Abstract:
A card exhibiting enhanced detection is provided. A plurality of detector shapes that may be associated with a detection system increases detection effectiveness, while reducing adverse effects of detection systems that may be operating within a electromagnetic field environment.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/309,806, titled “SYSTEMS AND METHODS FOR DETECTION MECHANISMS FOR MAGNETIC CARDS AND DEVICES,” filed Mar. 2, 2010, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to magnetic cards and devices and related systems. 
     SUMMARY OF THE INVENTION 
     A card may include a dynamic magnetic communications device, which may take the form of a magnetic encoder or a magnetic emulator. A magnetic encoder, for example, may be utilized to modify information that is located on a magnetic medium, such that a magnetic stripe reader may then be utilized to read the modified magnetic information from the magnetic medium. A magnetic emulator, for example, may be provided to generate electromagnetic fields that directly communicate data to a read head of a magnetic stripe reader. A magnetic emulator, for example, may communicate data serially to a read-head of the magnetic stripe reader. A magnetic emulator, for example, may communicate data in parallel to a read-head of the magnetic stripe reader. 
     All, or substantially all, of the front surface, as well as the rear surface, of a card may be implemented as a display (e.g., bi-stable, non bi-stable, LCD, or electrochromic display). Electrodes of a display may be coupled to one or more touch sensors, such that a display may be sensitive to touch (e.g., using a finger or a pointing device) and may be further sensitive to a location of the touch. The display may be sensitive, for example, to objects that come within a proximity of the display without actually touching the display. 
     A dynamic magnetic stripe communications device may be implemented on a multiple layer board (e.g., a two layer flexible printed circuit board). A coil for each track of information that is to be communicated by the dynamic magnetic stripe communications device may then be provided by including wire segments on each layer and interconnecting the wire segments through layer interconnections to create a coil. For example, a dynamic magnetic stripe communications device may include two coils such that two tracks of information may be communicated to two different read-heads included in a read-head housing of a magnetic stripe reader. A dynamic magnetic communications device may include, for example, three coils such that three tracks of information may be communicated to three different read-heads included in a read-head housing of a magnetic stripe reader. 
     One or more detectors may be provided, for example, to sense the presence of an external object, such as a person or device; which in turn, may trigger the initiation of a communication sequence with the external object. The sensed presence of the external object may then be communicated to a card, which in turn may direct the exchange of information between a card and the external object. Accordingly, timing aspects of the information exchange between a card and the various I/O devices implemented on a card may also be determined by a card. 
     The sensed presence of the external object or device may include the type of object or device that is detected and, therefore, may then determine the type of communication that is to be used with the detected object or device. For example, a detected object may include a determination that the object is a read-head of a magnetic stripe reader. Such an identifying detection, for example, may activate a dynamic magnetic stripe communications device (e.g., via a processor) so that information is communicated (e.g., electromagnetically) to the read-head of the magnetic stripe reader. 
     A read-head detector may be utilized in a variety of ways. For example, a read-head detector may cause a card to perform a particular function such as, for example, increase an internal counter indicative of the number of times the card has been swiped. 
     A detected object may include a determination that the card sends and/or receives information using, for example, visible light. Such an identifying detection, for example, may activate a communications device on the card that exchanges information using data that is modulated, for example, onto a visible data carrier. 
     One or more detectors may be utilized for passive and/or active detection. The detectors, for example, may detect proximity to an external object. Detectors may detect actual contact with an external object (e.g., a finger or pointing object). 
     Detectors may be shaped, for example, to reduce adverse effects that may be caused by exposing conductive materials to electromagnetic signals. The detectors may be shaped, for example, to increase effectiveness in performing proximity and/or actual contact detection. 
     One or more read-head detectors, for example, may be provided on one side of a card. The one or more read-head detectors may be provided as, for example, conductive pads that may be arranged along a length of the card having a variety of shapes. The shapes of the one or more conductive pads, for example, may be provided on the card to increase a conductive area of the conductive pad that is not positioned across from a dynamic magnetic stripe communications device. The shapes of the one or more conductive pads, for example, may be provided on the card to decrease a conductive area of the conductive pad that is positioned across from a dynamic magnetic stripe communications device. In doing so, for example, the amount of interference that a read-head detector imparts on a communicating dynamic magnetic stripe communications device may be reduced. 
     A processor may be used to implement an active search mode to detect, for example, a read-head housing of a magnetic stripe reader using, for example, read-head detectors. Accordingly, a dynamic magnetic stripe communications device may be activated in response to the detection. For example, one or more dynamic magnetic stripe communications devices may provide one or more tracks of magnetic stripe data in response to the detection. 
