Abstract:
The present invention relates generally to an adapter unit for a personal digital assistant. More specifically, this invention relates to an adapter unit that has a handle grip. The adapter unit provides additional functionality, and improved ergonomics and increased ruggedness to the personal digital assistant.

Description:
RELATED APPLICATIONS  
       [0001]    This application is a continuation in part application of pending U.S. patent application Ser. No. 09/912,195 filed Jul. 24, 2001 entitled Adapter Unit for a Personal Digital Assistant Having Automatically Configurable Application Buttons, which claims the benefits of the filing date of provisional application 60/263,438 filed Jan. 23, 2001, and a continuation in part application of pending U.S. patent application Ser. No. 09/835,733 filed Apr. 16, 2001 entitled Data Acquisition Apparatus, which is a continuation of U.S. patent application Ser. No. 09/528,239, filed Mar. 17, 2000 entitled “Data Acquisition Apparatus”, and issued as U.S. Pat. No. 6,244,513, which is a continuation of U.S. patent application Ser. No. 09/436,169, filed Nov. 9, 1999, entitled “Data Acquisition Device Having a Resilient Seal Interposed Between the Head Portion and the Handle Portion for Rest Stand” and issued as U.S. Pat. No. 6,123,265, which is a continuation of U.S. patent application Ser. No. 08/883,357, filed Jun. 26, 1997 entitled “Data Acquisition Device Having a Resilient Seal Interposed Between the Head Portion and the Handle Portion for Rest Stand”, and issued as U.S. Pat. No. 5,979,770. 
     
    
     
       FIELD OF USE  
         [0002]    The present invention relates generally to an adapter unit for a personal digital assistant. More specifically, this invention relates to an adapter unit that provides additional functionality, and improved ergonomics and increased ruggedness to the personal digital assistant.  
         BACKGROUND OF THE INVENTION  
         [0003]    Personal digital assistants (“PDA”) or hand-held computers have limited functions. These devices typically include internal memory for storing application programs and a local database. PDAs also include external connector used during synchronization procedure (“hot-sync”) with an external database located in a local or remote PC. The PDA is typically inserted into a “hot-sync” cradle, which is tethered to a desktop PC. The PC has a second database, which is similar to the local PDA database. During the “sync” operation both databases get updated with any information that was added to either one or the databases since the last synchronization procedure. While these devices can have various application programs running on them, they still have limited functionality. For example, a typical PDA may not have a detachable scanner or a detachable radio or a combination of both.  
           [0004]    The iPAQ PDA manufactured by Compaq Computer Corporation has an expansion connector for interconnecting with different compatible modules, such as a scanning module. The expansion slot does not replace the “sync” connector, but is provided in addition to it. Thus, the iPAQ has to have two separate connectors to accommodate expanded functionality and “sync” operation. Once a scanning module is connected to the IPAQ, the expansion connector is occupied and no other module can be interconnected with the iPAQ. In addition, the combined device is not rugged enough to be used in industrial environment. Other then interconnecting to the PDA via an electrical connector, the module is not well secured to the PDA and upon drop or vibration the two elements may break or come apart, this rendering the system inoperative.  
           [0005]    While the modules are able to provide additional functions to the personal digital assistant, such benefits come at a price. One of the advantages to the personal digital assistants is their portability. These units are designed to fit in a user&#39;s hand or palm. In many module designs, the depth and/or width of the combination personal digital assistant and module is considerably larger than originally designed by the personal digital assistant manufacturer. The combination of the two devices becomes difficult for a typical user to grasp.  
           [0006]    As additional functions are added to the PDA, there is a greater need to change the functionality of the application buttons on the PDA. Presently, in order to change the function of an application button a user must input data on a series of screens on the PDA indicating the function the user would like to assign to the button. This process requires a certain amount of training on the use of the PDA, can be time consuming and is prone to human errors.  
           [0007]    The PDA includes volatile memory such as RAM. Information stored in the volatile memory may be lost if the power level of the PDA&#39;s battery falls below a certain level.  
           [0008]    Therefore, a need exists to provide a rugged detachable adapter having additional functionality for a hand-held computer such as a PDA.  
           [0009]    A need exists to provide a rugged detachable adapter having scanning functionality for a hand-held computer, such as a PDA.  
           [0010]    A need exists to provide a rugged detachable adapter having wireless communication functionality for a hand-held computer, such as a PDA.  
           [0011]    A need exists to provide a detachable adapter having scanning and wireless communication functionality for a hand-held computer, such as a PDA.  
           [0012]    A need exists to provide a rugged detachable adapter having scanning functionality and a user accessible PCMCIA slot for a hand-held computer, such as a PDA.  
           [0013]    A need exists to provide an adapter having additional electronic functionality for a hand held computer such as a PDA.  
           [0014]    A need exists to provide an adapter having additional electronic functionality for a hand held computer such as a PDA, wherein the combination PDA and adapter connects to a communications cradle in order to communicate with a PC.  
           [0015]    A need exits to automatically change the functionality of one of the application buttons on the PDA in a manner that is seamless to the user.  
           [0016]    A need exists to provide an adapter having additional nonvolatile memory that can store PDA applications and data when power is critically low.  
