Abstract:
A tablet computer ( 10 ) is provided, having an integrated keyboard ( 14 ). Such a keyboard ( 23 ) may be derived from a transparent or translucent construction and overlay a tablet touch sensitive display ( 24 ) while enabling viewing of the display ( 24 ) through the keyboard. The keyboard ( 23 ) may support positioning for multiple display orientations, such as portrait or landscape.

Description:
TECHNICAL FIELD 
       [0001]    The invention is in the area of electronic computers, with primary focus on tablet computers. 
       BACKGROUND OF THE INVENTION 
       [0002]    Tablet computers have grown in popularity because of their portability and attractive applications (apps) they can run. However, conventional tablet computers still have some major shortcomings remain which are addressed by aspects of this invention. 
         [0003]    As shown in  FIG. 1 , a typical tablet computer includes a tablet computer housing  10  and a touchscreen panel  11  which is used for user input. Inside the housing  10  and underneath the touchscreen panel  11  there are the internal components of the computer (not shown in  FIG. 1 ), such as the motherboard, the data storage device, the battery and others.  FIG. 1  shows the tablet being held in portrait orientation. 
         [0004]      FIG. 2  shows the tablet computer being held in portrait orientation. 
         [0005]    The greatest shortcoming of the tablet computer as shown in  FIGS. 1 and 2  is the input. Normally the only way to input information into the computer is via the touchscreen. That is acceptable for simple Yes or No answers, or when it is enough to click on a box. However, sometimes the user needs to enter a substantial amount of information, such as to create a document, write an email, enter information into a form, etc. In that case, the touchscreen can still be used by displaying a keyboard image  12  (a so-called “virtual keyboard”) on the screen, as shown in  FIG. 3 . The user chooses each character by clicking on the corresponding key on this virtual keyboard. That is painfully slow and very error-prone. The lack of tactile feedback also makes it feel unnatural and unfriendly. As a result, for any serious work the tablet becomes inadequate and the user has to switch to a “real” computer, which relegates the tablet to the category of “toy” to play music, games and very superficial applications. The true potential of the tablet computer cannot be achieved without proper input. This invention corrects that shortcoming by giving the tablet computer real and practical input facilities. This and other aspects of the invention are disclosed and described below. 
     
    
     DESCRIPTION OF THE INVENTION 
       [0006]    In accordance with one aspect of the invention shown in  FIG. 4 , a tablet computer  13  is configured with a housing  13 , a touchscreen panel  15 , a keyboard  14 , a touchpad  16  and touch buttons  18  and  17 . This solution is workable, but it still has some serious shortcomings: a) it substantially increases the size of the tablet; and b) it works only in landscape mode.  FIG. 5  shows a slight variation of  FIG. 4  with the keyboard supporting a portrait orientation rather than a landscape orientation. However,  FIG. 5  supports only portrait mode. Since the user may need to use the tablet computer sometimes in landscape orientation and sometimes in portrait orientation, it is necessary to provide an input solution that supports both modes. 
         [0007]      FIG. 6  shows a tablet computer with a landscape keyboard  21  and a portrait keyboard  22 . This embodiment does provide support for both modes of operation, but at the same time it substantially increases the size, weight and cost of the tablet computer. 
         [0008]      FIG. 7  shows a preferred embodiment of this invention with a single keyboard  23 , which can support both portrait and landscape modes. This keyboard is made of a substantially transparent material, so that the key labels (such as A, B, C, etc.) can be displayed on the appropriate spots on the screen  24  and the user can clearly see them through the keys. The keyboard  23  is a mechanical keyboard with the normal features of such keyboards, such as tactile feedback and quick, multi-finger input. 
         [0009]      FIG. 8  shows that when the tablet computer of  FIG. 7  is rotated to portrait orientation, the contents of the screen is adjusted, including the orientation of the key labels, so that the keyboard remains fully usable.  FIG. 8  also shows another major advantage of the variable key labels: it is not necessary to put multiple labels on the keys, as typically done on conventional keyboards, or to have dedicated keys for numbers, punctuation, special symbols, etc. Instead, the user can press a key (probably labeled Num for Numbers, or something similar) and the keyboard can be instantly switched to numeric input, as shown in  FIG. 9 . The same can be achieved for punctuation, special symbols, foreign keyboards, etc. The keyboard can also be configured by the software application to cooperate with the application, such as defining certain keys as YES, NO, BACK, CONTINUE, GO, CANCEL, EXIT, etc. As a side benefit, this can lead to some level of standardization in application software which can simplify the learning and usage of software applications. 
