JP2002230616A - Coin identification method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coin identification method and a device therefor enabling the device to be small and to process coins at a high speed with high accuracy. SOLUTION: Light 103 is applied from a light source 102 to the edge of the surface of a coin C dropping in its forward direction through a coin passage 101, and the reflected light 104 from the coin C is inputted to an area sensor 105 to obtain an image signal of the edge of the coin C. The coin C is identified on the basis of the distance between the outer periphery and the projecting patterns of the coin and the distance between the projecting patterns, with the distances calculated respectively by an outer periphery/projecting position detecting part 108 and an inter-projection distance detecting part 109 on the basis of the image signal of the coin C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coin discriminating method and apparatus, and more particularly to a coin discriminating method and apparatus for discriminating coins based on a projection pattern engraved concentrically at equal intervals near the outer periphery of the coin. .

[0002]

2. Description of the Related Art Generally, in vending machines, currency exchange machines and the like using coins, it is necessary to identify the type and authenticity of the inserted coins.

Conventionally, this type of coin discriminating apparatus has one or a plurality of magnetic sensors disposed in a coin passage through which a coin inserted from a coin insertion slot passes, and the material, thickness, and size of the coin are determined by the magnetic sensors. The system is configured to determine the presence or absence of a hole and to discriminate the type and authenticity of the coin based on the determination result.

Further, a configuration has been proposed in which the thickness, size, and the like of a coin are detected by using an optical sensor with an image sensor.

[0005] However, in recent years, a foreign currency having a material and a shape similar to that of a domestic genuine coin has been produced in such a manner that the coin is processed to match the pattern of an optical sensor or a magnetic sensor obtained with the domestic genuine coin. As the processing accuracy has increased, there has been a problem that it is difficult to determine the authenticity of a conventional magnetic sensor or optical sensor. In particular, 50
Since 0 yen coins are high-valued coins, they have become a serious problem due to illegal use of foreign currencies.

Therefore, in order to discriminate this kind of altered coin, it is necessary to identify the coin with higher accuracy, and a method utilizing the features of the pattern of the coin has been proposed.

However, when the pattern on the entire surface of the coin is detected by the optical sensor, the illumination for irradiating the pattern with light becomes large, and the device becomes large accordingly.

In the case where the pattern of a coin rolling in the coin path is detected by an optical sensor, the pattern detected by the rotation of the coin differs. Therefore, the rotation angle is extracted, the rotation is corrected, and the pattern of the coin is corrected. A method of discriminating a pattern or a method of discriminating a pattern by obtaining a feature amount for each region concentrically cut out from the center of a coin has been proposed. However, in each case, the processing becomes complicated, and the processing speed becomes high. Would be difficult.

As an example aiming at miniaturization of the apparatus and high-speed processing, Japanese Patent Application Laid-Open No. 10-83471 discloses a method of detecting a protruding pattern (pearl) engraved concentrically at equal intervals on the edge of a coin. Have been.

[0010]

However, Japanese Patent Application Laid-Open No.
In the related art disclosed in Japanese Patent Application No. 0-83471, since the mounting position of the optical sensor is fixed at a position separated by a predetermined distance from the coin passage, the protrusion pattern of the coin falling freely in the coin passage is detected. In this case, since the coin does not fall freely to a position at a predetermined distance, the pattern of the coin cannot be detected.

Accordingly, the present invention provides a coin discriminating method and apparatus capable of detecting a pattern of a coin that is freely dropped or rolled, and enabling a compact apparatus and high-speed processing with high accuracy. Aim.

[0012]

In order to achieve the above object, according to the first aspect of the present invention, light from a light source is illuminated on the edge of a test coin, and reflected light from the edge is detected by an optical sensor. By receiving the light, an image including the protrusion pattern and the outer periphery of the edge of the test coin is acquired, and a first distance between the outer periphery of the test coin and the protrusion pattern is determined based on the acquired image. A second distance between the protrusion patterns is detected, and the detected first distance and the second distance are measured in advance. The test coins are identified by comparing the coins to be inspected.

Here, the projection pattern is a pattern that is arranged in a circular shape at equal intervals on the edge of a coin.

The outer peripheral portion is an edge portion formed along the outer periphery of the coin, and the first distance is exactly the edge portion of the coin detected based on the reflected light from the coin. It is the distance between the center position of the projection pattern (pearl) in the radial direction of the coin.

