JP2010134657A - Device and method for coin identification - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate a chip coin without degrading precision caused by the degradation of sensitivity due to the deterioration of dusts or the like even when large amounts of coins are allowed to flow while suppressing the rising of cost. <P>SOLUTION: In the coin identification device, a differential processing unit acquires the differential signal of a coin end by differentiating the output signal of a resonate type thickness sensor, and acquires a difference between the maximum value and minimum value in a prescribed section as an evaluation value about the acquired differential signal, and a memory stores a prescribed reference value, and a comparison unit compares the acquired evaluation value with the stored reference value, and a chip coin discrimination unit discriminates a chip coin based on the comparison results of the comparison unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coin discriminating apparatus having a resonant thickness sensor and a coin discriminating method using the resonant thickness sensor, and in particular, even when a large amount of coins are flowed while suppressing an increase in cost, The present invention relates to a coin discriminating apparatus and a coin discriminating method capable of discriminating a scraped coin without causing a reduction in accuracy due to a sensitivity drop.

  Conventionally, the fraudulent act of stealing merchandise and change from a vending machine using “sharp coins” made by cutting foreign coins of the same material but with a large radius and thickness has been a problem. For example, it has been confirmed that the outer circumference of a 100-won coin (Korea) having a low coin value is cut to the same diameter as the outer diameter of a 100-yen coin (Japan).

  Here, the vending machine is equipped with a coin discriminating device, and in such a coin discriminating device, authenticity determination of a coin is performed using a sensor that detects each component such as the diameter, thickness, and material of the coin with high accuracy. Is going. However, in the case of the above-described shaved coin, the material is the same as that of a genuine coin, and since the diameter and thickness are processed to be the same as those of a genuine coin, it is difficult to separate from the genuine coin.

  For this reason, a technique for detecting a scraped coin by reading the surface of the coin with an optical sensor has been proposed. For example, a technique has been proposed in which an image of a coin surface is acquired by a CIS (Coin Image Sensor), and authenticity determination is performed based on the acquired image pattern.

  Further, Patent Document 1 discloses that the above-described shaving coin is detected by detecting irregularities on the outer peripheral side surface of the coin (hereinafter referred to as “giza”) with a reflective optical sensor provided on the side wall of the conveyance path. A technique for discriminating is disclosed. And in this technique, it determines with the coin in which the jaggedness was not detected on the outer periphery being a shaving coin.

Japanese Patent No. 4157335

  However, when the above-described CIS is used, it is possible to detect a scraped coin with high accuracy. However, since the CIS itself is very expensive, there is a problem that the coin identifying device is also expensive.

  In addition, when a reflective optical sensor is used as in Patent Document 1, although there is no price problem as in the case of CIS, the distance characteristic is poor because it is a reflective type. A mechanism is required. In addition, when a large amount of coins is flowed, there is a problem that the sensor sensitivity is lowered due to dirt due to adhesion of coin powder.

  For these reasons, a coin discriminating device or coin discriminating device that can discriminate a scraped coin without causing a decrease in accuracy due to a decrease in sensitivity due to dust or the like even when a large amount of coins flows while suppressing an increase in cost. How to realize the method is a big issue.

  The present invention has been made in order to solve the above-described problems caused by the prior art. Even when a large amount of coins is caused to flow while suppressing an increase in cost, the accuracy is reduced due to a decrease in sensitivity due to dust or the like. It is an object of the present invention to provide a coin identifying device and a coin identifying method that can discriminate a scraped coin without waking up.

  In order to solve the above-described problems and achieve the object, the present invention is a coin discriminating apparatus having a resonance type thickness sensor, which obtains a differential signal by differentiating the output signal of the resonance type thickness sensor. A reference value storage for storing a predetermined reference value, and an evaluation value acquisition means for acquiring a difference between a maximum value and a minimum value in a predetermined interval as an evaluation value for the differential signal acquired by the differential signal acquisition means And a comparison means for comparing the evaluation value acquired by the evaluation value acquisition means with the reference value stored in the reference value storage means.

  The present invention further includes authenticity determination means for determining that the coin to be identified is a genuine coin when the evaluation value exceeds the reference value in the comparison by the comparison means. It is characterized by that.

  Further, the present invention is the above invention, wherein the evaluation value acquisition means is configured such that the evaluation value when the coin to be identified enters the resonance type thickness sensor and the coin to be identified are the resonance type. The exit evaluation value, which is the evaluation value when exiting from the thickness sensor, is obtained, and the comparison means stores the entry evaluation value and the exit evaluation value in the reference value storage means. It is characterized by comparing with each.

  Further, the present invention is the above invention, wherein the denomination discriminating means for discriminating the denomination of the coin based on the output signal of the denomination discriminating sensor provided on the upstream side in the transport direction with respect to the resonance type thickness sensor. In addition, the comparison unit uses the reference value corresponding to the denomination determined by the denomination determination unit.

