Abstract:
A keyboard attached to a personal digital assistant (PDA) set having: a hinge unit including a connector to transfer a keyboard input signal to the PDA, and upper and lower hinge covers; a connection unit placed inside of the hinge unit, and can be attached in the front direction or the back direction to the PDA; and a keyboard body connected with the hinge unit, folded and unfolded about the hinge unit, having a typing board on an upper side and a front panel controller (FPC) keypad to input a key pressed on the typing board. Therefore, the keyboard of the PDA can not only be attached in the front direction or the back direction to the PDA, but also separated from the PDA, thus making the usage and maintenance of the keyboard convenient.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    This application claims the benefit of Korean Application No. 2002-38466, filed Jul. 3, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to keyboard, and more particularly, to a keyboard of a PDA (personal digital assistant), which is attached to a PDA in a front direction when in use, and folded in a back direction to the back of the PDA or removed from the PDA when not in use, i.e., when a user uses only a screen of the PDA.  
           [0004]    In the front direction, the keyboard is placed in front of the screen of the PDA, and in the back direction, the keyboard is placed in the back of the PDA. The directions will be used in the same meaning through this specification.  
           [0005]    2. Description of the Related Art  
           [0006]    A conventional keyboard of a PDA (personal digital assistant) is not removable from the PDA as the keyboard is fixed to the PDA. Another case is that the keyboard is separated from the PDA and carried, and when a user needs to use the keyboard, the user attaches the keyboard to the PDA in the front direction.  
           [0007]    The first case has a disadvantage that the user cannot separate the keyboard when the user does not want the keyboard, and the second has a disadvantage that the user is required to carry the keyboard all the time while most of the keyboards are not small enough to carry. Moreover, the conventional keyboard of the PDA is inconvenient to use while moving and it bothers the user to change from the screen to the keyboard and vice versa.  
         SUMMARY OF THE INVENTION  
         [0008]    Accordingly, it is an object of the present invention to provide a keyboard of a PDA, which can be attached in the front direction and folded or unfolded. In another aspect of the invention, the keyboard can be attached in the back direction and folded up to the back of the PDA. Also, the keyboard can be separated from the PDA and carried separately.  
           [0009]    Furthermore, another aspect of the present invention is to provide a keyboard that is easily attached and separated to and from the PDA.  
           [0010]    It is yet another aspect of the present invention to provide a keyboard that can be folded and unfolded for  3600  in the connection to the PDA. Accordingly, the keyboard is easily used and maintained.  
           [0011]    Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.  
           [0012]    The foregoing and/or other objects of the present invention are achieved by providing a keyboard attached to a PDA set, comprising: a hinge unit having a connector to transmit a keyboard input signal to the PDA, and upper and lower hinge covers; a connection unit placed inside of the hinge unit attached in the front direction or the back direction to the PDA; and a keyboard body connected with the hinge unit, folded and unfolded with respect to the hinge unit, having a typing board on an upper side and a keypad formed therein to input a key pressed on the typing board.  
           [0013]    It is an aspect of the present invention that the connection unit comprises a bracket hinge inserted into the PDA in order to fix the hinge unit, a spring to elastically bias the bracket hinge toward a side so that the bracket hinge is automatically locked to the PDA when the bracket hinge is inserted into the PDA, and an ejector to release the lock of the bracket hinge by compressing the spring.  
           [0014]    It is an aspect of the invention that the connector is a pin contact connector connected with the keypad.  
           [0015]    It is another aspect of the invention that the upper hinge cover has a guide protrusion to inform an attaching position to the PDA.  
           [0016]    It is yet another aspect of the invention that the keyboard further comprises a hinge pipe to prevent the keyboard body from being worn by the friction with the fixed hinge unit when the keyboard body is folded and unfolded with respect to the hinge unit.  
           [0017]    The foregoing and/or other objects of the present invention may also be achieved by providing a keyboard attached to a PDA set, comprising: a hinge unit having a connector to provide a keyboard input signal to the PDA, and upper and lower hinge covers; a connection unit placed inside of the hinge unit and attachable in the front direction or the back direction to the PDA; a keyboard body having a typing board and a keypad formed therein to input a key pressed on the typing board; and a keyboard rotation unit to connect the hinge unit and the keyboard body as one side of the rotation unit is connected with the hinge unit and the other side of the rotation unit is connected with the keyboard body, and the keyboard rotation unit having a flexibility to fold and unfold the keyboard body for 360° with respect to the hinge unit.  
           [0018]    It is an aspect of the invention that the keyboard body is made of plastic and the keyboard rotation unit is made of leather having appropriate flexibility and durability.  
           [0019]    It is another aspect of the invention that the keyboard rotation unit is made of cloth.  
           [0020]    It is yet another aspect of the invention that the connector is a pin contact connector connected with the keypad through a connection member.  
           [0021]    It is still another aspect of the invention that the connection member comprises a conductive tape placed therein and a protective film to wrap and protect the conductive tape.  
