Abstract:
An integrated removable functional faceplate for a portable computer system. The removable functional faceplate employs specially located electrical contacts or pads that mate with similarly located electrical contacts mounted on the portable computer system, e.g., a personal digital assistant (PDA) or other electronic device. The electrical contacts of the functional faceplate carry signals that are responsive to the pressing of physical buttons which may be placed in any location on the functional faceplate. This allows individual faceplates to be developed that are specialized for a particular purpose, e.g., extended keyboards, adapted for gaming, adapted for music playing, etc. The functional faceplates may have specialized button types that are adapted for a particular use and are also located in custom positions that reflect the particular use employed. When the functional faceplate is removed from the portable computer system, it may have no buttons or it may provide a standard PDA button group. An identification circuit may be employed on the functional faceplate to indicate its button group and signaling characteristics. Alternatively, the functional faceplate may also include a data generation device, e.g., a global positioning system (GPS) or electronic thermometer, a music player, a smart card, etc. Alternatively, the functional faceplate may also include an auxiliary power supply.

Description:
RELATED US APPLICATION 
     This is a continuation of copending application(s) Ser. No. 09/844,558 filed on Apr. 27, 2001 now U.S. Pat. No. 6,747,578 which is hereby incorporated by reference to this specification 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of data entry devices. More specifically, embodiments of the present invention relate to removable faceplates for a portable computer system or other portable electronic device. 
     2. Related Art 
     As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. One of the new categories of computer systems is the “palmtop” computer system. A palmtop computer system is a computer that is small enough to be held in the hand of a user and can therefore be “palm-sized.” Most palmtop computer systems are used to implement various Personal Information Management (PIM) applications such as an address book, a daily organizer and electronic notepads, to name a few. Palmtop computers with PIM software have been know as Personal Digital Assistants (PDAs). Many PDAs have a small flat display screen associated therewith one or more buttons or keys that can be pressed by a user. 
     In addition to PDAs, small flat display screens and push buttons have also been implemented within other portable electronic devices, such as cell phones, electronic pagers, remote control devices and other wireless portable devices. 
     User convenience and device value are very important factors for portable electronic devices. Typically, portable electronic devices are employed while the user is on the run, e.g., in business meetings, on business travel, personal travel, in a vehicle, on foot, etc. Because the user may be occupied or busy while using the portable electronic device, the number of user steps or user tasks required in order to access information from an electronic device (or to store information into the electronic device) is crucial for producing a commercially successful and useful product. That is, the more difficult it is to access data from an electronic device, the less likely the user will perform those tasks to obtain the information. Likewise, the easier information is to obtain, the more likely the portable electronic device will be used to obtain that information and the more likely the portable electronic device will become a part of the user&#39;s everyday activities. 
     Similarly, the more useful the device, the more the device will be used and acquired. Accordingly, the more the device can be flexible and specialized for particular uses that are important to users, the higher the likelihood that the device will be employed. 
     One way to personalize or specialize a portable electronic device is to alter the appearance of its faceplate or front cover. Today, many cell phones offer removable faceplates which can be attached to the device. The faceplates have button holes that are adapted fit around existing buttons that are integrated with the cell phone body. The faceplates can alter the overall appearance (e.g., color, pattern, etc.) of the device to fit a user&#39;s taste or personal preference. These prior art faceplates, while altering the cosmetic appearance of the device, do not alter the functionality or placement of the underlying buttons which are integrated with the body of cell phone device. 
     Other faceplates have been offered that not only provide cosmetic changes to the device, but also add some special key designations or key types to the existing buttons of the underlying device. However, the existing buttons of the underlying device are still needed. For instance, some faceplates provide mechanical buttons that are designed to contact and fit over the existing buttons on the device&#39;s body. When the mechanical button on the faceplate is depressed, so is the underlying device&#39;s button. The mechanical buttons of these prior art faceplates can alter the designations of the existing buttons or add new button types. For instance, a joystick key type (on the faceplate) can be added over a group of existing keys of the device&#39;s body. When the joy stick is moved, different keys of the key group are then activated. However, since these prior art faceplates make use of the existing keys of the device, they are limited in their potential key placements, key functionalities and key types. These faceplates may also add significant size and weight to the overall device since their keys are additive to the underlying keys. 
