JP2014182539A - Coin identification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately identify a clad coin composed of a plurality of kinds of metals.SOLUTION: A coin identification device according to the present invention comprises: a first coil that faces a coin passage; a first coil sensor to which a second coil arranged to face the first coil across the coin passage is connected, and which forms a resonance system by a first frequency; a third coil that faces the coin passage; a second coil sensor to which a fourth coil arranged to face the third coil across the coin passage is connected, and which forms a resonance system by a second frequency; a switch that is switchable between the first coil sensor and the second coil sensor; and control means that changes over the switch in time division, and identifies a coin passing through the coin passage on the basis of an output value of the first coil sensor and an output value of the second coil sensor.

Description

  The present invention relates to a coin identifying device that performs authenticity determination of a coin (coin). In particular, the present invention relates to a coin identifying device capable of identifying a clad coin in which a plurality of types of metals are laminated.

  2. Description of the Related Art Conventionally, in vending machines or the like, a coin identifying device is used to identify the authenticity and type of coins to be inserted. In this coin identification device, the authenticity and type are discriminated by identifying the characteristics of the coin such as the material, thickness and outer diameter of the coin. It is common to use a magnetic field induced by a coil for a sensor that detects the material of a coin. The material sensor oscillates at a frequency at which the magnetic field penetrates into the coin.

  Using a coil to irradiate one side of a coin with a magnetic field of such a frequency, and measuring the frequency and voltage with a coil placed opposite the other side of the coin, characteristics according to the material Can be measured. Incidentally, in addition to coins made of one material, there are known what are called clad coins having a clad structure in which a plurality of types of materials (metals) are laminated, and bicolor clad coins having a central clad structure. ing.

  FIG. 1 shows the configuration of the clad coin Ca. FIG. 1 (A) shows a top view of the clad coin Ca, and FIG. 1 (B) shows a cross-sectional view of the clad coin Ca. The clad coin Ca shown in this figure uses the first metal C1 for the surface layer and the second metal C2 for the center layer.

  FIG. 2 (A) shows a top view of the bicolor clad coin Cb, and FIG. 2 (B) shows a cross-sectional view of the bicolor clad coin Cb. The bicolor clad coin Cb shown in this figure is a coin composed of three kinds of metals (C1 to C3), and uses a first metal C1 at the ring-shaped end portion, The second metal C2 is used for the surface, and the third metal C3 is used for the central layer at the center.

  When detecting the material of such a clad structure, it is not possible to cope with a single frequency, and it is conceivable to use a frequency corresponding to the surface of the coin and a frequency penetrating into the inside of the coin. However, when dealing with a plurality of frequencies, it is necessary to arrange a sensor corresponding to each frequency. Furthermore, in order to avoid the interference of the frequency corresponding to the surface and the inside of the coin, it is necessary to install each sensor at a distance. Considering the number of sensors and the arrangement position in this way, it is not easy to reduce the size of the coin identification device.

  In order to solve such a problem, Patent Documents 1 and 2 disclose that a single sensor can oscillate at a plurality of frequencies. Patent Document 1 discloses that a plurality of oscillators are provided, and the frequency applied to a single coil is switched according to the coin to be measured for oscillation. The coin can be identified by measuring the change in the frequency of the coil when the coin is in the vicinity of the coil. In Patent Document 2, an oscillation coil is oscillated at a plurality of frequencies by a random frequency oscillation circuit, and a reception coil is disposed in the vicinity of the oscillation coil or at a position opposed to each other with a passage interposed therebetween, thereby obtaining a change in the frequency of the reception coil Thus, it is disclosed that a coin is identified.

Japanese Patent No. 5034573 JP-A-8-44926

  The coin discriminating apparatus according to the present invention aims to provide a coin discriminating apparatus capable of switching to a plurality of types of frequencies with a simple configuration and discriminating the above-described coin clad structure. Another object of the present invention is to provide a small money discriminating apparatus without particularly increasing the number of parts of the money discriminating apparatus even when switching to a plurality of types of frequencies is possible.

