Abstract:
An expansion system for portable electronic devices is provided. A portable electronic device includes a main logic board and a battery component. The device includes a package for enclosing components of the device that is sealed to prevent ingress of foreign material from the surrounding environment. A mounting interface is provided that extends into the internal space of the package. The mounting interface mounts an expansion component that expands functionality of the device so that it is physically and mechanically spaced from the main logic board. The device may include an expansion interface mounted on the main logic board for logical communication between the main logic board and the expansion component.

Description:
FIELD OF INVENTION 
       [0001]    This invention relates to portable electronic devices, and more specifically to a system for expanding functionality of the portable electronic devices. 
       BACKGROUND OF THE INVENTION 
       [0002]    Portable electronic devices, such as personal digital assistants (PDAs), have become more popular due to their compact sizes and mobility. However, the portable devices suffers from their limited functionality. 
         [0003]    A typical conventional PDA includes an externally accessible connector to connect the PDA to another component, such as a computer, in order to expand the functionality of the PDA. However, to employ the externally accessible connector, it generally requires the enclosure of the PDA to be compromised, either a door opens or removal of a portion of the enclosure. This would cause the ingress of undesirable materials, such as water and dust. 
       SUMMARY OF THE INVENTION 
       [0004]    It is an object of the invention to provide an improved a portable electronic device expansion system that obviates or mitigates at least one of the disadvantages of existing systems. 
         [0005]    According to an aspect of the present invention there is provided a portable electronic device, which includes: a main logic board; an expansion device for expanding functionality of the portable electronic device; a flexible interconnection for logically connecting the expansion device to the main logic board; and a package for enclosing the main logic board and the expansion device together. The main logic board is mechanically isolated from the expansion device. The expansion device is physically spaced from the main logic board when enclosed in the package 
         [0006]    According to another aspect of the present invention there is provided an intrinsic expansion for a portable electronic device, which includes: an expansion board for expanding functionality of the portable electronic device, an expansion interface for logically connecting the expansion board to a main logic board of the portable electronic device, and a flexible interconnection for interconnecting the expansion board and the expansion interface. The expansion device is mounted in the portable electric device so as to be physically spaced from the main logic board when assembled. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein: 
           [0008]      FIG. 1  is a cross section view of an example of a portable electronic device with an intrinsic expansion in accordance with an embodiment of the present invention; 
           [0009]      FIG. 2  is a perspective view of a back cover and electronics mounted on the back cover of the portable electronic device of  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view of a main logic board and an expansion connector on the main logic board in the portable electronic device of  FIG. 1 ; 
           [0011]      FIG. 4  is a side view of the main logic board and an expansion connected to the main logic board via a connection; 
           [0012]      FIG. 5  is a schematic diagram illustrating expansion signals for the intrinsic expansion of  FIGS. 1-4 ; and 
           [0013]      FIG. 6  is a block diagram illustrating an example of the main logic board and the intrinsic expansion of  FIGS. 1-4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Embodiments of the present invention are described using a PDA. However, it would be appreciated by one of ordinary skill in the art that any portable devices, such as portable imagers, scanners, barcode readers, cell-phones, fall within the scope of the embodiments. As described below, the PDA according to the embodiments of the present invention includes an intrinsic expansion that allows for future expansion of the PDA capability without redesign of electronics mounted in the PDA and provides electrical interfaces such that they are protected from the environment in a robust mechanical manner. 
         [0015]    For clarity and without loss of generality, the front (side) of the PDA is one side of the PDA, which faces the user when using that PDA and may have a user interface, such as display, keyboards. The back (side) of the PDA is the side opposite to the front side. 
         [0016]    In the embodiments, relative terms, such as “back” and “front”, are used to describe the geographical sides on the portable electronic device. However, it will be appreciated by one of ordinary skill in the art that the terms “back” and “front” are examples only, and may encompass two different sides which may be changed, for example, according to the design requirement. In the embodiments, the terms “housing”, “cover”, “packaging” and “enclosure” may be used interchangeably. 
         [0017]    Referring to  FIGS. 1-4 , there is illustrated an example of a portable electronic device with an intrinsic expansion in accordance with an embodiment of the present invention. The portable electronic device  10  of  FIGS. 1-4  is a PDA. In  FIGS. 1-4 , components/elements/layers illustrated are schematic in nature and their shapes are not intended to illustrate their precise shapes. 
         [0018]    The PDA  10  includes an intrinsic mechanical, electrical and software ready interface for expanding the technical capabilities of the PDA  10 , without modifying a printed circuit assembly mounted on the device  10 . A party desiring to implement an expanding technology does not require to modify the printed circuit assembly as manufactured. Whereas the expansion interface is internal to the PDA  10 , the mechanical enclosure of the PDA  10  protects it from the environment, an external door/section is not required to be removed. The expansion interface is located in a manner that allows the expansion technology to interface to it remain flexible, and thus will not cause impact to the expansion interface. 
