Abstract:
A device for sensing predetermined characteristics of an object such as a coin or a token in order to determine its validity or genuineness and in some cases its denomination, the device including a combination of optical and electromagnetic sensors which operate together along a coin path and capable to analyze the coin or token in different positions so that if there are multiple holes or rings of transparent material they can be sensed and used to determine the coin or token&#39;s validity and denomination.

Description:
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/368,137 filed Jul. 27, 2010. The contents of said application are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Vending machines typically include devices capable of validating and accepting money like coin changers, bill acceptors, credit card readers, etc. Coin acceptor devices function to authenticate and denominate each of the coins inserted into the vending machine. Known coin detection and validation devices utilize various techniques and methods which include optical size detection and metallic content or characteristic detection. Examples of such coin detection devices are disclosed in U.S. Pat. Nos. 4,625,852, 4,646,904, 5,662,205, 5,673,781, 6,230,870. These patents relate to coin detection, validation and denomination and include some features which, in the general sense, relate to the present invention. All of these patents are assigned to the assignee of the present invention. 
     Typically, the coin acceptor has one coin inlet funnel for all coin inputs and which directs coins toward a sloped coin track along which are located optical and magnetic sensors to validate acceptable coinage and reject spurious materials. After being sensed for validity and denomination, the coin is directed in a number of directions. Valid coins are directed to coin inventory tubes, used for coin payback, or a cash box. Invalid denominations or counterfeit coins are directed to a coin return chute. 
     In order to properly sense the validity and denomination of the coin, a serpentine path directs the coin toward the beginning of a stainless steel validation rail. The validation rail will both stabilize the coin and guide it past the validation sensors. The rail combined with an inward lean will maximize coin lean against the sensors. 
     Coin validation begins once the coin acceptor recognizes a coin is passing by the optical and magnetic sensors. After proper coin validation, a series of decision gates actuated by solenoids will control the proper routing of the coin. 
     Coins containing holes or transparent portions or containing portions made from dissimilar materials represent a difficulty for prior art coin detectors. Coins with apertures of any kind allow light pass through the coin as the coin rolls past an optical sensors and coins having portions of dissimilar metals cause the magnetic sensors to fail to generate a consistent or expected waveform. 
     The prior art devices therefore do not address the problem of validating coins made of more than one different material with holes that are symmetrical or non-symmetrical, apertures or rings of transparent material. 
     Accordingly, it is desirable and advantageous to provide a coin detection device having optical and electromagnetic sensors and associated circuits capable of accurately authenticating and accepting coins of different denominations by measuring the unique characteristics of holes, apertures and transparent rings located on the coin. 
     SUMMARY OF THE INVENTION 
     A coin detection device for determining a size of a coin and a size of at least one aperture hole in the coin while the coin is traveling along a coin track, the device comprising a first inductive sensor array positioned along the coin track and/or a first optical sensor array positioned along the coin track, a processing circuit connected to the optical and inductive sensor arrays, each of the sensors providing an output signal to the processing circuit and the processing circuit determining a size of the coin and a size of at least one aperture hole in the coin based upon output signal from each of the optical and inductive sensor arrays. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial plan view of the internal portion of a coin acceptor according to an embodiment of the present invention; 
         FIG. 2  is shows examples of actual coins containing apertures or dissimilar metals; 
         FIG. 3  is a schematic representation of optical sensors according to an embodiment of the present invention; 
         FIG. 4  is a schematic representation of electromagnetic sensors according to an embodiment of the present invention; 
         FIG. 5  is a schematic representation of an embodiment of the present invention; 
         FIG. 6  is a schematic representation of an embodiment of the present invention; 
         FIG. 7  is a graphical representation of waveform outputs from optical sensors and magnetic sensors according to an embodiment of the present invention; 
         FIG. 8  is a schematic representation of representative types of coins and tokens that can be validated according to an embodiment of the present invention; 
         FIGS. 9-18  are schematic representations of coins passing sensor arrays along a coin path according to an embodiment of the present invention; 
         FIG. 19  is a schematic representation of different types of coins physical parameters that can be measured on each coin according to an embodiment of the present invention; and 
         FIG. 20  is a diagram showing the optical timing signal according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The coin detection device of the present invention is capable of determining a physical configuration of coins containing apertures or transparent portions and/or an arrangement of dissimilar metals as well as the size of those holes, apertures or transparent portions or the size of the portions containing dissimilar metals. This is accomplished with a special arrangement of optical and inductive sensors positioned along the coin track each of the sensors for providing an output signal to an electrical circuit. By examining the waveforms created by the optical and inductive sensors and comparing the waveform to expected waveforms for an acceptable coin, the coin denomination and validity can be determined. 