         [0010]    Since there is no need to dedicate keys, the keyboard can be made with significantly fewer keys than in conventional keyboards. Also, since there is no need to squeeze multiple labels on the keys, the key surface can be made smaller. As a result, the keyboard can be made significantly smaller than conventional keyboards.  FIG. 10  shows a small and narrow keyboard  24  at the bottom of the screen in portrait mode.  FIG. 11  shows the same keyboard  24  in landscape mode. 
         [0011]      FIG. 12  shows another possible embodiment of the invention:  25  is a narrow keyboard at the bottom of the screen in landscape mode. Because of the length available for the keyboard in this configuration, it can be designed in a very narrow configuration, possibly with just one or two rows of keys.  FIG. 13  is the same embodiment with the same keyboard  25  in portrait mode. 
         [0012]      FIGS. 14 through 18  describe how the partly transparent keyboard can be built for the keyboard of the present invention.  FIG. 14  is a top view of a key  30 , in this case for the letter A. The central area  32  with the letter A in it is transparent. The shaded area  31  is not necessarily transparent, and it generally will not be, because it can be used to hide the mechanical and electrical components of the keyboard.  FIG. 15  is a cross-section of the key, illustrating that the letter A is not on the key top  32 , but on the display screen  37  under the key. The conductive carrier  34  carries the keycap  39  and it is biased away from the keyboard PCB (printed circuit board)  35  by spring  36 . When the key is pressed down by a keystroke, it compresses the spring and the carrier  34  touches the PCB traces  36  and  36 A, closing the circuit between them. The PCB microprocessor interprets this closed circuit as the corresponding key having been pressed. This is just one of many possible architectures that can be used to implement this aspect of the invention. 
         [0013]      FIG. 16  is a more detailed version of the previous two figures. In particular, this figure shows the guidance structure of the key, which was omitted in  FIG. 15  for simplicity of the drawing. The conductive carrier  81  is guided by internal support  83 . 
         [0014]      FIG. 17  shows another embodiment of the transparent key structure, which is better suited for high volume mass production. The backplate of the keyboard is the transparent plate  100 , which holds most keyboard components. The backplate  100 , made of glass or transparent plastic, is attached to the display screen  101 . The keycap  90  is attached to the carrier  91 , which is guided by the internal support  92  (which is attached to the backplate  100 ). An elastomeric spring  94  biases the keycap  90  away from the backplate  100 . Layers  96  and  98  are separated by insulator layer  97 . The insulator layer  97  has multiple holes such as  95  and  96 , which are located across from the top conductive pad  93  and the bottom conductive pad  99 . 
         [0015]      FIG. 18  shows what happens when the keycap  90  is depressed by a force F applied by the user&#39;s finger. The keycap  90  descends, compressing spring  94 . At some point in its downward travel, the plunger  91  compresses the top layer  96 , squeezing the top conductive pad through the hole and therefore establishing contact between the two conductive pads. This contact between the pads is interpreted as the corresponding key having been pressed. 
         [0016]      FIG. 19  shows a different embodiment with a different type of keyboard intended to provide tactile feedback to the user without the need for a mechanical keyboard as the ones described in the previous embodiments. There have been numerous attempts to provide tactile feedback to touchscreen displays, but until now they have not been satisfactory.  FIG. 19  shows a grid or matrix  40  made of plastic, glass or similar transparent material, with a series of walls in X-direction (such as  42 ) and a series of walls in Y-direction (such as  41 ).  FIG. 20  is a cross-sectional view of the grid, showing that this grid has a bottom  43 , which defines a series of compartments  44 , each corresponding to a key. 
         [0017]      FIG. 21  shows the layers used to assemble the display unit according to this embodiment of the invention.  45  is the LCD panel,  40  is the previously described grid, and  47  is a flexible transparent overlay that is placed on top of the grid. 
         [0018]    Therefore the matrix  40  is “sandwiched” between the overlay and the LCD panel. The LCD panel can be a conventional LCD panel as commonly used in laptop computers or alternatively an electronic ink display as used in electronic reader devices such as the kindle. The term “LCD or similar” in this document includes electronic displays. 
         [0019]      FIG. 22  shows the assembled display unit. Each one of the compartments  48  may be optionally filed with air or with an elastic medium such as foam. 