     SUMMARY OF THE INVENTION 
     Accordingly, embodiments of the present invention provide an electronic device, e.g., a cell phone, portable computer system, PDA, electronic pager, etc., having a removable functional faceplate. The removable functional faceplate provides additional keys and key functionality that are in addition to any underlying keys of the electronic device (if it has any at all). For instance, removable faceplates can add extended keyboards, gaming controls, etc. The new keys and key functionality can be placed in any location on the faceplate and may be of any key type without restriction to the underlying keys of the electronic device (if it has any at all). Additionally, the functional faceplates may provide circuits which add functionality to the electronic device other than, or in addition to, new keys, e.g., increased memory capacity, increased power capacity, music playing capacity, measurement devices, etc. The faceplates are removable, and in one embodiment, designed to be readily removed and installed by the user. By providing the ability to add new keys to the faceplate, the present invention provides an electronic device that may be substantially customized for a particular user or for a particular and specialized use. The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow. 
     An integrated removable functional faceplate is described herein for a portable computer system. The removable functional faceplate employs specially located electrical contacts or pads that mate with similarly located electrical contacts mounted on predetermined positions of the portable computer system, e.g., a personal digital assistant (PDA) or other electronic device. The electrical contacts of the functional faceplate carry signals that are responsive to the pressing of physical buttons which may be placed in any location on the functional faceplate. This allows individual faceplates to be developed that are specialized for a particular purpose, e.g., extended keyboards, adapted for gaming, adapted for music playing, adapted for email, paging, etc. The functional faceplates may have specialized button types that are adapted for a particular use and are also located in custom positions that reflect the particular use employed. When the functional faceplate is removed from the portable computer system, it may have no buttons or it may provide a standard PDA button group. 
     An identification circuit may be employed on the functional faceplate to indicate its button group and signaling characteristics. Alternatively, the functional faceplate may also include a data generation device, e.g., a global positioning system (GPS) or electronic thermometer, a music player, a smart card, etc. In this case, one or more of the electrical contacts are adapted to receive data signals from this data generation device. Alternatively, the functional faceplate may also include an auxiliary power supply (e.g., battery, solar power, etc.). In this case, one or more of the electrical contacts are adapted to receive a power signal from this auxiliary power source. 
     The removable integrated functional faceplate of the present invention permits a user to add additional specific functionality to its PDA, for instance gaming (e.g., controls, four way control, joystick, etc.) and email (e.g., a keyboard). In order to lessen the size and weight of the PDA, in one embodiment, the functional faceplates may become an integrated part of the PDA and not an add-on accessory. In one implementation, the faceplates may be molded in plastic and removably attached to the PDA via a hook and snaps combination, although any attachment mechanism can be used, e.g., rail and slot, screws, etc. It is appreciated that the faceplate does not need to be of the same size as the PDA, but could be larger depending on the type of use intended. 
     More specifically, an embodiment of the present invention includes a faceplate for an electronic device comprising: a housing adapted to be removably secured onto the electronic device; a plurality of electrical contacts disposed on the housing and operable to mate with corresponding electrical contacts of the electronic device when the housing is secured onto the electronic device; and a plurality of buttons disposed on the housing and, when activated, for causing signals to be generated over the electrical contacts indicating which buttons were activated and when activated. Embodiments include the above and further comprising a code generation device responsive to activation of the plurality of buttons and coupled to the electrical contacts of the faceplate, the code generation device for generating the signals over the electrical contacts which indicate which buttons where activated and when activated. 
     Embodiments include the above and further comprising an identification unit disposed on the housing and coupled to the electrical contacts of the faceplate, the identification unit for identifying the faceplate to the electronic device. Embodiments include the above and further comprising an auxiliary power supply disposed on the housing and coupled to the electrical contacts of the faceplate, the auxiliary power supply for supplying power to the electronic device. 
     Embodiments include the above and further comprising a data signal generation device disposed on the housing and coupled to the electrical contacts of the faceplate, the data signal generation device for supplying data signals to the electronic device wherein the data signal generation device may be a music player or an environmental measuring device or a memory card or a global positioning system (GPS). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a logical block diagram of components of an exemplary portable computer system, e.g., personal digital assistant, that can be used in accordance with an embodiment of the present invention. 