     In one specific embodiment, a coin detection device for detecting a characteristic of a coin comprises a processing circuit, an arrangement of optical sensors and an arrangement of electromagnetic sensors. Each of these arrangements of sensors is connected to a processing circuit. The optical sensors produce a size related output signal and the magnetic sensors provide an output signal to the processing circuit indicative of the interaction of an electromagnetic field with the coin. The optical and magnetic sensors being in a special location relationship to each other based on the size of the coin and the size and location of the holes or transparent portions of the coin, and the processing circuit for determining whether the coin is acceptable based upon a comparison of the output signals. 
     Another form of the present invention is a metal detector which comprises a first array of optical sensors and a second array of inductive elements, or magnetic sensors, the first and second arrays being connected to processing circuits, the arrays being in a mechanical relationship to each other, the first and second circuits each providing an output signal to the processing circuit, the output signals being produced by the presence of a metallic object and the processing circuit for detecting a characteristic of the metallic object based upon a ratio of the a diameter size and an aperture size to determine a coin&#39;s validity. 
     Referring now to the drawings,  FIG. 1  shows a coin acceptor device  10  comprising a coin entry portion  12 , a coin track portion  14 , and a coin sensor portion  16 . When the coin is inserted into the coin entry portion  12  of the coin acceptor device  10 , it moves through the device  10  until it rolls down the coin track portion  14  and past the coin detector portion  16 . The coin detector portion  16  comprises a plurality of electromagnetic and optical components, as discussed below, for detecting the denomination and validity of the coin. 
       FIG. 2  shows exemplary coins and tokens that include voids and openings which present difficulty for coin acceptors of the prior art to determine denomination and validity due to those voids. 
       FIG. 3  is an electrical schematic showing an embodiment for an arrangement of optical sensors in accordance with the present invention. In the exemplary arrangement three light emitting diodes (LEDs)  20 ,  20 ′, and  20 ″ are arrangement proximate to three phototransistors  26 ,  26 ′, and  26 ″ which detect light from the LEDs  20 ,  20 ′ and  20 ″. The LEDs  20 ,  20 ′, and  20 ″ may emit light in the visible or invisible range of the spectrum; however, the LED must be matched to the sensible range of the phototransistors  26 ,  26 ′ and  26 ″. Each corresponding pair of LEDs  20 ,  20 ′ and  20 ″ and phototransistor  26 ,  26 ′,  26 ″ are referred to herein as an optical sensor. The state of the phototransistors is transmitted to a logic circuit  32  via an interface circuit  34 . Physically a LED and its corresponding phototransistor could be located across a coin track or coin path from one another or on a single side of the coin path with the light emitted by the LED being redirected to the phototransistor by a mirror. It will be understood by one of ordinary skill in the art while the arrangement of optical sensors is shown as comprising three sensors for purposes of illustration any number of a plurality of optical sensors could be utilized to accomplish the arrangement. The logic circuit  32  and interface circuit  34  will transform the sensors&#39; output created by the passage of a coin into logical signals, as discussed below. 
