Abstract:
Described is a device including a processor, a wireless arrangement including an antenna, and a memory arrangement storing first data and second data. The first data includes predetermined antenna characteristics and the second data includes predetermined triggering characteristics for triggering a function of the device. When third data fails to match the first data, the processor compares the third data to the second data, the third data being indicative of characteristics changes of the antenna. The processor triggers a corresponding function of the device as a function of the third data and the second data.

Description:
FIELD OF INVENTION 
       [0001]    The present application generally relates to trigger arrangements for activating an electronic device. 
       BACKGROUND INFORMATION 
       [0002]    Electronic devices often utilize trigger arrangements for triggering functions of the devices. The trigger arrangements generally comprise a mechanical trigger that is engaged by a user. For instance, handheld devices may include a gun-style trigger that is pulled with a finger. Other types of triggers include push buttons and switches. Regardless of the type of trigger used, the trigger requires additional hardware to implement. This increases manufacturing costs and requires allocation of additional space in a device&#39;s physical design. In addition, movable triggers are subject to wear and breakage resulting from repeated use. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention relates to a device including a processor, a wireless arrangement including an antenna, and a memory arrangement storing first data and second data. The first data includes predetermined antenna characteristics and the second data includes predetermined triggering characteristics for triggering a function of the device. When third data fails to match the first data, the processor compares the third data to the second data, the third data being indicative of characteristics changes of the antenna. The processor triggers a corresponding function of the device as a function of the third data and the second data. 
         [0004]    The present invention also relates to a method including the step of storing first data and second data in a memory arrangement of a device including an antenna and a processor, the first data including predetermined characteristics of the antenna, the second data including predetermined triggering characteristics for triggering a function of the device. The method also includes the step of comparing the first data to third data, wherein when the third data fails to match the first data, the processor compares the third data to the second data, the third data being indicative of characteristics changes of the antenna. The method also includes the step of triggering a corresponding function of the device when the third data matches the second data. 
         [0005]    The present invention also relates to a device including a processing means, a wireless arrangement including a wireless signal sensing means, and a storage means storing first data and second data, the first data including predetermined sensing means characteristics, the second data including predetermined triggering characteristics for triggering a function of the device. When third data fails to match the first data, the processing means compares the third data to the second data, the third data being indicative of characteristics changes of the sensing means. The processor triggers a corresponding function of the device as a function of the third data and the second data. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  shows an exemplary embodiment of a mobile device according to the present invention. 
           [0007]      FIG. 2  shows a block diagram of an exemplary embodiment of the mobile device of  FIG. 1 . 
           [0008]      FIG. 3  shows an exemplary embodiment of an antenna detection arrangement according to the present invention. 
           [0009]      FIG. 4  shows another exemplary embodiment of an antenna detection arrangement according to the present invention. 
           [0010]      FIG. 5  shows an exemplary method for generating a user profile according to the present invention. 
           [0011]      FIG. 6  shows an exemplary method for triggering a device according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are provided with the same reference numerals. The present invention relates to triggering arrangements for electronic devices. Various embodiments of the present invention will be described with reference to a radio-frequency identification (“RFID”) reader. However, those skilled in the art will understand that the present invention may be implemented with any electronic device that utilizes a wireless arrangement. For example, other electronic devices may include cell phones, PDAs, wireless headsets, media players, wireless routers, global position system devices, mobile computers, Bluetooth radios, televisions, walkie-talkies, etc. 
         [0013]      FIG. 1  shows an exemplary embodiment of an electronic device (e.g., a mobile device  100 ) according to the present invention. The device may include a display  120 , such as an LCD or a touch screen. The device  100  may also include an input arrangement  110 , such as a keypad, a keyboard, a touch-sensitive interface, etc. 
         [0014]    As shown in  FIG. 1 , the device  100  may further include a wireless arrangement comprising an antenna  130 . The antenna  130  may be an external antenna (e.g., a retractable antenna or a stub). However, in other embodiments the antenna  130  may be located within a housing of the device  100  (e.g., an internal antenna). The antenna  130  may be any type of antenna such as a dipole, a monopole, a parabolic reflector, etc. The antenna  130  may enable transmission and/or reception of wireless signals between the device  100  and another device. For example, in an exemplary embodiment the antenna  130  may be an RFID antenna that enables the device  100  to read data from an RFID tag. However, in other embodiments the antenna  130  may enable communication of data in other types of protocols or formats (e.g., 802.11x, 802.16, Wi-Max, Bluetooth, VHF signals, AM/FM signals, etc.). 