  Further, the present invention is a coin identifying method for identifying a coin using a resonance type thickness sensor, wherein a differential signal acquisition step of acquiring a differential signal by differentiating an output signal of the resonance type thickness sensor, and the differentiation An evaluation value acquisition step for acquiring a difference between a maximum value and a minimum value in a predetermined section as an evaluation value for the differential signal acquired by the signal acquisition step, and a reference value storage step for storing a predetermined reference value in a storage unit A comparison step of comparing the evaluation value acquired by the evaluation value acquisition step with the reference value stored in the storage unit.

  In addition, the present invention further includes a true / false determination step of determining that the coin to be identified is a genuine coin when the evaluation value exceeds the reference value in the comparison in the comparison step. .

  According to the present invention, a differential signal is acquired by differentiating an output signal when a coin passes through a resonance type thickness sensor, and a difference between a maximum value and a minimum value in a predetermined section is evaluated for the acquired differential signal. It is obtained as a value, memorized a predetermined reference value, and compared the obtained evaluation value with the memorized reference value. Also, it is possible to discriminate scraped coins without causing a decrease in accuracy due to a decrease in sensitivity due to dust or the like.

  Further, according to the present invention, when the evaluation value exceeds the reference value in the comparison, it is determined that the coin to be identified is a genuine coin, so that it is possible to determine the shaving coin without applying a processing load. There is an effect that can be.

  Further, according to the present invention, an entry evaluation value that is an evaluation value when a coin to be identified enters the resonance type thickness sensor and an exit evaluation that is an evaluation value when the coin to be identified exits from the resonance type thickness sensor. Since the value is acquired and the entry evaluation value and the exit evaluation value are compared with the stored reference values, the discrimination result of the coins is improved by using the comparison result at the time of entry and the comparison result at the time of exit. There is an effect that can be made.

  Further, according to the present invention, the denomination of the coin is determined based on the output signal of the denomination determining sensor provided on the upstream side in the transport direction with respect to the resonance type thickness sensor, and the determined denomination corresponds. Since the reference value is used, there is an effect that it is possible to discriminate cutting coins corresponding to various coins.

  Exemplary embodiments of a coin identifying device and a coin identifying method according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, a case will be described in which a scraped coin is discriminated using an output value of a resonance-type thickness sensor in which coils provided respectively on the upper surface side and the lower surface side of the conveyance path are connected. Such a resonance type thickness sensor is a sensor conventionally used for detecting the thickness of a coin.

  Moreover, below, after describing the outline | summary of the coin identification method which concerns on this invention using FIG. 1, the Example about the coin identification device which applied the coin identification method which concerns on this invention is used using FIGS. I will explain.

  First, the outline | summary of the coin identification method based on this invention is demonstrated using FIG. FIG. 1 is a diagram showing an outline of a coin identification method according to the present invention. Note that (A) in the figure shows a comparison between genuine coins and shaved coins, and (B) in the figure shows an outline of the shading coin discrimination process based on the sensor output value of the resonance type thickness sensor. ing.

  As shown in FIG. 1A, Japanese genuine coins have a slightly thicker and flat edge on the outer periphery of the coin. On the other hand, the shaving coin 1b having the same diameter as the genuine coin by cutting the outer periphery of the foreign coin 1a having a diameter larger than that of the true coin does not have an edge like a true coin.

  Therefore, the coin identification method according to the present invention detects the presence / absence of such an edge based on the sensor output value of the resonance type thickness sensor (hereinafter simply referred to as “sensor output value”), whereby the scraped coin 1b is detected. It was decided to distinguish. Below, the outline | summary of this cutting coin discrimination | determination process is demonstrated.

  As shown in FIG. 1B, the curve 1c indicating the change in the sensor output value when the coin enters the sensing position of the resonance type thickness sensor begins to rapidly decrease from the output value without the coin, It takes a stable value after entering the coin. Here, in the curve portion 1d at the time of entry, in the case of a genuine coin, the slope of the curve 1c changes particularly due to the influence of the edge of the outer peripheral portion.

  For this reason, in the coin identification method according to the present invention, by calculating the differential value of the sensor output value (see (B-1) in the figure), the change in the slope of the curve 1c is detected in more detail. did. Here, a curve 1e shown in the figure is obtained by calculating a differential value by differentiating the curve 1c indicating a change in the sensor output value, and taking the absolute value of the calculated differential value. The curve 1e calculated in this way has a waveform shape that repeatedly rises and falls as shown in FIG.

  Specifically, for example, the curve 1e indicating the differential value of the sensor output value takes the first maximum value at the outermost peripheral portion of the coin and then takes the minimum value 1f at the edge portion of the outer peripheral portion. Then, the second maximum value 1 g is taken at the inner periphery of the edge.

  Here, when the difference between the maximum maximum value 1g and the minimum minimum value 1f in a predetermined section such as the curve portion 1d at the time of entry is an evaluation value (see (B-2) in the figure), there is an edge on the outer peripheral portion. It has been found that a certain genuine coin has a large evaluation value as compared with the sharpened coin 1b having no edge on the outer periphery.

  Therefore, in the coin identification method according to the present invention, the scraped coin 1b and the genuine coin are separated by comparing the evaluation value with a predetermined reference value (see (B-3) in the figure). . Here, the reference value refers to a threshold value prepared in advance for each denomination. The reason why the reference value is prepared for each denomination is that the coin having a larger diameter tends to have a larger edge thickness.