         [0019]    The intrinsic expansion of the PDA  10  supports specific signal protocols such as Universal Serial Bus (USB), Serial and Compact Flash (CF), as described below. For example, USB or Serial may be used for RFID; USB may be used for the printer; and USB/Serial may be used for Biometrics. Direct host battery power is provided to the intrinsic expansion. 
         [0020]    The PDA  10  includes a packaging having a front cover  12  and a back cover  14  and electronics (e.g.,  16 ,  20 ,  24  of  FIG. 1 ). The front cover  12  and the back cover  14  are, for example, custom plastic covers, and are molded so as to meet design requirements (e.g., sealing, size, weight etc) and enclose the electronics. 
         [0021]    The electronics enclosed in the PDA  10  include a main logic board  24  (printed circuit board) for operating the PDA  10 , and an expansion board  16  for expanding the functionality of the PDA  10 . The electronics enclosed in the PDA  10  may further include, for example, but not limited to, a speaker  20 . The speaker  20  is mounted on the inside of the back cover  14 , and is directly connected to the main logic board  24 . A USB hub may be in the PDA 10 . 
         [0022]    One of ordinary skill in the art would appreciate that the portable electronic device  10  of  FIGS. 1-4  may include electronics/optics/components/elements not illustrated in the drawings, such as, cell phone functionality, a microphone, a scanner, a volume controller, a visual indicator, and a battery component. 
         [0023]    The main logic board  24  contains a plurality of primary components, as it would be understood by one of ordinary skill in the art. For example, the main logic board  24  includes a processor, a main memory, and support circuitry. Field Programmable Gate Array (FPGA) is located on the main logic board  24  (e.g.,  60  of  FIG. 6 ). The main logic board  24  can be electrically coupled to the components of the PDA  10 . The main logic board  24  may also be electrically connected to a battery component (not shown) for powering the main logic board  24  and the components of the PDA  10 . 
         [0024]    The expansion board  16  is mounted on the inside of the back cover  14  through a mounting interface  18 . The mounting interface  18  positions the expansion board  16  in the PDA  10 . When assembled, the expansion board  16  is internally mounted in the PDA  10  so that it is physically spaced from the main logic board  24 . The expansion board  16  is not mounted on the main logic board  24 . The expansion board  16  is mechanically disconnected from the main logic board  24 . 
         [0025]    In this example, the mounting interface  18  is on the back cover  14 , and provides a support for mounting the expansion board  16  on the back cover  14 . The mounting interface  18  may be, for example, but not limited to, a frame or a mounting boss. The boss may be molded with the back cover  14 . The frame may be formed on the back cover  14 . In this example, the back cover  14  is molded so as to provide the mounting interface  18  and space the expansion board  16  from the main logic board  24 . The expansion board  16  may be sealed from the main logic board  24  by pressing a sealing sheet around the expansion board  16  or the frame. The sealing sheet may have an opening through which a connection (e.g.,  28 ) passing between the expansion board  16  and the main logic board  24 . 
         [0026]    The functionality of the PDA  10  is expanded through the expansion board  16 , as designed. The expanded functionality may include, for example, but not limited to, RFID, scanner, printer, biometrics, WAN radio. The mounting interface  18  located on the back cover  14  minimizes impact on existing mechanical restraints. 
         [0027]    The expansion board  16  is logically connected to the main logic board  24  through an expansion connector  22  mounted on the main logic board  24 . The expansion board  16  is interconnected to the expansion connector  22  through a flexible interconnection  28 , such as a flex circuit or equivalent. The flexible interconnection  28  is releasably connected to the expansion connector  22 , the expansion board  16 , or a combination thereof. The expansion connector  22  may have, for example, but not limited to, a latch for releasably latching the flexible interconnection  28 . The expansion board  16  may have, for example, but not limited to, a latch for releasably latching the flexible interconnection  28 . The expansion board  16  interfaces with the expansion connector  22  to receive/transmit relevant information/data according to, for example, USB, Serial or CF formats. Power is also supplied to the expansion board  16 , through the main logic board  24 , using the interconnection  28 . 
         [0028]    The interconnection  28  may be a custom flex cable, and is long enough to interconnect it to the expansion connector  22  without damaging the main logic board  24 . The expansion connector  22 , the expansion board  16  and the interconnection  28  allow for each component to be reinstalled or replaced in the field without giving mechanical impact on each other. 
         [0029]    The expansion connector  22  is, for example, but not limited to, a  60  pin connector with standard protocol signals and power. In this example, the expansion connector  22  is an industry standard connector. The expansion connector  22  may be electrically connected to a battery component (not shown), and provides system battery power directly to the expansion board  16 . 