         SUMMARY OF THE INVENTION  
         [0017]    The present invention provides an adapter unit that can be detachably secured to a hand-held computer, such as a portable digital assistant (“PDA”) computer presently available on the market. Examples of such computers are the iPAQ manufactured by Compaq Computer Corporation, the Palm series manufactured by Palm, Inc. and the Visor series manufactured by Handspring Inc. The invention includes an adapter that adds functionality and ruggedness to a commercially designed device for use in a more industrial environment. The adapter has a PDA connector for interconnecting to the PDA&#39;s expansion connector. A scanner, battery and radio functions may be integrated in the adapter. Specifically, the adapter may include a card for wireless local area communication such as the Spectrum24® card manufactured by Symbol Technologies Inc., a card for wireless personal area network and/or a card for wireless wide area network communication. The adapter may include additional memory for storing data. This memory may include nonvolatile memory such as flash memory for storing drivers that support the functions added by the adapter. For example, the memory may store drivers for a scanner or a wireless local area network. In an alternative embodiment the adapter has a separated expansion connector for accommodating various functional modules. In certain cases, the adapter may also have its own sync connector, allowing it to be directly inserted into the PDA cradle.  
           [0018]    In a preferred embodiment the invention includes an adapter unit that connects to PDA via the PDA&#39;s expansion connector. The adapter unit enhances mechanical ruggedness of the PDA and protects the PDA during drop and vibration. The adapter easily slides on the PDA and may incorporate a retainer clip to lock the adapter and the PDA together. Electronics in the adapter add bar code scanning, imaging capability, additional power, wireless and other PC card support.  
           [0019]    In another preferred embodiment the invention includes an adapter unit having a gripping surface that enhances the ergonomics of the adapter and helps prevent the adapter from slipping out of a user&#39;s hand.  
           [0020]    In another preferred embodiment the invention includes an adapter unit having a gripping surface that enhances the comfort to a user using a personal digital assistant.  
           [0021]    In another preferred embodiment of the invention, the function of one or more of the application buttons on the PDA automatically changes upon the attachment of a device to the PDA.  
           [0022]    In another preferred embodiment of the invention, when the PDA&#39;s battery is critically low, information stored in the PDA&#39;s volatile memory is automatically stored in a nonvolatile memory.  
           [0023]    A strap can also be added on the back of the adapter for ergonomic and comfort reasons.  
           [0024]    In an alternative embodiment a handle is added to the design, such that a handle supports the adapter, and the PDA/adapter combination is held as a gun-shaped terminal in the hand of a user. Batteries, both rechargeable and disposable, chargers and control systems can be added to the adapter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 a  is a side view of an embodiment of the adapter of the present invention;  
         [0026]    [0026]FIG. 1 b  is a top perspective view of an embodiment of the adapter of the present invention;  
         [0027]    [0027]FIG. 1 c  is a back view of an embodiment of the adapter of the present invention;  
         [0028]    [0028]FIG. 1 d  is a bottom view of an embodiment of the adapter of the present invention;  
         [0029]    [0029]FIG. 1 e  is a front view of an embodiment of the adapter of the present invention;  
         [0030]    [0030]FIG. 1 f  is another side view of an embodiment of the adapter of the present invention;  
         [0031]    [0031]FIG. 1 g  is a bottom perspective view of an embodiment of the adapter of the present invention;  
         [0032]    [0032]FIG. 2 a  is a side view of an embodiment of the adapter of the present invention illustrating release of the PDA retaining mechanism;  
         [0033]    [0033]FIG. 2 b  is a PDA of the present invention;  
         [0034]    [0034]FIG. 2 c  is an illustration of an embodiment of the adapter of the present invention connected to a PDA;  
         [0035]    [0035]FIG. 3 is an electrical schematic of an embodiment of the adapter of the present invention incorporating a scanner therein;  
         [0036]    [0036]FIG. 4A is a drawing of a primary side view of a circuit board of an embodiment of the adapter of the present invention;  
         [0037]    [0037]FIG. 4B is a drawing of a secondary side view of a circuit board of an embodiment of the adapter of the present invention;  
         [0038]    [0038]FIG. 5 illustrates an adapter and a hand strap according to the invention;  
         [0039]    [0039]FIG. 6 shows compartment for a rechargeable battery located inside the adapter;  
         [0040]    [0040]FIG. 7 shows an adapter with a handle grip;  
         [0041]    [0041]FIGS. 8 a  and  8   b  show a bottom perspective view of another embodiment of the present invention;  
         [0042]    [0042]FIG. 9 shows an exploded perspective view of the embodiment of the present invention shown in FIGS. 8 a  and  8   b;    
         [0043]    [0043]FIG. 10 shows a top view of the embodiment of the present invention shown in FIGS. 8 a  and  8   b;    
         [0044]    [0044]FIG. 11 shows a bottom view of the embodiment of the present invention shown in FIGS. 8 a  and  8   b;    
         [0045]    [0045]FIG. 12 shows a side view of the embodiment of the present invention shown in FIGS. 8 a  and  8   b;    
         [0046]    [0046]FIG. 13 is a view taken along line A-A of FIG. 12;  
         [0047]    [0047]FIG. 14 shows a flowchart representing a configuration routine for a preferred embodiment of the present invention wherein an adapter is attached to the PDA;  
         [0048]    [0048]FIG. 15 shows a flowchart representing a configuration routine for another preferred embodiment of the present invention wherein an adapter is attached to the PDA;  
         [0049]    [0049]FIG. 16 shows a flowchart representing a configuration routine for a preferred embodiment wherein an adapter is removed from the PDA;  