         [0020]      FIG. 23  shows light gun  46  which sends a light ray such as an infrared signal to receptor  49 , which detects and reports any interruption of the light reception. That happens when the user touches the screen overlay in  FIG. 24 . A small but perceivable elastic deformation takes place, providing the sensation of a yielding key and its elastic resistance, thus giving the desired tactile feedback to the user. At the same time, the light ray is temporarily interrupted and the receptor  49  reports the event, which is appropriately interpreted by the touchscreen processor. Since there are light guns and receptors in both X and Y directions, actually two light rays get interrupted, and the processor can assign coordinates X and Y to the point of touch. Of course, instead of infrared or light signals other standard touchscreen technologies can be used in conjunction with the tactile feedback method described herein, including but not limited to resistive touchscreens, capacitive touchscreens, 
         [0021]    SAW technology, other sonic, optical and magnetic sonic technologies and other methods. This is shown in  FIG. 25 , which does not have a light emitter and a light receptor, but instead a touchscreen layer  53  located between the display and the matrix (in this case the matrix needs to have an open bottom to facilitate contact between the depressed overlay and the touchscreen). 
         [0022]      FIG. 26  shows that the grid  50  can be shaped in a rounded, wavy pattern (as opposed to a straight angle matrix) which makes it less visible through the overlay. The curvature of the grid can also be used as a set of lenses to make it easier to read the key labels. 
         [0023]      FIG. 27  shows that an approximately oppositely curved grid  51  can be used to correct distortions and optical aberrations caused by the grid. 
         [0024]      FIG. 28  is used to illustrate another problem area of tablet computers: tablets periodically need to connect with a dock in order to recharge and also to interface with other devices. Tablets are typically equipped with a docking connector that is used to plug the tablet into the dock  113 . The dock connector forces the tablet to be held in portrait orientation, which may not be the orientation needed or desired by the user. Another shortcoming is that the tilting angle of the tablet computer when inserted into the dock is constant, resulting in a viewing angle that is not adequate for many users. 
         [0025]      FIG. 29  shows a tablet computer  120  is configured with dual docking connectors  122  and  123 . This gives the user the option to mount the tablet computer in the dock in either a landscape or a portrait orientation, depending on the particular application and preferences of the user. The internal configuration of the tablet computer (not shown here) requires appropriate wiring between the motherboard, the internal devices and the two dock connectors  122  and  123 . An orientation detection system such as gravity sensors or accelerometers may be required too to switch the display from landscape to portrait mode or vice versa. A sensing pin can also be used to detect orientation when the tablet is plugged into the dock. An internal switchboard may be needed too to deactivate circuits and branches inside the tablet computer that are not used in one mode or the other, which also serves the purpose of not having live energized connectors on the outside of the computer when they are not in use. 
         [0026]      FIG. 30  shows a front view of tablet computer  120  inserted into dock  132  in portrait mode. 
         [0027]      FIG. 31  shows the same tablet computer  120  now inserted into the same dock  132  in landscape mode. This is a new capability provided by this invention. 
         [0028]      FIG. 32  shows an improved dock which comprises a dock base  153  and a pivotable dock body  152  with a docking connector  151 . This improved dock allows the user to adjust the viewing angle according to his or her needs. That is a new capability provided by this invention. 
         [0029]      FIG. 33  shows another improvement to a tablet computer. The tablet computer  160  is equipped with an extendable and retractable keyboard  161 , which adds convenience and portability to the tablet computer, because the touchscreen is generally nor adequate for typing or entry of large amounts of data. For small amounts of data entry the touchscreen is sufficient, but there is a need for a faster and more reliable data entry method for tablet computers, and this keyboard, which can be of a miniature size to save space and weight, can provide that capability. 
         [0030]      FIG. 34  shows another improvement for tablet computers, which currently lack a support system of their own to hold them in a position convenient to the user. A dock can provide that capability, but most users don&#39;t travel with a dock. Therefore, according to this invention, the tablet computer  170  has deployable supports  171  that can support the tablet computer in a desired position. The edge of the tablet computer can be equipped with an anti-slip surface  172  made of rubber or similar material, while the support beam  171  can be equipped with a rubber tip  173  to prevent sliding. In addition an adjustable detent mechanism (not shown) can be provided to prevent unintended changes in the angle.  FIG. 34  shows the support structure before deployment.  FIG. 35  shows the support structure after deployment