Therefore, the coin identification device according to the present invention is characterized by the following matters.
A first coil sensor facing a coin path and a second coil arranged facing the first coil across the coin path and forming a resonance system with a first frequency; and
A second coil sensor connected to a third coil facing the coin passage and a fourth coil arranged facing the third coil across the coin passage to form a resonance system at a second frequency;
A switch that enables switching between the first coil sensor and the second coil sensor;
The switch is switched in a time-sharing manner, and control means for identifying the coin that has passed through the coin path based on the output value of the first coil sensor and the output value of the second coil sensor. And

Furthermore, in the coin identification device according to the present invention,
The switch is characterized by switching a resonance system by switching connection between a capacitor, the first coil and the second coil, or the third coil and the fourth coil.

Furthermore, in the coin identification device according to the present invention,
The first coil and the second coil, and the third coil and the fourth coil are arranged concentrically.

  In the coin discriminating apparatus according to the present invention, a coin discriminating apparatus capable of discriminating the clad structure of a coin by switching the frequency of magnetic lines of force applied to the coin to a plurality of types with a simple configuration of switching a plurality of coils with a switch. It becomes possible to provide. Even when switching to a plurality of types of frequencies is possible, the number of parts of the currency identification device is not increased significantly. Furthermore, the response characteristic of the output signal is improved by switching the coil.

The figure which shows the structure of the clad coin used as the identification object of the coin identification device which concerns on embodiment of this invention. The figure which shows the structure of the bicolor clad coin used as the identification object of the coin identification device which concerns on embodiment of this invention. The figure which shows the internal structure of the coin identification device which concerns on embodiment of this invention. Sectional view when cutting the material sensor with respect to the coin passing direction The figure which shows a structure when it sees from a side wall side about a material sensor The figure which shows the structure of the material sensor which concerns on other embodiment. 1 is a circuit diagram of a coin identification device according to an embodiment of the present invention. The figure which shows the oscillation waveform (at the time of coin non-passing) of the coin identification device which concerns on embodiment of this invention. The figure which shows the output waveform (A) of the oscillation circuit at the time of coin passage in the coin identification device which concerns on embodiment of this invention, and the output waveform (B) of a detection circuit (at the time of a single frequency) The figure which shows the output waveform of the detection circuit at the time of coin passage of the coin identification device which concerns on embodiment of this invention (at the time of multiple frequencies) The flowchart which shows the coin identification process of the coin identification device which concerns on embodiment of this invention. The figure for demonstrating the pulse count which concerns on embodiment of this invention

  Now, an embodiment of the coin identification device according to the present invention will be described. FIG. 3 is a diagram illustrating an internal configuration of the coin identifying device according to the embodiment of the present invention, and particularly an internal diagram illustrating the arrangement of various sensors for coin identification. The coin identification device 1 is a device used as a settlement machine such as a vending machine, a ticket machine parking lot, a pay copy machine, and the like, and performs authenticity determination on an inserted coin (coin).

  As shown in FIG. 3, a coin slot 2 is provided in the upper part of the coin discriminating apparatus main body 1, and a coin passage 3 inclined toward the right direction is connected to the bottom of the coin slot 2. An identification sensor 4 is disposed on the side wall of the coin passage 3. In the present embodiment, the identification sensor 4 uses a plurality of sensors 5 to 7 corresponding to the characteristics of coins. In the example of FIG. 3, a material sensor 5, a thickness sensor 6, and an outer diameter sensor 7 are arranged in order from the upstream of the coin passage 3. The coin inserted from the insertion slot 2 rolls through the coin passage 3 by its own weight and passes through the identification sensor 4, whereby its authenticity and type are determined.

  Moreover, the coin identification device 1 has a detection means (not shown) for detecting the output of these identification sensors 4 (5 to 7), and a storage means (not shown) for storing in advance data that serves as a reference for the correctness and type of coins. 2) and a control means for comparing the output from the detection means and the reference data of the storage means to determine whether the coin passing through the coin passage 3 is true or false, the type, and the like. With such a configuration of the coin identification device 1, the coin passing through the coin passage 3 has a material sensor 5 for the material of the coin, a thickness sensor 6 for the coin thickness, and an outer diameter sensor 7 for the outer diameter of the coin. By comparing with the reference data that has been detected and stored in advance in the storage means, the correctness, type, etc. are determined.