         [0050]    [0050]FIG. 17 shows a flowchart representing a memory backup system for a preferred embodiment of the present invention;  
         [0051]    [0051]FIG. 18 shows a perspective view of adapter unit secured to a PDA in accordance with one embodiment of the present invention;  
         [0052]    [0052]FIG. 19 shows a bottom view of the present invention shown in FIG. 18 with the PDA removed from the adapter;  
         [0053]    [0053]FIG. 20 shows a side view of the present invention shown in FIG. 18;  
         [0054]    [0054]FIG. 21 shows a bottom view of another embodiment of the present invention with a PDA secured to the adapter;  
         [0055]    [0055]FIG. 22 shows a perspective view of another embodiment the present invention; and  
         [0056]    [0056]FIG. 23 shows a perspective view showing the bottom of the handle grip of another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0057]    [0057]FIG. 1 a  represents a side view of a preferred embodiment of the adapter  100  of the present invention. FIG. 1 b  shows the sled adapter from a top perspective view. FIG. 1 g  is a bottom perspective view of an embodiment of the adapter of the present invention. As shown in FIGS. 1 a  and  1   b , the sled-type adapter includes a cover  104  and a carrier  106 . The carrier  106  includes a bottom wall  108  and two sidewalls  110  extending from bottom wall  108 . An interface circuit board and a scanner, a radio, RFID tag reader, global positioning system, telephone, and/or some other module, is housed between the cover  104  and the bottom wall  108  of the adapter. The adapter of FIG. 1 a  includes an integrated radio with a hidden antenna and an interface board that allows connection to the PDA. FIG. 1 e  is a front view of the adapter. FIG. 1 e  shows an adapter having an integrated scanner located behind the scanning window  120 . Sidewalls  110  of carrier  106  are curved in such a way that they surround the PDA on both sides and protect the PDA from side-to-side movement and side impact. Sidewalls  110  prevent the adapter from being pulled off the PDA. FIG. 1 c  is a back view of the adapter of the present invention. It shows the edges of curved sidewalls  110  and the adapter connector  124  extending from the circuit board. A wall portion  106  of the adapter overlaps sidewalls  110 , thus creating a seam overlap between the different portions of the adapter. The overlap helps the user to more easily hold the adapter/PDA combination device. FIG. 1 d  is a view of the adapter from the bottom, exposing the bottom wall  108  of the carrier from underneath. It shows four fasteners  109  that attach carrier  106  to cover  104 , enclosing the electronics between carrier  106  and cover  104 . Carrier  106  can be attached to the cover  104  and the electronics by snap-in features, screws or glue. It is preferable to make the adapter as thin and as small as possible in order to make it low profile and enhance its ergonomics. When, as in the presently illustrated case, the sidewalls are designed to protect the sides of the PDA, the height of the sidewalls is dictated by the height of the PDA to which the adapter attaches. In other designs the sidewalls may only partially cover the sides of the PDA.  
         [0058]    At the extreme case, when no side protection of the PDA is needed, the sidewalls may be replaced by a pair of rails that mate with the corresponding guides on the PDA. However, when the sidewalls are eliminated, the overall ruggedness of the adapter/PDA-combined device is reduced.  
         [0059]    [0059]FIGS. 1 f - g  are additional views of the adapter when it is placed upside down.  
         [0060]    When adapter  100  is connected to the PDA, sidewalls  110  restrict the side-to-side movements of the PDA with respect to adapter  100 . Adapter connector  124  restricts movement of the PDA in one direction along the length of adapter  100 . In order to restrict the movement of the PDA in the other direction along the length of adapter  100 , and to fully secure adapter  100  to the PDA, a retainer clip  112  is provided as part of adapter  100 . Retainer clip  112  is shown in FIGS. 1 a ,  1   b ,  1   f  and  1   g . Retainer clip  112  secures the PDA to adapter  100  and prevents accidental disconnects between the two devices upon vibration or drop. In alternative embodiments the retainer can be replaced by snap fasteners, interference-fit, or detent features designed into the PDA and the adapter.  
         [0061]    [0061]FIGS. 2 a - c  illustrate the method of attachment of a PDA  50  to adapter  100  of the present invention. PDA  50  includes an expansion connector  52 . First, retainer clip  112  is pushed out of the path of PDA  50  that is being inserted into the adapter. Second, PDA  50  is fully inserted into adapter  100  and the PDA&#39;s expansion connector  52  is mated with the corresponding adapter connector  124 . Third, retainer clip  112  is pushed back to its original position, fully securing PDA  50  within adapter  100  and preventing accidental separation of adapter  100  from PDA  50 . Thus, when PDA  50  is inserted into adapter  100  of the preferred embodiment, adapter  100  protects PDA  50  on five of the PDA&#39;s six surfaces. The only PDA surface that remains exposed is the PDA&#39;s display surface.  
         [0062]    [0062]FIG. 3 is an electrical schematic of the interface board of the adapter of the present invention. The interface board includes circuitry for communicating with a bar code scanner via connector JP 1 . Alternatively, the interface board could include circuitry for an imager such as a charged coupled device (CCD) or similar technology known to those of skill in the art.  
         [0063]    [0063]FIGS. 4 a  and  4   b  show the primary and secondary sides, respectively, of a printed circuit board of the adapter according to the present invention. Connector JP 1  interfaces electronics on the circuit board with a scanner module. An external connector JH 1  interfaces electronics on the circuit board with the iPAQ PDA. A 68-pin connector JH 2  interfaces electronics on the circuit board with a PC card having radio or other functionality. Thus, the adapter integrates both the scanner module and the radio module, together with an antenna, inside it. Some of the electronic components between the two modules can be shared.  