         [0015]      FIG. 2  shows a block diagram of an exemplary embodiment of the device  100 . As shown in  FIG. 2 , the device  100  may include a wireless arrangement  140  comprising the antenna  130 , a communication arrangement  142  and an antenna detection arrangement (“ADA”)  144 . The device  100  may also include the input arrangement  110 , a power supply  150 , a memory  160  and a controller  170 . 
         [0016]    The communication arrangement  142  may enable wireless communication by transmitting and receiving wireless signals via the antenna  130 . The communication arrangement  142  may include any combination of hardware and/or software necessary for processing the wireless signals. For example, the communication arrangement  142  may include a digital signal processor, a transmit buffer, a receive buffer, and a wireless controller. The communication arrangement  142  may format outbound data into an appropriate format (e.g., 802.11g) as well as convert incoming data into a format that can be interpreted by the controller  170  (e.g., decoding and/or decrypting data). 
         [0017]    The ADA  144  may include any combination of hardware and/or software necessary for detecting wireless characteristics of the antenna  130 . The wireless characteristics may include any number of factors indicative of the antenna&#39;s  130  ability to transmit and/or receive wireless signals. For example, the wireless characteristics may include data that enables the device  100  to determine an impedance of the antenna  130 . As will be discussed in detail below, changes in the impedance may be detected and utilized for triggering a function of the device  100 . 
         [0018]    The power supply  150  may be any power source such as an AC-to-DC adaptor, a rechargeable battery, a non-rechargeable battery, a solar cell, etc. The power supply  150  may provide power to any of the components of the device  100 , including the memory  160 , the controller  170  and the wireless arrangement  140 . 
         [0019]    The memory  160  may comprise any type of readable and/or writeable storage device, such as a hard drive, a recordable medium (e.g., a compact disc or a flash card), a physical memory (e.g., RAM, EPROM or Flash memory), etc. The memory  160  may contain data required for operation of the device  100 . For example, as will be discussed in further detail below, the memory  160  may include one or more base profiles and one or more user profiles, each of which may correspond to predetermined or user determined antenna characteristics (e.g., the wireless characteristics). In addition, the memory  160  may include operating system and/or application program data. 
         [0020]    The controller  170  controls operation of the device  100  and may comprise any type of control circuit known in the art, including a microprocessor, an application-specific integrated circuit, an embedded controller, etc. The controller  170  may be communicatively coupled to the memory  160 , the input arrangement  110  and the wireless arrangement  140 . The controller  170  may send and receive data to/from each of these components in accordance with the operation of the device  100 . The controlling of the device  100  will be described in further detail below. 
         [0021]    Exemplary embodiments of ADAs will now be described with reference to  FIGS. 3 and 4 . The exemplary ADAs will be discussed with reference to the detection of impedance changes in the antenna  130 . However, those skilled in the art will understand that other types of antenna characteristics may also be utilized. 
         [0022]    An impedance of the antenna  130  may be changed by, for example, placing a portion of the user&#39;s body (e.g. a finger) within proximity of the antenna  130 . In one embodiment, the user may grasp the antenna  130  between a thumb and a forefinger. As will be discussed in detail below, changes in the impedance may be detected and used to trigger a function of the device  100 . Thus, user interaction may constitute user input that causes triggering. 
         [0023]    If the antenna  130  is the internal antenna, the user interaction may not involve actual contact with the antenna  130 . Instead, the user may interact with the housing of the device  100 . For example, the user may bring the finger into proximity or in contact with a portion of the housing that is adjacent or proximal to the antenna  130 . In this manner, the impedance of the antenna  130  is changed even though the user has not directly interacted with the antenna  130 . 