  As described above, in the coin identification method according to the present invention, the scraped coin 1b and the genuine coin are separated based on the output value of the resonance type thickness sensor, which is a magnetic sensor conventionally used for coin thickness detection. The cost increase of the coin identification device can be suppressed. In addition, since the scraped coin 1b is discriminated using a magnetic sensor instead of an optical sensor, even if a large amount of coins is flowed, accuracy is not lowered due to sensitivity reduction due to dust or the like.

  Note that in the coin identification method according to the present invention, evaluation values are acquired not only when coins enter the resonance type thickness sensor but also when coins exit, which will be described later with reference to FIG. 9 and the like. And Below, the Example about the coin identification device to which the coin identification method demonstrated using FIG. 1 is applied is described.

  FIG. 2 is a block diagram illustrating a configuration of the coin identifying device 9 according to the present embodiment. As shown in the figure, the coin identifying device 9 includes a sensor unit 10, a control unit 13, and a storage unit 14. The sensor unit 10 includes a resonance type thickness sensor 11 and a denomination sensor 12. It has more.

  Moreover, the control part 13 is further provided with the differentiation process part 13a, the comparison part 13b, and the cutting coin discrimination | determination part 13c, and the memory | storage part 14 memorize | stores the reference value information 14a. In FIG. 2, only components necessary for explaining the features of the coin identifying device 9 according to the present embodiment are shown, and descriptions of general components such as a transport mechanism are omitted. .

  The sensor unit 10 is a unit including various sensors such as a resonant thickness sensor 11 and a denomination sensor 12. The resonance-type thickness sensor 11 is a thickness sensor having a so-called LC self-excited oscillation circuit. A coil provided on the upper surface side of the conveyance path and a coil provided on the lower surface side are connected in series, and the coil and the capacitor resonate. An LC self-excited oscillation circuit is configured by forming a circuit.

  In the coin identifying device 9, the shaving coin and the genuine coin are separated based on the sensor output value of the resonance type thickness sensor 11. Since a general circuit can be used for the LC self-excited oscillation circuit, description thereof is omitted.

  The denomination sensor 12 is a sensor provided on the upstream side of the conveyance path with respect to the resonance type thickness sensor 11, and is composed of a reflection type material sensor and a transmission type material / diameter sensor. Here, the arrangement and configuration example of each sensor (resonance type thickness sensor 11 and denomination sensor 12) will be described with reference to FIGS.

  FIG. 3 is an external view of the sensor unit 10. In addition, (A) of the same figure shows the top view 10a of the sensor unit 10, and (B) of the same figure shows the side view 10b of the sensor unit 10, respectively. In the figure, a coin 100 to be identified and a conveyance direction 101 of the coin 100 are also shown.

  As shown in FIG. 3A, the coin 100 is transported in the transport direction 101 along the side-by-side transport path wall 31. Further, as shown in FIG. 3B, the coin 100 is transported on a transport path formed by the lower unit upper surface 32c of the sensor unit 10 and the lower surface of the upper unit.

  Here, the upper unit is composed of a side-by-side upper unit 32a and a counter-side-side upper unit 32b. In addition, although the description that the coin 100 is conveyed along the one-side conveyance path wall 31 was performed, the coin 100 is strictly moved to the one-side conveyance path wall 31 as in the case of using an optical sensor. There is no need to keep it along.

  FIG. 4 is a cross-sectional view of the sensor unit 10. In addition, (A) in the figure shows a cross-sectional view when the upper unit is cut in parallel with the transport surface, and (B) in the same figure shows a cross section taken along the b1-b2 shown in (A) of the same figure. A cross-sectional view and (C) of the same figure show a cross-sectional view of the c1-c2 cross section, respectively.

  As shown in FIG. 4A, the side-shifting side upper unit 32a in the b1-b2 cross section has a side-shifting side transmission secondary coil 12a, and the counter-side-shifting side upper unit 32b in the b1-b2 cross section has The counter-shifting side transmission secondary coil 12b is provided.

  Further, a pot core type sensor coil (coin passage upper surface side) 11a constituting the resonance type thickness sensor 11 is provided in the one-side-upper upper unit 32a in the c1-c2 section, and a counter-side-upper side upper unit 32b in the c1-c2 section A pot core type sensor coil (coin path upper surface side) 41a constituting the resonance type material sensor 41 is provided. In the following, “(coin passage upper surface side)” is simply referred to as “(upper surface side)” and “(coin passage lower surface side)” is simply referred to as “(lower surface side)”.

  Further, as shown in FIG. 4B, the lower unit in the b1-b2 cross section has a one-sided transmission side secondary coil 12a, a counter-side-side transmission secondary coil 12b, or a reflection sensor 12d. An exciting primary coil 12c that performs excitation is provided, and a reflection sensor 12d is provided at the center of the exciting primary coil 12c.

  Here, the side-by-side transmission secondary coil 12a and the excitation primary coil 12c are connected to the side-by-side transmission sensor 12L, and the counter-side-by-side transmission secondary coil 12b and the excitation primary coil 12c are connected to the side from the counter-shifting side. Each of the transmission sensors 12R is configured.

