Abstract:
A media handler for detecting counterfeit media is described. The media handler comprises: a plurality of discrete sensors distributed along a transport path operable to transport a media item, and a controller operable to receive signals from the plurality of discrete sensors. The controller is also operable to make a decision on validity of the transported media item based on the received signals.

Description:
FIELD OF INVENTION 
     The present invention relates to counterfeit media detection. 
     BACKGROUND OF INVENTION 
     It is important to be able to detect counterfeit media when such media is deposited into a self-service terminal, such as when counterfeit banknotes are inserted into an automated teller machine (ATM) equipped with automated banknote validation technology. Such automated banknote validation technology typically includes high resolution line sensors. These sensors are expensive. 
     There is now a requirement to detect counterfeit banknotes as they are being dispensed from ATMs. This requirement has arisen because some ATM replenishers have been accessing currency cassettes to be inserted into an ATM and fraudulently substituting counterfeit banknotes for valid banknotes in those currency cassettes. 
     It is not practical to include banknote validation technology in every ATM because such technology is expensive and would significantly increase the transaction time for each currency dispense transaction. 
     It would be advantageous to have a low-cost banknote validator that does not significantly increase transaction time. 
     SUMMARY OF INVENTION 
     Accordingly, the invention generally provides methods, systems, apparatus, and software for media validation, the apparatus comprising: a plurality of discrete sensors distributed along a transport path, and a controller operable to receive signals from the plurality of discrete sensors and to make a decision on validity of a transported media item based on the received signals. 
     In addition to the Summary of Invention provided above and the subject matter disclosed below in the Detailed Description, the following paragraphs of this section are intended to provide further basis for alternative claim language for possible use during prosecution of this application, if required. If this application is granted, some aspects may relate to claims added during prosecution of this application, other aspects may relate to claims deleted during prosecution, other aspects may relate to subject matter never claimed. Furthermore, the various aspects detailed hereinafter are independent of each other, except where stated otherwise. Any claim corresponding to one aspect should not be construed as incorporating any element or feature of the other aspects unless explicitly stated in that claim. 
     According to a first aspect there is provided a media handler for detecting counterfeit media, the media handler comprising: a plurality of discrete sensors distributed along a transport path operable to transport a media item, and a controller operable to receive signals from the plurality of discrete sensors and to make a decision on validity of the transported media item based on the received signals. 
     The transport path may comprise a banknote dispense path operable to pick media items from a currency cassette and to dispense those picked media items to a customer. The discrete sensors may be distributed along a transport path between (i) a pick area adjacent a pick unit, and (ii) a media item divert area in the vicinity of (or adjacent to) a purge container. The discrete sensors may not all be housed within a single module. This allows the sensors to be moved relative to each other, so that each media handler does not sense the same part of a media item as other media handlers of the same design. This ensures that counterfeiters cannot merely provide a genuine portion of a media item at a location on the media item corresponding to the position of the discrete sensors. 
     Optionally, the transport path may comprise a banknote deposit path operable to receive media items from a customer and to deposit those received media items into a media item container. 
     Optionally, the transport path may comprise a bi-directional banknote dispense and deposit path operable to receive media items from a customer and to dispense media items to a customer. 
     The discrete sensors may comprise two or more of the following types of discrete sensor: a UV sensor, an IR sensor, a sensor generally operable in a green portion of the electro-magnetic visible spectrum, a sensor generally operable in a red portion of the electro-magnetic visible spectrum, a sensor generally operable in a blue portion of the electro-magnetic visible spectrum, and an ultrasonic sensor. 
     The discrete sensors may comprise spot sensors (as opposed to line sensors that are typically more expensive). 
     The discrete sensors may sense transmission through, or reflection from, the media item. 
     The discrete sensors may be offset laterally from each other so that each discrete sensor senses a different portion of a surface of the media item. 
     One or more of the discrete sensors may be used instead of a track sensor so that the discrete sensor is used to indicate if a transported media item is present or skewed. 