       FIG. 4  is an electrical schematic showing an embodiment for an arrangement of magnetic sensors comprising sensitive coils  36 ,  36 ′ and  36 ″ whose electromagnetic field interacts with coins that pass by the arrangement of sensors. Coils can be arranged on one or either side of the coin track. The coils may be powered by a tank circuit, an oscillator circuit or a pulsing device to generate the electromagnetic field. Like the optical sensors, above, the state of the magnetic sensors  36 ,  38  and  40  is transmitted through the interface  34  and to the logic circuit  32 . It will be understood by one of ordinary skill in the art while the arrangement of electromagnetic sensors is shown as comprising three sensors for purposes of illustration any number of a plurality of optical sensors could be utilized to accomplish the arrangement. The logic circuit  32  and interface circuit  34  will transform the sensors&#39; output created by the passage of a coin into logical signals, as discussed below. 
     As shown in  FIGS. 5 and 6 , a coin track  42  of a coin acceptor routes a coin  44  past the arrangements of optical and electromagnetic sensors  46 ,  48 ,  50 ,  52 . The optical sensors comprise pairs of LEDs  20  and phototransistors  26 , and the electromagnetic sensors comprise coils  36 . The arrangements of sensors may be located on a single side of the coin, as in sensors  46 ,  48  and  52 , or on opposite sides of the coin as in sensors  50  and  52 . 
       FIGS. 7   a  and  7   b  show waveforms created by a coin passing by an optical sensor ( FIG. 7   a ) and a magnetic sensor ( FIG. 7   b ). In the case of  FIG. 7   a , point T 1  represents a detection of the leading edge of a coin passing by an optical sensor and point T 2  represents a trailing edge of a coin passing by the same optical sensor. Point T 3  represents the leading edge of the same coin passing another optical sensor within the same optical sensor arrangement but located at a different point along the same coin path  42  and point T 4  represents the trailing edge of that coin from the same optical sensor. 
     In the case of  FIG. 7   b , point T 5  represents a detection of the leading edge of a coin passing by an electromagnetic sensor and point T 6  represents a trailing edge of a coin passing by the same electromagnetic sensor. Point T 7  represents the leading edge of the same coin passing another electromagnetic sensor within the same electromagnetic sensor arrangement but located at a different point along the same coin path  42  and point T 8  represents the trailing edge of that coin from the same electromagnetic sensor. 
       FIG. 8  shows schematically examples of coins that may be validated and denominated using the present invention. Coin  56  is a solid coin made of single metal or alloy. Coin  58  is a solid coin having a center A made of one alloy and an outer portion made of a different alloy B (which may also be a of same or different color). Coin  60  is a solid coin having a center A and two circumferential outer rings B and C made from different alloys. Coin  62  comprises a central aperture A defined by an outer ring B. Coin  64  defines a central aperture A surrounded by four regularly spaced apertures B. Coin  66  defines four ovular and regularly spaced apertures. Coin  68  has a center A made from a first alloy, a surrounding ring B made from a second alloy, a transparent ring C, and an outer ring made from yet a third alloy D. 
       FIG. 9  shows schematically the coin path  42  and the coin  68  moving down the track  42  in a direction Z. An array of optical sensors  70  and an array  72  of electromagnetic sensors  72  detect coin  68 &#39;s leading and trailing edges, as well as reacts the coin  68 &#39;s various alloys and transparent sections. The optical sensor array  70  and magnetic sensor array  72  are arranged in a horizontal and parallel position with respect to the coin path  42 . Each optical sensor and each electromagnetic sensor will create the same waveform in reaction to the passing coin  68 , though each waveform will be out of phase in the time domain due to the linear placement of the sensors within the along the coin path  42 . If the coin (as in the coin  68 ) is bilaterally symmetrical along any bisecting diameter of the coin, the phase separation of the waveforms can further be used to determine the diameter of the coin  68 . 
