Abstract:
A personal digital assistant (PDA) which includes a body portion and a keyboard adapted to be coupled to the body portion. The keyboard is a standard keyboard size when in use. The keyboard is also foldable to act as a cover for the body portion. In a preferred embodiment, the keyboard attaches directly to the PDA and when not in use acts as a cover for the display of the PDA. When the keyboard is unfolded and the PDA is placed onto a flat surface, the user is able to input information using their familiar touch-typing skills with a full-size keyboard.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to portable digital assistants and more particularly to a portable digital assistant which includes a keyboard. 
     BACKGROUND OF THE INVENTION 
     Personal digital assistants (PDA) are utilized in a variety of applications. When a user wishes to record a message or create a memo using a PDA, the user currently has essentially four choices as to how the data can be physically inputted into the device. 
     a. Written: One letter at a time, typically in a small specifically designated area on the screen. The use of a stylus is usually required. 
     b. Touch screen keyboard: The screen will display some form of a keyboard. The size of the keyboard is limited by the size of the screen. Again because of this “virtual” keyboard&#39;s limited size, a stylus is typically used. Also, the virtual keyboard provides no tactile feel and can be cumbersome to use specifically when the user is required to input a multiple key operation (i.e., Ctrl-Shift-Backspace). 
     c. Small keyboard: Some PDA are specifically designed with a small built-in keyboard. Unfortunately, this changes the aspect ratio of the PDA (The PDA tends to be long and thin) and the keyboard tends to be small. 
     d. Separate external keyboard: Although this provides the user with the comfort and familiar feel of a full-size keyboard, the user loses the portability which is part of the attraction of the PDA. 
     The choice of the input mechanism is typically specific to the model of the PDA. Except for the external keyboard, the input method may be satisfactory for brief messages of a few words. However, if the user wishes to input a longer message, or create a memo, the first three input methodologies listed above tend to be cumbersome and slow. Paramount to the problem is that these methods do not allow a user to apply any of the traditional “touch typing” skills which most computer users today are familiar and comfortable using. 
     A small keyboard is available for the PDA referred to as the Da Vinci PDA which is manufactured by Royal. The keyboard is foldable, and because the keyboard folds in the middle the keys are displaced from the position of a typical QWERT keyboard. Furthermore, the keyboard serves no other purpose. The keyboard simply folds to allow it to be carried separately in a more convenient fashion. Finally, although the separate external keyboard allows the touch typing skills to be used, it lacks the portability which is inherent to the PDA. Similarly, there exist the Stowaway portable keyboard by Think Outside. Although this keyboard, when unfolded, has the standard key placement, it is not incorporated as a cover to the PDA when the keyboard is not in use nor does it incorporate the novel sliding key concept. 
     Accordingly, what is needed is a system and method for allowing a user to efficiently input long messages without requiring a separate keyboard. The system and method should be cost-effective, adaptable and easily implemented in existing PDAs. The present invention addresses such a need. 
     SUMMARY OF THE INVENTION 
     A personal digital assistant (PDA) which includes a body portion and a keyboard adapted to be coupled to the body portion. The keyboard is a standard keyboard size when in use. The keyboard is also foldable to act as a cover for the body portion. 
     In a preferred embodiment, the keyboard attaches directly to the PDA and when not in use acts as a cover for the display of the PDA. When the keyboard is unfolded and the PDA is placed onto a flat surface, the user is able to input information using their familiar touch-typing skills with a full-size keyboard. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a personal digital assistant (PDA) in accordance with the present invention. 
     FIG. 2 illustrates a side of the PDA of FIG.  1 . 
     FIG. 3 a  illustrates the keyboard in its position when used. 
     FIG. 3 b  illustrates the keyboard and the keys when the keyboard is prepared to be placed into its folded position. 
     FIG. 3 c  illustrates a top view of the five key components which compose the folding keyboard. 
     FIG. 3 d  illustrates a side view of two of the key components of FIG. 3 c.    
     FIG. 4 a  illustrates a side view of the keyboard acting as a cover for the PDA. 
     FIG. 4 b  illustrates a top view of the keyboard acting as a cover for the PDA. 