     A processor may enter and exit sleep modes during the active search mode to reduce power consumption. For example, the processor may enter and exit sleep modes at a particular frequency for a period of time. The period of time may end, for example, when the processor detects, for example, a read-head housing. Idle states may be used to further reduce power consumption, for example, by delaying the active search mode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The principles and advantages of the present invention can be more clearly understood from the following detailed description considered in conjunction with the following drawings, in which the same reference numerals denote the same structural elements throughout, and in which: 
         FIG. 1  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 2  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 3  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 4  is an illustration of circuitry, and associated waveforms, constructed in accordance with the principles of the present invention; 
         FIG. 5  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 6  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 7  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 8  is an illustration of a card constructed in accordance with the principles of the present invention; 
         FIG. 9  is an illustration of detection circuitry constructed in accordance with the principles of the present invention; 
         FIG. 10  is an illustration of a process flow chart constructed in accordance with the principles of the present invention; 
         FIG. 11  is an illustration of a process flow chart constructed in accordance with the principles of the present invention; and 
         FIG. 12  is an illustration of process flow charts constructed in accordance with the principles of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows card  100  that may include, for example, a dynamic number that may be entirely, or partially, displayed using a display (e.g., display  106 ). A dynamic number may include a permanent portion such as, for example, permanent portion  104  and a dynamic portion such as, for example, dynamic portion  106 . Card  100  may include a dynamic number having permanent portion  104  and permanent portion  104  may be incorporated on card  100  so as to be visible to an observer of card  100 . For example, labeling techniques, such as printing, embossing, laser etching, etc., may be utilized to visibly implement permanent portion  104 . 
     Card  100  may include a second dynamic number that may also be entirely, or partially, displayed via a second display, e.g., display  108 . Display  108  may be utilized, for example, to display a dynamic code such as a dynamic security code. Card  100  may also include third display  122  that may be used to display graphical information, such as logos and barcodes. Third display  122  may also be utilized to display multiple rows and/or columns of textual and/or graphical information. 
     Persons skilled in the art will appreciate that any one or more of displays  106 ,  108 , and/or  122  may be implemented as a bi-stable display. For example, information provided on displays  106 ,  108 , and/or  122  may be stable in at least two different states (e.g., a powered-on state and a powered-off state). Any one or more of displays  106 ,  108 , and/or  122  may be implemented as a non-bi-stable display. For example, the display is stable in response to operational power that is applied to the non-bi-stable display. Other display types, such as LCD or electrochromic, may be provided as well. 
     Persons skilled in the art will appreciate that card  100  may, for example, be a self-contained device that derives its own operational power from one or more batteries  158 . Furthermore, one or more batteries  158  may be included, for example, to provide operational power to card  100  for a period of time (e.g., approximately 2-4 years). One or more batteries  158  may be included, for example, as rechargeable batteries. 
     Other permanent information, such as permanent information  120 , may be included within card  100 , which may include user specific information, such as the cardholder&#39;s name or username. Permanent information  120  may, for example, include information that is specific to card  100  (e.g., a card issue date and/or a card expiration date). Information  120  may represent, for example, information that includes information that is both specific to the cardholder, as well as information that is specific to card  100 . 
     Card  100  may accept user input data via any one or more data input devices, such as buttons  110 - 118 . Buttons  110 - 118  may be included to accept data entry through mechanical distortion, contact, or proximity. Buttons  110 - 118  may be responsive to, for example, induced changes and/or deviations in light intensity, pressure magnitude, or electric and/or magnetic field strength. Such information exchange may then be determined and processed by card  100  as data input. 
     Card  100  may be implemented using architecture  150 , which may include one or more processors  154 . One or more processors  154  may be configured to utilize external memory  152 , memory internal to processor  154 , or a combination of external memory  152  and internal memory for dynamically storing information, such as executable machine language, related dynamic machine data, and user input data values. 
     One or more of the components shown in architecture  150  may be configured to transmit information to processor  154  and/or may be configured to receive information as transmitted by processor  154 . For example, one or more displays  156  may be coupled to receive data from processor  154 . The data received from processor  154  may include, for example, at least a portion of dynamic numbers and/or dynamic codes. The data to be displayed on the display may be displayed on one or more displays  156 . 
     One or more displays  156  may be, for example, touch sensitive and/or proximity sensitive. For example, objects such as fingers, pointing devices, etc., may be brought into contact with displays  156 , or in proximity to displays  156 . Detection of object proximity or object contact with displays  156  may be effective to perform any type of function (e.g., transmit data to processor  154 ). Displays  156  may have multiple locations that are able to be determined as being touched, or determined as being in proximity to an object. 
     Input and/or output devices may be implemented on card  100 . For example, integrated circuit (IC) chip  160  (e.g., an EMV chip) may be included on card  100 , that can communicate information with a chip reader (e.g., an EMV chip reader). Radio frequency identification (RFID) module  162  may be included within card  100  to enable the exchange of information between an RFID reader and card  100 . 
     Other input and/or output devices  168  may be included on card  100 , for example, to provide any number of input and/or output capabilities on card  100 . For example, other input and/or output devices  168  may include an audio device capable of receiving and/or transmitting audible information, such as for example, dual-tone multi-frequency (DTMF) signaling that may facilitate I/O data exchange between card  100  and a telephony system. Other audible signaling may include, for example, modem signaling to facilitate I/O data exchange between card  100  and a device that utilizes modulation/demodulation (MODEM) techniques to modulate an analog carrier with analog and/or digital information. 
     Other input and/or output devices  168  may include a device that exchanges analog and/or digital data using a visible data carrier, such as light amplification by stimulated emission of radiation (LASER), light-emitting diode (LED), etc. Other input and/or output devices  168  may include a device, for example, that is sensitive to a non-visible data carrier, such as an infrared data carrier or electromagnetic data carrier. Any type of tactile, audible, visible, and/or non-visible means of information exchange may be provided on card  100 . 