       FIG. 10  shows schematically the same elements as depicted in  FIG. 9  but that the coin  68  is now located in the proximity of the sensors  70 ,  72 . The optical sensors  70  are blocked as soon as the front edge of the coin reaches them and unblocked as soon as the transparent portion C of the coin  68  arrives or the trailing edge of the coin  68  passes. The magnetic sensors  72  will react differently to the alloy of the center A of the coin  68 , the ring B of the coin  68 , the ring C of the coin and the ring D of the coin, thereby creating a unique waveform as the coin passes. As such, each sensor with the optical array  70  and the electromagnetic array  72  will generate waveforms, as described in  FIGS. 7   a  and  7   b.    
       FIGS. 11 and 12  are similar to  FIGS. 9 and 10 , but show the passage of coin  66  comprising a single alloy but multiple apertures. The optical sensors  70  are blocked as soon as the front edge of the coin  66  reaches them and unblocked as soon as the transparent portion C of the coin  66  arrives, apertures passes or the trailing edge of the coin  66  passes. The magnetic sensors  72  will react differently to the alloy of the coin  66  or the apertures of the coin  66  as they pass, again creating a unique waveform as the coin  66  passes. 
     In alternative embodiment,  FIG. 13  shows schematically the coin track  42  and the coin  68  moving down the track  42  in a direction Z. An array of optical sensors  70  and an array of magnetic sensors  72  are placed in a vertical or perpendicular arrangement with respect to the coin path  42 .  FIG. 14  shows schematically the same elements as depicted in  FIG. 13  except that the coin  68  is now located in the proximity of the sensor array  70 ,  72 . The optical sensors of the optical sensor array  70  will be blocked as soon as the front edges of the coin riches them and unblocked as soon as the transparent portion of the coin  68  or the trailing edge of the coin  68  arrives. The magnetic sensors will be react differently to the center of the coin and various rings, as they are made of different materials. Every sensor will generate waveforms as described with respect to  FIGS. 7   a  and  7   b . The primary difference between the embodiment of  FIGS. 9 and 10  and  FIGS. 13 and 14  is with respect to the embodiment of  FIGS. 9 and 10 , each sensor is expected to have a waveform of generally the same form but not in phase. 
     With respect to the embodiment of  FIGS. 13 and 14 , sensors of the arrays  70  and  72  which are equidistant from coin&#39;s center can be expected to have the same waveform but out-of-phase and sensors at the top of the array can be used to detect the upper edge of the coin to determine diameter. 
       FIGS. 15 and 16  show schematically the same preferred embodiment of the present invention as presented in the  FIGS. 11 and 12  with coin  66  passing the sensor arrays  70 ,  72  arranged in the vertical orientation of  FIGS. 13 and 14 . 
       FIG. 17  and  FIG. 18  show schematically a further embodiment of the present invention with two different types of coins  66 ,  68  rolling down the coin path  42  and arriving in the proximity of optical sensor array  70  and  70 ′ and electromagnetic sensor array  72  and  72 ′. In this embodiment, vertical and horizontal optical sensor arrays  70  and  70 ′ and magnetic sensor arrays  72  and  72 ′ interact with the coins  66  and  68 . In this embodiment, the waveforms of the embodiments of  FIGS. 9 &amp; 13  and  11  &amp;  15  are all created such that more information about the coin may be analyzed. 
       FIG. 19  shows schematically the physical parameters that are measured on different coins using the preferred embodiments above. With reference now to  FIG. 19 , coin  56  is a solid coin for which the processor  35  will receive waveform information and will calculate at least diameters A-B and C-D and also many chords parallel with these two diameters. The diameters and the chords will be calculated based on optical sensors outputs and magnetic sensors outputs as described above. The processor  35  will finally compare the optical and magnetic calculated diameters and chords with pre-stored magnetic and optical diameters and decide if the coin  56  is valid and of what denomination. 
