Patent Publication Number: US-8120594-B2

Title: Three-dimensional contact-sensitive feature for electronic devices

Description:
RELATED APPLICATION INFORMATION 
     This application is a continuation of U.S. patent application Ser. No. 11/869,701, filed Oct. 9, 2007 now U.S. Pat. No. 7,986,310 entitled, “THREE-DIMENSIONAL CONTACT-SENSITIVE FEATURE FOR ELECTRONIC DEVICES,” which is a continuation of U.S. patent application Ser. No. 11/112,051, filed Apr. 22, 2005 entitled, “THREE-DIMENSIONAL CONTACT-SENSITIVE FEATURE FOR ELECTRONIC DEVICES,” which issued as U.S. Pat. No. 7,800,591 on Sep. 21, 2010, which is a divisional application of U.S. patent application Ser. No. 09/871,322, filed May 30, 2001 entitled, “THREE-DIMENSIONAL CONTACT-SENSITIVE FEATURE FOR ELECTRONIC DEVICES,” which issued as U.S. Pat. No. 6,924,752 on Aug. 2, 2005. All of the aforementioned parent applications are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to input mechanisms for electronic devices. In particular, the present invention relates to contact-sensitive input features for electronic devices. 
     BACKGROUND OF THE INVENTION 
     Typical input mechanisms for electronic devices and computers include button mechanisms and mechanical actuation switches. These input mechanisms can be subject to failure through repeated use. They require multiple components that can move relative to one another, and may require hinges, springs or joints that are subject to fatigue. 
     Another type of input mechanism is a digitizer. The digitizer can detect contact on a surface that is typically incorporated with a display. The digitizer may be a component of small computing devices, such as handheld computers, or personal digital assistants (PDAs). An assembly of the digitizer assigns identifying voltage values for different contact points distributed across the digitizer&#39;s surface. This allows the user to distinguish a communication by positioning an external object on a specific position of the digitizer. 
     Inputs such as gestures, taps, and drags are made on the surface of the digitizer through contact. Icons or other visual cues may be employed with the digitizer to give a user an indication that contact with a specific position on the digitizer will cause a processor of the device to perform a specific function. Digitizers are relatively planar, so that contact points on the surface of the digitizer are positions on the same plane. When users enter input through a digitizer, the user selects planar positions on the digitizer&#39;s surface for contact with the external object. 
       FIG. 10  is an illustration of a prior art display module  900 . The display module  900  is contact-sensitive to produce electrical signals in response to contact. The electrical signals are subsequently converted to input. The display module  900  includes an exterior layer  910 , a conductive layer  920 , a substrate  930  and a display  940 . The exterior layer  910  is a polyester (PET) film. The conductive layer  920  comprises a first conductive film  922 , an air gap  926  formed by spacers  945 , and a second conductive film  924 . The conductive films  922 ,  924  are formed of Indium Tin Oxide material, which has a paste constituency. The spacers  945  are formed from glass or plastic. The substrate  930  is also formed from glass or plastic. The layers formed above display  940  provide a digitizer for the device. The combination of layers for the digitizer is clear to enable viewing of an image created by display  940 . 
     Mechanical buttons are sometimes preferred for certain functions because they provide a better tactile feedback for the function being requested by the input. For example, navigation buttons for scrolling a display of a handheld computer are often mechanical buttons, because they provide a better feel of movement being created when scrolling the display. 
     SUMMARY OF THE INVENTION 
     An electronic device is provided that has a contact-sensitive, three-dimensional surface feature for receiving input. The surface feature enables users to enter input with a tactile feel for a corresponding function. In addition, the surface feature has fewer mechanically combined components, making it more resilient than other input mechanisms. The user can enter input easier than with more traditional mechanical buttons. Furthermore, embodiments of the invention are operable with fingers as well as a stylus, and may be made to be responsive to grips rather than only distinct touches. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. Like reference numerals are intended to refer to similar elements among different figures. 
         FIG. 1  is an exploded, isometric view of an electronic device including a contact-sensitive surface feature, under an embodiment of the invention. 
         FIG. 2A  is a cross-sectional view of a length of the electronic device&#39;s housing, cut along lines A-A of  FIG. 1 , under an embodiment of the invention. 