  FIG. 4 is a cross-sectional view of the material sensor 5 described in FIG. 3 when cut in the coin currency direction. The coin passage 3 is composed of one side wall 32, a rail 33 positioned below, and the other side wall 31 formed integrally with the rail 33. Further, the coin passage 3 is inclined toward the side wall 32 as shown in the figure, and the coin passing through the coin passage 3 is configured to roll while being inclined toward the side wall 32. By tilting such a coin passage 3, compared with the case where the coin passage 3 is not tilted, flickering of the coin C in the coin passage 3 is suppressed, and the characteristics of the coin C are detected in a stable state. It becomes possible to do.

  The material sensor 5 includes a front sensor 51 and a rear sensor 52 that are installed to face the side walls 31 and 32, respectively. Each sensor 51, 52 has a plurality of coils wound concentrically. In this embodiment, the front sensor 51 has a first front coil 51a and a second front coil 51b, and the rear sensor 52 has a side. Are provided with a first rear coil 52a and a second rear coil 52b. Since the front sensor 51 and the rear sensor 52 have substantially the same configuration, the configuration of the front sensor 51 will be described here.

FIG. 5 is a view of the front sensor 51 as viewed from the side wall 31 in FIG. The front sensor 51 has a ferrite core 51c having two concentric grooves, a first front coil 51a is provided in the inner groove, and a second front coil 51b is provided in the outer groove. Is provided. The two coils 51a and 51b have different inductances by changing the number of turns of the coil. The ferrite core 51c forming the two grooves is provided with a wiring groove, and the lead wire 51d of the first front coil 51a and the lead wire 51e of the second front coil 51b are led out through the wiring groove. Is done. The rear sensor 52 has the same configuration as the front sensor 51.

  The front sensor 51 and the rear sensor 52 of the present embodiment have a configuration in which the arrangement space is suppressed by arranging the two coils concentrically as described above. Further, the magnetic field lines output from the first and second coils are output concentrically, and the material characteristics at the same position of the coin can be detected at each of the two frequencies.

  The front sensor 51 and the rear sensor 52 are disposed so as to face each other with a coin passage formed by the side walls 31 and 32 interposed therebetween. By aligning the coil centers of both the sensors 51 and 52, it is possible to effectively detect a change in magnetic field lines due to the passage of the coin C. In the front sensor 51 and the rear sensor 52, the operating coils are switched by a switch S described later. Specifically, the mode is switched to a first mode in which the first front coil 51a and the first rear coil 52a operate, and a second mode in which the second front coil 51b and the second rear coil 52b operate. As described above, the inductance is set to a different value between the first front (rear) coil 51a (52a) and the second front (rear) coil 51b (52b). In each mode, since a resonance circuit using a common capacitor is formed, magnetic field lines having different frequencies are generated in the first mode and the second mode.

  FIG. 6 shows a configuration of a material sensor 51 (front sensor) according to another embodiment. In the material sensor 51 described with reference to FIGS. 4 and 5, the first front coil 51a and the second front coil 51b are concentrically arranged in each of the two grooves separated by the ferrite core 51c. In the sixth embodiment, the first front coil 51a is arranged around the center core of the ferrite core 51c, and the second front coil 51b is arranged around the first front coil 51a. Even in such a configuration, by switching between the first mode in which the first front coil 51a is operated by the switch S and the second mode in which the second front coil 51b is operated, magnetic lines of force having different frequencies are generated.

  FIG. 7 shows a circuit diagram of the coin identifying device according to the embodiment of the present invention. The coin identification device includes a resonance element 11 including the coils described in FIGS. 4 and 5, an oscillation circuit 10 including a feedback circuit 12, a detection circuit 13, and an MPU 20. The oscillation circuit 10 and the detection circuit 13 are connected by a coupling capacitor C3. The MPU 20 (control means) includes a pulse counter 21, an AD converter 22, a memory 23, and an identification means 24. The MPU 20 receives output signals from the oscillation circuit 10 and the detection circuit 13, and determines the authenticity of the coin, the type determination, etc. The coin identification process is executed.