         FIG. 2A  is a front view of a portable computer system of one embodiment of the present invention having its removable faceplate removed thereby exposing its button bezel region which has multiple electrical contacts disposed therein. 
         FIG. 2B  is a front view of a portable computer system of another embodiment of the present invention having its removable faceplate removed thereby exposing its button bezel region which has multiple electrical contacts disposed therein along with some fixed-position integrated buttons. 
         FIG. 3  is a side view of a portable computer system of another embodiment of the present invention having its electrical contacts mounted along the side edge of the device. 
         FIG. 4  is a perspective view of a portable computer system having its removable faceplate attached thereto in accordance with embodiment of the present invention. 
         FIG. 5A  is a perspective view of a portable computer system having snapped thereon a basic removable faceplate in accordance with an embodiment of the present invention. 
         FIG. 5B  is a perspective view of a portable computer system having snapped thereon a basic removable faceplate with a slot for receiving a removable memory device in accordance with an embodiment of the present invention. 
         FIG. 6  is a perspective view of a portable computer system having snapped thereon an extended removable faceplate in accordance with an embodiment of the present invention. 
         FIG. 7  illustrates the back side of a removable faceplate in accordance with an embodiment of the present invention having freely positioned buttons and specially located electrical contacts. 
         FIG. 8  is a perspective view of a portable computer system having snapped thereon a gaming removable faceplate in accordance with an embodiment of the present invention. 
         FIG. 9  illustrates the back side of a removable faceplate in accordance with an embodiment of the present invention having an identification code installed therein. 
         FIG. 10  is a perspective view of a portable computer system having snapped thereon a special function removable faceplate in accordance with an embodiment of the present invention. 
         FIG. 11  illustrates the back side of a removable faceplate in accordance with an embodiment of the present invention having a data generation device installed therein. 
         FIG. 12  illustrates the back side of a removable faceplate in accordance with an embodiment of the present invention having an auxiliary power source installed therein. 
         FIG. 13  illustrates the back side of a removable faceplate in accordance with an embodiment of the present invention having a receiving slot (for a memory card) and associated chipset installed therein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the present invention, an integrated removable functional faceplate for a portable computer system or other intelligent device, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details or with equivalents thereof. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. 
     Exemplary Portable Electronic Device Platform 
     Although the functional faceplate of the present invention can be implemented in a variety of different electronic systems such as a pager, a cell phone, a remote control device, etc., one exemplary embodiment includes the integration of the faceplate with a portable electronic device or PDA. 
       FIG. 1  illustrates circuitry of an exemplary portable computer system  100 . Computer system  100  includes an address/data bus  99  for communicating information, a central processor  101  coupled with the bus  99  for processing information and instructions, a volatile memory  102  (e.g., random access memory RAM) coupled with the bus  99  for storing information and instructions for the central processor  101  and a non-volatile memory  103  (e.g., read only memory ROM) coupled with the bus  99  for storing static information and instructions for the processor  101 . 
     Computer system  110  also includes an optional data storage device  104  (e.g., thin profile removable memory) coupled with the bus  99  for storing information and instructions. Device  104  can be removable. Device  104  may also be an SDROM card reader or equivalent removable memory reader. 
     Also included in computer system  100  of  FIG. 1  is an alphanumeric input device  106  which in one implementation is a handwriting recognition pad (“digitizer”) and may include integrated push buttons in one embodiment. Device  106  can communicate information (spatial data and pressure data) and command selections to the central processor  101 . The digitizer  106  records both the (x, y) coordinate value of the current location of the stylus and also simultaneously records the pressure that the stylus exerts on the face of the digitizer pad. The coordinate values (spatial information) and pressure data are then output on separate channels for sampling by the processor  101 . In one implementation, there are roughly 256 different discrete levels of pressure that can be detected by the digitizer  106 . Since the digitizer&#39;s channels are sampled serially by the processor, the stroke spatial data are sampled “pseudo” simultaneously with the associated pressure data. The sampled data is then stored in a memory by the processor  101  for later analysis. 