Here, the distance between the edge portion of the coin in the image obtained based on the reflected light from the coin and the center position of the protrusion pattern in the radial direction of the coin changes depending on the illumination direction of light from the light source to the coin. However, if the illumination direction of the light from the light source to the coin is constant, the first distance is constant.

According to a second aspect of the present invention, in the first aspect of the present invention, the first distance is such that the projection pattern is aligned with an image including a projection pattern and an outer periphery of an edge of the test coin. The projection calculation in the direction is performed, and the calculation is performed based on the peak-to-peak distance of the one-dimensional waveform obtained from the projection calculation result.

According to a third aspect of the present invention, in the first aspect of the present invention, the second distance is an image including only the protrusion pattern from an image including a protrusion pattern and an outer periphery of an edge of the test coin. And performs a projection operation on an image including only the cut-out projection pattern in a direction orthogonal to a direction in which the projection patterns are arranged, and obtains the image based on a peak-to-peak distance of a one-dimensional waveform obtained from the projection operation result. It is characterized by the following.

Further, according to a fourth aspect of the present invention, there is provided a light source for illuminating the edge of the coin to be inspected, and an edge of the coin to be inspected by receiving light reflected from the edge of the coin to be inspected. An optical sensor for acquiring an image including a projection pattern and an outer periphery of the coin, and first detection means for detecting a first distance between the outer periphery of the test coin and the projection pattern based on the image acquired by the optical sensor. And second detection means for detecting a second distance between adjacent protrusions of the test coin based on an image acquired by the optical sensor, a distance between the outer periphery of the coin to be detected and the protrusion, and Storage means for measuring and storing a distance between adjacent protrusion patterns in advance; and storing the first distance detected by the first detection means and the second distance detected by the second detection means in advance. Between the circumference of the coin to be detected and the protrusion pattern stored in the memory Wherein by comparing the respective distance between the projection pattern pre adjacent characterized by comprising the identifying means for identifying a test coin.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the first detecting means is configured such that the projection pattern is formed on an image including a projection pattern at the edge of the test coin and an outer periphery thereof. Projection calculation means for performing a projection calculation in a line-up direction, and first distance detection means for detecting the first distance based on a distance between peaks of a one-dimensional waveform obtained from a calculation result of the projection calculation means. It is characterized by the following.

According to a sixth aspect of the present invention, in the fourth aspect of the present invention, the second detecting means determines a direction in which the protrusion patterns are arranged from an image including a protrusion pattern and an outer periphery of an edge of the test coin. Position detecting means for detecting the position of, the image cutting means for cutting out an image containing only the projecting pattern based on the position detected by the position detecting means, and an image containing only the projecting pattern cut out by the image cutting means Projection operation means for performing a projection operation in a direction orthogonal to the direction in which the projection patterns are arranged, and 1 obtained from the operation result of the projection operation means.
A second distance detecting means for detecting the second distance based on a distance between peaks of the dimensional waveform.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a schematic configuration of a coin discriminating apparatus according to the present invention.

As shown in FIG. 1, a coin discriminating apparatus according to the present invention comprises a coin passage 101 for dropping a test coin C (hereinafter referred to as a coin C) in a direction indicated by an arrow, and a light 103 on the surface of the coin C. An illumination 102 for irradiation, an area sensor 105 for inputting a reflected light 104 reflected on the surface of the coin C to obtain an image signal of the surface of the coin C, and converting the obtained image signal of the surface of the coin C into a digital image signal An A / D converter 106, an image memory 107 for temporarily storing digitized image signals, and a coin C
The outer periphery / projection position detection unit 108 detects the outer periphery position and the center position of the protrusion pattern, and calculates the distance between the outer periphery and the protrusion pattern, and extracts an area including only the protrusion pattern based on the detected center position of the protrusion pattern of the coin C. A projection pattern distance detecting unit 109 for calculating a projection pattern distance from an image signal in an area including only the projection pattern, and the calculated outer circumference-projection pattern distance and the projection pattern distance are selected in advance. The coin is provided with a coin identification unit 110 for identifying coins by comparing the distance between the outer periphery of the denomination and the projection pattern and the distance between the projections.

In the above configuration, when the coin C is inserted into the coin discriminating apparatus, the coin C falls freely down the coin passage 101. When the coin C that falls freely in the coin passage 101 reaches the position where the area sensor 105 is provided, this is detected by a sensor (not shown), and the light source 103 is turned on based on the detection output of this sensor.