         [0024]      FIG. 3  shows an exemplary embodiment of an ADA  300 , which may include a signal generator  310 , a power amplifier (“PA”)  320 , an analog-to-digital (“A/D”) convertor  340  and a host processor  350 . The signal generator  310  may be an alternating current (“AC”) source outputting a constant-frequency signal to the PA  320 . The output of the signal generator  310  may comprise a carrier signal which is amplified by the PA  320  and which can be modulated with a signal and subsequently transmitted by the antenna  130 . 
         [0025]    The PA  320  may include one or more amplifying components  30  in series with each other. For example, the amplifying components  30  may be any analog or digital component that receives an input and produces a higher voltage output, such as an operational amplifier, a differential amplifier, a transistor amplifier, etc. Thus, an output of the PA  320  may be an amplified version of the carrier signal. The PA output may be applied to the antenna  130  via a feed line  33 . 
         [0026]    The antenna  130  may be viewed as a transmission line with a known or measurable base impedance (e.g., a characteristic impedance). When the antenna  130  operates free of interference such as physical contact with the object, an impedance of the antenna  130  may remain unchanged (e.g., the impedance is approximately equal to the base impedance). However, if the antenna is interrupted (e.g., by bringing the object into contact with, or within close proximity to, the antenna  130 ), the impedance may change. Changes in the impedance may be detected using demodulation. For example, the ADA  300  may comprise an envelope detector that samples a reverse power reflected back from the antenna  130  to a driving source (e.g., the signal generator  310 ). The envelope detector may include a diode  330  attached to a tap line  35  of the antenna  130 . Output of the diode  330  may be received by the A/D converter  340 , which may be coupled to the host processor  350 . 
         [0027]    The host processor  350  may be any processing device such as a microprocessor, an embedded controller, an application-specific integrated circuit, etc. The processor  350  may receive a digital output of the A/D convertor  340 . As will be described in detail below, the processor  350  may compare the digital output to stored antenna characteristics to determine whether triggering should occur. For example, the processor  350  may compare the digital output to stored threshold values. 
         [0028]      FIG. 4  shows an exemplary embodiment of an ADA  400 , which may include a signal generator  410 , a PA  420 , a vector demodulator  430 , two or more A/D converters  43  and  45 , and a host processor  460 . Similar to the ADA  300  described with reference to  FIG. 3 , the ADA  400  may detect changes in the impedance of the antenna  130 . The ADA  400  may comprise a demodulator that demodulates two or more components (e.g., vector components) of a reflected signal. 
         [0029]    The signal generator  410  may produce an AC signal, which may be amplified by one or more amplifying components  40  of the PA  420 . Output of the PA  420  may then be inputted into the antenna  130  via a feed line  43 . 
         [0030]    The reflected signal may be received by the vector demodulator  430  via a tap line  45 . The vector demodulator  430  may separate the reflected signal into two or more components using a phase generator  450  and a plurality of mixers  433  and  443 . The output of each mixer  433 ,  443  may be respectively received by buffers  431  and  441 . Each buffer  431  and  441  may produce an output comprising a separate output channel (e.g., an “I channel” and a “Q channel”) of the vector demodulator  430 . The channel outputs may differ in phase as a function of outputs produced by the phase generator  450 . For example, the phase generator  450  may sample the carrier signal of the signal generator  410  and derive inputs of the mixers  433 ,  443  that are ninety degrees out of phase relative to each other. In this manner, the vector components of the reflected signal may be separated. 
         [0031]    A degree with which the impedance matches the base impedance may be inversely proportional to a vector sum of values outputted by the I and Q channels. This vector information may represent a reflection coefficient of the antenna, which may vary in response to changes in antenna tuning or changes in an environment that the antenna has illuminated with RF energy. Those skilled in the art will understand that a magnitude of the reflection coefficient change may be proportional to a coupling factor of the change experienced by the antenna  130 . That is, the closer to the antenna the object becomes, the greater a potential change that the reflected signal can cause. This change may be detected primarily when the object is located within a near field of the antenna  130 . If the object is located beyond the near field, changes to the reflection coefficient as a result of the presence of the object may be negligible. A magnitude of the change in the output of the I and Q channels may indicate whether the user is interacting with the antenna  130 . For example, two-dimensional threshold values may indicate values associated with the finger touching the antenna  130 . 