         FIG. 2B  is a cross-sectional view of a length of the electronic device&#39;s housing, under another embodiment of the invention. 
         FIG. 2C  is a cross-sectional view of a length of the electronic device&#39;s housing, under another embodiment of the invention. 
         FIG. 3  is a close-up view of a recess shown by line C in  FIG. 2A , under an embodiment of the invention. 
         FIG. 4  is a close-up view of another type of surface feature combination for use with an electronic device, under an embodiment of the invention. 
         FIG. 5  is a close-up view of another type of surface feature combination for use with an electronic device, under an embodiment of the invention. 
         FIG. 6  is a close-up view of another type of surface feature combination for use with an electronic device, under an embodiment of the invention. 
         FIG. 7  is a cross-sectional view of a length of the electronic device&#39;s housing, the housing including a protruding contact-sensitive surface feature, under another embodiment of the invention. 
         FIG. 8  is a cross-sectional view of a length of the electronic device&#39;s housing, the housing including a surface mounted feature for entering input, under another embodiment of the invention. 
         FIG. 9  is a hardware diagram of an electronic device, under an embodiment of the invention. 
         FIG. 10  is a prior art illustration of a display module including a digitizer. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the invention describe three-dimensional contact-sensitive input mechanisms for electronic devices. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention. 
     A. OVERVIEW 
     Embodiments of the invention provide an input mechanism for an electronic device. The input mechanism is a shaped feature combined with a contact-sensitive material. The input mechanism may be integrated with a display module or housing of the electronic device. 
     Under an embodiment of the invention, an electronic device is formed at least partially from a deflectable material that generates an electrical signal in response to contact. The first material is integrated with a portion of the electronic device to provide a shaped feature on an exterior surface of the housing and/or display module. The shaped feature detects contact with an external object on one or more contact points. The contact points correspond to regions where contact is interpreted as a defined input that is signaled for a processor of the electronic device. 
     In an embodiment, the deflectable material with the shaped feature may be an integrated or unitary function of a display module for the electronic device. Alternatively, the deflectable material and shaped feature can be included with the housing. 
     In an embodiment, the contact-sensitive feature may be unitarily formed with a housing of the electronic device. The housing of the electronic device may also be combined with a display module. As used herein, unitarily formed means that the components are combined in a manufacturing process to be one component or item for the end user. The components may be combined on a molecular level in order to be unitarily formed. 
     B. ELECTRONIC DEVICE WITH CONTACT-SENSITIVE SURFACE FEATURE 
       FIG. 1  illustrates an electronic device  100  equipped with a display module  120 , under an embodiment of the invention. The electronic device  100  includes a housing  110  having a front panel  112  to provide a display surface  122  of housing  110 . One or more contact-sensitive, three-dimensional features are formed on an exterior surface of the electronic device  100 . The front panel  112  extends between a top  102  and a bottom  104 , and between opposing lateral sides  105 . 
     In an embodiment, electronic device  100  is a handheld computer, such as a PDA manufactured by Palm Inc, or a device operating a POCKET PC or WINDOWS CE operating system, manufactured by MICROSOFT. In other embodiments, electronic device  100  includes devices such as touch-sensitive computer tablets, laptop computers, mobile phone devices, or any other device containing processing resources. 
     In an embodiment, housing  110  is formed at least partially from a contact-sensitive material that generates an electrical signal in response to being contacted by an external object. The material is deflectable or otherwise deformable to generate a voltage differential, causing a current to be generated as a signal. 
     The display module  120  may include components for detecting contacts on display surface  122 . As such, display module  120  may be formed from the same contact-sensitive material used with housing  110 . Alternatively, display module  120  is formed from a different type of contact sensitive material. Still further, housing  110  may contain display module  120 , with contact-sensitive features being provided only on display surface  122 . 
     The electronic device  100  includes a plurality of surface features, provided on front panel  112  and/or display surface  122 . The surface features are formed from the contact-sensitive material on the remainder of housing  110 . The contact-sensitive material is shaped or molded into a three-dimensional feature provided on a surface of housing  110 . 