     A discrete ultrasonic sensor may be used as part of the discrete sensor arrangement and also to detect multiple media item picks being transported as a single media item. 
     The controller may be operable to divert the transported media item if any of the discrete sensors indicates that the media item does not correspond to a valid media item. Since counterfeit banknotes inserted into a currency cassette are typically very low quality, the sensors may be used to detect the presence or absence of the appropriate radiation (for example, if infra-red is absorbed or not, or if ultra-violet is absorbed or not). 
     Alternatively, the controller may be operable to aggregate the signals received from the discrete sensors and apply artificial intelligence (using, for example, fuzzy logic, an artificial neural network, or the like) to ascertain if the media item is counterfeit. 
     Each of the discrete sensors may comprise a circuit board on which is mounted a transmitter and receiver. The transmitter and receiver may be integrated into a single device (for example, a transceiver), or implemented as two (or more) devices (for example, each discrete sensor may comprise a transmitter/receiver pair, or may comprise more transmitters than receivers, or vice versa). 
     According to a second aspect there is provided a method of detecting counterfeit media, the method comprising: picking a media item from a media item container; sensing the media item at a first position on a transport path using a first circuit; transporting the media item; sensing the media item at a second position on a transport path using a second circuit; transporting the media item; sensing the media item at a third position on a transport path using a third circuit; and diverting the media item to a reject container (also called a purge container) in the event that one of the circuits indicates that the media item is a counterfeit. 
     The step of sensing the media item at a third position on a transport path using a third circuit may include the further step of using an ultrasonic sensor to detect the media item. 
     The method may further comprise the step of: diverting the media item to a reject container in the event that one of the circuits indicates that the media item comprises a plurality of media items being transported as a single item. 
     According to a third aspect there is provided a currency dispenser operable to detect counterfeit banknotes, the currency dispenser comprising: a pick unit operable to pick individual media items from a currency cassette; a transport path operable to transport a media item from the pick unit to a dispense port; a first sensor located at the transport path near to the pick unit; a second sensor located at the transport path and longitudinally spaced apart from the first sensor; and a controller operable to divert the transported banknote in the event that one of the sensors indicates that the banknote is counterfeit. 
     The second sensor may be laterally offset from the first sensor. 
     The currency dispenser may comprise a third sensor located at the transport path near a diverter. 
     According to a fourth aspect of the present invention there is provided a cash dispenser comprising a plurality of sensors mounted along a transport path and coupled to a controller operable to make a validity decision about a transported banknote based on the outputs of the plurality of sensors. 
     The validity decision may be made in real time without slowing down the banknote transport speed. 
     The validity decision may be made as the banknote is being transported. The plurality of sensors may be located on each of two sides of a corner around which the transport path conveys the banknote. 
     According to a fifth aspect of the present invention there is provided a method of retro-fitting a cash dispenser by mounting a plurality of sensors in spaced relation along an existing banknote transport path and providing a controller operable to receive signals from the plurality of sensors and to detect counterfeit banknotes as they are being transported along the transport path. 
     The controller may be operable to detect counterfeit banknotes as they are being transported along the transport path without slowing down the speed of transport of the banknotes. 
     For clarity and simplicity of description, not all combinations of elements provided in the aspects recited above have been set forth expressly. Notwithstanding this, the skilled person will directly and unambiguously recognize that unless it is not technically possible, or it is explicitly stated to the contrary, the consistory clauses referring to one aspect are intended to apply mutatis mutandis as optional features of every other aspect to which those consistory clauses could possibly relate. 
     These and other aspects will be apparent from the following specific description, given by way of example, with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified schematic diagram of a media handler, in the form of a banknote dispenser, according to one embodiment of the present invention; 
         FIG. 2  is a simplified schematic diagram illustrating discrete sensors mounted in the banknote dispenser of  FIG. 1 ; and 
         FIG. 3  is a flowchart illustrating the operation of the banknote dispenser of  FIG. 1  when a banknote being dispensed is validated by the discrete sensors of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference is first made to  FIG. 1 , which is a simplified schematic diagram of a media handler  10 , in the form of a banknote dispenser, according to one embodiment of the present invention. 
