JPH0675064U - Deformed coin detector - Google Patents

Abstract

(57) [Abstract] [Object] An object of the present invention is to provide a deformed coin detecting device capable of detecting a deformed coin with high accuracy. According to the present invention, a plurality of detecting units 3 are arranged below a conveying path for coins 2 at predetermined intervals along a width direction of the conveying path and detect a distance to a coin moving on the conveying path.
First processing means for comparing the maximum output value from the output of the detecting means, and second processing means for comparing the position of the maximum output value from the output
Third processing means for comparing the shape of the top portion of the output value
And a fourth processing means for comparing inflection points, and a determination means for determining whether or not the coin is a modified coin from the outputs of the first to fourth processing means. Is characterized by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a modified coin detecting device.

[0002]

[Prior art]

 It is extremely important for coin processing devices such as vending machines to detect and eliminate false coins. However, even genuine coins may be deformed, distorted, chipped, or scratched. Receiving such coins as they are not only causes a jam problem in the coin processing machine, but also causes the loss money to be distributed as it is, which is a serious problem in currency distribution.

[0003]

[Problems to be solved by the device]

 As described above, according to the conventional coin sorting apparatus, various methods have been proposed for detecting counterfeit coins and they have been put into practical use, but there is a problem that no consideration is given to detecting deformed coins. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a deformed coin detecting device capable of detecting a deformed coin with high accuracy.

[0005]

[Means for Solving the Problems]

 In view of this, in the present invention, a plurality of detecting units are arranged below the coin transport path along the width direction of the transport path at predetermined intervals and detect the distance to the coins moving on the transport path. First processing means for comparing the highest output value from the output, second processing means for comparing the position of the highest output value from the same output, and third processing means for comparing the shape of the top portion of the output value. A fourth processing means for comparing the inflection points, and a judging means for judging whether or not the coin is a modified coin based on the outputs of the first to fourth processing means. To do.

[0006]

[Action]

 According to the above configuration, a plurality of sensors such as the reflected light detecting means provided along the width in the conveying direction detect the distance to the coin moving on the conveying path, and the maximum output of the plurality of distance information. Whether the connection of values is less than or equal to a threshold value, what kind of variation the peak position of the maximum output value has, whether the shape of the top part of the output value is flat, how many inflection points According to this, the process is selected and it is determined whether or not it is a modified coin, so that whether or not it is a modified coin can be detected with high accuracy.

That is, when there is one inflection point, it is possible to detect whether or not it is normal by examining the peak value (maximum value) of the second derivative, and when there are two or more, the second floor By checking the peak level (maximum value) of the differential and the output level at the peak position, it is possible to detect with high accuracy whether or not it is normal. This is because even if the Japanese yen, 50-yen, and 100-yen coins have jagged edges and are slightly raised, the rising edge of this edge is detected and the number of inflection points is detected. Will be more than one. Therefore, by detecting the number of inflection points and comparing the magnitudes of the inflection point outputs in accordance with this number, it is possible to easily determine that such a thing is normal.

Further, even if the maximum output is smaller than the threshold value, the peak positions are compared, and the maximum variation of the peak positions of the three sensor outputs is more than the threshold value, or the number of inflection points is If it is larger than one and the shape of the top of the output value is not flat, it is a deformed coin, etc. Since comprehensive judgment can be made from four outputs, it is possible to eliminate misidentification and perform highly accurate detection. You can

Furthermore, if the maximum output value is smaller than the threshold value, the position of the maximum output value is toward the end, or the number of inflection points is one, the normal coin is conveyed obliquely. Even if the number of inflection points is not one, if the shape of the peak of the output value is flat, it is judged to be a normal currency.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1A and 1B are views showing a modified coin detecting device according to an embodiment of the present invention.

Here, a coin 2 is configured to be conveyed in the direction of arrow A on the surface of the abrasion resistant plate 1, and four sensor array ch. 1-ch. 4, a sensor unit 3 configured to detect the passage of coins and a pressing belt 4 that faces the sensor unit and conveys the coins 2 while pressing them are installed, and the output of the sensor unit 3 is processed. It is configured to lead to the circuit 5 and determine whether or not it is a genuine coin.

As shown in the enlarged views of FIGS. 2 (a) and 2 (b), this sensor unit includes the first and second sensor ch. 1, ch. 2 and the third and fourth sensor ch. 3, ch. 4 are equal to each other, and these intervals, that is, the second and third sensor ch. 2, ch. The coins are arranged in a line in the width direction of the coin transport path so that the distance of 3 is 3: 8.

FIG. 3 shows a conceptual diagram of the waveform of this sensor output. For example, in the case of normal coins, the sensor output waveform is close to a rectangular wave as shown in Fig. 3 (a). In addition, if the center of the rectangle projects upward along the transport direction, the top of the rectangular wave will have a concave shape, as shown in Fig. 3 (b). On the other hand, if the peripheral portion is projected upward along the transport direction, the top of the rectangular wave is projected as shown in FIG. 3 (c).