     System  110  of  FIG. 1  also includes an optional cursor control or directing device  107  coupled to the bus for communicating user input information and command selections to the central processor  101 . In one implementation, device  107  is a touch screen device (also a digitizer) incorporated with screen  105 . Device  107  is capable of registering a position on the screen  105  where the stylus makes contact and the pressure of the contact. The digitizer of  106  or  107  can be implemented using well known devices, for instance, using the ADS-7846 device by Burr-Brown that provides separate channels for spatial stroke information and pressure information. 
     System  100  also contains a flat panel display device  105  coupled to the bus  99  for displaying information to the computer user. The display device  105  utilized with the computer system  100  may be a liquid crystal device, cathode ray tube (CRT), field emission device (FED, also called flat panel CRT) or other display device suitable for creating graphic images and alphanumeric characters recognizable to the user. Any of a number of display technologies can be used, e.g., LCD, FED, plasma, etc., for the flat panel display  105 . In one embodiment, the display  105  is a flat panel multi-mode display capable of both monochrome and color display modes. 
     Signal communication device  108 , also coupled to bus  99 , can be a serial port (or USB port) for communicating with a cradle. In one embodiment, the serial communication interface  108  is a serial communication port, but could also alternatively be of any of a number of well known communication standards and protocols, e.g., parallel, SCSI, Firewire (IEEE 1394), Ethernet, etc. In addition to device  108 , wireless communication links can be established between the device  100  and a host computer system (or another portable computer system) using a Bluetooth wireless device  360 , an infrared device  355 , a GSM radio device  240 , or a CDMA device, or a W-CDMA device or a 802.11 device. Device  100  may also include a wireless modem device  240  and/or a wireless radio, e.g., a GSM wireless radio with supporting chipset. The wireless modem device  240  is coupled to communicate with the processor  101  but may not be directly coupled to port  108 . 
     In one implementation, the Mobitex wireless communication system may be used to provide two way communication between system  100  and other networked computers and/or the Internet, e.g., via a proxy server. In other embodiments, TCP protocol can be used or SMS can be used. System  100  of  FIG. 1  may also contain batteries for providing electrical power. 
     Also shown in  FIG. 1  are a group of electrical contacts or pads  220  that are disposed on the portable computer system and made available for mating with a removable faceplate, in accordance with an embodiment of the present invention. These electrical contacts  220  are internally coupled to bus  99 . In one embodiment, these electrical contacts are exposed when the removable faceplate is removed from the device  100 . Depending on the particular embodiment, as discussed below, some of the pads  220  are used to carry different signal types that may be generated from the faceplate, e.g., they are used (1) to carry code signals used by the processor  101  to differentiate between which buttons are pressed on the faceplate and when; (2) to carry power; (3) to carry an identification code of the faceplate; and (4) to carry data signals from a data signal generation device on the faceplate. 
     Functional Faceplate of the Present Invention 
       FIG. 2A  illustrates a front view of a portable computer system  100   a  in accordance with one embodiment of the present invention with its faceplate removed. In this example, system  100   a  may be a hand-held computer system or PDA but could be any portable electronic device (e.g., pager, cell phone, etc.). Flat panel display screen  105  is located in the central portion. A recess  210  may be cut out for receiving a button region from a removable faceplate (not shown). Also shown are the electrical contacts  220  which are disposed within the recess  210  in this embodiment and are exposed. There may be as few as two electrical contacts  220  in accordance with the present invention. The electrical contacts  220  are for mating with contacts from a removable faceplate. These electrical contacts or pads  220  allow the removable faceplate to communicate signals with the device  100   a , e.g., button selection signals and other data, and/or power signals. In the example  100   a  shown in  FIG. 2A , there are no keys or buttons located on the face of device  100   a  with the faceplate removed. In this particular embodiment, the device  100   a  requires a faceplate for full functionality. 
       FIG. 2B  illustrates another embodiment  100   b  of the present invention.  FIG. 2B  illustrates a front view of a portable computer system  100   b  with its faceplate removed. As in  FIG. 2A , electrical contacts  220  of  FIG. 2B  are also located within region  210  of device  100   b . In this example, there is some basic button functionality  230  on device  100   b  even when the faceplate of the present invention is removed. Buttons  230  are located within recess  210  and are integrated within the body of device  100   b . Any faceplate that is to be attached to device  100   b  will generally have cut-outs to accommodate the existing buttons  230  and may also add other, additional, buttons which communicate using pads  220  as described further below. 