     In an embodiment, the surface features include a first recess  130  and a pair of second recesses  132 . Each recess  130 ,  132  is formed to detect a contact from an external object, such as a contact mechanism, stylus, finger or other extension. The recesses  130 ,  132  can be deflected by contact to generate electrical signals that are received as input by electronic device  100 . 
     In one configuration, first recess  130  is positioned adjacent to display surface  122 , between the display surface and a bottom edge  104  of housing  110 . Second recesses  132  are shown between display surface  122  and a lateral side  105  of housing  110 . Each recess  130 ,  132  is actuatable through contact to signal a command for a processor. The recesses  130 ,  132  may be pre-associated with one or more functions that can be performed by the processor. 
     In an embodiment, second recesses  132  are actuatable as switches. That is, the second recesses  132  may be contacted to cause one signal assertion, similar to the operation of a button. The first recess  130  includes multiple contact points to enable users to create multiple signal assertions from the same relative position. The multiple contact points of recess  130  allow for multiple inputs, where each input is distinguished by the position of the external object contacting the first recess  130 . For example, recess  130  may be contacted in a portion proximate to display surface  122  to cause an image appearing on display surface  122  to scroll upwards. Likewise, recess  130  may be contacted in a position distal to display surface  122  to cause an image appearing on display surface  122  to scroll downwards. 
       FIG. 1  shows that first recess  130  may be coupled to an optional contact mechanism  140  to facilitate entering contacts. The contact mechanism  140  may be coupled to recess  130  during a manufacturing step, or may be configured to be attachable to one or more of the recesses  130 ,  132  by an end user. In one embodiment, contact mechanism  140  includes a swivel  144  that can be pivoted within first recess  130 . The swivel  144  includes an opening  147  for an end piece  148 . The end piece  148  fits into opening  147  to provide an exterior contact surface for swivel  144 . Swivel  144  includes a bottom portion  145  that rests in recess  130 . The bottom portion  145  is contoured or rounded to enable swivel  144  to rock along an axis X and/or Y. In this way, swivel  144  can be pivoted in at least two directions to generate different input signals from recess  130 . When pivoted, swivel  144  may be directed into a contact point of recess  130 , so as to cause an input signal to be signaled to the processor of electronic device  100 . 
     In another implementation, contact points are provided on recess  130  so that swivel  144  can be directed in eight directions within contact recess  130 . Each contact point may correspond to a different input. This allows swivel  144  and end piece  148  to be operated like a multi-directional joystick. 
     Portions of electronic device  100  are formed from a conductive, contact-sensitive material that is pliable into to different types of surface features. The contact-sensitive material may be integrated with the housing  110  and/or display module  120 . A surface feature shaped by the contact-sensitive may be viewed as a portion of display module  120  if the surface feature is formed as an integrated extension of display  120 , even if the surface feature is provided on a region of the electronic device that is outside the footprint of display surface  122 . The surface feature may alternatively be viewed as a portion of housing  110  if the surface feature is formed on a structure that is distinct from display module  120 . Therefore, the surface feature is formed on a region of a layer formed from the contact-sensitive material. The layer of contact-sensitive may overlap a portion of the front panel&#39;s footprint. 
       FIG. 2A  is a cross-sectional view of display module  120  of handheld computer  100 , cut along lines A-A of  FIG. 1 , under an embodiment of the invention. The display module  120  includes a digitizer pad  250  to enable the display module to detect contact. An embodiment incorporates a surface feature on a segment of digitizer pad  250 . The digitizer pad  250  includes an exterior layer  222 , an intermediate conductive section  224 , interior layer  226 , and substrate  228 . The digitizer pad  250  may be incorporated to form a contact-sensitive portion of housing  110 , and/or of display module  120 . To this end, digitizer pad  250  may be extended over a region that overlaps display module  120  and portions of front panel  112 . Opposing sealing elements  229  form a boundary for the conductive portion of digitizer pad  250 . 
     When incorporated with display module  120 , digitizer pad  250  extends over a display  230 . The display  230  includes pixels or other display elements for creating an image from a processor signal. The layers of display module  120  overlaying display  230  are clear or translucent to enable a user to view the image. 