    
    
     DETAILED DESCRIPTION 
     The present invention relates to an improvement in portable digital assistants (PDAs). The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown, but is to be accorded the widest scope consistent with the principles and features described herein. 
     A system in accordance with the present invention comprises a personal digital assistant (PDA) with a detachable keyboard, which when folded acts as a cover for the PDA and when unfolded is a full size QWERT keyboard. In a preferred embodiment, the keyboard is a tri-fold design which is attached to the body portion of a PDA. A key feature in the keyboard is the sliding a slideable key row which minimizes the width of the keyboard when the keyboard is folded yet maintains the staggered key positioning of the QWERT keyboard when the keyboard is in use. The keys of the slideable key row are referred to as the “sliding keys.” The sliding keys allow the sections of the keyboard to have straight smooth edges at which the sections of the keyboard are hinged. Also in a preferred embodiment, when folded the keyboard has the same width and height as the PDA to which it is attached. 
     To describe the present invention in more detail, refer now to the following description in conjunction with the accompanying figures. FIG. 1 illustrates a personal digital assistant (PDA)  100  in accordance with the present invention. As seen in the figure, attached to the PDA display unit  102 , via a hinge  104 , is a keyboard  106 . The keyboard  106  includes in a preferred embodiment three sections  108 ,  110  and  112 . Each section  108 - 112  has the same height and width dimensions as the PDA display unit  102 . The three sections  108 - 112  are hinged to each other using the hinges  113   a  and  113   b  in the figure. When unfolded as shown in the figure, the three sections  108 - 112  create a standard keyboard  106 . The precise layout of the keys which make up the keyboard  106  will be discussed in detail below. 
     FIG. 2 illustrates a side view of the PDA  100  of FIG.  1 . To facilitate the use of the PDA  100  when the user is typing on the keyboard  106 , the PDA  100  includes a support  111 . 
     This support  111  is lowered and locked into position as shown in FIG.  2  and supports the PDA Display Unit  102  in a comfortable viewing angle while the keyboard  106  is in use. 
     Referring back to FIG. 1, a key feature of the present invention is the design of the keys on the sections  108 - 112  of the keyboard  106 . A specific feature of keyboard  106  is the sliding “keys”. This feature allows the keyboard  106  to fold into three sections  108 - 112  while still maintaining the staggered column key positions of a standard QWERT keyboard. The keyboard  106  utilizes the slide control arms  130 ,  132  to relocate certain keys of the keyboard. 
     In FIGS. 3 a  and  3   b , two positions of the folding keyboard  106  are shown. FIG. 3 a  illustrates the keyboard  106  is its “in use” or locked position. In this position, the keys of the keyboard  106  are arranged as they would be when the user intends to type on the keyboard  106 . When the keyboard  106  is in this position, the keys are arranged as they would be on any other typical QWERT keyboard  106 . (The rows of keys are staggered one from the other). 
     The keyboard  106  is divided into three sections  108 - 112  (labelled labeled Keyboard Panel  1   108 , Keyboard Panel  2   110 , and Keyboard Panel  3   112  respectively). These three sections  108 - 112  are connected together via two hinges  113   a  and  113   b . The left side edge of Keyboard Panel  3   112  is connected via hinge  113   b  to the right side edge of Keyboard Panel  2   110 . The right side edge of Keyboard Panel  1   108  is connected via hinge  113   a  to the left side edge of Keyboard Panel  2   110 . On the Keyboard Panel  1   108  and Keyboard Panel  3   112 , there are slide control arms  130  and  132  which are used to position the sliding key rows on Keyboard Panel  1   108  and Keyboard Panel  3   112  respectively. (There are no sliding keys on the Keyboard Panel  2   110 , therefore there is no slide control arm for this keyboard panel.) 
     FIG. 3 b  illustrates the position of the keys after the slide control arms  130  and  132  of both the Keyboard Panel  1   108  and Keyboard Panel  3   112  have been moved into their “folding” position. This illustration shows the keyboard  106  ready to be folded. The specific keys which are effected by the motion of the slide control arms  130  and  132  are highlighted by the letter “X”. It is these keys, and only these keys, which actually change position when the two slide control arms  130  and  132  are moved. These keys are referred to as the “sliding keys”. This illustration also shows the direction of the slide control arms  130  and  132  would have been moved in order to reposition the sliding keys from their “in use” position to their “folding” position. The slide control arms  130  and  132  operate independently of each other and must both be moved in order to allow the keyboard  106  to be completely folded. As can be seen in the figure, when the keys have been slid into their “folding” position, there are straight line edges between the three sections. It is along these two straight edges that the three sections  118 - 112  are hinged. 