  The reflection sensor 12d corresponds to a secondary coil when the primary coil for excitation 12c is a primary coil. The reflection sensor 12d may be configured by a primary coil wound around the outer periphery of the pot core and a secondary coil wound around the center core.

  Further, as shown in FIG. 4C, a pot core type sensor coil (upper surface side) 11a is provided in the shift-side upper unit 32a in the section c1-c2, and a pot core type sensor coil (lower surface side) is provided in the lower unit. 11b is provided so as to face the conveyance path, and the resonant thickness sensor 11 is configured by the pot core type sensor coil (upper surface side) 11a and the pot core type sensor coil (lower surface side) 11b.

  In the c1-c2 cross section, a pot core type sensor coil (upper surface side) 41a is opposed to the counter unit side upper unit 32b, and a pot core type sensor coil (lower surface side) 41b is opposed to the conveyance path in the lower unit. The resonance type material sensor 41 is composed of a pot core type sensor coil (upper surface side) 41a and a pot core type sensor coil (lower surface side) 41b.

  FIG. 5 is a diagram showing a list of sensors. As shown in the figure, the sensors included in the coin discriminating device 9 are roughly classified into “excitation / detection method” and “resonance method” when classified by the sensor method. Here, the side-shift side transmission secondary coil 12a, the counter-side-shift side transmission secondary coil 12b, the excitation primary coil 12c, and the reflection sensor 12d constituting the denomination sensor 12 are classified as “excitation / detection methods”. The Further, the resonance type thickness sensor 11 and the resonance type material sensor 41 are classified as “resonance type”.

  First, sensors classified into excitation / detection methods will be described. The excitation primary coil 12c is applied with a superimposed signal of low and medium frequencies such as 8 kHz and 250 kHz, for example. Then, a sensor output corresponding to 250 kHz detected by the biasing-side transmission secondary coil 12a by applying a signal to the exciting primary coil 12c (see “Transmission (250 kHz) L” in the figure), and the counter-shifting side transmission By combining with the sensor output corresponding to 250 kHz detected by the secondary coil 12b (see “Transmission (250 kHz) R” in the figure), it can serve as a diameter sensor.

  Further, a sensor output corresponding to 8 kHz detected by the biasing-side transmission secondary coil 12a by applying a signal to the exciting primary coil 12c (see “Transmission (8 kHz) L” in the figure) and anti-shifting side transmission A sensor output corresponding to 8 kHz detected by the secondary coil 12b (see “Transmission (8 kHz) R” in the figure) can be combined to serve as a material sensor and a diameter sensor.

  The reflection sensor 12d serves as a reflection type material sensor by using a sensor output corresponding to an 8 kHz signal applied to the exciting primary coil 12c (refer to “reflection (8 kHz)” in the figure). Will be fulfilled.

  Next, sensors classified as resonance methods will be described. For example, a signal of 330 kHz is applied to the pot core type sensor coil (upper surface side) 41a and the pot core type sensor coil (lower surface side) 41b constituting the resonance type material sensor 41, and the sensor output ("resonance material (330 kHz in FIG. ) ”) Is detected.

  For example, a 180 kHz signal is applied to the pot core type sensor coil (upper surface side) 11a and the pot core type sensor coil (lower surface side) 11b constituting the resonance type thickness sensor 11, and the sensor output ("resonance material" Thickness (180 kHz) ") is detected. The resonance type thickness sensor 11 also serves as a material sensor.

  FIG. 6 is a diagram illustrating a circuit example of the denomination sensor. As shown in the figure, the 250 kHz signal generated by the medium frequency transmitter 61a and the 8 kHz signal generated by the low frequency transmitter 61b are added (superimposed) by the adder 61d, and amplified by the current amplifier 61e. And applied to the exciting primary coil 12c.

  The signals induced in the counter-shifting side transmission secondary coil 12b of the counter-shifting side transmission sensor 12R are amplified by the amplifier 62 and output to the HPF (high pass filter) 63a and the LPF (low pass filter) 64a, respectively. The signal passing through the HPF 63a is rectified by the half-wave rectifier 63b and filtered by the LPF (low-pass filter) 63c to be output as a “transmission (250 kHz) L” signal.

  On the other hand, the signal passing through the LPF 64a is output as a “transmission (8 kHz) L” signal after being rectified by the half-wave rectifier 64b and filtered by the LPF (low-pass filter) 64c.

  In addition, the signal induced in the shift-side transmission secondary coil 12a of the shift-side transmission sensor 12L is amplified by the amplifier 65 and output to the HPF (high pass filter) 66a and the LPF (low pass filter) 67a. The signal passing through the HPF 66a is output as a “transmission (250 kHz) R” signal through rectification by the half-wave rectifier 66b and filtering by the LPF (low-pass filter) 66c.

  On the other hand, the signal passing through the LPF 67a is rectified by the half-wave rectifier 67b and filtered by the LPF (low-pass filter) 67c and output as a “transmitted (8 kHz) R” signal.