  The resonance element 11 constituting the oscillation circuit 10 includes a first front coil 51a and a first rear coil 52a, a second front coil 52b and a second rear coil 52b, a capacitor C1, a capacitor C2, and a switch S. The switch S includes a first mode in which the first front coil 51a, the first rear coil 52a and the capacitors C1 and C2 are connected to oscillate at the first frequency, the second front coil 51b, the second rear coil 52b, and the capacitors C1 and C2. To the second mode for oscillating at the second frequency. The connection of the switch S is executed by the MPU 20 as control means. In this embodiment, since the configuration in which the connection of the plurality of coils is switched by the switch S is employed in this embodiment, the response characteristic of the output signal when the switch S is switched is also improved.

The oscillation frequency fc1 (first frequency) in the first mode and the oscillation frequency fc2 (second frequency) in the second mode can be expressed by the following equations.
fc1 = 1 / 2π√ ((Lf1 + Lr1) * (C1 * C2 / (C1 + C2))) (1)
fc2 = 1 / 2π√ ((Lf2 + Lr2) * (C1 * C2 / (C1 + C2))) (2)
However,
Lf1: Inductance of the first front coil Lr1: Inductance of the first rear coil Lf2: Inductance of the second front coil Lr2: Inductance of the second rear coil C1: Capacitance of the capacitor C1 C2: Capacitance of the capacitor C2

  The feedback circuit 12 includes a feedback amplifier circuit configured by an amplifier A1, a resistor R1, and a resistor R2, a transistor Tr1, bias resistors R3, R5, and an emitter resistor R5.

  The detection circuit 13 includes a rectifier circuit including a diode D1 and a diode D2 connected to a coupling capacitor C3 connected to the output of the oscillation circuit 10, and an integration circuit including a resistor R6 and a capacitor C4.

  With such a circuit configuration, the first output signal Sg <b> 1 is output from the oscillation circuit 10 to the pulse counter 21. A second output signal Sg2 is output from the detection circuit 13 to the AD converter 22 of the MPU 20. The AD converter 22 digitizes each received output signal and stores it in the memory 23. The discriminating means 24 executes a coin discriminating process based on each accumulated output signal. Further, the MPU 20 switches the switch S in a time division manner to switch to the first mode in which the resonant element 11 oscillates at the first resonant frequency and the second mode in which the resonant element 11 oscillates at the second resonant frequency. . In this embodiment, each reactance is set so that the first resonance frequency in the first mode is 50 [kHz] and the second resonance frequency in the second mode is 200 [kHz], and The degree of penetration of magnetic lines of force into different coins is different.

  Further, the MPU 20 as the control means switches the switch S every period T (T = 0.5 to 10 [ms] in the present embodiment), so that several coins pass several to several hundreds while passing one coin. It is possible to obtain an output signal at each frequency. FIG. 8 shows an oscillation waveform (when no coin passes) of the coin identification device according to the embodiment of the present invention. By irradiating the coins with magnetic field lines based on such an oscillation frequency, an output signal corresponding to the material of the surface layer portion of the coin passing through in the high frequency period is applied to the material of the deep layer (center layer) portion of the coin in the low frequency period. A corresponding output signal can be acquired.

  9A shows an output signal waveform (capacitor C3 portion) of the oscillation circuit 10 at the time of coin passage in the coin identification device according to the embodiment of the present invention, and FIG. 9B shows an output of the detection circuit 13. A signal waveform is schematically shown. Here, the output signal waveform is obtained when the switch S is not switched and oscillates at a single frequency.

  As shown in FIG. 9A, as the coin passes, the waveform of the output signal attenuates, and the amount of attenuation is maximized in the vicinity where the central portion of the coin passes through the sensor central portion. The detection circuit 13 is a circuit that detects the lower envelope of FIG. 9A, and the lower envelope of FIG. 9A is output as the output signal Sg2 of the detection circuit 13 as shown in FIG. 9B. The In the present embodiment, the maximum value Va of the output signal Sg2 is detected, and compared with the characteristic value of each coin stored in advance, the coin identifying process is executed.