           [0022]    It yet another aspect of the invention that the protective film is urethane foam.  
           [0023]    It is still another aspect of the invention that the lower hinge cover has a guide protrusion to inform an attaching position to the PDA.  
           [0024]    It is still another aspect of the invention that the connection unit comprises a hook hinge to be inserted into the PDA and locked, and a spring or a plate spring to lock the hook hinge by pushing the hook hinge to a side.  
           [0025]    It is still another aspect of the invention that a magnet is disposed at right and left corners of the keyboard body in order to allow the keyboard body to be attached to the PDA when the keyboard body is folded or rotated by 360° to be contacted with the screen of the PDA or with the back of the PDA.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    These and other objects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
         [0027]    [0027]FIG. 1 is an exploded perspective view showing a keyboard of a PDA according to an embodiment of the present invention;  
         [0028]    [0028]FIG. 2 is a perspective view showing the keyboard of FIG. 1, being attached in the front direction to the PDA and spread for 180°;  
         [0029]    [0029]FIG. 3A is a view showing the keyboard of FIG. 1 being attached in the front direction and folded on the screen of the PDA;  
         [0030]    [0030]FIG. 3B is a view showing the keyboard of FIG. 1 being attached in the front direction and spread for 180° to a using position;  
         [0031]    [0031]FIG. 3C is a view showing the keyboard of FIG. 1 being attached in the back direction and folded up to the back of the PDA;  
         [0032]    [0032]FIG. 4 is an exploded perspective view showing a keyboard of a PDA according to another embodiment of the present invention;  
         [0033]    [0033]FIG. 5is an extracted schematic view showing a connection member that connects a keypad and a connector and transfers a signal input from the keyboard according to the embodiment of FIG. 4;  
         [0034]    [0034]FIG. 6 is a perspective view showing the keyboard of FIG. 4 being attached in the front direction to the PDA;  
         [0035]    [0035]FIG. 7A is a view showing the keyboard according to the embodiment of FIG. 4 being attached on the screen of the PDA and in a closed position;  
         [0036]    [0036]FIG. 7B is a view showing the keyboard according to the embodiment of FIG. 4 being spread out at 180° to be used; and  
         [0037]    [0037]FIG. 7C is a view showing the keyboard of FIG. 4 being attached at the back of a PDA when not in use.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]    Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0039]    [0039]FIG. 1 is an exploded perspective view showing a keyboard of a PDA according to an embodiment of the present invention.  
         [0040]    As shown in FIG. 1, the keyboard for a PDA according to this embodiment can be divided into a hinge unit  11 , a keyboard body  23  and a connection unit  13 .  
         [0041]    The hinge unit  11  includes an upper cover  18  having two guide protrusions  19 , a lower cover  20 , a pin contact connector  16  and a pipe hinge  26 .  
         [0042]    The connection unit  13  comprises two bracket hinges  10  placed inside of the hinge upper cover  18  and inserted into the PDA, a spring  12  disposed at the side of the bracket hinges  10  and an ejector  14  placed between the bracket hinges  10 .  
         [0043]    The keyboard body  23  includes an upper keyboard case  24 , a lower keyboard case  25 , a typing board  22  and a keypad (not shown) placed inside of the upper and lower keyboard cases  24  and  25 . The keyboard body  23  covers the outer circumference of the pipe hinge  26  of the hinge unit  11  so that the keyboard body  23  is connected with the hinge unit  11 .  
         [0044]    The pin contact connector  16  has a plurality of protruding pins that can be contracted, and is connected with the keypad (not shown) having the keyboard body  23  and transmits a signal input into the keypad to the PDA.  
         [0045]    An example of a distinguishing aspect of the keyboard of a PDA according to the embodiments of the present invention is that the keyboard can be attached to the PDA in both the front and back directions. When a user wants to use the keyboard of the PDA shown in FIG. 1, the user has the two bracket hinges  10  disposed on the hinge unit  11  inserted into the PDA in association with the guide protrusions  19  formed on the upper cover  18 . Then, the spring  12  at the side of the bracket hinge  10  pushes the bracket hinge  10  to one side, thus the bracket hinges  10  are locked to the PDA.  
         [0046]    [0046]FIG. 2 is a perspective view showing the keyboard of FIG. 1, which is attached in the front direction to the PDA and spread out at 180°.  
         [0047]    When the keyboard is attached in the front direction to be used, the pin contact connector  16 , connected with the FPC keypad placed at the keyboard body  23 , is connected with a signal terminal (not shown) of the PDA  9  so that the signal input into the keyboard can be transmitted to the PDA  9 . Moreover, the keyboard can be folded and unfolded about the hinge unit  11 .  
         [0048]    When the user does not want to use the keyboard, but touches an LCD screen  28  of the PDA  9  instead, the keyboard according to this embodiment can be separated from the PDA  9  and kept separately. Moreover, the keyboard can be attached in the back direction by turning the bracket hinges  10  of the hinge unit  11  and folding it towards the back of the PDA  9 .  