  The signal induced in the reflection sensor 12d is amplified by the amplifier 68 and output to the LPF (low-pass filter) 69a. The signal passing through the LPF 69a is rectified by the half-wave rectifier 69b and filtered by the LPF (low-pass filter) 69c. Then, it is output as a “reflected (8 kHz)” signal.

  FIG. 7 is a diagram illustrating a circuit example of a resonance type sensor (resonance type thickness sensor 11 and resonance type material sensor 41). As shown in the figure, the resonant thickness sensor 11 is configured by connecting a pot core type sensor coil (upper surface side) 11a and a pot core type sensor coil (lower surface side) 11b in series. The pot core type sensor coil (upper surface side) 11 a and the pot core type sensor coil (lower surface side) 11 b are connected to the LC self-excited oscillation circuit (180 kHz) 71.

  The output from the LC self-excited oscillation circuit (180 kHz) 71 is rectified by the half-wave rectifier 74a and output to the LPF (low-pass filter) 74b. The signal passing through the LPF 74b is added to the offset signal by the adding circuit 74c. It is output as a “resonance material pressure (shifted side)” signal.

  The resonance type material sensor 41 is configured by connecting a pot core type sensor coil (upper surface side) 41a and a pot core type sensor coil (lower surface side) 41b in series, and the pot core type sensor coil (upper surface side) 41a and The pot core type sensor coil (lower surface side) 41 b is connected to an LC self-excited oscillation circuit (320 kHz) 72.

  The output from the LC self-excited oscillation circuit (320 kHz) 72 is rectified by the half-wave rectifier 73a and output to the LPF (low-pass filter) 73b. The signal passing through the LPF 73b is added to the offset signal by the adding circuit 73c. It is output as a “resonance material (anti-shift side)” signal.

  FIG. 8 is a diagram showing a configuration of a pot core type sensor coil. As the pot core type sensor coil, as shown in FIG. 4C, the pot core type sensor coil (upper surface side) 11a and the pot core type sensor coil (lower surface side) 11b constituting the resonance type thickness sensor 11, resonance, There are a pot core type sensor coil (upper surface side) 41a and a pot core type sensor coil (lower surface side) 41b constituting the mold material sensor 41.

  As shown in FIG. 8, the pot core type sensor coil includes a core 81 having a space between the center axis 81 a and the outer periphery, and a bobbin 82. The central portion of the bobbin 82 is hollow, and a coil is wound around the recess on the outer periphery of the bobbin 82. Further, by inserting the cavity of the bobbin 82 into the central axis 81 a of the core 81, a pot core type sensor coil is configured.

  Returning to the description of FIG. 2, the control unit 13 will be described. The control unit 13 is a processing unit that performs the cutting coin discrimination based on the sensor output from the resonance type thickness sensor 11 and the denomination from the denomination sensor 12.

  The differential processing unit 13a obtains a differential signal by differentiating the sensor output of the resonance type thickness sensor 11, and takes the difference between the maximum maximum value and the minimum minimum value of the differential signal in a predetermined section, It is a process part which performs the process which calculates the evaluation value which concerns on cutting coin discrimination | determination.

  Specifically, the differential processing unit 13a differentiates the sensor output of the resonance type thickness sensor 11 and sets the absolute value of the differential value as a differential signal. In addition, the differential processing unit 13a detects a maximum value and a minimum value in a predetermined section (for example, a section where the differential signal decreases rapidly (coin entry section) or a section where the differential signal increases rapidly (coin exit section)). The absolute value of the difference between the maximum maximum value and the minimum maximum value is calculated as the evaluation value, and the calculated evaluation value is output to the comparison unit 13b.

  The comparison unit 13b is a processing unit that performs a process of comparing the evaluation value received from the differentiation processing unit 13a with the reference value information 14a in the storage unit 14. Specifically, the comparison unit 13b performs denomination determination processing based on the signal received from the denomination sensor 12, selects a reference value corresponding to the determined denomination from the reference value information 14a, and selects the selected reference value. And the evaluation value are compared. Then, the comparison result between the reference value and the evaluation value is cut and output to the coin discriminating unit 13c. Here, in the denomination determination process performed by the comparison unit 13b, the corresponding denomination is determined based on the diameter signal and the material signal from the denomination sensor 12.

  The sharpened coin discriminating unit 13c is a processing unit that performs processing for discriminating whether or not the coin 100 related to the evaluation value is a sharpened coin based on the comparison result received from the comparing unit 13b. Specifically, when the evaluation value is larger than the reference value, the shaving coin discriminating unit 13c determines that the coin is not a genuine coin, that is, a shaving coin, and when the evaluation value is equal to or less than the reference value, It is determined that it is a coin.

  The shaving coin discriminating unit 13c is configured to discriminate the shading coin based on the combination of the comparison result between the evaluation value and the reference value in the coin entry section and the comparison result between the evaluation value and the reference value in the coin withdrawal section. Can also be done.

  For example, when the evaluation value is larger than the reference value in both the coin entry section and the coin withdrawal section, the shaving coin discriminating unit 13c can determine that the coin 100 related to the evaluation value is not a shaving coin. When the evaluation value in the coin entry section is larger than the reference value or the evaluation value in the coin exit section is larger than the reference value, it is determined that the coin 100 is not a scraped coin. It is good as well.