         [0064]    In another alternative embodiment, the modules are not be integrated inside the adapter, but are selectively plugged into the adapter. For this, either the JP 1  or JH 2 , must also be an external connector. For example, if the adapter has a PCMCIA compatible connector, any PCMCIA compatible module can be plugged into the adapter, thus expanding system flexibility even further. Module compatible interface connectors, other than the PCMCIA interface connectors are envisioned to be within the scope of the present invention.  
         [0065]    As can be gathered from the above description, while the adapter must have a PDA compatible connector for interfacing to the PDA, the expansion module connector is optional.  
         [0066]    FIGS.  8 - 13  are drawings of an alternative embodiment of the present invention. The adapter  200  includes a cover  204  and a carrier  206 . The carrier  206  includes a bottom wall  208  and two sidewalls  210  extending from bottom wall  208 . Curved portions  211  of sidewalls  210  of carrier  206  are curved in such a way that they partially cover the sides of the PDA. Curved portions  211  protect the PDA from side-to-side movement and side impact. Curved portions  211  also prevent adapter  200  from being pulled off the PDA and protect the PDA from front impact. An interface circuit  227  board and a scanner, a radio, RFID tag reader, global positioning system, telephone, or some other module, is housed between the cover  204  and the bottom wall  208  of the adapter. The adapter of FIG. 8 a  shows an adapter having an integrated scanner located behind the scanning window  220 .  
         [0067]    Sidewalls  210  include a gripping surface  213  for improved ergonomics. As electronic components are added to the adapter, the overall thickness of adapter may increase. Users with small hands may have difficulty wrapping their fingers all the way around to the curved portion of the sidewalls. Gripping surface  213  provides a surface for these users to place their fingertips allowing them to grasp the adapter in a secure manner. Users with larger hands may choose to place their fingertips either on the side of the PDA or on gripping surface  213 . When viewing the adapter from a horizontal position, the gripping surface  213  has a portion that is below bottom wall  208  and a portion that is above bottom wall  208 .  
         [0068]    As illustrated in FIG. 13, gripping surface  213  has a portion that radiates in an outward direction relative to a vertical axis  270 . An angle a is formed along vertical axis  270  and the gripping surface  213 . Angle a may change depending on where along gripping surface  213  it is measure. An angle β is formed along vertical axis  270  and a side section  215  above the gripping surface  213 . Side section  215  consists of portions of carrier  206  and cover  204  (not shown in FIG. 13). FIG. 13 shows a seam  217  where carrier  206  meets cover  204 . Alternatively, the side section could consist of portions of only the carrier or only the cover. Gripping surface  213  and side section  215  meet to form a ridge  260 . Ridge  260  improves the ergonomics of adapter  200  and helps prevent a user&#39;s fingers from slipping off gripping surface  213 .  
         [0069]    [0069]FIG. 10 shows a notch  270  where a tether or strap (not shown) can be attached to adapter  200 . The tether allows the operator to carry the device without worrying about dropping it. Tether is preferably attached to the top of adapter  200  so if adapter  200  hangs from the tether the PDA would be in an upright position and less likely to slip out of the adapter.  
         [0070]    Adapter  200  shown in the embodiment of FIGS.  8 - 13  does not have a retainer clip. In an alternative embodiment adapter  200  could include a retainer clip to lock the adapter and the PDA together as shown in the embodiments of FIGS. 1 a ,  1   b ,  1   e ,  1   f  and  1   g . When adapter  200  is connected to the PDA, curved portions  211  restrict the side-to-side movements of the PDA with respect to adapter  200 . Adapter connector  224  restricts movement of the PDA along the length of adapter  200 .  
         [0071]    A connector interface  205  is flexibly secured to adapter  200 . Connector interface  205  may be secured by a spring or similar arrangement to allow it to move in an orthogonal direction relative to the bottom wall  208 . The connector interface  205  has ribbed members  205   a  that engage with a receiving receptacle on the PDA (not shown). When the PDA is inserted into adapter  200 , connector interface  205  is forced down until the PDA&#39;s receiving receptacle engages ribbed members  205   a . At this moment ribbed members  205   a  springs up into the PDA&#39;s receiving receptacle creating an audible click. The audible click notifies the user that adapter  200  is fully secured to the PDA.  
         [0072]    [0072]FIG. 5 illustrates an adapter having a hand strap  130 . Hand strap  130  is attached to the top of the adapter and allows the operator to carry the device without worrying about dropping it. The adapter, which is typically made out of plastic material, can have a rubber over-mold with a finger grip designed into it.  
         [0073]    [0073]FIG. 6 shows compartment for a rechargeable, or a disposable, battery located inside the adapter. The battery is accessed via a battery door  140  that forms a part of the adapter&#39;s top cover. The adapter may also include a vibrating mechanism. The vibrating mechanism vibrates to the adapter to act as an alert the user. This feature is particularly useful in applications where there is a lot of background noise and an audio alter would not be heard.  