       FIG. 3  illustrates another embodiment  100   c  of the present invention. In this example, device  100   c  is shown in side-view and its electrical contacts  220  are located along the side of the device  100   c . It is appreciated that the electrical contracts may be located within region  210  of the device as well as along the edge of the device. Provided electrical contacts are located along the edge of the device, corresponding mating contacts would be required along the back side of the edge of any removable faceplate adapted for attaching to device  100   c.    
       FIG. 4  illustrates a perspective view of a faceplate  250 , in accordance with an embodiment of the present invention, and also a portable computer system  100   a  adapted to receive the faceplate  250 . In one embodiment, the faceplate  250  is removably attached to device  100   a  by pressure and by snap fitting hooks and mechanisms. In this way, the faceplate  250  can readily be removed from device  100   a  and replaced. The front side of the faceplate  250  is shown and is made of a housing (e.g., molded plastic) that bears buttons  270  or “keys.” 
     The faceplate keys  270 , in accordance with the present invention, may be placed in any location and are not limited in position to the locations of any keys that are integrated on device  100   a  (if any). In the example shown in  FIG. 4 , the device  100   a  does not have any keys on its face. The front side of faceplate  250  illustrates a cut-out region  260  for positioning around display  105 . When attached to the device  100   a , contacts (not shown) on the rear side of the faceplate  250  will come into physical contact with electrical pads  220  located on the device  100   a . In this way, the faceplate  250  may communicate with the electronics of device  100   a . It is appreciated that the exterior of device  100   a  may include a recess of roughly the same area and size as the faceplate  250  and this recess may be used to accept the faceplate  250  therein. In this way, the overall size of the PDA with the attached faceplate is reduced and the faceplate  250  becomes integrated with the PDA  100   a.    
       FIG. 5A  illustrates one example device  310   a  in accordance with an embodiment of the present invention. In this example, faceplate  250   a  is attached to and integrated with device  100   a . This faceplate  250   a  is roughly the same width and length as the device  100   a  but could be larger in size. The faceplate  250   a  is a housing that contains multiple standard buttons  270  for PDA access, e.g., six buttons are shown. This faceplate  250   a  is contemplated as being a basic or base faceplate that would be shipped with the PDA  100   a . Not shown are internal electrical contacts on the rear side of the faceplate  250   a  that make contact with corresponding electrical contacts of the front side of device  100   a  when the two components are snapped together. These contacts  222  are shown in  FIG. 7 . In the embodiment of  FIG. 5A , user selections of buttons  270  are translated into coded signals which are generated over the electrical contacts and processed by device  100   a . Using these coded signals, the device  100   a  can determine which buttons where pressed and when. 
       FIG. 5B  is analogous to  FIG. 5A  except the portable computer system  310   b  has snapped thereon a basic removable faceplate with a slot  312  for receiving a removable memory device in accordance with an embodiment of the present invention. 
       FIG. 6  illustrates one example device  320  in accordance with an embodiment of the present invention using an extended faceplate integrated with the device  100   a . In this example, an extended faceplate  250   b  is attached to device  100   a . This faceplate  250   b  is roughly the same width as device  100   a  but is longer in length to accommodate an extended keyboard. The faceplate is a housing that contains the six standard buttons  270  for PDA access but also contains a full alphanumeric keyboard  280  which may be used for text entering. Also included are function keys  272 . This faceplate  250   b  can be used by any user requiring the particular key layout shown to customize the device to their particular needs and work. Not shown are internal electrical contacts on the rear side of the faceplate  250   b  that make contact with corresponding electrical contacts of the front side of device  100   a  when the two components are snapped together. In this embodiment, user selections of buttons  270 ,  272  or  280  are translated into coded signals which are generated over the electrical contacts and processed by device  100   a . Using these coded signals, the device  100   a  can determine which buttons where pressed and when. 
     Importantly, faceplates  250   a  or  250   b  can interchangeably be removed attached to device  100   a  depending on the user&#39;s needs. For instance, if a user performs a large degree of text data entering or responds to pages, he/she may want a pager-like interface with their PDA  100   a . In this case, faceplate  250   b  can be used to customize the PDA  100   a  for this particular use. However, if the user wants a smaller footprint, e.g., they are traveling, then faceplate  250   a  can be used. 