     The banknote dispenser  10  comprises: a removable currency cassette  12 ; a pick unit  14 ; a transport path  16 ; a stacker wheel  18 ; a presenter path  20 ; a controller  22 , and a purge (or reject) bin  24 . These components are all housed within a chassis  26 . 
     The chassis  26  defines an exit port  28  at an end of the presenter path  20  opposite the stacker wheel  18 . 
     The transport path  16  comprises an upright portion  30  for receiving a picked banknote from the pick unit  14 , a generally horizontal portion  32  for conveying a picked banknote to the stacker wheel  18 , and an inclined section  34  for conveying a picked banknote to the purge bin  24 . The transport path  16  and the stacker wheel  18  are conventional components of a currency dispenser. 
     The destination of a picked banknote (the stacker wheel  18  or the purge bin  24 ) depends on the position of a pivoting divert gate  36 . The pivoting divert gate  36  moves (in response to a signal from the controller  22 ) in the direction shown by double-headed arrow  38 . 
     As is known to those of skill in the art, the transport path  16  includes belts, skid plates, and/or gear trains to transport banknotes from the pick unit  14  to either the stacker wheel  18  (under normal conditions) or to the purge bin  24  (if an exception occurs, as will be described in more detail below). 
     A plurality of discrete sensors are located at different points along the transport path  16 , as will now be described with reference to  FIG. 2 , which is a simplified schematic diagram illustrating the positions of six discrete sensors  40  to  50  disposed along the transport path  16 . In  FIG. 2 , the transport path  16  is illustrated in a linear manner for simplicity of illustration. In  FIG. 2 , the longitudinal direction is illustrated by double-headed arrow  54  and the lateral direction is illustrated by double-headed arrow  56 . The direction of motion of a banknote  58  is shown in  FIG. 2  by arrow  60 . 
     Each of the discrete sensors comprises a circuit board on which is mounted a transmitter and receiver. The transmitter and receiver may be in the form of an integrated transceiver, for example, where the sensor measures reflectance. Alternatively, the transmitter and receiver pair may comprise a separate transmitter and receiver, for example, where the sensor measures transmission. Each discrete sensor circuit board is connected to the controller  22  and sends signals thereto indicative of measurements taken from a banknote travelling along the transport path  16  as it passes that discrete sensor. 
     As illustrated in  FIG. 2 , the first discrete sensor  40  comprises a first circuit board  40   a  on which is mounted (i) an ultrasonic sensor  40   b . The ultrasonic sensor  40   b  can detect multiple superimposed banknotes being transported as a single banknote (which occurs when an accidental double pick happens). Thus, the ultrasonic sensor  40   b  can replace a conventional multiple banknote detector, which is used in ATMs. 
     The ultrasonic sensor  40   b  can also detect when multiple parts of a banknote are adhered to form a single composite banknote (which is a known type of counterfeiting activity). Thus, ultrasonic sensor  40   b  has the advantage that it can detect a single banknote composed of multiple banknote (and/or non-banknote) portions. 
     Unlike optical sensors, an ultrasonic sensor does not confuse a transparent window in a banknote with absence of a banknote. This is advantageous because a transparent window is included in some banknote designs, particularly where the banknote substrate is made from a polymer. 