         [0074]    [0074]FIG. 7 shows an adapter having a handle grip  150  extending from the surface of the adapter. Handle grip  150  may be detachable from the adapter. In addition, handle grip  150  includes a trigger mechanism  152  for triggering (“energizing”) the module that is integrated inside the adapter. Handle grip  150  has a battery compartment  154  inside it, such that the device can be operated for longer periods of time. As an alternative, the adapter may not have any batteries inside, and would receive its power from handle grip  150 . Handle grip  150  also includes a wrist tether  156  allowing the operator to carry the device without having to grip it.  
         [0075]    Changing Functionality of Application Buttons  
         [0076]    In one embodiment of the present invention a user can change the functionality of one or more of the application buttons on the PDA in a manner that is seamless to the user. For example, one of the buttons on the PDA may be dedicated to functioning as an audio recording button. When a user attaches an adapter that has scanning capability, the user may want to use that button to trigger a scanning operation instead of audio recording. According to a preferred embodiment, by attaching the adapter to the PDA, the functionality of the button may be reconfigured to a scanning function without any additional steps by the user.  
         [0077]    [0077]FIG. 14 shows a flowchart representing a configuration routine for a preferred embodiment of the present invention. Step  302  represents a PDA having an application button that is assigned a certain function. In this preferred embodiment the adapter includes nonvolatile memory that includes a configuration program. The configuration program may include a program that includes routines for changing the functionality of one or more of the application buttons on the PDA. The configuration program changes application button mappings within the PDA to produce the desired functionality. When a device (such as an adapter) is attached to the PDA (and when the PDA is turned on) at  304 , the PDA will run the configuration program at  306 . At step  308 , the configuration program will change the application button mapping in the PDA to change the functionality of one or more of the application buttons from an original function to a reconfigured function. Thus, the change of function of the buttons is seamless to the user. The reconfigured function of the button will preferably be related to a function that was added by the attachment of the adapter to the PDA.  
         [0078]    [0078]FIG. 15 shows a flowchart representing a configuration routine for another preferred embodiment of the present invention. Step  312  represents the PDA having an application button with a certain function wherein the PDA has a configuration program stored in a memory. Alternatively, the configuration program could reside on a remote site that is accessible by the PDA. At step  314 , the PDA could poll its expansion connector to detect the presence of any attached devices. An attachable device (such as an adapter) may have associated with it an identification code. The identification code may include a portion that identifies a manufacturer and a portion that identifies a device. If the device is attached to the PDA, the PDA will check the identification code of the attached device at  316 . Once the PDA determines the identification code of the attached device, at  318  the PDA accesses configuration data that provides information for the PDA to change the functionality of the application buttons. The configuration data may be determined by accessing a look up table (stored either locally on the PDA or remotely). Alternatively, instead of having an identification code associated with the attached device, the device may store the reconfiguration data in the device&#39;s nonvolatile memory. At  319 , the configuration program may change the application button mapping in the PDA in order to change the functionality of one or more of the application buttons from an original function to a reconfigured function. Thus, the change of function of the buttons is seamless to the user. Again, the reconfigured function of the button will preferably be related to a function that was added by the attachment of the device to the PDA.  
         [0079]    [0079]FIG. 16 shows a flowchart representing a configuration routine for a preferred embodiment wherein the adapter is removed from the PDA. Step  322  represents the PDA having an application button with a certain reconfigured function. In this preferred embodiment of the invention, the reconfigured function of the application button will revert back to the original function when the adapter is removed. The PDA may include a routine for polling the PDA&#39;s expansion connector to determine whether any devices are attached. At step  324  the PDA polls the expansion connector. If the polling routine determines that an adapter is no longer connected to the PDA, -the configuration program may be activated at  326 . At step  328  the configuration program may change the application button mapping in the PDA in order to change the functionality of the application buttons from the reconfigured function back to the original function. Thus, when a user no longer needs to use the additional functions provided by the adapter unit, he does not have to input any data into the PDA to revert back to the original function of the application buttons. The user can simply detach the adapter from the PDA, and the PDA could automatically reconfigure the application buttons.  
         [0080]    Memory Feature  
         [0081]    In another preferred embodiment of the invention, the adapter may include a memory backup system. The memory backup system helps prevent the PDA from losing information stored in the PDA&#39;s volatile memory in the event that the PDA&#39;s battery source is critically low.  
         [0082]    PDA&#39;s typically include a battery monitoring circuit that monitors the PDA&#39;s battery source to determine an energy level. If the energy level falls below a certain shut down value, the PDA automatically shuts down. The manufacturer or programmer of the PDA sets the shut down value to be large enough so that some power is reserved to maintain the contents of the PDA&#39;s volatile memory. However, this system does not guarantee that the contents of the PDA&#39;s volatile memory will be preserved. The energy level may continue to decrease over time until the data stored in the volatile memory becomes irretrievable.  
         [0083]    [0083]FIG. 17 shows a flowchart representing a memory backup system for a preferred embodiment of the present invention. Step  332  represents a PDA having a volatile memory attached to an adapter. The adapter has a nonvolatile memory capable of storing data and application programs. The system measures the energy level of the battery source at  334  and compares the energy level to a certain backup value at  336 . If the energy level of the battery source falls below the backup value, at step  338  the data stored in the PDA&#39;s volatile memory is copied in the adapter&#39;s nonvolatile memory or to a remote storage area. The remote storage area may include a facility linked to a wide area network or a local area network. The backup value may be set to be equal to or different than the shut down value. If the data stored in the PDA&#39;s volatile memory is irretrievable because the energy level of the battery source is too low to maintain the memory, the data may be reconstructed by using the data stored in the adapter&#39;s nonvolatile memory.  