       FIG. 7  illustrates the rear or back side view of faceplate  250   a  (and can also represent the rear side view of faceplate  250   b ). According to this embodiment, mechanical buttons  270   a - 270   e  are electrically connected to a code generation device  410  via ribbon cable (or “flex circuits”)  430   a  and  430   b . The mechanical buttons  270   a - 270   e  are mounted on housing  420  and may be placed in any location on the housing  420  and are basically electrical switches with a mechanical key. In one embodiment, the housing  420  is made of a molded plastic or resin or a flexible metal material. 
     The code generator device  410  is disposed on housing  420  is connected to electrical contacts  222  via ribbon cable (“flex circuits”)  430   c . As discussed above, contacts  222  are operable to come into physical contact with electrical pads  220  of device  100   a  when faceplate  250   a  is attached to device  100   a . The code generator  410  is responsive to signals from cables  430   a  and  430   b  which indicate which button is pressed and when. The code generator  410  is capable of generating a unique digital or analog signal (button code) over contacts  222  indicating which button was pressed. It is appreciated that the button code is generated over contacts  222  simultaneously with the button being pressed. It is appreciated that many well known code generators could be used for this function, including numerous different types of digital and/or analog code generators. 
     It is appreciated that the key or button layout of faceplate  250   a  is very flexible in that keys or buttons can be placed in any position on the faceplate housing  420 . Further, these keys  270   a - 270   e  can be made available to the device  100   a  as a result of the contacts  222  which are positioned at predetermined locations for mating with contacts  220  of device  100   a.    
       FIG. 8  illustrates one example device  330  in accordance with an embodiment of the present invention. In this example, a faceplate  250   c  is attached to and integrated with device  100   a  but is used with the PDA in such a way that it is held length-wise rather than width-wise. The buttons  274  are then placed on the left and right sides to facilitate gaming. This faceplate  250   c  is roughly the same width but longer in length than the device  100   a . The faceplate is a housing that contains special buttons  274  adapted for gaming applications (e.g., start, stop, reset, A/B, joystick, etc.). The buttons  274  are also positioned in places to provide the best gaming experience possible. Not shown are internal electrical contacts on the rear side of the faceplate  250   c  that make contact with corresponding electrical contacts of the front side of device  100   a  when the two components are snapped together. In this embodiment, user selections of buttons  274  are translated into coded signals which are generated over the electrical contacts and processed by device  100   a . Using these coded signals, the device  100   a  can determine which buttons where pressed and when. 
     Importantly, faceplates  250   a - 250   c  can interchangeably be attached to device  100   a  depending the way in which the user wants to use the device  100   a . For instance, if a user plays games, he/she may want a game-like interface with the PDA  100   a . In this case, faceplate  250   c  can be used to customize the PDA  100   a  for this particular use. Therefore, the removable integrated functional faceplates discussed herein permit the user to add additional specific functionality to their PDA such as gaming (joystick) and email (keyboard) or standard PDA use. Also, the faceplates of the present invention, when installed, become an integrated part of the PDA and are not necessarily an add-on accessory which potentially could add additional size to the device. 
       FIG. 9  illustrates the rear or back side view of faceplate  250   c  in block diagram form. Faceplate  250   c  is similar to faceplate  250   a  ( FIG. 7 ) except that the keys are laid out differently and faceplate  250   c  utilizes an optional identification code device  450 . Identification code device  450  can be realized either using either electrical components or mechanical components. Identification code device  450  is coupled to an electrical contact  222  and is able to communicate a code to device  100   a  indicating the identity or type of faceplate that it is. The identity code can help the device  100   a  to interpret the coded signals generated by the code generator  410 . Using the identification code  450 , each faceplate adapted for coupling with the device  100   a  would have its own ID code value. In one embodiment, identification code  450  can be realized using a programmed memory cell. 