         [0030]    The expansion connector  22  is packaged in a robust manner. For example, the expansion connector  22  is directly soldered to the main logic board  24  and allows for the communications signals according to, for example, but not limited to, USB, Serial, CF, RS232 formats. The processor of the main logic board  24  logically recognizes the expansion board  16 , through the expansion connector  22 . The standard protocols supports plug and play capability of the interconnection  28  into the expansion connector  22 . 
         [0031]    The PDA  10  may have a seal  26 . The seal  26  is a mechanical enclosure that ensures environmental seal of the PDA  10 . The seal  26  is, for example, a rubber gasket. The seal  26  may be a H-connector. The seal  26  goes around the circumference of the front cover  12  and the back cover  14 . The seal  26  joints the front cover  12  and the back cover  14 . The seal  26  is designed so that the PDA  10  has optimal pressures around the seal  26 . The seal  26  is designed so that force is distributed all around the seal  26 . The seal may be designed so as to meet IEC Ingress Penetration (IP) rating of IP  65 . 
         [0032]    With reference to  FIGS. 1-5 , expansion signals are described in detail. In one example, the expansion board  16  is connected to the expansion connector  22  through a I2C bus  30 , a USB (Universal Serial Bus)  32 , an expansion interface bus  34 , a powered logic line  40 , a logic power line  42 , and a battery power line  44 . The I2C  30  and USB  32  perform the data transmission. An address and data bus  38  is provided for communications. The powered logic line  40  provides, for example, a wakeup command to the expansion board  16 . The lines  42  and  44  provide power to the expansion board  16  where the amount of current is, for example, &lt;100 mA ( 42 ) and &lt;2A ( 44 ). 
         [0033]    A complex programmable logic device (CPLD)  36  may be employed to provide additional control and signal enabling/disabling, similar to the FPGA, which assists in achieving the functional control for the expansion device. 
         [0034]    The main logic board  24  is mechanically isolated from the expansion board  16 . Thus, it is not required to modify the main logic board  24  to expand the functionality of the PDA  10 . The expansion board  16  will be chosen, changed or implanted within the requirements for the expansion connector  22 . 
         [0035]    The expansion board  16  is insulated from the electrical interface of the expansion connector  22 . Thus the connector  22  can be chosen, which suits the expansion board  16 . 
         [0036]    In addition, heat generated from the main logic board  24  and the expansion board  16  would not affect each other since there are not mechanically interconnected to each other, so that heat dissipation issue would be minimized. 
         [0037]    Hardware Development Kit (HDK) may be provided to define electrical interfaces, pinouts, signal quality and characteristics, states of operation, power requirements (power quality and characteristics). HDK may be the interface to the main logic board  24  and mechanical details for the packaging (e.g., back cover  14 , front cover  12 , seal  26 ) and any required hardware to assemble the PDA as a whole. 
         [0038]    There is a software isolation between communications with the expansion board  16  and communications with the expansion connector  22 . Through the FPGA firmware, software can be isolated and control the communications between the expansion device and the main logic board  24  to enable or disable its functionality. 
         [0039]    The intrinsic expansion interface of the PDA  10  gives the opportunity to the host designer, or external groups to develop to their requirements an enclosure of the device, which mounts the expanding technology, and have the electrical connections and interface ready and available. Having such availability ensures that the enclosure is not compromised from the environmental. 
         [0040]    Referring to  FIGS. 1-4  and  6 , one example of the expansion interface (e.g., connector  22 ) and FPGA on the main logic board  24  is explained. The expansion interface  50  includes 1) interface to the FPGA  60  on the main logic board  24 , 2) interface to USB hub, and 3) interface to direct battery power. 
         [0041]    The FPGA  60  serves to control the communications/signaling/control between the expansion device and the core of the PDA technologies. The FPGA  60  provides a plurality of services, including: buffering and multiplexing Compact Flash (CF) signals (e.g.,  62  of  FIG. 6 ) to the main CPU of the PDA  10  (e.g.,  70  of  FIG. 6 ); direct address allocation of Serial Peripheral Interface (SPI) (e.g.,  64  of  FIG. 6 ) for synchronous serial data link to the CPU of the PDA  10 ; multiplexing camera interface (e.g.,  66  of  FIG. 6 ) for multi-imaging devices (camera and other add on imaging engines); identification ID to allow enable/disabling of signals and power; and I2C connectivity. 
         [0042]    The expansion interface  50  furthermore directly extends the expansion device ( 16 ) to a USB hub in the PDA  10 . In addition, the expansion interface  50  provides direct system power to the expansion device ( 16 ). 
         [0043]    One or more currently preferred embodiments have been described by way of example. It will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as defined in the claims.