As described above, whether the coin is a normal coin or not is detected by the shape of the detected wave or the like. Next, the algorithm of this process will be described with reference to the flowchart of FIG. First, the coin moves on the sensor unit, and the sensor detects the coin. First, the time when the coin is detected and the signal is output is the data acquisition start time (step A1). The sensor that first detects the coin is used as the reference sensor (step A2). The first to fourth sensor ch. 1-ch. The highest output value is extracted from the outputs of No. 4 and these are compared (step A3). Further, the peak positions are compared (step A4). Then, it is further determined whether or not there is one inflection point of these outputs (step A5), and if there is one, the peak shapes are compared (step A6). The detection is further continued, and it is judged whether or not to enter the next coin detecting step (step A7), and if it is entered, the process returns to step A1.

If it does not enter again, the process ends.

On the other hand, when there is not one inflection point, the peak shapes are compared (step A8), and the outputs of the inflection points are compared (step A9).

Next, the operation of the output processing circuit of this sensor will be described with reference to the flowchart of FIG.

First, the coin moves on the sensor unit, and the sensor detects the coin. The sensor that first detects the coin is used as the reference sensor. The reference sensor is the first to fourth sensor ch. 1-ch. 4 is determined (step S1), and the reference sensor is the second and third sensor ch. 2, ch. 3, the signals for comparing the maximum output peak positions are sent to the first to third sensor ch. 1-ch. 3 and outputs these signals as Sig11, 12, 13 and other processed signals as the second and third sensor ch. 2, ch. 3 and outputs these signals Sig21, 22 (step S2). The reference sensor previously determined the variation t _m of advance threshold V and time as shown in FIG. 7, the reference sensor and Suruga first sensors exceeds a threshold value, threshold within that time t _m If there are two sensors that exceed the value V, those two sensors are used as reference sensors.

It should be noted that the reference sensor is determined here in the case of coins with holes, such as 5 yen and 50 yen, because there are sensors that are affected by the holes, and for coins with a small diameter, the end sensor has an effective output. Since the height may not be obtained, pick up a sensor that is not affected by it. When the number of reference sensors is one, sensor outputs on both sides of the reference sensor are taken out as data. When there are two reference sensors, the two outputs of the reference sensors are used as data.

Further, the reference sensor is the second sensor ch. 2 is the signal for comparing the highest output peak positions, the first to third sensor ch. 1-ch. 3, the respective signals are Sig11, 12, 13 and the other processed signals are the first and third sensor ch. 1, ch. 3 and outputs these signals Sig21, 22 (step S3).

Further, the reference sensor is the third sensor ch. 3, the signal for comparing the highest output peak position is set to the second to fourth sensor ch. 2-ch. 4 and outputs the respective signals as Sig11, 12, 13 and the other processed signals as the second and fourth sensor ch. 2, ch. 4 and outputs these signals Sig21 and Sig22 (step S4).

Then, the maximum output value and the maximum output position of the signals Sig11, 12, 13 are extracted from the outputs of these steps S2-4 (step S5). When there is one reference sensor, the peak values of that sensor and the sensors on both sides are the peak values pk1, pk2, pk3. When there are two reference sensors, the peak value of one of the two sensors and the sensors on both sides is set. The peak values are pk1, pk2, and pk3. The positions of the highest outputs of the signals Sig11, 12, 13 are p1, p2, p3.

Next, the inflection points of the two extracted data are examined. That is, there are four representative examples shown in FIGS. 9 (a) to 9 (d) in which there is one inflection point where the sign of the inclination of the tangent line changes. Here, even if the slope of the tangent changes at the boundary of the flat area as shown in (b), there is only one inflection point. As can be seen from the comparison between Figs. 9 (a) and 9 (b), even when there is only one inflection point, there are cases where the coin is deformed so that it is convex on the sensor side, and when it is a normal coin.

From the outputs of these steps S2-4, the number of inflection points n1, n2 of the signals Sig21, 22 and the inflection point output value V11, ... Are extracted (step S6).

Furthermore, the second-order differential signals d1,2 of the signals Sig21,22 are obtained from the outputs of these steps S2-4 (step S7).

Further, the maximum output values of the outputs of step S5 are compared (step S8). The difference between the peak values pk1, pk2 and pk3 is divided by the inter-sensor distances l ₁ and l ₂ , respectively, and ΔV1 and ΔV2 are obtained and compared.

[0028] ΔV1 = (pk1 -pk2) / l 1 ΔV2 = (pk2 -pk3) / l 2 i.e. [Delta] V = [Delta] V1 -.DELTA.V2 is equal to or larger than the threshold value (Step-up S9). As a result, when .DELTA.V = .DELTA.V1-.DELTA.V2 is smaller than the threshold value as shown in FIG. Therefore, even if the normal coin is conveyed while being inclined, it is prevented from being erroneously recognized as deformation, and in the case of deformation as shown in FIG. 8 (b), it is determined that ΔV1 −ΔV2 is larger than the threshold value and therefore deformation. .

When the difference ΔV between the maximum output values is smaller than the threshold value, the peak positions are compared to calculate the maximum variation Δt in peak position (step S11). In addition, the position of the inflection point should be measured because it is possible to use a normal coin that floats diagonally as in the case of Fig. 9 (c) and (d). Then, the distance Δt between the positions p1 and p2 of the inflection points is taken.