     The second discrete sensor  42  is longitudinally spaced apart from the first discrete sensor  40 . The second discrete sensor  42  is “downstream” of the first discrete sensor  40  in that the banknote  58  passes the first discrete sensor  40  before it passes the second discrete sensor  42 . The second discrete sensor  42  comprises a second circuit board  42   a  on which is mounted (i) an ultra-violet (UV) reflective transceiver  42   b  and (ii) a position sensor  42   c  (in the form of a white LED transceiver). The UV transceiver  42   b  is laterally spaced apart from both the ultrasonic sensor  40   b  on the first circuit board  40   a , and the position sensor  42   c  on the second circuit board  42   a . The UV transceiver  42   b  emits radiation at approximately 365 nm. The UV transceiver  42   b  performs two functions. The first function is to validate the banknote  58  as it is transported across the first discrete sensor  42 . The second function is to operate as a position sensor (complementary to position sensor  42   c ). 
     The position sensor  42   c  (in common with the other position sensors described below) is a conventional sensor that is used to detect if the banknote  58  is correctly located on the transport path  16 . 
     The third discrete sensor  44  is downstream of the first and second discrete sensors  40 ,  42 . The third discrete sensor  44  comprises a third circuit board  44   a  (which straddles the transport path  16 ; that is, it is both above and below the transport path  16 ). On an upper part of the third circuit board  44   a  (the part above the transport path  16 ), a green transmissive emitter (not shown individually) is mounted; and on a lower part of the third circuit board  44   a  (the part below the transport path  16 ), a green transmissive receiver (not shown individually) is mounted. The numeral  44   b  refers to the combined green transmissive emitter/receiver pair. 
     The combined green transmissive emitter/receiver pair  44   b  is mounted laterally offset from both the ultrasonic sensor  40   b  and the UV transceiver  42   b . This is to ensure that a different part of the banknote  58  is measured by each of these sensors. 
     A position sensor  44   c  (in the form of a white LED transceiver) is also mounted on the third circuit board  44   a , offset from the green transmissive emitter/receiver pair  44   b.    
     In a similar manner to the UV transceiver  42   b , the green transmissive emitter/receiver pair  44   b  also performs the two functions of banknote validation and position sensing. The green transmissive emitter/receiver pair  44   b  emits radiation at approximately 510 nm. 
     The fourth discrete sensor  46  is downstream of the first to third discrete sensors  40 ,  42 ,  44 . The fourth discrete sensor  46  comprises a fourth circuit board  46   a  on which is mounted (i) a first infra-red (IR) reflective transceiver  46   b  and (ii) a position sensor  46   c  (in the form of a white LED transceiver), laterally spaced apart from the first IR transceiver  46   b . The first IR transceiver  46   b  emits radiation at approximately 930 nm. The first IR transceiver  46   b  has two functions. The first function is to validate the banknote  58  as it is transported across the fourth discrete sensor  46 . The second function is to operate as a position sensor (complementary to position sensor  46   c ). 
     The first IR transceiver  46   b  is mounted laterally offset from (i) the ultrasonic sensor  40   b , (ii) the UV transceiver  42   b , and (iii) the combined green transmissive emitter/receiver pair  44   b . This is to ensure that a different part of the banknote  58  is measured by each of these sensors. 
     The fifth discrete sensor  48  is downstream of the first to fourth discrete sensors  40  to  46 . The fifth discrete sensor  48  comprises a fifth circuit board  48   a  on which is mounted a second IR reflective transceiver  48   b  and (ii) a position sensor  48   c  (in the form of a white LED transceiver), laterally spaced apart from the second IR transceiver  48   b . The second IR transceiver  48   b  is laterally offset from (i) the ultrasonic sensor  40   b , (ii) the UV transceiver  42   b , (iii) the combined green transmissive emitter/receiver pair  44   b , and (iv) the first IR transceiver  46   b.    
     The second IR transceiver  48   b  emits radiation at approximately 800 nm. The second IR transceiver  48   b  has two functions: (i) banknote validation, and (ii) position sensing. 