         [0032]    In addition to indicating whether the user is interacting with the antenna  130 , the I and Q channel outputs may indicate a location along the antenna  130  at which the interaction is occurring. This may be indicated by comparing a phase relationship between the I and Q channel outputs. Thus, the ADA  400  may distinguish between a plurality of potential interaction locations such as along a proximal, a middle, or a distal portion of the antenna  130 . The host processor  460  may determine whether the interaction is occurring and the location of the interaction. 
         [0033]      FIG. 5  shows an exemplary embodiment of a method  500  according to the present invention. The method  500  may be implemented on the device  100 , in any combination of hardware and/or software. Performance of the method  500  may occur anytime (e.g., during device manufacturing, during an initial setup, after beginning to operate the device  100 , etc.). In step  510 , the device  100  determines characteristics of the antenna  130  using the ADA  144 , which may be an envelope detector (e.g., the ADA  300 ) or a vector demodulator (e.g., the ADA  400 ). The antenna characteristics are indicative of an output of the antenna  130  (e.g., the impedance) generated in response to one or more inputs and/or antenna variables (e.g., input power, input frequency, antenna geometry, etc.). The antenna characteristics may be predetermined (e.g., a known characteristic impedance) or determined experimentally by measuring signal reflections of the antenna  130 . For example, if the ADA  144  is the envelope detector, a magnitude of a reflected signal may be measured. Alternatively, if the ADA  144  is the vector demodulator, both a magnitude and a phase of two or more vector components of a reflected signal may be measured. 
         [0034]    In some embodiments, the device  100  may calculate the antenna characteristics in addition, or in alternative to, measuring the antenna characteristics experimentally. For example, the antenna characteristics may be calculated in accordance with predetermined equations and/or known data values (e.g., antenna geometry, operating frequency, power, etc.). After determination, the antenna characteristics may be stored for future use (e.g., in the memory  160 ), as will be explained below. 
         [0035]    In step  520 , the device  100  generates a base profile as a function of the antenna characteristics. For example, the base profile may include a two-dimensional plot of the electric field and/or the magnetic field as a function of spatial position for various locations along the antenna. In some embodiments, an entire base impedance (e.g., a two-dimensional representation of the base impedance) may be reconstructed using antenna vector impedance characteristics. The base profile may correspond to one or more predetermined operating parameters such as frequency or operating power. The base profile may also correspond to either the base impedance, or any other impedance that is substantially free of user interaction. Thus, the base profile is a representation of the antenna characteristics when the antenna  130  is operating under normal conditions. The base profile may be stored in the memory  160  for comparison to future antenna measurements, as will be explained below. 
         [0036]    In step  530 , the device  100  receives user preferences, which may include triggering preferences. For example, the user may specify a location along the antenna  130  (e.g., the proximal end) and may further specify a function that will be triggered if the user interacts with the specified location (e.g., bringing fingers into proximity or in contact with the specified location). The user preferences may also include triggering sensitivity. For example, the user may specify whether merely bringing the fingers into proximity is sufficient to cause triggering, or whether actual touching is required. The user may also specify a duration requirement, such as bringing the fingers into proximity for at least one second before triggering occurs. 
         [0037]    The user preferences may correspond to specific interruption patterns. For example, a pattern corresponding to a touching of the proximal end may differ from a pattern corresponding to a touching of the distal end. This difference may include differences with respect to any antenna characteristic, such as impedance, electric/magnetic field strength, radiation intensity, etc. Thus, each specific pattern may be unique to a particular antenna location and/or finger position. The specific patterns may be experimentally determined by having the user interact with the device  100  (e.g., during a training session) or may be predetermined based on pattern predictions. The specific patterns may be stored in the memory  160  as predetermined characteristics, to later be used during a comparison to measured antenna characteristics. 
         [0038]    In step  540 , the device  100  generates a user profile based on the user preferences. The user profile may be associated with user information such as a user name, a password, user contact information, user authorization or permission information, etc. If the user profile is a preexisting profile, a new profile may not be necessary because the existing profile can be updated with any new user preferences. The user profile is then saved in the memory  160  and accessed if the user chooses to identify himself to the device  100  during future use. The device  100  is now fully initialized and ready for use in normal operations. 