  Furthermore, the shaving coin discriminating unit 13c may determine that the coin 100 related to the evaluation value is a shaving coin when the evaluation value is equal to or less than the reference value in both the coin entry section and the coin withdrawal section.

  The storage unit 14 is a storage unit configured by a storage device such as a nonvolatile memory or a hard disk drive, and stores reference value information 14a. The reference value information 14a is information in which a threshold value for each denomination for comparison with an evaluation value is defined as a reference value. In addition, the reference value in the above-described coin entry section and the reference value in the above-mentioned coin exit section can be defined respectively.

  Next, the output signal of the resonance type thickness sensor 11 will be described with reference to FIG. FIG. 9 is a diagram illustrating an output signal of the resonance type thickness sensor 11. The output signal shown on the left side of the figure is a signal for a genuine coin having an edge on the outer periphery. A curve 91 shown on the left side of the figure is a graph showing a time transition of the output signal, and (A-1), (A-2), (A-3) and (B) shown on the right side of the figure. ) Represents the positional relationship between the coin 100 transported in the transport direction 101 and the resonant thickness sensor 11.

  As shown in (A-1) on the right side of the figure, when the outer periphery of the coin 100 begins to enter the resonance type thickness sensor 11, as shown in the left section 91a-91b in the figure, the output signal The value decreases rapidly. Further, as shown in (A-2) on the right side of the figure, when a portion whose inner thickness is thinner than the edge of the coin 100 is detected, as shown in the section 91b-91c on the left side of the figure, output is performed. The degree of decrease in the signal value becomes slightly moderate temporarily.

  When the coin 100 further enters as shown in (A-3) on the right side of the figure, the output signal value rapidly decreases again as shown in the left section 91c-91d in the figure. Subsequently, as shown in (B) on the right side of the figure, when the portion inside the edge of the coin 100 occupies the entire detection range of the resonance type thickness sensor 11, the section 91d-91e on the left side of the figure As shown, the output signal value has a substantially constant value.

  When the coin 100 leaves the resonance type thickness sensor 11, the output signal value increases rapidly in the state (C-3) corresponding to (A-3) (the section 91e on the left side of the figure). In the state of (C-2) corresponding to (A-2) and (A-2), the degree of increase in the output signal value is temporarily moderated (see the section 91f-91g on the left side of the figure). Then, in the state of (C-1) corresponding to (A-1), the output signal rapidly increases again (see the left section 91g-91h in the figure).

  Next, the differential signal of the output signal shown in FIG. 9 will be described with reference to FIG. FIG. 10 is a diagram illustrating a differential signal of the resonance type thickness sensor 11. Note that (A) in the figure shows an output signal 201 and a differential signal 202 for a genuine coin, and (B) in the figure shows an output signal 301 and a differential signal 302 for a shaved coin, respectively. .

  As shown in FIG. 10A, the differential signal 202 in the coin entry section 201a of the output signal 201 for the genuine coin is expressed as a curve connecting a plurality of maximum values and minimum values. Here, assuming that the maximum maximum value in the coin entry section 201a is the maximum value 202b and the minimum minimum value is 202a, the evaluation value in the section is αA indicating the value obtained by subtracting the minimum value 202a from the maximum value 202b. . Similarly, the evaluation value in the coin withdrawal section 201b is βA indicating a value obtained by subtracting the minimum value 202d from the maximum value 202c.

  On the other hand, as shown in FIG. 10 (B), the output signal 301 about the shaving coin in the coin entry section 301a does not have a clear stay like the output signal 201 of the genuine coin. Therefore, the evaluation value αB obtained by subtracting the local minimum 302a from the local maximum 302b is smaller than αA shown in FIG. Similarly, the evaluation value βB in the exit section 301b is smaller than βA shown in FIG.

  Thus, the true coin evaluation value (αA) tends to take a larger value than the shaving coin evaluation value (αB). Moreover, the evaluation value (βA) of genuine coins tends to be larger than the evaluation value (βB) of shaving coins. Therefore, if the evaluation value is compared with a predetermined threshold, it can be determined whether the coin 100 related to the evaluation value is a genuine coin or a shaved coin.

  FIG. 11 is a distribution diagram of samples. In addition, the vertical axis | shaft of the figure has shown the evaluation value at the time of approach, and the horizontal axis of the figure has shown the evaluation value at the time of leaving. Here, the sample is obtained by actually obtaining an evaluation value for a coin that is known in advance as a scraped coin or a genuine coin by the coin identifying device 9.

  As shown in the figure, when a sample is plotted in a two-dimensional space with the vertical axis representing the entry evaluation value and the horizontal axis representing the exit evaluation value, a shaved coin (see “×” in the figure) and a true coin (same as above) It can be seen that they are clearly separated from each other.

  Specifically, in the figure, if the evaluation value at the time of entry is α or less or the evaluation value at the time of exit is β or less, it can be determined that the coin is a shaving coin. In addition, it is good also as determining with a condition that the evaluation value at the time of approach is (alpha) or less and the evaluation value at the time of exit is (beta) or less that it is a shaving coin.