FIG. 10 is a diagram illustrating a waveform of the output signal Sg2 of the detection circuit 13 when the coin passes through the coin identification device according to the embodiment of the present invention. By switching the switch S, the first frequency, the second The case of oscillating at a frequency is shown. It can be seen that two curves having different maximum values are drawn by switching between the first frequency and the second frequency. The first maximum value Va at the first frequency indicates the characteristic value due to the second metal C2 located in the center layer of FIG. 1, and the second maximum value Vb at the second frequency is the surface layer of FIG. The characteristic value by the 1st metal C1 located in will be shown. Therefore, by comparing each maximum value Va and Vb with the characteristic value of each coin stored in advance, it is possible to perform coin identification processing such as authenticity determination and type determination.

  By using the maximum value in this way, the output signal is used in a state where the center of the coin and the material sensor 5 is substantially coincident, that is, a state where the magnetic field lines irradiated by the material sensor 5 are sufficiently irradiated to the coin. Therefore, stable identification processing can be performed. Further, in the case of the bicolor clad coin Cb described with reference to FIG. 2, the clad structure having a plurality of layers is the central part of the coin, and therefore the identification process can be accurately performed on the clad structure by using the maximum value. It becomes possible.

  Further, in the present embodiment, the coin identifying process is executed on the output signal Sg1 near each maximum value based on the frequency characteristics. In this case, by using the output signal Sg1 in the vicinity of the maximum values Va and Vb of the output signal Sg2 described above, similarly stable identification processing is performed, and accurate identification processing for the bicolor clad coin Cb is performed. It becomes possible.

  FIG. 11 is a flowchart showing a coin identifying process of the coin identifying apparatus according to the embodiment of the present invention. Here, although the identification of coins using the material sensor 5 will be described, coins are actually identified including the identification results of the other sensors 6 and 7. In FIG. 3, when it is confirmed that a coin has been inserted from the coin insertion slot 2, this coin identification process is started. In the coin identification process, the amplitude change of the output signal Sg1 is monitored in order to confirm the coin currency in the material sensor 5 (S101). When it is determined that an amplitude change has occurred and the coin has started to pass through the material sensor 5 (S101: Yes), the MPU 20 stores the output signals Sg1 and Sg2 output from the pulse counter 21 and the AD converter 22 in the memory 23. Starts to be written (S102).

  If a certain number of data is stored in the memory 23 after the start of writing (S103: Yes), writing to the memory 23 is stopped, and the process proceeds to the determination processing of S104 to S109. In the present embodiment, determination processing using amplitude values using the second output signal Sg2 (S104 to S105) and determination processing using frequencies using the first output signal Sg1 (S107 to S109) are performed. The determination process can be performed with either the amplitude value or the frequency, but by performing the determination process using both the amplitude value and the frequency in this way, the reliability of the determination process can be improved.

  First, in the determination process based on the amplitude value, the first maximum value (Va in FIG. 10) of the second output signal Sg2 is acquired in S104, and the second maximum value (Vb in FIG. 10) of the second output signal Sg2 in S105. ) Is acquired. Since the MPU 20 controls the switching of the switch S, it is possible to determine in which period the maximum value (first maximum value, second maximum value).

  In S106, the first and second maximum values of Sg2 acquired in S104 are compared with the amplitude reference data stored in advance for each coin type, and the corresponding values, that is, both maximum values fall within a predetermined range. Determine the coin type. If there is no coin type that falls within the predetermined range (S106: No), the processing is terminated assuming that the coin to be identified is not a genuine coin. On the other hand, when there is a coin type that falls within the predetermined range (S106: Yes), determination processing by frequency is further executed.

  The determination process based on the frequency according to the present embodiment is performed by pulse counting. FIG. 12 is a schematic diagram for explaining the pulse count according to the embodiment of the present invention. 12A shows the first output signal Sg1 output from the oscillation circuit 10, and FIG. 12B shows the base clock used in the MPU 20. As shown in FIG. In the determination process based on the frequency according to the present embodiment, the determination is made by comparing the frequency change of the first output signal Sg1 with the base clock of the MPU 20.