         [0084]    FIGS.  18 - 20  show an adapter unit  400  in accordance with one embodiment of the present invention. FIG. 18 shows a perspective view of adapter unit  400  having a PDA  50  secured to the adapter unit. The PDA is an SPT-1700 manufactured by the assignee of the present invention. The adapter unit may also be used with other types of PDAs. The adapter unit includes a handle grip  450  integrated into a body  404  of the adapter. Body  404  may be comprised of two or more sections that are secured together. Handle grip  450  includes a trigger mechanism  152  for triggering (“energizing”) the module that is integrated inside the adapter. A scanning window  420  is provided at a first distal end of PDA  50 . Within PDA  50  is a scanning module for scanning objects in a direction that is outward from the distal end. In an alternative embodiment, the scanning module may be within the adapter unit. Handle grip  450  extends from the end of the adapter unit near the distal end of the adapter. Handle grip  450  extents in a downward angular direction with respect the PDA, as will be further described.  
         [0085]    The PDA includes the optical scanning module, a microcomputer for acquiring data and a power supply. Preferably, PDA includes a radio for sending data, such as inventory data, to a master station or to a nearby cash register, such as a checkout station or to another scanning device. The radio may comply with protocols for a wireless local area network (such as the Spectrum24® manufactured by the assignee of the present invention), a wireless wide area network, the Institute of Electrical and Electronic Engineers (IEEE) 802.11 standard of unlicensed spread spectrum communications and/or the IEEE Bluetooth standard. Alternatively, a cord providing power and data communications may be provided.  
         [0086]    The upper surface of the PDA  50  includes a digital display  424  and keys  422 . The display may be a touch sensitive data entry display. The display is rectangular in shape and has a vertical and horizontal configuration. The display may be switched between such configurations to adapt to a user&#39;s preference. In addition, the horizontal configuration can be further configured for left-hand or right-hand use so as to be adapted for a wider range of users.  
         [0087]    The scanning module within the PDA is of a conventional type known in the art, for example, as described in the above referenced U.S. patents owned by the assignee of the present application. In a battery-operated configuration, handle grip  450  may include a connector at the lower end thereof, to be received in a cradle in which the battery of PDA  50  can be recharged. Alternatively, the adapter could be configured to provide for a direct link with a battery charger. When in a cradle, PDA  50  may be used for hands-free scanning. The cradle may also be equipped to provide read-out of acquired data through infrared communication ports or other forms of communication ports, as will be further described.  
         [0088]    [0088]FIG. 19 shows a bottom view of adapter unit  400 . The adapter unit includes a connecting interface  405  that assists in securing the PDA to the adapter unit. Connector interface  405  is flexibly secured to the adapter. Connector interface  405  may be secured by a leaf spring, retaining spring or similar arrangement to allow it to move in an orthogonal direction relative to a bottom wall  408  of the adapter. Extending from bottom wall  408  are two sidewalls  410 . The connector interface  405  engages with a receiving receptacle on the bottom of the PDA (not shown). The bottom receiving receptacle may be any cavity within the PDA including a screw cavity. When the PDA is inserted into the adapter, connector interface  405  is forced down until the PDA&#39;s bottom receiving receptacle engages connector interface  405 . At this moment connector interface  405  springs up into the PDA&#39;s bottom receiving receptacle. This may create an audible click. The audible click notifies the user that the adapter is fully secured to the PDA. To remove the PDA from the adapter, a securing latch  465  (shown, for example, in FIG. 18) coupled to connector interface  405  is engaged. Engaging securing latch  465  causes connector interface  405  to be flush or nearly flush with bottom wall  408 . Thus, the PDA may be slid out of the adapter unit. The PDA and adapter combination may be designed so that the two components break away from each other in the event the combination is dropped or if a user forces the two apart (without engaging securing latch). The break away feature allows the components to separate with causing permanent damage to either component. The invention may further include a mechanism whereby a user may adjust the force required to separate the two components. In an alternative embodiment, the connector interface may comprise a screw that engages a threaded receiving receptacle on the PDA. The securing latch may comprise a knob that may be twisted to lock the PDA into the adapter.  
         [0089]    A faceplate  460  is secured to one end of the adapter unit. Each side of faceplate  460  is secured using a screw  462  which engages a boss member  463 . Faceplate  460  prevents the adapter from being pulled off the PDA and protects the PDA from front impact. Faceplate  460  is generally “U-shaped” having two sections along the sides of adapter. The faceplate can have numerous configurations. FIG. 21 shows a bottom view of another embodiment of the present invention with a PDA secured to the adapter unit. The adapter includes a faceplate  460 ′ that has generally a reverse “L-shape.” Faceplate  460 ′ has only one side section. The side section may be located on the left or right side, and the configuration may be optimized for left-handed or right-handed users. In another embodiment, the faceplate may not have any sections along the sides of the adapter. The faceplate may extend over the PDA only along the bottom of the PDA.  
         [0090]    The PDA may be further secured to the adapter via one or more retaining prongs. FIG. 21 shows retaining prongs  464  which go over the top portion of the face of the PDA. One end of retaining prongs  464  is secured to the adapter unit and the other end is pulled over the face of the PDA. Retaining prongs  464  may serve the dual purposes of securing the adapter to the PDA and protecting the adapter and PDA from impact. Retaining prongs  464  may be made of a somewhat flexible material so they can be stretched over the PDA. Alternatively, the retaining prongs may be secured to the adapter unit in a hinge arrangement and made with a more rigid material. The retaining prongs may be offered in different lengths to accommodate PDA&#39;s having different thicknesses.  