  That is, in the case shown in FIG. 11, the reference value (threshold value) for comparing with the evaluation value at the time of entry is set to α, and the reference value (threshold value) for comparing with the evaluation value at the time of leaving is set to β, Sharpened coins can be separated.

  It may be determined that the coin is a genuine coin on the condition that the evaluation value at the time of entry is larger than the predetermined threshold value α (first condition) and the evaluation value at the time of departure is larger than the predetermined threshold value β (second condition). Good. Further, even if either the first condition or the second condition is not satisfied, it may be determined as a genuine coin. For example, when a new threshold value γ is defined and an expression “evaluation value at entry + evaluation at departure> γ” is satisfied, it can be determined that the coin is a genuine coin.

  Next, the process procedure which the coin identification device 9 performs is demonstrated using FIG. FIG. 12 is a flowchart showing a processing procedure executed by the coin identifying device 9. As shown in the figure, the coin identifying device 9 performs a sensor check of each sensor (step S101).

  If the sensor check result is OK (step S101, Yes), a sensor gain correction value is set for each sensor (step S102). If the determination condition in step S101 is not satisfied (step S101, No), a sensor error is determined (step S114), and the process ends.

  Following step S102, the coin identifying device 9 sets a sensor temperature correction value for each sensor (step S103). If a coin approach is detected by a timing sensor (not shown) or the like (step S104), a denomination determination process based on the sensor output value of the denomination sensor 12 is performed (step S105).

  Then, it is determined whether or not the denomination of the denomination discrimination result corresponds to a deliberate denomination (step S106). If the denomination corresponds to a presumed denomination (step S106, Yes). ), The denomination determination frame is expanded (step S107), and various determination processes are executed (step S108). In addition, when the determination condition of step S106 is not satisfied (step S106, No), it determines with a reject coin (step S113), and complete | finishes a process.

  Here, the determination frame developed in step S107 indicates a threshold group such as a numerical range, an upper threshold, and a lower threshold that can be allowed for each denomination. In addition, various determination processes in step S108 include processes such as a basic magnetic determination process, a basic magnetic combination determination process, a resonant magnetic determination process, and a resonant magnetic combination determination process.

  Specifically, in the basic magnetism determination process, it is determined whether each sensor peak value in the excitation / detection method is within an appropriate numerical range. In the basic magnetic combination determination process, each sensor peak in the excitation / detection method is determined. It is determined whether the combination of values is within an appropriate numerical range.

  In the resonance magnetism determination process, it is determined whether or not each sensor peak value of the resonance method is within an appropriate numerical range. In the resonance magnetic combination determination process, the combination of the sensor peak values of the resonance method is an appropriate value. It is determined whether it is within the range.

  Then, if all the determination results in step S108 are valid (step S109, Yes), a shading coin determination process is executed (step S110). If the determination condition in step S109 is not satisfied (step S109, No), it is determined as a reject coin (step S113), and the process ends. Note that the scraped coin determination process in step S110 will be described in more detail with reference to FIG.

  Following step S110, it is determined whether or not the determination result in step S110 is OK (step S111). If the determination result is OK (step S111, Yes), it is determined as a genuine coin (step S112). ), The process is terminated. On the other hand, when the determination condition of step S111 is not satisfied (step S111, No), it is determined as a reject coin (step S113), and the process ends.

  In the sensor check shown in step S101 of FIG. 12, the sensor level value during standby is detected. If the standby level value is large, the threshold values (α, β, and γ) described with reference to FIG. 11 are used. When the standby level value is small, the correction process for reducing each threshold value is also performed.

  Next, the processing procedure of the shading coin determination process shown in step S110 of FIG. 12 will be described with reference to FIG. FIG. 13 is a flowchart showing the processing procedure of the sharpened coin determination process. As shown in the figure, when the comparison unit 13b acquires the denomination discrimination result from the denomination sensor 12 (step S201), the comparison unit 13b develops the reference value corresponding to the denomination from the reference value information 14a of the storage unit 14. (Step S202).

  Further, the differential processing unit 13a performs differential processing on the output value from the resonance type thickness sensor 11 (step S203), and then obtains an evaluation value by taking the difference between the maximum value and the minimum value of the differential value in a predetermined section. Calculate (step S204).

  Subsequently, the comparison unit 13b compares the evaluation value calculated in step S204 with the reference value of the corresponding denomination developed in step S202 (step S205), and determines whether or not the evaluation value is larger than the reference value. Determination is made (step S206).

  If the evaluation value is larger than the reference value (step S206, Yes), the determination result is OK (step S207), and the process ends. On the other hand, when the determination condition of step S206 is not satisfied (step S206, No), the determination result is NG (step S208), and the process ends.

  In step S206, whether or not the evaluation value is larger than the reference value is set as a determination condition. However, as shown in FIG. 11, whether or not each of the evaluation value at the time of entry and the evaluation value at the time of departure is larger than a predetermined threshold value. It may be set as a determination condition.