     The sixth discrete sensor  50  is downstream of the first to fifth discrete sensors  40  to  48 . The sixth discrete sensor  50  comprises a sixth circuit board  50   a  on which is mounted (i) a second ultra-violet (UV) reflective transceiver  50   b  and (ii) a position sensor  50   c  (in the form of a white LED transceiver). The second UV transceiver  50   b  emits radiation at approximately 254 nm. In a similar manner to the first UV transceiver  42   b , the second UV transceiver  50   b  also performs the two functions of banknote validation and position sensing. 
     The second UV transceiver  50   b  is mounted laterally offset from (i) the ultrasonic sensor  40   b , (ii) the first UV transceiver  42   b , (iii) the combined green transmissive emitter/receiver pair  44   b , (iv) the first IR transceiver  46   b , and (v) the second IR transceiver  48   b . This is to ensure that a different part of the banknote  58  is measured by each of these sensors; thereby ensuring that a good quality counterfeit (or even part of a real banknote) at one part of the banknote is unlikely to be validated by all of the discrete sensors. 
     All six discrete sensors  40  to  50  are mounted adjacent the transport path  16  and between the pick unit  14  and the pivoting divert gate  36 . 
     The operation of the media handler  10  will now be described with reference to  FIG. 3 , which is a flowchart  100  illustrating the operation of the banknote dispenser  10  when a banknote being dispensed is validated by the discrete sensors  40  to  50 . 
     Initially, the controller  22  receives a command to pick a banknote from the currency cassette  12  (step  102 ). 
     The pick unit  14  picks a banknote (the banknote  58 ) (step  104 ) in response to an instruction from the controller  22 , and then the controller  22  actuates motors (not shown) to move the picked banknote along the transport path (step  106 ). 
     When a leading edge of the picked banknote  58  reaches the first discrete sensor  40  this is detected by the ultrasonic sensor  40   b  (step  108 ). 
     The ultrasonic sensor  40   b  then takes a measurement from a portion of the banknote that is in registration with it (that is, in registration with the ultrasonic sensor  40   b ) as the banknote  58  passes under the ultrasonic sensor  40   b  (step  110 ). 
     The first discrete sensor  40  then transmits the measurements to the controller  22  (step  112 ). 
     The controller  22  then ascertains if this is the last discrete sensor (step  114 ). Each of the discrete sensors has a unique identification, which is transmitted together with the measurements it has taken from the banknote  58 . The controller  22  is programmed so that it knows that the sixth discrete sensor  50  is the last sensor, so when the unique identification from the sixth discrete sensor  50  is received, the controller  22  knows that the last discrete sensor has been reached. 
     If the last discrete sensor has not been reached, then the flow returns to step  106  (that is, the controller  22  continues transporting the banknote  58 ). 
     If the last discrete sensor has been reached, then the controller  22  processes all of the received measurements from the six discrete sensors (step  116 ) to ascertain if the banknote is valid (step  118 ). 
     If one or more of the six discrete sensors  40  to  50  indicates that the banknote  58  is not valid (or if multiple banknotes are present) then the controller  22  activates the pivoting divert gate  36  (step  120 ). 
     The banknote  58  (which may actually comprise multiple superimposed banknotes transported erroneously as a single banknote) is then routed to the purge bin  24  via the inclined section  34  (step  122 ). 
     If all of the six discrete sensors  40  to  50  indicate that the banknote  58  is valid (which includes no multiple banknotes being present), or at least not invalid based on the measurements taken, then the controller  22  transports the banknote  58  to the stacker wheel  18  (step  124 ). 
     The process  100  shown in  FIG. 3  can be repeated until all required banknotes have been picked and loaded into the stacker wheel  18 . The banknotes in the stacker wheel  18  can then be stripped off and presented as a bunch to a customer via exit port  28 . 
     It should be appreciated that the controller  22  is programmed to reach a decision before the transported banknote  58  reaches the pivoting divert gate  36  so that a decision can be made to divert the banknote, if necessary. 
     The controller  22  may execute a real time operating system to enable it to process data within a defined time (that is, prior to a transported banknote reaching the pivoting divert gate  36 ). 