         [0091]    [0091]FIG. 22 shows an embodiment of the adapter unit that uses side interfaces to secure the adapter to the PDA. A side interface  466  is an element that engages a side edge of the PDA. On the opposing side of side interface  466  is another side interface (not shown). The adapter unit of FIG. 22 is designed for a PDA that has a side receiving receptacle on each side of the PDA (not shown) for engagement with each of the side interfaces. When the PDA is inserted into the adapter, side interface  466  engages the PDA&#39;s side receiving receptacle. To remove the PDA from the adapter, a securing latch  468  coupled to the side interface is engaged. Engaging securing latch  468  causes side interface  466  to be flush or nearly flush with the side wall of the adapter unit. Thus, the PDA may be slid out of the adapter unit. The side interface shown in FIG. 22 has a cylindrical shape. Other shapes may be employed without departing from the invention including rectangular or square. In an alternative embodiment, the side interface may comprise a screw that engages a threaded side receiving receptacle on the PDA. The securing latch may comprise a knob that may be twisted to lock the PDA into the adapter.  
         [0092]    In a preferred embodiment, the adapter unit includes ruggedized bumpers to protect the adapter unit and PDA from impacts. FIGS.  18 - 20  show a bumper  470  that is secured to a proximal end of adapter  400 . Bumper  470  is from about 1 mm to about 10 mm thick. Preferably, the bumper is thick enough to extend beyond any vulnerable portions of the adapter. As shown in FIG. 19, bumper  470  extends beyond boss member  463 . Thus, if the adapter falls on its side, bumper  470  will hit the ground—not boss member  463 . Bumper  470  may be made of rubber, plastic or similar ruggedized material.  
         [0093]    As shown in FIG. 19, within the center of the adapter unit is a well  469 . Well  469  is a recess within the adapter that can accommodate a hand strap or tether that may be attached to the back of the PDA. Thus, a PDA that has a hand strap or tether accessory can be secured to the adapter without removing the accessory.  
         [0094]    One feature of the preferred embodiment shown in FIG. 20 is the arrangement of handle grip  450  near the distal end of the adapter. When adapter unit  400  is held in a user&#39;s hand  423  as shown in FIG. 20, the handle arrangement causes the proximal end of the adapter to extend over the radial surface  421  of the user&#39;s hand  423 , such that the body  404  portion rests on and is supported by the radial hand surface  421 . In this arrangement, the weight of the PDA and adapter unit is easily supported by the user during operation of the scanning device. When the user enters data by operating keys  422 , body  404  is firmly supported by the radial hand surface  421  against the force of key strokes, avoiding a tendency to exert unsupported force on the handle grip of the user which would require a greater gripping force. Keys  422  and display  424  are arranged for easy access to the user and easy viewing when the scanning device is held in the hand.  
         [0095]    As is known for such scanning devices, handle grip  450  includes trigger button  152  which may be a two-finger trigger and provide multiple functions, such as read only or read and store, and/or scroll menu utility. Handle grip  450  may have a battery compartment inside it, such that the PDA can be operated for longer periods of time. In a preferred embodiment, a shock absorbing material is placed between the electronic circuitry with the handle grip and the adapter cover. In the event the adapter unit is dropped or banged against a hard surface, the shock absorbing material acts to prevent damage to the electrical circuitry. As an alternative, the PDA may not have any batteries inside, and would receive its power from handle grip  450 . Handle grip  450  also includes a wrist tether allowing the operator to carry the device without having to grip it.  
         [0096]    In a preferred embodiment, the PDA is automatically configured to recognize the activation of trigger  152  as a scanning function. After the expansion connector of the PDA is mated with the adapter&#39;s adapter connector, signals can be sent between trigger  152  and circuitry within the PDA. The activation of trigger  152  sends an interrupt signal to the PDA. In order to minimize the number of interrupts, the system can share interrupts. For instance, the interrupt used to activate the trigger may be the same interrupt used to activate a hot sync operation. A hot sync is initiated upon activation of a button on the hot sync cradle that causes an interrupt signal to be sent to the PDA. In order to distinguish between a hot sync activation and a trigger activation, the adapter may have two of the pins in the adapter connector shorted. Upon receiving the interrupt, an interrupt handler checks to determine whether the PDA is in the adapter. This may be achieved by sending a signal on one of the two shorted pins and checking to see if the same signal is received on the other pin. If the signals are the same, the PDA is in the adapter. Since the pins are not shorted on the hot sync cradle, if the signals are different, the PDA must be in the hot sync cradle. If the PDA is in the adapter, the activation of the trigger will generate a start decode event, and on release of the trigger a stop decode event. The start decode event and stop decode event are signals sent to the scanning module to start and stop, respectively, the decoding process. If the PDA is in the hot sync cradle, the activation of the hot sync button will generate a hot sync operation. Other automatic configuration features may be employed in the present invention to allow the PDA to recognize other features provided by the adapter unit. For instance, the adapter unit may have a button that enables a user to speak into a microphone for wireless voice transmission. The button may be automatically configured to activate this function.  