     In an embodiment, an exterior layer  222  of the contact-sensitive portion is formed of a PET film. The exterior layer  222  may have a thickness range between 75-180 micrometers. The exterior layer  222  forms a protective barrier for display module  120 , while providing display surface  122  as a smooth area for receiving contact by a stylus tip or other instrument. In an embodiment, segments  117  of front panel  112  are provided over regions of digitizer pad  250  where contact-sensitive input is not wanted, corresponding to where sealing elements  229  are located. 
     The conductive section  224  includes a first conductive layer  221 , an air gap  223  and a second conductive layer  227 . The first and second conductive layers  221  and  227  are formed of a material having a property of generating an electrical signal when made to contact one another. A plurality of spacers  225  define air gap  223 . The first conductive layer  221  may be deflected into air gap  223  to make contact with second conductive layer  227 . When first conductive layer  221  is made to contact second conductive layer  227 , a signal is generated for the processor of electronic device  100 . The signal may be differentiable to indicate a position where the first conductive layer  221  is made to contact the second conductive layer  227 . 
     In an embodiment, the conductive layers  221  and  227  are each formed by a PET layer combined with a conductive paste. The conductive paste is clear or translucent, and can be formed into a three-dimensional shape during a manufacturing process. At least the first conductive layer  221  is deformable to extend across air gap  223  and make contact with second conductive layer  227 , resulting in a voltage signal that is later interpreted as processor signals. Opposing sealing components  229  form a boundary for conductive section  224 . The spacers  225  may be formed from glass or clear plastic. In one implementation, the conductive paste for conductive layers  221  and  227  is a clear paste commercially available under the trade name ELECTRODAG, manufactured by ACHESON. This material also has the property of being pliable for creating shapes and other features. NISSHA of Japan manufactures a film product for conductive layers  221  and  227 , using ELECTRODAG. 
     A thickness of conductive section  224  for each conductive layer  221  and  227  ranges between 150-220 micrometers, and preferably at about 180-200 micrometers. The thickness for air gap  223  may range between 200-400 micrometers, and corresponds to a diameter of spacers  225 . 
     As an alternative, conductive section  224  may be formed of Indium Tin Oxide. The spacer balls  225  may be distributed within conductive section  224  to create a support structure for a three-dimensional feature. 
     The interior layer  226  is optional. The interior layer  226  may be formed from a PET material similar to exterior layer  222 . The conductive section  224  can generate a differentiable voltage signal for substrate  228  when first conductive layer  221  is made to contact second conductive layer  227 . The substrate  228  includes traces and other electronic contacts that signal voltage differentials generated from conductive section  224  to a component such as an analog-digital converter. The AD converter converts the voltage differential signal to a digital format for the processor of the electronic device. 
     In an embodiment, a footprint of display  230  is smaller than a footprint of the other layers of display module  120 . As described with  FIG. 1 , the conductive section  224  of display module  120  may extend across a majority of front panel  112  ( FIG. 1 ). 
     The surface feature creates a variable thickness in digitizer pad  250 . This may correspond to a region of housing  110  and/or display module  120 . When the surface feature is employed on front panel  112  (or other housing surface), the front panel  112  may include impression or shape of variable thickness corresponding to the surface feature. The exterior layer  222  one or more contact points for digitizer  250 . 
     In one embodiment, the layers forming digitizer pad  250  are contoured or shaped with the impression on the exterior surface.  FIG. 2A  shows that first conductive layer  221 , second conductive layer  227 , and interior layer  226  may be contoured or indented inward (or outward). The substrate  228  may also be contoured. Therefore, multiple layers of the contact-sensitive portion, including first conductive layer  221  and second conductive layer  227 , are contoured to match the shape of recess  130 . 
       FIG. 2B  illustrates an embodiment where only the exterior layer  222  and the first conductive layer  221  are contoured to provide recess  130 . The second conductive layer  227  is planar with substrate  228 . The air gap  223  therefore narrows between the first and second conductive layers  221  and  227 . The narrow region of air gap  223  may be used to provide a feature that is more sensitive to contact. 
     In an embodiment shown by  FIGS. 2A and 2B , recess  130  is formed on a portion of display module  120  that extends beyond the footprint of display  230 . The recess  130  may be formed to appear as either a portion of housing  110  or as a feature of display module  120 . 