     Coin  58  or coin  62  defines either an aperture or comprises bi-alloy composition wherein the center material is either opaque or transparent. The center hole may also contain an electronic chip. For the case that the coin has a hole or a hole filled with a transparent substance, the processor  35  would implement the waveforms, as described above, to determine diameters A-D and E-F, diameter of the hole B-C, ring chords A-B, C-D. The processor will finally compare the optical and magnetic calculated diameters and chords with pre-stored magnetic and optical diameters and decide if the coin  58  or  62  is valid and of what denomination. 
     Similarly for coin  60 , the processor  35  uses the optical and magnetic waveforms transmitted from the optical and magnetic sensor arrays  70 ,  72  to calculate the diameter of the coin  60 , diameters of the two rings, diameters of the center hole, rings chords, center hole chords. The processor  35  will finally compare the optically and magnetically calculated diameters and chords with pre-stored magnetic and optical diameters and decide if the coin is valid and of what denomination. 
     The processor  35  uses the optical and magnetic waveforms transmitted from the optical and magnetic sensor arrays  70  and  72  to determine the diameter of the coin  68 , diameters of the two solid rings  4  and  2 , diameter of the transparent ring  1 , diameters of the center hole, rings chords, center hole chords. The processor  35  will finally compare the optical and magnetic calculated diameters and chords with pre-stored magnetic and optical diameters and decide if the coin is valid and of what denomination. 
     Referring to  FIGS. 17-19 , due to the ringed construction of the coins  58  or  62 ,  60 ,  66  and  68  the ring portions will interact differently with the optical coin sensing devices in the horizontal optical and electromagnetic sensors arrays  70  and  72  than the vertical optical and electromagnetic sensors arrays  70 ′ and  72 ′. With reference now to  FIGS. 17 and 18  and in the case of the coin  66  of  FIG. 19  rolling down the coin path  42 , during the portions a-b, c-d, optical sensors in the horizontal array  70  will be blocked and they will be open during the portion b-c when they see the transparent portion of the coin. The signal generated by every one of the optical sensors in array  1  is transferred to the processor  35  via the interface and logic circuits  32  and  34  of  FIG. 5 . The processor  35  will further calculate optical sizes for the ring portions scanned by the optical sensors of the horizontal array  70 . At the same time the magnetic sensors of the vertical electromagnetic array  72 ′ will interact differently with the ring portions of the coin based on the material content of those portions. The signal generated by every one of the magnetic sensors is transferred to the processor  35  via the interface and logic circuits  32  and  34  of  FIG. 5 . The processor will further calculate “magnetic” sizes for the ring portions scanned by the magnetic sensors of horizontal electromagnetic array  72 . Using these waveforms, the processor  35  will calculate optical and magnetic sizes for every ring and hole portion of the coin  66  scanned by the sensors. Furthermore the processor  35  will calculate ratio of the magnetic to optical sizes for all the calculated dimensions of the coin, coin rings and coin holes. Finally, the processor  35  compares these measurements with pre-stored data and decides if the coin is real and of what denomination. 
     Referring to  FIGS. 9 ,  10 ,  13  and  17 , with coin  68  of  FIG. 19  rolling down the track and positioned in the proximity of the horizontal sensor arrays  70  and  72 , intermediate optical sensors within vertical optical sensor array  70 ′ of  FIG. 9  will be located in the transparent ring portion b-c of the coin  68 . All of the other optical sensors within vertical optical sensor array  70 ′ interact with the solid portion of the coin  68 . The processor  35  will generates an optical timing event signal when individual optical sensors in the array  70 ′ go from OFF to ON when a solid portion of the coin  68  follows a transparent portion of the coin  68  and when a transparent portion of the coin  68  ends and a solid portion of the coin  68  follows. This optical timing event signal is unique for the given coin as it moves along the optical array. The processor  35  will compare the optical timing event signal with pre-stored optical timing events and decide if the coin is valid and of what denomination. 
     It will be apparent to those skilled in the art that many changes, modifications, variations, and other uses of the subject coin detection device are possible and contemplated. All changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.