         [0097]    An additional feature of the preferred embodiment of the present invention is that the forward edge of the PDA forms a resting stand. The resting stand consists of the surfaces of the distal end of the PDA and the end of the handle grip  450 . The place of a resting surface is shown by the dotted line  438  of FIG. 20. The surfaces may be configured either as a linear edge or as a multi-point stand. This enables the PDA and adapter combination to be conveniently rested against a flat horizontal surface in a stable position. The resting configuration may be further improved by providing a boot  432  on the lower end of handle grip  450 , for providing a stable rest configuration. Boot  432  includes a boot ring  433  that goes around the circumference of the handle grip  450 . Alternatively, boot  432  may be molded as part of handle grip  450 . Boot  432  may also be part of a resilient gasket between portions of the handle. Boot  432  may be extended sideways, to provide greater stability as a stand and a resting ridge for handle grip  450 . The resting configuration of the preferred embodiment enables a user to easily grasp the adapter when the PDA/adapter combination is resting against a surface.  
         [0098]    [0098]FIG. 23 shows an adapter unit that includes a communications port  472  on the bottom of the handle. Communications port  472  may be a serial port or any communication configuration known to those of skill in the art. Communications port  472  enables communication between the adapter unit (or an attached PDA) and another device. The linked devices may be a printer, computer, charger, radio, cradle, power source etc. The adapter unit may include battery contacts that allow a battery within the adapter or PDA to be recharged. The adapter may also include elements that enable it to be removably secured to the linked devices. The embodiment of FIG. 23 shows an adapter that has a boot  432   a  that includes a pair of boot recesses  471 . Boot recesses  471  can receive a gripping element (not shown) associated with the linked device. For instance, a vehicle cradle may include a housing having a gripping element for engaging boot recesses  471 . When a driver returns to his vehicle he can secure the adapter unit to the vehicle cradle. The adapter unit can communicate with the vehicle cradle via communications port  472 . The vehicle cradle may be able to supply power to the adapter unit, download information from the adapter unit or upload information from the adapter unit. The vehicle cradle may have a wireless radio capable of transmitting information downloaded from the adapter unit.  
         [0099]    The adapter unit may include a short range wireless radio to communicate with other devices. One example of such a radio is an infrared radio (although other radios known to those of skill in the art may be employed). The adapter unit may then communicate with a device that has an infrared receiver. For instance, if a printer has an infrared receiver, the adapter unit can send information wirelessly to the printer.  
         [0100]    The embodiment of the present invention shown in FIG. 22 includes a filler block  440 . Filler block  440  includes one or more securing teeth  442 . The bottom wall of the adapter includes securing receptacles  443 . Securing teeth  442  engage with securing receptacles  443  to form an integrated adapter unit. Filler block  440  allows the adapter to accommodate PDA&#39;s of various thicknesses. In the event of a narrow PDA, filler block  440  may be employed. Without filler block  440  there would be a visible gap between the PDA and the adapter. In the event of a thick PDA, filler block  440  may be removed from the adapter. The features of the PDA may dictate its thickness. For instance, a PDA having a radio card may be thicker than a PDA without the card. The thickness of the PDA may also depend upon the manufacturer of the PDA. Filler blocks of various thicknesses may be provided to allow a continuous spectrum of PDA thicknesses.  
         [0101]    The adapter unit of FIG. 22 also includes a magnetic strip reader  467 . Magnetic strip reader  467  enables a user to use the PDA as a card reader. After swiping a card through magnetic strip reader  467  the PDA can display information included on the swiped card. Various locations could be chosen for magnetic strip reader  467 . It may be located on the side of the adapter unit or on a portion that goes over the face of the PDA.  
         [0102]    The adapter unit of the present invention is capable of providing other enhanced or additional features to a PDA. For instance, for some applications it would be desirable to provide an enhanced keyboard, a radio frequency identification reader (RFID), a printer, an enhanced microphone or an enhanced speaker. The term “enhanced” means that a PDA may have a particular feature but the feature may be improved. For example, the limited number of keys on a PDA is sufficient for many applications, but for some applications it is desired to have a QWERTY keyboard. Also, a PDA may have a speaker, but in some industrial applications it is desired to have a loader speaker. The enhanced or additional features can be incorporated within the housing of the adapter unit. Alternatively, the enhanced or additional features can be within modular elements that are linked to the adapter unit. The adapter unit may be configured to receive a keyboard module, a magnetic strip reader module, a RFID module, a printer module, a microphone module or a speaker module. When a user needs a particular feature, the user can simply attach the module that has the feature. Afterward, the user can simply remove the module.  
         [0103]    The adapter unit can be secured to a user via a fastening accessory. Fastening accessories include a belt clip, a holster or a loop. The belt clip is a clip that is secured to the adapter unit and can be secured to the belt of a user. The holster (like a holster for a gun) can be secured to a user&#39;s belt, pants, solder or ankle, and is configured to receive and secure the adapter unit. The loop comprises a loop or ring that can be secured to a user, and is configured to receive the adapter&#39;s handle grip. Another accessory that may be offered for the present invention is a weather guard to protect the PDA from the elements. The weather guard covers vulnerable portions of the PDA that are exposed after the PDA is secured to the adapter unit. In a preferred embodiment, the weather guard is shaped along the contours of the adapter unit so when the weather guard is secured to the adapter unit/ PDA combination, there are minimal exposed surfaces of the PDA. Preferably, the weather guard is made of a plastic material and includes a clear portion that allows a user to view the PDA&#39;s display even when the weather guard is in place.