     Dynamic magnetic stripe communications device  102  may be included on card  100  to communicate information to, for example, a read-head of a magnetic stripe reader via, for example, electromagnetic signals. For example, electromagnetic field generators  170 - 174  may be included to communicate one or more tracks of electromagnetic data to read-heads of a magnetic stripe reader. Electromagnetic field generators  170 - 174  may include, for example, a series of electromagnetic elements, where each electromagnetic element may be implemented as a coil wrapped around one or more materials (e.g., a soft-magnetic material and/or a non-magnetic material). Additional materials may be placed outside the coil (e.g., a hard magnetic material). 
     Electrical excitation by processor  154  of one or more coils of one or more electromagnetic elements via, for example, driving circuitry  164  may be effective to generate electromagnetic fields from one or more electromagnetic elements. One or more electromagnetic field generators  170 - 174  may be utilized to communicate electromagnetic information to, for example, one or more read-heads of a magnetic stripe reader. 
     Timing aspects of information exchange between card  100  and the various I/O devices implemented on card  100  may be determined by card  100 . One or more detectors  166 , such as non-invasive detectors, may be utilized, for example, to sense the proximity, mechanical distortion, or actual contact, of an external device, which in turn, may trigger the initiation of a communication sequence. The sensed presence or touch of the external device may then be communicated to (e.g., processor  154 ), which in turn may direct the exchange of information between card  100  and the external device. The sensed presence, mechanical distortion, or touch of the external device may be effective to, for example, determine the type of device or object detected. Persons skilled in the art will appreciate that communications directed to the detected device or object may be compatible with the detected device or object. 
     For example, the detection may include the detection of, for example, a read head of a magnetic stripe reader. In response, processor  154  may activate one or more electromagnetic field generators  170 - 174  to initiate a communications sequence with, for example, one or more read-heads of a magnetic stripe reader. The timing relationships associated with communications to one or more electromagnetic field generators  170 - 174  and one or more read-heads of a magnetic stripe reader may be provided through use of the detection of the magnetic stripe reader. 
     Persons skilled in the art will appreciate that processor  154  may provide user-specific and/or card-specific information through utilization of any one or more of buttons  110 - 118 , RFID  162 , IC chip  160 , electromagnetic field generators  170 - 174 , and other input and/or output devices  168 . 
     One or more non-invasive detectors  124  may be implemented to detect, for example, the proximity, or actual contact, of an object, such as a read-head of a magnetic stripe reader. Non-invasive detectors  124  may be utilized, for example, to sense contact with, or the presence of objects (e.g., a read head of a magnetic stripe reader) while minimizing interference with the electromagnetic signals that may be generated by dynamic magnetic stripe communications device  102 . 
       FIG. 2  shows card  200 . Card  200  may include front surface  202  having a dynamic magnetic stripe communications device  204  and a back surface  252  having one or more detectors  254 . 
     A physical location of one or more detectors  254  on surface  252  and a physical location of dynamic magnetic stripe communications device  204  on surface  202  may be at any location on card  200 . For example, physical locations of detectors  254  and dynamic magnetic stripe communications device  204  may be provided across from one another. Accordingly, for example, detectors  254  may interfere with the communicated signals as may be generated by dynamic magnetic stripe communications device  204  during communications with an external device. For example, the communicated signals may induce an electrical current (e.g., an eddy current) within detectors  254 , which may then interfere with the communicated signals. Accordingly, attributes (e.g., shapes) of detectors  254  may reduce such interference. 
     Card  200  may be a laminated structure. Persons skilled in the art will appreciate that some or all components of a card may be embedded within card  200 . For example, detectors  254  may be provided on surface  252  or may be embedded below one or more layers of lamination. Similarly, dynamic magnetic stripe communications device  204  may be embedded beneath one or more layers of lamination. 
       FIG. 3  shows card  300 . Card  300  may include, for example, an orientation of detectors (e.g., conductive pads  326 ), whereby one or more conductive pads  302 - 316  may be, for example, arranged along a length of card  300 . Conductive pads  302 - 316  may be provided, for example, using an additive technique, whereby patterns of a conductive element (e.g., copper) may be applied to a PCB substrate according to a patterning mask definition layer. Conductive pads  302 - 316  may be provided, for example, using a subtractive technique whereby patterns of a conductive element (e.g., copper) may be removed from a pre-plated PCB substrate according to an etching mask definition layer. Other non-PCB fabrication techniques may be used to implement conductive pads  302 - 316  as may be required by a particular application. 
     Active/passive circuitry  320  may be utilized to incorporate conductive pads  302 - 316  and processor  318  into a detection system. Persons skilled in the art will appreciate that a pad may be utilized by a processor as a capacitive sensing pad. Persons skilled in the art will further appreciate that a processor may include the functionality to control and determine when an object is in the proximity of the pad via a capacitive sensing technique. 
       FIG. 4  shows an active detection system that may be included on a card. A conductive pad may be utilized, for example, as a conductor of a capacitive device within a resistor/capacitor (RC) circuit to determine the capacitance of a detector and determine whether it is below, equal to, or above one or more predetermined thresholds. 