       FIG. 2C  illustrates another configuration where recess  130  is formed on a portion of front panel  112  separated from display surface  122  through surface housing segments  117 . In this configuration, recess  130  forms a portion of the housing  110  ( FIG. 1 ) for electronic device  100 . A rigid layer such as provided by housing segments  117  precludes first conductive layer  221  from being deformed to make contact with second conductive layer  227 . 
     Alternatively, the front panel  112  may include recess  130  and be isotropic with display module  120 , so that the front panel and display surface  122  are relatively seamless. The spacers  245  of air gap  223  may be configured to preclude first conductive layer  221  from contacting second conductive layer  227  in that localized region. Thus, the contact required for entering input through the digitizer portion of the housing may be localized to the region of recess  130 . 
     In another embodiment, recess  130  forms a portion of the display surface  122  ( FIG. 1 ) that is inoperative. Still further, another embodiment may provide that recess  130  is formed onto an active portion of display surface  122 , within the footprint of display  230 . 
     C. CONFIGURATIONS AND MECHANISMS FOR CONTACT-SENSITIVE SURFACE FEATURE 
       FIG. 3  is a close-up view of recess  130 , under an embodiment of the invention. The recess  130  is shaped to be coupled with contact mechanism  140  ( FIG. 1 ). The exterior layer  222 , first conductive layer  221 , second conductive layer  227 , and interior layer  226  are all contoured to define a shape for recess  130 . The substrate  228  ( FIGS. 2A and 2B ) may also be shaped for recess  130 . The first and second conductive layers  221  and  227  are formed from a pliable material that can be shaped to define recess  130 , or another feature. One or more contact points may be included on recess  130  to define where first conductive layer  221  may be combined with second conductive layer  227  to signal the processor of the electronic device  100 . 
     According to embodiment, a first contact point  232  is disposed towards bottom  104  of housing  110  ( FIG. 1 ), and a second contact point  234  is disposed towards top  102  of housing  110  ( FIG. 1 ). Each contact point  232 ,  234  is a region or segment of the shaped feature aligned or otherwise coupled to an electrical lead for detecting a voltage differential generated in that region from contact. Additional contact points may be similarly provided on recess  130 . The swivel  144  of contact mechanism  140  pivots within recess  130  to make contact with contact points  232  and  234 . Alternatively, other external objects such as stylus tips and fingers may be used to make contact with contact points  232  and  234 . 
       FIG. 4  illustrates another embodiment where a gel cap  330  is positioned within recess  130  to facilitate a user in actuating the contact points  232 ,  234 . The gel cap  330  is fixed to recess  130  at bottom position  335 . Adhesives or other fasteners may be used to fix gel cap  330 . The mass within gel cap  330  can be moved within recess  130  through contact. When moved, the shape of gel cap  330  can be deformed to apply sufficient pressure for effectuating a contact with contact points  232  and  234 . Examples of materials that may be used for gel cap  330  include elastomers and foam. 
     Among advantages provided by gel cap  330 , users can more readily use fingers to actuate contact points  232  and  234 . The gel cap  330  has a tactile feedback that allows users to make incremental adjustments to the position of the gel cap&#39;s mass within recess  130 . The gel cap  330  can be gripped with a sustained contact and moved to contact points  232 ,  234  as desired. Furthermore, the motion required by the user is lateral, to enable contact points  232  and  234  of recess  130  to be actuated when, for example, the user&#39;s arm is extended while placing a thumb on the gel cap  330  to enter input. 
       FIG. 5  illustrates a gel filler  420  combined with a moveable surface  430  on recess  130 . The gel filler  420  is formed from a sealed gelled mass that is fixed to recess  130  at bottom position  335 . The moveable surface  430  is mounted over the gel filler  420 . The moveable surface  430  may be fixed to an exterior surface  422  of gel filler  420 . The mass of the gel filler  420  may be moved within recess  130  when moveable surface  430  is directed in one direction or another. The moveable surface  430  is moved to displace the interior mass of gel filler  420 , so as to apply pressure or cause contact for actuating contact points  232  and  234 . 
       FIG. 6  illustrates a moveable surface  530  mounted over gel filler  420 , under another embodiment of the invention. The moveable surface  530  includes an extension  532  extending from a base  535 . The extension  532  facilitates finger contact by a user to displace mass within gel fill  420 , so as to enable base  535  to make contact with contact points  232  and  234 . 