     Most counterfeit notes inserted into a currency cassette are low quality counterfeits, so it may be possible to detect these using a simple binary function applied to each of the discrete sensors (for example, presence or absence of infra-red absorption for the first IR reflective transceiver  46   b ). Alternatively, if more accurate analysis is required then more complex validation algorithms may be used. For example, the controller  22  may use one or more of the algorithms described in U.S. Pat. Nos. 7,639,858 and 8,086,017, and the algorithms described in US published applications US 2008-0159614 and US 2008-0123931; all of which are assigned to the assignee of this application, and all of which are incorporated herein by reference. 
     This embodiment has the advantage that the ultrasonic sensor  40  is the first sensor that a banknote reaches. This means that even if the banknote includes a transparent window, the sensor will unambiguously detect the banknote; whereas, an optical sensor might not be able to differentiate between the window and the edge of a banknote. 
     Various modifications may be made to the above described embodiment within the scope of the invention, for example, in other embodiments, the dispenser may comprise a ballistic stacking dispenser. 
     In other embodiments, the media handler may comprise a recycler for receiving banknotes from a customer and dispensing the received banknotes to a subsequent customer. 
     In other embodiments, the media handler may comprise a greater or fewer number of discrete sensors than the six discrete sensors described above. 
     In the above embodiment, each discrete sensor conveyed a signal to the controller  22  for processing by the controller  22 . In other embodiments, each discrete sensor may include a dedicated processor which outputs a digital signal indicating whether the media item is valid or invalid, based on the measurement recorded by that discrete sensor. In such embodiments, an OR Boolean function may be used to gate the outputs from each discrete sensor such that if even one discrete sensor indicates that the output is invalid then the media item is categorized as an invalid media item (for example, it may be categorized as a counterfeit or as a suspect counterfeit). The output of the dedicated processor may be an analogue signal, in which case additional processing would be performed on that output signal to ascertain if the media item is valid or invalid. 
     In the above embodiment, most of the discrete sensors are illustrated above the transport path. In other embodiments, most of the discrete sensors may below the transport path, or some of the discrete sensors may be above the transport path, others below the transport path, and others on either side of the transport path (for example, for a transmissive measurement). 
     In some embodiments, the transport path may be vertically oriented, rather than horizontally oriented as described in the above embodiment; in other words, media items may be transported on their edge (with their faces vertically aligned) rather than on their face (with their faces horizontally aligned). For a vertically oriented transport path, the discrete sensors may be on one or both sides of the transport path. 
     In other embodiments, different sensors may be used to those described above. For example, different types of sensors, different wavelengths of sensors, different numbers of sensors, different configurations of sensors may be used. 
     In other embodiments the discrete sensors may include a magnetic sensor or a metallic sensor. 
     In other embodiments, an iodine dropper could be provided on the transport path to apply some iodine to a banknote as it is being transported. Further downstream from the iodine dropper, an optical sensor may be provided to test the color of the iodine impregnated region on the banknote. Low quality counterfeit banknotes are typically printed on paper that includes starch, which reacts to iodine. The optical sensor could detect if the iodine has changed color (reacted with starch), thereby indicating that the banknote is a counterfeit. 
     The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. The methods described herein may be performed by software in machine readable form on a tangible storage medium or as a propagating signal. 
     The terms “comprising”, “including”, “incorporating”, and “having” are used herein to recite an open-ended list of one or more elements or steps, not a closed list. When such terms are used, those elements or steps recited in the list are not exclusive of other elements or steps that may be added to the list. 
     Unless otherwise indicated by the context, the terms “a” and “an” are used herein to denote at least one of the elements, integers, steps, features, operations, or components mentioned thereafter, but do not exclude additional elements, integers, steps, features, operations, or components. 
     The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other similar phrases in some instances does not mean, and should not be construed as meaning, that the narrower case is intended or required in instances where such broadening phrases are not used. 
     The reader&#39;s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.