     A conductive pad, for example, may form a portion of a capacitive element, such that plate  416  of capacitive element  414  may be implemented by a conductive pad and the second plate of capacitive element  414  is implemented by element  410 . Element  410  may represent, for example, the device or object whose proximity or contact is sought to be detected. 
     The capacitance magnitude of capacitive element  414  may exhibit, for example, an inversely proportional relationship to the distance separation between plate  416  and device  410 . For example, the capacitance magnitude of capacitive element  414  may be relatively low when the corresponding distance between plate  416  and device  410  may be relatively large. The capacitance magnitude of capacitive element  414  may be relatively large, for example, when the corresponding distance between plate  416  and device  410  is relatively small. 
     Detection, for example, may be accomplished actively via circuit  400  of  FIG. 4 . Through a sequence of charging and discharging events, an average capacitance magnitude for capacitive element  414  may be determined over time. Accordingly, for example, the spatial relationship between plate  416  and device  410  may be determined. 
     Charge sequence  450  may, for example, be invoked, such that switch  404  may be closed at time T 1 , while switch  406  may remain open. Accordingly, for example, current may flow from voltage supply  402  through switch  404  and resistive component  408 . In doing so, for example, an electrostatic field may be generated that may be associated with capacitive component  414 . During the charge sequence, for example, the voltage at node  412  may be monitored to determine the amount of time required (e.g., T CHARGE =Δ1−T 1 ) for the voltage at node  412 , V 412 , to obtain a magnitude that is substantially equal to, below, or above a first threshold voltage (e.g., equal to V 1 ). 
     Discharge sequence  460  may, for example, be invoked, such that switch  406  may be closed at time T 2 , while switch  404  may remain open. During the discharge sequence, for example, the electric field associated with capacitive element  414  may be allowed to discharge through resistive component  408  to a reference potential (e.g., ground potential). The voltage at node  412  may be monitored to determine the amount of time required (e.g., T DISCHARGE =Δ2−T 2 ) for the voltage at node  412 , V 412 , to obtain a magnitude that is substantially equal to, below, or above a second threshold voltage (e.g., equal to V 2 ). 
     Once the charge time, T CHARGE , and discharge time, T DISCHARGE , are determined, the charge and discharge times may be utilized to calculate a capacitance magnitude that may be exhibited by capacitive element  414 . For example, given that the magnitude of voltage, V 1 , may be equal to approximately 67% of the magnitude of voltage, V S , then a first relationship may be defined by equation (1) as:
 
 T   CHARGE   =R   408   *C 1,  (1)
 
     where R 408  is the resistance magnitude of resistive element  408  and C 1  is proportional to a capacitance magnitude of capacitive element  414 . 
     Similarly, for example, given that the magnitude of voltage, V 2 , may be equal to approximately 33% of the magnitude of voltage, V S , then a second relationship may be determined by equation (2) as:
 
 T   DISCHARGE   =R   408   *C 2,  (2)
 
where C 2  is proportional to a capacitance magnitude of capacitive element  414 . The capacitance magnitudes, C 1  and C 2 , may then be calculated from equations (1) and (2) and averaged to determine an average capacitance magnitude that may be exhibited by capacitive element  414 .
 
     Persons skilled in the art will appreciate that switches  404  and  406  may be opened and closed by a processor. Accordingly, for example, a processor may control when the charge and discharge events occur. Persons skilled in the art will further appreciate that a processor may be placed into a sleep mode (e.g., a power-save mode) during times (e.g., T CHARGE  and T DISCHARGE ). Accordingly, for example, the processor may conserve power. Interrupts may be used, for example, to wake the processor up from sleep mode when a signal (e.g. voltage V 412 ) is equal to, less than, or more than a predetermined threshold. 
     Persons skilled in the art will appreciate that a processor may include one or more low-power sleep modes. The processor may be placed into a sleep mode and may awaken from a sleep mode at any time. A processor may, for example, put itself into sleep mode and awaken itself from sleep mode either via an external signal or an internal timer. Accordingly, for example, a processor may be placed into sleep mode and awaken from sleep mode at a particular frequency in order to reduce power consumption. 
     More particularly, a card may be placed into a mode where the card is determining whether a read-head detector detects a read-head. During this mode, for example, a processor may periodically go into a sleep mode and awake from a sleep mode. The frequency that this occurs may be fast enough such that a processor may awake, determine whether or not a detector has sensed a read-head, and then go back to sleep faster than the amount of time it takes a read-head to pass by that detector during a swipe. In doing so, for example, the processor may detect a read-head at some point the read-head is in the vicinity of the detector, but may be otherwise in sleep mode. In doing so, power consumption may be reduced. 
     A processor may enter sleep mode, and awaken from sleep mode, numerous times. For example, a processor may enter sleep mode, and awaken from sleep mode at least 5 times per second (e.g., at least 20 times per second) while the processor is in a mode searching for a read-head (e.g., a mode that may span approximately 5-15 minutes). 
     Turning back to  FIG. 3 , a series of charge and discharge sequences for the remaining conductive pads  304 - 316 , may be executed to determine a relative capacitance magnitude that is exhibited by each of the remaining conductive pads  304 - 316 . A series of charge and discharge sequences for each of conductive pads  302 - 316  may then be executed in order to obtain a capacitance characteristic for each of conductive pads  302 - 320  over time. 