When the maximum variation Δt of the peak position is equal to or less than the threshold value, the process proceeds to the next step S12 shown in FIG.

On the other hand, when the maximum variation Δt of the peak position is large as in the cases of FIGS. 9 (e) and 9 (f) and is equal to or more than the threshold value, it is determined that the coin is a modified coin, and step S of FIG. Proceed to 21.

Further, when the difference ΔV between the maximum output values is larger than the threshold value in step S9, it is determined that the coin is a deformed coin, and the process proceeds to step S21 in FIG.

Further, with reference to FIG. 6, a judgment process in the case where there is little variation in the maximum output value and the maximum peak position and there is a high possibility that the coin is not a deformed coin will be described. Here, the second derivative is performed to see the peak shape.

First, it is judged whether or not there is one inflection point (step S 12), and when the number of inflection points n 1 or n 2 is 1, the peak shapes are compared and the second derivative signal A value (Vc = (V1-V2) / V1) obtained by dividing the difference between the maximum value and the minimum value by the minimum value is obtained (step S13), and it is determined whether or not this value Vc is larger than the threshold value. If it is less than the threshold value (step S14), it is determined to be a normal coin (step S15). Here, as shown in FIGS. 10 (a) and 10 (b), which shows the second derivative in the case of normal and the case of deformation, V2 is 0 in the case of normal coins, whereas in any part of the deformed coins V2 does not become 0.

On the other hand, when both the number of inflection points n1 and n2 are greater than 1 in the inflection point determination step (step S12), the value obtained by dividing the difference between the maximum and minimum values of the second derivative signal by the minimum value ( Vc = (V1-V2) / V1) is calculated (step S16), and it is determined whether or not this value Vc is larger than the threshold value (step S17).

Here, for example, when there are three inflection points, as shown in FIGS. 11 (a) to 11 (c), it is necessary to judge whether these are normal or not. Here, it can be seen that it can be judged whether or not it is normal by checking the peak value change state. Therefore, when the difference is less than the threshold value, the inflection point outputs are further compared and the difference between the maximum and minimum inflection point outputs V is divided by the maximum value (PC = (Vmax-Vmin) / Vmax). Is calculated (step S18), it is judged whether or not this value PC is larger than a threshold value (step S19), and if it is equal to or smaller than the threshold value, it is judged as a normal coin (step S15). .

On the other hand, when it is above the threshold value in step 17 and above the threshold value in step 19, it is judged to be a modified coin (step S21).

Next, a specific modification will be described together with a detection flow.

First, in the case of a deformed coin as shown in FIGS. 12 (a) and 12 (b), the reference sensor S2 is S3, but here, the determination step S9 for determining the variation of the maximum output value is performed. It becomes larger than the value and is judged to be a modified coin.

In the case of a deformed coin as shown in FIG. 12 (c), the number of inflection points is two or more, and the process proceeds to step 19 for comparing variations in the inflection point output, where it is determined that the coin is a deformed coin. Be done.

Further, in the case of a deformed coin as shown in FIG. 12 (d), the reference sensor is ch3, but it is larger than the threshold value in the judgment step S11 for judging the variation of the peak position and is a deformed coin. To be judged.

In the above-mentioned example, the four-channel magnetic head is used as the detection means for detecting the distance, but the number and position of the channels may be changed as appropriate, and instead of this, an LED array and a photo sensor may be used. The distance to the coin may be obtained by using a sensor array or an ultrasonic sensor.

[0043]

[Effect of device]

 As described above, according to the present invention, it is possible to highly accurately detect whether the coin is a normal coin or a modified coin.

[Brief description of drawings]

FIG. 1 is a diagram showing a modified coin detecting device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the device.

FIG. 3 is a conceptual diagram of a sensor output waveform.

FIG. 4 is a flowchart showing an algorithm of processing in the device.

FIG. 5 is a flowchart showing an algorithm of processing in the device.

FIG. 6 is a flowchart showing an algorithm of processing in the device.

FIG. 7 is an explanatory diagram of a data extraction process.

FIG. 8 is an explanatory diagram of peak value check.

FIG. 9 is a diagram showing an example of sensor output when there is one inflection point.

FIG. 10 is a diagram showing a secondary differential value of output.

FIG. 11 is a diagram showing an example of sensor output when there are three inflection points.

FIG. 12 is a diagram showing modified coins and an output example.

[Explanation of symbols]

 1 Abrasion resistant plate 2 Coin 3 Sensor part 4 Holding belt 5 Processing circuit

Claims (1)

[Scope of utility model registration request] 1. A detecting unit, which is arranged below the coin conveying path along the width direction of the conveying path at a predetermined interval and detects a distance to a coin moving on the conveying path; A first processing means for comparing the highest output value from the output, a second processing means for comparing the position of the highest output value from the same output, and a third processing means for comparing the shape of the top portion of the output value of the same output. The processing means and fourth processing means for detecting the inflection point of the output and comparing the detection points are provided, and it is determined from the outputs of the first to fourth processing means whether or not the coin is a modified coin. Deformation coin detecting device comprising: