. The pivotal axis of the pivotal section  15  has an inclined angle  22  with respect to a vertical line  21  of the interface  2  (the vertical line  21  is also vertical to the keyboard body  1 ). When the interface  2  is rotated 180 degrees to the positioning groove  16 , there is an included angle  24  between the interface  2  and the keyboard body  1 . And, the included angle  24  is two times of the inclined angle  22 . Therefore, when the interface  2  is connected to a mobile device such as a cellular phone  3  or a PDA, the keyboard body  1  has an included angle  24  with respect to the mobile device to facilitate view of the display panel  30  of the cellular phone  3 . 
     Moreover, after the interface  2  is rotated to the positioning recess  16 , the interface  2  is placed at the junction of the two panels  11  and  12  of the keyboard body  1 . At this time, the interface  2  is clamped by the clamping means  17  and the two panels  11  and  12  of the keyboard body  1  are prohibited from folding due to the interface  2 . Therefore, by the present invention, the keyboard body  1  has an included angle  24  with respect to the mobile device to facilitate operation by a user and the two panels  11  and  12  of the keyboard body  1  are clamped in an open or expanded state. 
     Moreover, after the interface  2  is rotated to the positioning recess  16 , the interface  2  is electrically connected to the keyboard body  1  through a connection unit  18  to transmit the command input from the keyboard body  1  to the interface  2 . The command then is transmitted from the mobile device. 
     FIG. 8 shows a top view of another preferred embodiment of the present invention. The keyboard body  1  is an integrally formed one rather than a foldable one; therefore, the keyboard body  1  does not have clamping problem. 
     Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.