     By comparing the time-based capacitance characteristic of conductive pad  302 - 316  to a threshold capacitance value, a determination may be made, for example, as to when conductive pads  302 - 316  are in a proximity, or touch, relationship to a device whose presence is to be detected. For example, a sequential increase in the relative capacitance magnitudes of conductive pads  302 - 308  may be detected to determine, for example, that a device is moving substantially in direction  322  relative to card  300 . A sequential increase in the relative capacitance magnitudes of conductive pads  310 - 316  may be detected, for example, to determine that a device is moving substantially in direction  324  relative to card  300 . 
     Persons skilled in the art will appreciate that by electrically shorting pairs of conductive pads together (e.g., pair  302 / 310 , pair  304 / 312 , pair  306 / 314 , etc.) directional vectors  322  and  324  become insubstantial. For example, regardless of whether a device is moving substantially in direction  322  or substantially in direction  324  relative to card  300 , a determination may nevertheless be made that a device is close to, or touching, card  300 . 
     A controller, such as processor  318 , may be used in conjunction with, for example, active/passive circuitry  320  and one or more conductive pads  302 - 316 , for example, to determine that a device (e.g., a read-head housing of a magnetic stripe reader) is in close proximity, or touching, one or more detectors. Once the location and/or type of a device is detected, processor  318  may prepare, for example, dynamic magnetic stripe communications device  328  for communication. For example, one or more electromagnetic field generators may be included within dynamic magnetic stripe communications device  328  to communicate one or more tracks of electromagnetic data to, for example, a read head of a magnetic stripe reader. The electromagnetic field generators of dynamic magnetic stripe communications device  328  may include, for example, a series of electromagnetic elements. 
     Electrical excitation of each electromagnetic element may generate, for example, an electromagnetic field having a variable polarity and/or magnitude. In so doing, for example, one or more electromagnetic field generators may be utilized to communicate electromagnetic information to, for example, a read-head of a magnetic stripe reader. 
     Dynamic magnetic stripe communications device  328  and conductive pads  326  may be positioned in proximity to one another (e.g., along opposing surfaces of card  300 ). Accordingly, for example, eddy currents may be induced within one or more conductive pads  302 - 316  in the presence of an electromagnetic field that may be generated by dynamic magnetic stripe communications device  328 . Such eddy currents may then induce electromagnetic fields associated with one or more conductive pads  302 - 316  that oppose the transfer of electromagnetic information from dynamic magnetic stripe communications device  328  to, for example, a read-head of a magnetic stripe reader. 
       FIG. 5  shows card  500  having conductive pads  502 - 504 . Conductive pads  502 - 504  may be operative, for example, to reduce a magnitude of eddy current generated within one or more of conductive pads  502 - 504  when, for example, an electromagnetic field generator on card  500  is utilized to communicate electromagnetic information. Conductive pads  502 - 504  may be any size and/or any shape (e.g., substantially rectangular in shape with substantially sharp corners). 
     One or more portions  506 - 520  may, for example, be eliminated from conductive pads  502 - 504 . The shape of portions  506 - 520  may, for example, be any size and/or any shape (e.g., substantially square or rectangular in shape with substantially sharp corners). Accordingly, for example, the area of conductive material contained within conductive pads  502 - 504  may be reduced. More particularly, for example, portions  506 - 520  may be positioned across from a physical location of an electromagnetic field generator on card  500 , thereby reducing the area of conductive material within which eddy current may be formed. Persons skilled in the art will appreciate that a manufacturing process used to generate, for example, sharp corners may be more complex than a manufacturing process used to generate, for example, rounded corners. 
       FIG. 6  shows card  600  having conductive pads  602 - 604 . Conductive pads  602 - 604  may be operative to reduce the magnitude of eddy current generated within one or more of conductive pads  602 - 604  when, for example, two electromagnetic field generators on card  600  are utilized to communicate electromagnetic information. Conductive pads  602 - 604  may be any size and/or any shape (e.g., substantially rectangular in shape with substantially sharp corners). 
     Portions  606 - 620  may be eliminated from conductive pads  602 - 604 , so as to reduce the area of conductive material contained within conductive pads  602 - 604 . The shape of portions  606 - 620  may, for example, be any size and/or any shape (e.g., substantially square or rectangular in shape with substantially sharp corners). More particularly, for example, portions  606 - 620  may be positioned across from a physical location of an electromagnetic field generator on card  600 , thereby further reducing the area of conductive material within which eddy current may be formed. 
       FIG. 7  shows card  700  having conductive pads  702 - 704 . Conductive pads  702 - 704  may be operative to reduce the magnitude of eddy current generated within one or more of conductive pads  702 - 704  when, for example, three electromagnetic field generators on card  700  are utilized to communicate electromagnetic information. Conductive pads  702 - 704  may be any size and/or any shape (e.g., substantially rectangular in shape with substantially sharp corners). 
     Portions  706 - 720  may be eliminated from conductive pads  702 - 704 , so as to further reduce the area of conductive material contained within conductive pads  702 - 704 . The shape of portions  706 - 720  may, for example, be any size and/or any shape (e.g., substantially square or rectangular in shape with substantially sharp corners). More particularly, for example, portions  706 - 720  may be positioned across from a physical location of an electromagnetic field generator on card  700 , thereby further reducing the area of conductive material within which eddy current may be formed. 