       FIG. 10  illustrates one example device  340  in accordance with an embodiment of the present invention that adds special functionality to the PDA in addition to buttons and button layouts. In this example, a faceplate  250   d  is attached to a device  100   a  and adds global positioning system (GPS) functionality. This faceplate  250   d  is roughly the same size as the device  100   a  but a GPS receiver  510  is mounted on the housing of the faceplate  250   d . The faceplate also contains standard PDA buttons  270  adapted for PDA applications. Not shown are internal electrical contacts on the rear side of the faceplate  250   d  that make contact with corresponding electrical contacts of the front side of device  100   a  when the two components are snapped together. In this embodiment, user selections of buttons  270  are translated into coded signals which are generated over the electrical contacts and processed by device  100   a . Using these coded signals, the device  100   a  can determine which buttons where pressed and when. The GPS device  510  also communicates with device  100   a  using these contacts. 
     Faceplates  250   a - 250   d  can interchangeably be attached to device  100   a  depending on the user&#39;s need. For instance, if a user needs GPS functionality, he/she may snap-on faceplate  250   d . In this case, faceplate  250   d  can be used to customize the PDA  100   a  for this particular use. 
       FIG. 11  illustrates the rear or back side view of faceplate  250   d  in block diagram form. Faceplate  250   d  is similar to faceplate  250   a  ( FIG. 7 ) except that faceplate  250   d  contains a data signal generation device  460 . The data signal generation device  460  in this example is a GPS device, but could be any module. The data signal generation device  460 , including device  510 , is coupled to electrical contacts  222  and is able to communicate data signals to device  100   a  in this fashion. GPS applications on device  100   a  can then be used to present the data signals to the user. Other possible data signal generation devices  460  could include environmental measuring devices, such as an electronic thermometer, an electronic light meter, an electronic wind meter, an electronic sound meter, an electronic color meter, etc. An optional identification circuit  450  may also be employed. 
     Using data signal generation devices  460 , the faceplates of the present invention can add significant optional features and capabilities to the standard PDA unit  100   a  in a flexible and readily user-installable fashion. 
       FIG. 12  illustrates the rear or back side view of another faceplate  250   e  which adds an auxiliary power supply module  470  to housing  420 . Faceplate  250   e  is similar to faceplate  250   d  except that faceplate  250   e  contains the auxiliary power supply module  470 . The auxiliary power supply module  470  is useful for providing extra power to device  100   a  for applications that consume large amounts of battery power, e.g., music playing applications and related electronics, etc. The auxiliary power supply module  470  is coupled to electrical contacts  222  and is able to provide power to device  100   a  in this fashion. It is appreciated that module  470  may be a battery (replaceable or rechargeable) or may be a solar cell. An optional identification circuit  450  may also be employed. 
       FIG. 13  illustrates the rear or back side view of another faceplate  250   f  which is similar to faceplate  250   d  except the data signal generation device is a data storage device rather than a data measurement device. In this example, the data storage device  480  includes a memory slot to receive a memory card (e.g., flash, SDROM, Memory Stick, etc.), and associated chipset electronics. The memory module  480  is useful for providing additional removable storage capability for the device  100   a  (e.g., provided unit  104  is also a memory card slot) or memory module  480  can be used to provide removable memory storage functionality for a device  100   a  not already having such functionality. The memory module  480  is coupled to electrical contacts  222  and is able to provide memory storage (e.g., data) for device  100   a  in this fashion. Alternatively, device  480  could also be a music storage and playback device. The identification code device  450  is optional. 
     Other functionality that could be added by unit  480  includes an expansion module connector or bus that is adapted for receiving standard sized electronic modules. Also possible are wireless communication devices, such as Bluetooth modules, IR modules, etc. The unit  480  could also be an expanded display screen. An such device would be coupled to contacts  222 . 
     According to the various embodiments of the present invention, the electrical contacts  222  may carry a number of different signal types. For instance, some contacts may be reserved for key code information relating to the buttons that were pressed. In addition, two contacts may be reserved to supplying auxiliary power to the device  100   a . Also, various contacts may be reserved for supplying an identification code to device  100   a  to indicate the faceplate type, e.g., standard PDA type, extended keyboard type, gaming type, GPS type, music type, etc. Other contacts can be reserved for supplying data signals (analog or digital) to device  100   a.    
     The preferred embodiment of the present invention, an integrated removable functional faceplate for a portable computer system or other intelligent device, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.