  The period of the first output signal Sg1 changes between when the coin is not passing and when the coin is passing. As shown in FIG. 12A, the cycle T2 when the coin passes changes with respect to the cycle T1 when the coin does not pass. In the present embodiment, such a period change (equivalent to a frequency change) is determined based on a comparison with the base clock. The base clock always operates at a constant frequency. Here, the frequency is simply determined based on the number of rises of the base clock in one cycle of the first output signal Sg1.

  The number of rises of the base clock during one cycle (T1) period (between the rises of the pulses) of the first output signal Sg1 when the coin does not pass in FIG. 12 is four as shown by the arrows in the figure. On the other hand, the base clock rises 8 times during one cycle (T2) of the first output signal Sg1 (between the rises of the pulses) when the coin passes as shown in FIG. In practice, it is possible to accurately determine the frequency change of the first output signal Sg1 by performing the processing on the base clock of a large number of pulses.

  The discriminating means 24 performs such frequency determination processing based on the output of the pulse counter 21. When the first maximum value Va in the Ta period (first mode period) in FIG. 10 is detected and the second maximum value Vb in the Tb period (second mode period) is detected, the first maximum value Va is detected. The number of rises of the base clock per cycle of the output signal Sg1 (the number of pulse counts at the first maximum value Va and the number of pulse counts at the second maximum value Vb) is stored, and each is compared with the frequency reference data. Thus, it is possible to perform material determination for each of the deep layer portion and the surface layer portion in the cladding structure.

  Returning to the flowchart of FIG. 11, in S107, the number of pulse counts at the first maximum value Va during the Ta period is acquired. In S108, the number of pulse counts at the second maximum value Vb during the Tb period is acquired. In S109, both the number of pulse counts corresponding to the first maximum value Va acquired in S107 and S108 and the number of pulse counts corresponding to the second maximum value Vb are the frequency reference data of the coin type determined in S106. It is determined whether or not it is suitable. When both counts match the frequency reference data (for example, within the allowable range indicated by the frequency reference data), it is determined that the coin to be identified is a genuine coin and its type (S110). On the other hand, if any one of S107 and S108 does not match the frequency reference data, it is determined that the coin C is not a genuine coin.

  As described above, in the coin identification process of the present embodiment, the determination process based on the amplitude value and the determination process based on the frequency are combined to improve the coin identification accuracy. A form using either value or frequency, or other methods may be adopted. In addition, for the determination processing based on the frequency, it is conceivable to employ various methods such as detecting frequency characteristics by performing frequency conversion such as FFT as well as comparison with the base clock.

  Note that the present invention is not limited to these embodiments, and embodiments configured by appropriately combining the configurations of the respective embodiments also fall within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Coin identification apparatus 2 ... Coin slot 3 ... Coin channel | path 4 ... Identification sensor 5 ... Material sensor 6 ... Thickness detection sensor 7 ... Outer diameter sensor 10 ... Oscillation circuit 11 ... Resonance element 12 ... Feedback circuit S ... Switch 20 ... MPU (Control means)
21 ... Pulse counter 22 ... AD converter 23 ... Memory 24 ... Identification means 31, 32 ... Side wall 51 ... Front sensor 51a ... First front coil 51b ... Second front coil 51c ... Ferrite core 52a ... First rear coil 52b ... Second rear coil 52c ... ferrite core Ca ... clad coin Cb ... bicolor clad coin C1 ... first metal C2 ... second metal C3 ... third metal

Claims (3)

A first coil sensor facing a coin path and a second coil arranged facing the first coil across the coin path and forming a resonance system with a first frequency; and
A second coil sensor connected to a third coil facing the coin passage and a fourth coil arranged facing the third coil across the coin passage to form a resonance system at a second frequency;
A switch that enables switching between the first coil sensor and the second coil sensor;
The switch is switched in a time-sharing manner, and control means for identifying the coin that has passed through the coin path based on the output value of the first coil sensor and the output value of the second coil sensor. A coin identification device. 2. The switch according to claim 1, wherein the switch switches a resonance system by switching a connection between a capacitor, the first coil and the second coil, or the third coil and the fourth coil. Coin identification device. The coin identifying apparatus according to claim 1, wherein the first coil and the second coil, and the third coil and the fourth coil are arranged concentrically.

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