       FIG. 8  shows card  800 . Card  800  may, for example, include one or more conductive pads  810  and electromagnetic field generators  802 - 806 . One or more conductive pads  810  may exist on a first surface of card  800  and one or more electromagnetic field generators  802 - 806  may exist on a second surface of card  800 . 
     Persons skilled in the art will appreciate that minimization of conductive area associated with one or more conductive pads  810  within respective one or more regions  808  may be implemented to reduce a magnitude of eddy current generated within one or more conductive pads  810  that may be caused by the magnetic field generated by electromagnetic field generator  802 . Persons skilled in the art will further appreciate that minimization of conductive area associated with one or more conductive pads  810  within one or more regions  812  and  814  may be implemented to reduce a magnitude of eddy current generated within one or more conductive pads  810  that may be caused by the magnetic field generated by electromagnetic field generators  804  and  806 , respectively. 
     Persons skilled in the art will further appreciate that one or more conductive pads  810  need not necessarily be implemented with shapes as shown in  FIG. 8 . Other shapes, as shown in  FIG. 9 , for example, may instead be implemented with similar (e.g., substantially similar) results. 
     The shapes of one or more conductive pads may be implemented so as to reduce the amount of magnetic flux that is incident upon the conductive pads, thereby minimizing the magnitude of eddy current that may be induced within the conductive pads. In one example, the area of conductive material that is across from one or more of electromagnetic field generators may be minimized. Accordingly, for example, the voided portions and semi-voided portions of conductive pads  902 - 948 , as shown in  FIG. 9 , exemplify portions of conductive pads  902 - 948  that may be substantially devoid of conductive material. As a result, the amount of conductive material that may exist across from one or more of electromagnetic field generators is minimized, thereby reducing the magnitude of eddy current that may be induced within conductive pads  902 - 948 . 
     Persons skilled in the art will appreciate that the capacitance magnitude associated with conductive pads  902 - 948  is directly proportional to the total area of conductive material contained within conductive pads  902 - 948 . Accordingly, the area of conductive material that is not across from one or more electromagnetic field generators may be increased to, for example, enhance detection capability. 
     Persons skilled in the art will appreciate that each of conductive pads  902 - 916 , and/or any shape and size conductive pad, may be implemented to minimize eddy current generation while maximizing the capacitance magnitude associated with conductive pads  902 - 916  when, for example, a single electromagnetic field generator is utilized. Persons skilled in the art will further appreciate that conductive pads  902 - 916  may be arranged to facilitate directional detection of a device whose presence, or contact, is to be detected. 
     Persons skilled in the art will appreciate that each of conductive pads  918 - 932 , and/or any shape and size conductive pad, may be implemented to minimize eddy current generation while maximizing the capacitance magnitude associated with conductive pads  918 - 932  when, for example, two electromagnetic field generators are utilized. Persons skilled in the art will further appreciate that conductive pads  918 - 932  may be arranged to facilitate directional detection of a device whose presence, or contact, is to be detected. 
     Persons skilled in the art will appreciate that each of conductive pads  934 - 948 , and/or any shape and size conductive pad, may be implemented to minimize eddy current generation while maximizing the capacitance magnitude associated with conductive pads  934 - 948  when, for example, three electromagnetic field generators are utilized. Persons skilled in the art will further appreciate that conductive pads  934 - 948  may be arranged to facilitate directional detection of a device whose presence, or contact, is to be detected. 
     The shape of conductive pad  902  may, for example, be substantially square or rectangular and may include, for example, a single voided portion with a substantially square or rectangular shape. Conductive pad  902  may, for example, have substantially sharp corners and sharp edges. The single voided portion of conductive pad  902  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  918  and  934  may, for example, be substantially square or rectangular and may include, for example, two or three voided portions, respectively, with substantially square or rectangular shapes. Conductive pads  918  and  934  may, for example, have substantially sharp corners and sharp edges. The voided portions of conductive pads  918  and  934  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pad  904  may, for example, be substantially square or rectangular and may include, for example, a single voided portion with a substantially circular or elliptical shape. Conductive pad  904  may, for example, have substantially sharp corners and sharp edges. The single voided portion of conductive pad  904  may, for example, have a substantially rounded edge. 
     The shape of conductive pads  920  and  936  may, for example, be substantially square or rectangular and may include, for example, two or three voided portions, respectively, with substantially circular or elliptical shapes. Conductive pads  920  and  936  may, for example, have substantially sharp corners and sharp edges. The voided portions of conductive pads  920  and  936  may, for example, have substantially rounded edges. 
     The shape of conductive pad  906  may, for example, be substantially circular or elliptical and may include, for example, a single voided portion with a substantially square or rectangular shape. Conductive pad  906  may, for example, have substantially rounded edges. The single voided portion of conductive pad  906  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  922  and  938  may, for example, be substantially circular or elliptical and may include, for example, two or three voided portions, respectively, with substantially square or rectangular shapes. Conductive pads  922  and  938  may, for example, have substantially rounded edges. The voided portions of conductive pads  922  and  938  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pad  908  may, for example, be substantially circular or elliptical and may include, for example, a single voided portion with a substantially circular or elliptical shape. Conductive pad  908  may, for example, have substantially rounded edges. The single voided portion of conductive pad  908  may, for example, have substantially rounded edges. 