       FIG. 7  illustrates another embodiment illustrating a contact-sensitive surface feature shaped as a protrusion  620 . The protrusion  620  may include multiple contact points  622 ,  624 . The contact points  622 ,  624  may be positioned to indicate a function to the user. For example, first contact point  622  may direct the contact towards the display surface  122  ( FIG. 1 ) of electronic device  100  to indicate an upward navigation or scroll for the display surface  122 . Likewise, a second contact point  624  may direct away from display surface  122  to indicate navigation or scrolling in an opposite direction. 
     Shapes other than recesses and protrusions illustrated by  FIGS. 1-7  are under different embodiments of the invention. The conductive section  224  may be formed into a variety of shapes to create an input mechanism that facilitates use of electronic device  100 . 
     D. OTHER EMBODIMENTS 
     While other embodiments described herein provide for a shaped contact-sensitive feature, another embodiment may incorporate three-dimensional contact-sensitive effect on a surface of the housing  110  for the electronic device  100 .  FIG. 8  is a cross-sectional view illustrating a surface mounted gel volume  730  on display surface  722 , formed as an exterior to a first layer  710 . The first layer  710  is substantially planar, and forms a portion of a contact-sensitive display module  720 . The gel volume  730  may be fixed to the surface of front panel  112 . A moveable component  735  is mounted over the gel volume  730 . The moveable component  735  can be directed to displace the interior mass of gel volume  730  so as to cause contact with one or more contact points  722  on the underside of the gel volume  730 . For example, the combination of moveable component  735  on gel volume  730  can be operated similar to a button if moveable component  725  is directed towards surface  710 . 
     Alternatively, the combination of the moveable component  735  and gel volume  730  can be operated as a navigation or swivel input mechanism. This may be accomplished by distributing a plurality of contact points on surface  710  in position to be contacted or pressured by movement of moveable component  735 . 
     Structures similar to input mechanisms such as described with recesses  130  and  132  ( FIG. 1 ) may alternatively be employed as sensor mechanisms. In one embodiment, housing  110  ( FIG. 1 ) may be lined with a layer formed from contact-sensitive material, such as ELECTRODAG. At certain regions on housing  110 , the contact-sensitive lining may be made to act as sensors that detect contact by a user&#39;s hand. The electronic device  100  may be configured based on the sensors detecting the hand or other component. As an example, sensors on a backside of housing  110  may detect whether a user is employing a left hand or right hand to hold the electronic device. The operations of the electronic device  100  may then be configured for left-handed or right-handed users, as detected by the sensors. 
     E. HARDWARE COMPONENTS 
       FIG. 9  is a block diagram of electronic device  100 , including components for receiving input from the contact-sensitive surface or feature shown with  FIGS. 1-8 . According to an embodiment, electronic device  100  includes a processor  840  coupled to a first memory  844  and a second memory  846 . The processor  840  is coupled to a display driver  822 . The processor  840  combines with display driver  822  to process and signal data for presentation on a module display  820 . A digitizer  830  is coupled to processor  840  via an analog-digital (AD) converter  832 . The AD converter  832  is coupled to substrate  228  ( FIG. 2 ) to receive voltage differential signals generated through deflection of conductive section  224  ( FIG. 2 ). In an embodiment, AD converter  832  includes first channel  833  and second channel  837  to receive voltage differential signals and generate a corresponding digital signal for processor  840 . 
     The electronic device  100  may include one or more expansion slots. In an embodiment shown, a first peripheral port  802  enables one or more types of accessory devices to be connected to processor  840 . In addition, electronic device  100  may include a wireless peripheral port  804  that enables information to be communicated to processor  840  from an external source. The wireless peripheral port  804  forwards incoming communications to an amplifier  806  for processor  840 . A second processor  808  intercepts communications incoming to and/or outgoing from wireless peripheral port  804  for purpose of facilitating conversion of data signals between formats and protocols of wireless communications, and those that can be processed by processor  840 . 
     The display module  820  cooperates with display driver  822  to display images on display surface  822 . The first memory  844  may be non-volatile. The processor  840  combines with display driver  822  to present the data in a paginated format on display module  820 . 
     F. CONCLUSION 
     In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.