  For example, it may be determined that the coin is a genuine coin on the condition that the evaluation value at the time of entry is larger than the predetermined threshold value α (first condition) and the evaluation value at the time of departure is larger than the predetermined threshold value β (second condition). Good. Even if either the first condition or the second condition is not satisfied, the coin is a genuine coin when the predetermined threshold value γ satisfies the expression “evaluation value at entry + evaluation at exit> γ”. It is good also as determining.

  As described above, in the present embodiment, the differential processing unit acquires the differential signal by differentiating the output signal of the resonance type thickness sensor, and the acquired differential signal has a maximum value and a minimum value in a predetermined interval. Is obtained as an evaluation value, the storage unit stores a predetermined reference value, the comparison unit compares the acquired evaluation value with the stored reference value, and the shaving coin discriminating unit is compared by the comparison unit. The coin discriminating apparatus was configured to discriminate the scraped coins based on the result.

  Thus, even if the coins are made to flow in large quantities while suppressing the increase in the cost of the entire coin discriminating apparatus by discriminating the scraped coins using the resonance type thickness sensor used conventionally. It is possible to discriminate a scraped coin without causing a decrease in accuracy due to a decrease in sensitivity due to dust or the like.

  As described above, the coin discriminating apparatus and the coin discriminating method according to the present invention are useful when it is desired to discriminate a scraped coin without causing a decrease in accuracy due to a decrease in sensitivity due to dust or the like even when a large amount of coins is flowed. Especially, it is suitable when it is desired to suppress the cost increase related to coin identification.

It is a figure which shows the outline | summary of the coin identification method based on a present Example. It is a block diagram which shows the structure of the coin identification device which concerns on a present Example. It is a general-view figure of a sensor unit. It is sectional drawing of a sensor unit. It is a figure which shows the list of sensors. It is a figure which shows the circuit example of a money type sensor. It is a figure which shows the circuit example of a resonance type sensor. It is a figure which shows the structure of a pot core type sensor coil. It is a figure which shows the output signal of a resonance type thickness sensor. It is a figure which shows the differential signal of a resonance type thickness sensor. It is a distribution map of a sample. It is a flowchart which shows the process sequence which a coin identification device performs. It is a flowchart which shows the process sequence of a cutting coin determination process.

Explanation of symbols

9 Coin Identification Device 10 Sensor Unit 10a Sensor Unit (Top View)
10b Sensor unit (side view)
11 Resonance type thickness sensor 11a Pot core type sensor coil (upper surface side)
11b Pot core type sensor coil (lower side)
DESCRIPTION OF SYMBOLS 12 Denomination sensor 12a Side-shift side transmission secondary coil 12b Counter-side-shift side transmission secondary coil 12c Excitation primary coil 12d Reflective sensor 12L 13b Comparison unit 13c Sharpened coin discriminating unit 14 Storage unit 14a Reference value information 31 Side feed side conveyance path wall 32a Side feed side upper unit 32b Counter side feed upper unit 32c Lower unit top surface 41 Resonance type material sensor 41a Pot core type sensor coil ( Top side)
41b Pot core type sensor coil (underside)
100 coins 101 transport direction

Claims (6)

A coin identification device having a resonant thickness sensor,
Differential signal acquisition means for acquiring a differential signal by differentiating an output signal of the resonance type thickness sensor;
For the differential signal acquired by the differential signal acquisition means, an evaluation value acquisition means for acquiring a difference between a maximum value and a minimum value in a predetermined section as an evaluation value;
Reference value storage means for storing a predetermined reference value;
Comparing means for comparing the evaluation value acquired by the evaluation value acquiring means with the reference value stored in the reference value storage means. The authenticity judgment means which discriminate | determines that the coin to be identified is a genuine coin when the said evaluation value exceeds the said reference value in the comparison by the said comparison means is further provided. Coin identification device. The evaluation value acquisition means includes
An entry evaluation value that is the evaluation value when the coin to be identified enters the resonance type thickness sensor and an exit evaluation value that is the evaluation value when the coin to be identified exits the resonance type thickness sensor are acquired. And
The comparison means includes
3. The coin identifying device according to claim 1, wherein the approach evaluation value and the exit evaluation value are respectively compared with the reference value stored in the reference value storage unit. A denomination discriminating means for discriminating the denomination of the coin based on the output signal of the denomination discriminating sensor provided on the upstream side in the transport direction with respect to the resonance type thickness sensor;
The comparison means includes
The coin identifying apparatus according to claim 1, 2, or 3, wherein the reference value corresponding to the denomination determined by the denomination determining unit is used. A coin identifying method for identifying a coin using a resonance type thickness sensor,
A differential signal acquisition step of acquiring a differential signal by differentiating the output signal of the resonance type thickness sensor;
About the differential signal acquired by the differential signal acquisition step, an evaluation value acquisition step of acquiring a difference between a maximum value and a minimum value in a predetermined section as an evaluation value;
A reference value storing step of storing a predetermined reference value in the storage unit;
A coin identifying method, comprising: a comparing step of comparing the evaluation value acquired in the evaluation value acquiring step with the reference value stored in the storage unit. 6. The authenticity determination step of determining that the coin to be identified is a genuine coin when the evaluation value exceeds the reference value in the comparison in the comparison step. Coin identification method.

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