     The shape of conductive pads  924  and  940  may, for example, be substantially circular or elliptical and may include, for example, two or three voided portions, respectively, with substantially circular or elliptical shapes. Conductive pads  924  and  940  may, for example, have substantially rounded edges. The voided portions of conductive pads  924  and  940  may, for example, have substantially rounded edges. 
     The shape of conductive pad  910  may, for example, be substantially square or rectangular and may include, for example, a single semi-voided portion with a substantially square or rectangular shape having criss-cross conductive strips. Conductive pad  910  may, for example, have substantially sharp corners and sharp edges. The single semi-voided portion of conductive pad  910  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  926  and  942  may, for example, be substantially square or rectangular and may include, for example, two or three semi-voided portions, respectively, with substantially square or rectangular shapes having criss-cross conductive strips. Conductive pads  926  and  942  may, for example, have substantially sharp corners and sharp edges. The semi-voided portions of conductive pads  926  and  942  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pad  912  may, for example, be substantially square or rectangular and may include, for example, a single semi-voided portion with a substantially square or rectangular shape having a single conductive strip at a substantially non-vertical angle that is angled from right to left. Conductive pad  912  may, for example, have substantially sharp corners and sharp edges. The single semi-voided portion of conductive pad  912  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  928  and  944  may, for example, be substantially square or rectangular and may include, for example, two or three semi-voided portions, respectively, with substantially square or rectangular shapes having single conductive strips at substantially non-vertical angles that are angled from right to left. Conductive pads  928  and  942  may, for example, have substantially sharp corners and sharp edges. The semi-voided portions of conductive pads  928  and  942  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pad  914  may, for example, be substantially square or rectangular and may include, for example, a single semi-voided portion with a substantially square or rectangular shape having a single conductive strip at a substantially vertical angle. Conductive pad  914  may, for example, have substantially sharp corners and sharp edges. The single semi-voided portion of conductive pad  914  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  930  and  946  may, for example, be substantially square or rectangular and may include, for example, two or three semi-voided portions, respectively, with substantially square or rectangular shapes having single conductive strips at substantially vertical angles. Conductive pads  930  and  946  may, for example, have substantially sharp corners and sharp edges. The semi-voided portions of conductive pads  930  and  946  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pad  916  may, for example, be substantially square or rectangular and may include, for example, a single semi-voided portion with a substantially square or rectangular shape having a single conductive strip at a substantially non-vertical angle that is angled from left to right. Conductive pad  916  may, for example, have substantially sharp corners and sharp edges. The single semi-voided portion of conductive pad  916  may, for example, have substantially sharp corners and sharp edges. 
     The shape of conductive pads  932  and  948  may, for example, be substantially square or rectangular and may include, for example, two or three semi-voided portions, respectively, with substantially square or rectangular shapes having single conductive strips at substantially non-vertical angles that are angled from left to right. Conductive pads  932  and  948  may, for example, have substantially sharp corners and sharp edges. The semi-voided portions of conductive pads  932  and  948  may, for example, have substantially sharp corners and sharp edges. 
     Persons skilled in the art will appreciate that formation of conductive areas and voided areas within conductive pads having sharp corners and sharp edges may be more complex as compared to, for example, conductive areas and voided areas that do not have sharp corners and sharp edges. Accordingly, for example, conductive pads and voided areas that do not have sharp corners and sharp edges may be less expensive and less time consuming to manufacture. Persons skilled in the art will further appreciate that conductive areas within conductive pads are continuous. In particular, for example, voided areas or semi-voided areas within the conductive pads do not break the continuity of each conductive area within the conductive pads. 
     Turning to  FIG. 10 , a flow diagram of a detection/activity operation of a card is shown. In step  1002 , a card may exist within an idle state (e.g., a low-power sleep mode) whereby a magnitude of operational power consumed by a card is, for example, reduced or at zero. Triggering event  1004  may transition the card from the idle state into, for example, an active mode, whereby for example, one or more detectors may be used to determine whether a card is in a proximate, or touching, relationship with an object or device. 
     According to step  1006 , a card may linger in idle state  1010  before entering search mode  1008 . State  1010  may reduce the amount of time that may be necessary to successfully execute a detection search. Persons skilled in the art will appreciate that the number of charge/discharge sequences that may be executed to perform an active detection search may be reduced by delay  1010  without sacrificing the effectiveness of the detection search. Persons skilled in the art will further appreciate, therefore, that a reduction in the consumption of operational power may be realized. 
     Once detection has occurred, as in step  1012  for example, a card may then transition into an active mode as in step  1014 . The activity mode may be, for example, an information exchange event, whereby information is exchanged between a card and any number of devices that are detected to be operative to communicate with a card via any number of audible, visible, electrical, or electromagnetic means as necessary. 