         [0039]      FIG. 6  shows an exemplary embodiment of a method  600  according to the present invention. The method  600  may be performed during normal operations at anytime after the device  100  has been initialized by the method  500 . In step  610 , the device  100  measures current antenna characteristics. This measurement may be similar to that used in experimentally determining the antenna characteristics during step  510  of the method  500  (e.g., using the envelope detector or the vector demodulator). 
         [0040]    In step  620 , the device  100  determines whether the current characteristics match the base characteristics. The determination may be performed at the controller  170 . However, in some embodiments, the determination may be performed by a dedicated processor such as the host processor  350  or the host processor  460 . A matching procedure may involve performing a direct comparison of each current characteristic against each base characteristic of the same type (e.g., impedance). In this manner, the device  100  can evaluate whether the current characteristics are consistent with normal operations (e.g., when the user is not interacting with the device  100 ). 
         [0041]    Accuracy of the matching procedure may be dependent on an error margin. If a difference between a base characteristic and a current characteristic is within the error margin, a match is found. However, if the difference is greater than the error margin, then a mismatch is determined. A wide error margin may allow for a higher degree of tolerance towards variations in the current characteristics. For example, different users may interact with the device  100  in a similar manner (e.g., touching the proximal end), yet may nevertheless produce very different interruption patterns. Even a single user may not consistently produce the same interrupted pattern each time. The error margin may either be user-selectable or fixed. If a match is found, the method  600  returns to step  610 , where new measurements are taken. 
         [0042]    In step  630 , a match has not been found and the device  100  determines whether the current characteristics match the predetermined characteristics. For example, the device  100  may determine whether the impedance associated with the current characteristics is similar to any specific impedance stored in the memory  160 . This step may also be performed on the controller  170  or the dedicated processor and may utilize a second error margin. 
         [0043]    In step  640 , a match has not been found, meaning that the current characteristics will not result in triggering. 
         [0044]    Thus, an error condition is generated. The error condition may be as simple as ignoring the current characteristics and allowing the device  100  to detect new characteristics by repeating the method  600 . Alternatively, in some embodiments the error condition may include an alert (e.g., a graphical or audio signal) that informs the user of the error, thereby allowing the user to reattempt interaction. 
         [0045]    In step  650 , a match is found and a function of device (e.g., RF pinging) is triggered in accordance with the user preferences. That is, if a function to be triggered may be specified by the user preferences as being associated with the current characteristics. 
         [0046]    Based on the exemplary embodiments described above, it can be seen that the present invention provides substantial benefits to users of wireless devices. Triggering in accordance with the present invention does not require a separate trigger. By utilizing existing wireless hardware (e.g., the antenna  130 ) to perform trigger, manufacturing costs are reduced. 
         [0047]    In addition, the present invention provides for flexible triggering. The user may specify what functions to trigger and/or how trigger should occur. For example, the user may specify tapping the proximal end to begin RF pinging, which may continue until the user taps the proximal end once more. In a multi-function device such as an RFID reader-barcode scanner combination, the user may select a first type of action (e.g., tapping the proximal end) for triggering an RFID function (e.g., toggling RF pinging) and select a second type of action (e.g., holding onto the proximal end) for triggering a barcode function (e.g., activating the barcode scanner). Thus, any number of triggering actions may be possible based on different user interactions with the same antenna. Those skilled in the art will understand that the present invention is not limited to RFID antennas, but may be implemented with any type of antenna, including antennas for local area network (“LAN”) devices, wide area network (“WAN”) devices, Bluetooth devices, etc. 
         [0048]    The present invention has been described with reference to the above exemplary embodiments. One skilled in the art would understand that the present invention may also be successfully implemented if modified. For example, other embodiments of the present invention may utilize a form of triggering in which a first antenna plane is moved relative to a second antenna plane (e.g., a ground plane). If the antenna is formed of a soft, pliable material a portion of the antenna containing the first plane (e.g., a coil) may be moved relative to a portion of the antenna containing the second plane (e.g., a loop). Thus, other embodiments may utilize other forms of manual engaging (e.g., squeezing) in addition to those of touch and proximity engaging. Accordingly, various modifications and changes may be made to the embodiments without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings, accordingly, should be regarded in an illustrative rather than restrictive sense.