     In FIG. 3 c , the five (5) fundamental components of the folding keyboard  106  are shown. Here, the Keyboard Panel  1   108 , Keyboard Panel  2   110 , and Keyboard Panel  3   112  are shown with their stationary keys (stationary keys are those keys which do not slide). 
     Also shown in FIG. 3 c , are the two key carriers  202  and  204 . The key carriers  202  and  204  are the structure to which the “sliding” keys are attached. There is a key carrier  202  for the sliding keys of the Keyboard Panel  1   108  and one key carrier  204  for the sliding keys of the Keyboard Panel  3   112 . (The shape of the two key carriers  202  and  204  are mirror images of each other). As shown, the slide control arm for each of the key carriers  202  and  204  is part of the key carrier structure. The key carriers  202  and  204  allowed the sliding keys of the appropriate keyboard panel to move as a single unit. A cross section of the Keyboard Panel  1   108  is shown and is labeled section A—A. In this cross-section, it can be seen that the Keyboard Panel  1   108  had two channels  203  and  205  (or slots) cut into it. It is in these channels  203  and  205  that the carrier  202  travels. When the key carrier  202  is moved, it slides in these channels  203  and  205 . Similarly there is an equivalent set of channels in Keyboard Panel  3   112  in which key carrier  204  slides. The shape of the cross section of the channels are such that the bottom of the channels are wider than the top of the channels. This shape corresponds to the shape of the key carriers  202  and  204 . This matching shape keeps the key carriers  202  and  204  in the channels. 
     When the key carriers  202  and  204  are slid into their “in use” position, the tabs  207  of the key carriers  202  and  204  slide into a set of channels  206  in the Keyboard Panel  2   110 . The channels in the Keyboard Panel  2   110  have the same cross-section as the channels  203  and  205  in the Keyboard Panel  1   108  and Keyboard Panel  3   112 . Sliding the tabs  207  of the key carriers  202  and  204  into the channels  206  of the Keyboard Panel  2   110  both “lock” the left and keyboard panel  1   108  and keyboard panel  3   112  into their “in use” position as well as make the electrical connection for the keyboard panel  1   108  and keyboard panel  3   112  to the Keyboard Panel  2   110 . The locking action prevents the Keyboard Panel  1   108  and Keyboard Panel  3   112  from folding while the keyboard  106  is in use. 
     FIGS. 4 a  and  4   b  illustrate the keyboard  106  acting as a cover for the PDA  100 . FIG. 4 a  illustrates a side view and FIG. 4 b  illustrates a top view. When the user has completed with their use of the PDA  100 , the keyboard  106  is then folded against the PDA  100  as shown in FIGS. 4 a  and  4   b . The support for the PDA display unit  102  while the keyboard  106  is in use is shown in FIGS. 4 a  and  4   b  in a folded position in a groove  105  on the back of the PDA  100 . It can be noted that by leaving the keys of Keyboard Panel  3   112  in the folding position, and leaving Keyboard Panel  3   112  unfolded. Keyboard Panel  3   112  can be used as a numeric keypad. This is due to the fact that the keys of Keyboard Panel  3   112 , when the keys are in the folding position, are aligned as they would be on a standard numeric keypad. 
     Accordingly a system in accordance with the present invention comprises a personal digital assistant (PDA) with a detachable keyboard, which when folded acts as a cover for the PDA and when unfolded is a full size QWERT keyboard. In a preferred embodiment, the keyboard is a tri-fold design which is attached to a body portion of a PDA. A key feature of the keyboard are the sliding row keys which minimize the width of the keyboard when the keyboard is folded yet maintain the staggered key positioning of the QWERT keyboard when the keyboard is in use. Finally, in a preferred embodiment, when folded the keyboard has the same width and height as the body portion of the attached PDA. 
     Although the present invention has been described in accordance with the a embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.