     While a card remains in activity mode  1102  of  FIG. 11 , a card may re-enter a detection search mode, as in step  1106  for example, to verify that a card either remains in a proximate, or touching, relationship with a device, or to verify that a card has reentered into a proximate, or touching, relationship with a device. Similarly as discussed above, delay  1108  may be optionally executed to reduce an amount of time that may be necessary to successfully execute the detection search of step  1106 . Persons skilled in the art will appreciate that the number of charge/discharge sequences that may be executed during an active detection search may be reduced by delay  1108  without sacrificing the effectiveness of the detection search. Persons skilled in the art will further appreciate, therefore, that a reduction in the consumption of operational power may be realized. 
       FIG. 12  shows flow charts of sequences  1210 - 1230 . Step  1211  of sequence  1210  may, for example, include placing a processor into a sleep mode, whereby the processor draws little or no power during the sleep mode. In step  1212 , a processor may be awakened from a sleep mode to perform an activity during an activity mode. The processor may, for example, be awakened from a sleep mode by an external event (e.g., pressing of a button on a card). In step  1213 , a processor may, for example, sleep and awaken multiple times during an activity mode. For example, a processor may sleep and awaken multiple times per second (e.g., at least 20 times per second) during an activity mode. In so doing, for example, the processor may consume less power during the activity mode. 
     Step  1221  of sequence  1220  may, for example, place a processor into a sleep mode (e.g., a low-power mode of operation). In step  1222 , a processor may be awakened from a sleep mode by an external event (e.g., pressing a button on a card). While a processor operates during an activity mode, the processor may be placed back into a sleep mode (e.g., as in step  1223 ) during an amount of time when the processor is not utilized during the activity mode. In step  1224 , a processor may be awakened from a sleep mode by an external event (e.g., a processor interrupt) when the processor is required to, for example, perform operations during the activity mode. The processor may then be placed back into a sleep mode when the necessary operations are completed. 
     Step  1231  of sequence  1230  may, for example, place a card into a search mode. For example, a card may actively search for the presence of a read-head housing of a magnetic stripe reader during the search mode. A processor of a card may, for example, charge and discharge one or more conductive pads during the search mode to detect, for example, a capacitance change in the one or more conductive pads (e.g., as may be caused by the presence of a read-head housing of a magnetic stripe reader). Accordingly, for example, a search mode may progress for a number of minutes until a read-head housing of a magnetic stripe reader is detected or a timeout occurs. 
     In step  1232 , a processor may, for example, initiate the charging and discharging of the one or more conductive pads during the search mode and then go to sleep while the one or more conductive pads are being charged and/or discharged. The processor may, for example, be awakened during the search mode when the one or more conductive pads achieve a threshold level (e.g., the processor may be interrupted from a sleep mode when the one or more conductive pads achieve a signal magnitude that triggers a processor interrupt). 
     Once awakened, the processor may, for example, measure a capacitance change in the one or more conductive pads and then re-initiate a charge/discharge sequence of the one or more conductive pads. Accordingly, for example, a processor may cycle between sleep and awake modes multiple times per second. In so doing, a power savings may be achieved while the card is actively searching for the presence of, for example, a read-head housing of a magnetic stripe reader. 
     In step  1233 , a card may be swiped through a magnetic stripe reader that may, for example, cause a capacitance change to occur in one or more conductive pads on the card. Accordingly, for example, a processor of a card may detect the presence of the magnetic stripe reader (e.g., as in step  1234 ) and may then initiate a communication sequence with the magnetic stripe reader. 
     Persons skilled in the art will appreciate that a button may be pressed in order to provide electrical energy to read-head detectors such that read-head detectors may detect an object (e.g., a read-head housing). A period of time may be provided in which the electrical energy is delayed from being provided to the read-head detectors after a button is pressed. This delay may be, for example, between approximately one-hundredth of a second and one second (e.g., between approximately one quarter and one half of a second). In doing so, electrical energy provided to a read-head detector may be reduced in the amount of time it takes a user to press a button and swipe a card. During this period of delay, for example, a processor may be put into sleep mode once or multiple times (e.g., at a particular frequency). A read-head detector detecting a read-head may provide information to a processor and the processor may, in turn, cause a communication to occur from a dynamic magnetic stripe communications device. The card may automatically go into a sleep mode after a period of time after a card is detected as being swiped (e.g., approximately between 5 seconds and sixty seconds such as approximately between 10 seconds and thirty seconds). If the card is re-swiped before the card goes into sleep mode for not being swiped, this period of time may be reset such that a card may be re-swiped continually so long as the card is re-swiped in this period of time. At the beginning of each re-swipe period, a period of delay may occur before electrical energy is introduced to the read-head detectors in order to reduce power. This period of delay may be, for example, between approximately one hundredth of a second and one second (e.g., between approximately one quarter and one third of a second). The period of delay to provide electrical energy to a read-head detector for a re-swipe period may be, for example, less than the period of delay to provide electrical energy to a read-head detector after a button is pressed. Persons skilled in the art will appreciate that providing electrical energy to a read-head detector may be, for example, a processor utilizing a read-head detector to start attempts at detecting an object such as a read-head detector housing. 
     Persons skilled in the art will also appreciate that the present invention is not limited to only the embodiments described. Instead, the present invention more generally involves dynamic information and the exchange thereof. Persons skilled in the art will also appreciate that the apparatus of the present invention may be implemented in other ways than those described herein. All such modifications are within the scope of the present invention, which is limited only by the claims that follow.