         [0049]    [0049]FIGS. 3A, 3B and  3 C are views showing the keyboard of the PDA  9  according to this embodiment of the present invention. FIG. 3A is a view showing the keyboard attached in the front direction and folded to the screen of the PDA  9 . FIG. 3B is a view showing the keyboard attached in the front direction and spread out at 180°. FIG. 3C is a view showing the keyboard attached in the back direction and folded to the back of the PDA  9  when not in use.  
         [0050]    As described above, the keyboard according to this embodiment can be attached in front and back directions, and folded to the screen or to the back of the PDA  9 . Thus, when the user wants to use the screen only, in addition to the option of separating the keyboard and keeping it in the safe place, the user also can have the option of attaching the keyboard in the back direction and having the keyboard folded up to the back especially when the user is on the move or when it is difficult to separate the keyboard. Therefore, it is more convenient for the user to use the PDA  9 .  
         [0051]    [0051]FIGS. 4 through 7 are views showing a keyboard used with a PDA according to another embodiment of the present invention.  
         [0052]    Referring to FIG. 4, the keyboard includes a hinge unit  39 , a keyboard body  55 , a keyboard rotation unit  50  made of leather or cloth having good flexibility in order to rotate 360° in the front and the back directions, a pin contact connector  52  to transmit a keyboard input signal, and connection units  43 .  
         [0053]    The hinge unit  39  includes an upper hinge cover  42  having cover holes  44 , a lower hinge cover  46  having guide protrusions  47 , and the pin contact connector  52 .  
         [0054]    The connection units  43  include hook hinges  40  and springs  48  to push the hook hinges  40  to be automatically locked to the PDA.  
         [0055]    The keyboard body  55  includes a typing board  58 , a keyboard body case  56 , a keypad (not shown) placed inside of the keyboard body case  56 , and a magnet  57  to maintain the status of the keyboard being attached when the keyboard is folded in the front or the back direction and stored.  
         [0056]    The pin contact connector  52  is connected with the keypad through a connection member  54 , and transmits the keyboard input signal to the PDA. As the connection member  54  passes through the inside of the keyboard rotation unit  50 , materials with good flexibility and durability are used for the connection member  54 .  
         [0057]    [0057]FIG. 5 is an enlarged view schematically showing the connection member  54 . As shown in FIG. 5, the connection member  54  has a conductive tape  54   a  made of thin fiber material provided therein, and a protective film  54   b  wrapping the conductive tape  54   a . The protective film  54   b  is made of urethane foam.  
         [0058]    As the connection member  54  has the above structure, the connection member  54  has enough flexibility and durability. Moreover, the connection member  54  can rotate 360° like the keyboard rotation unit  50 , and signals can be easily transmitted.  
         [0059]    [0059]FIG. 6 is a perspective view showing another embodiment of the present invention. In FIG. 6, the keyboard is attached in the front direction to be used. FIGS. 7A, 7B and  7 C are views showing the keyboard attached in the front direction and folded or unfolded.  
         [0060]    In other words, the connection and usage of the keyboard to the PDA  41  according to this embodiment is as follows: the user moves the hook hinges  40  of the connection units  43  to a direction of compressing the springs  48  and inserts the guide protrusions  47  into insertion holes (not shown) of the guide protrusions  47 . Then, as the user unhands the hook hinges  40 , the hook hinges  40  are returned to their initial position by the recovering force of the springs  48  and locked in the PDA  41 .  
         [0061]    As described before, when the hook hinges  40  are attached in the front direction, the pin contact connector  52  is connected with the signal terminal (not shown) of the PDA  41 , and transmits the input signal of the keyboard to the PDA  41 .  
         [0062]    Moreover, when the user does not use the keyboard, the keyboard can be attached in the back direction to the PDA  41  in the same manner.  
         [0063]    [0063]FIG. 7A is a view showing the status of the keyboard according to this embodiment attached in the front direction, and folded to the screen of the PDA. FIG. 7B is a view showing the keyboard unfolded to be used. FIG. 7C is a view showing the keyboard attached on the back of the PDA when the user uses the PDA by touching the screen of the PDA.  
         [0064]    The keyboard according to the embodiments of the present invention can be rotated at 360° with the keyboard being attached in the front or the back direction, thus the keyboard can be attached on the screen or on the back of the PDA.  
         [0065]    The keyboard according to the embodiments of the present invention for a PDA can be attached in the front direction or the back direction to the PDA set, and separated after use. Therefore, the keyboard can be more easily used and kept.  
         [0066]    In addition, as the keyboard according to the embodiments of the present invention has a simplified hinge unit that is inserted and locked to the PDA, the keyboard can be easily connected with and separated from the PDA.  
         [0067]    Furthermore, as the keyboard according to the embodiments of the present invention can be attached on the screen of the PDA, there is no need to provide a cover to protect the screen.  
         [0068]    Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.