In this case, the lighting time of the light source 103 is set to a short time corresponding to the response time of the area sensor 105, so that the area sensor 105
It is possible to acquire a still image of the coin C that freely falls down 01.

In this embodiment, the coin C is identified based on an image signal corresponding to the still image.

In the above description, the case where the coin C freely falls down the coin passage 101 is shown. However, the coin passage 101 is inclined obliquely, and along the bottom surface of the coin passage 101 inclined obliquely. The coin C can be configured to roll, and in this case also, the instantaneous lighting of the light source 103 allows the area sensor 105 to acquire a still image of the rolling coin C in the same manner as described above.

FIG. 2 is an explanatory view of a projection pattern of a 500 yen coin.

As shown in FIG. 2, the 500-yen coin has concentric projections 201 engraved at equal intervals on the front and back edges. The outer circumference-projection pattern distance 202 of the 500 yen coin is about 1.3 mm. The distance 203 between the projections of the 500 yen coin is about 0.75 mm.

Next, the processing procedure of the coin identification performed by the coin identification device according to the present invention will be described as follows.
An example will be described using a zero yen coin.

Light 103 is emitted from the light source 102 to the edge of the surface of the 500-yen coin falling in the traveling direction along the coin passage 101, and the reflected light 104 reflected from the edge of the surface of the 500-yen coin is area sensor 105. Is input, and an image signal of the edge of the 500 yen coin is obtained. The area sensor 105
Uses a CCD sensor or the like. The acquired image signal of the edge of the 500 yen coin is digitized and output to the outer circumference / projection position detection unit 108 to calculate the outer circumference-projection pattern distance 202 of the 500 yen coin.

Here, since the light source 102 emits light from below to the edge of the surface of the 500-yen coin, in the image obtained by the area sensor 105, the image corresponding to the outer periphery of the coin is: An image corresponding to the inner edge of the edge portion formed along the outer circumference of the coin is formed, and the outer circumference-projection pattern distance 20 detected by the outer circumference / projection position detection unit 108 is obtained.
2 is smaller than the actual distance between the outer periphery and the projection pattern (about 1.3 mm) of a 500 yen coin.

FIG. 3 is a view for explaining the process of calculating the distance between the outer circumference and the projection pattern performed by the outer circumference / projection position detection unit.

FIG. 3A is an image of an edge portion of a 500 yen coin, in which an outer periphery and a plurality of projections of the 500 yen coin are imaged.

As shown in FIG. 3A, the direction in which the projection patterns are arranged is defined as an X direction, and the direction perpendicular to the direction in which the projection patterns are arranged is defined as a Y direction. Then, an X-direction projection operation is performed on the image to create a one-dimensional waveform.

FIG. 3B shows a one-dimensional waveform created by performing a projection operation in the X direction on an image of an edge portion of a 500 yen coin.

As shown in FIG. 3B, since the white pixels are concentrated on the outer periphery of the 500-yen coin and on a portion where a plurality of projections are imaged, it is created by performing a projection operation in the X direction. The one-dimensional waveform has two peaks, two peaks at 5
It shows the outer peripheral position of a 00 yen coin and the center position of a plurality of projections.

From the two peaks of the one-dimensional waveform, the outer peripheral position of the 500 yen coin and the center position of the plurality of projections are detected, and the outer periphery-projection pattern distance 202 is calculated from the distance between the two peaks.

Next, the image signal of the edge of the 500-yen coin and the center position of the plurality of projections detected by the outer periphery / projection position detection unit 108 are output to the inter-projection distance detection unit 109, and the area including only the projection pattern is output. Is extracted.

FIG. 4 is a diagram for explaining a process of extracting a projection pattern area performed by the inter-projection distance detection unit.

FIG. 4A is an image of an edge of a 500-yen coin, and FIG. 4B is an image created by performing a projection operation in the X direction on the image of an edge of a 500-yen coin. It is a dimensional waveform.

Then, an image in the projection pattern area 401 is cut out based on the center positions of the plurality of projection patterns. Where 50
The protruding pattern area 401 of the zero-yen coin is a rectangular area of a preset size, and the protruding pattern area 401 is extracted with the center position of the plurality of protruding patterns detected by the outer periphery / protrusion position detecting unit 108 as the center of the rectangular area.

Next, a projection calculation in the Y direction is performed on the image in the cut-out projection pattern area 401 to calculate the distance 203 between the projection patterns of a 500 yen coin.

FIG. 5 is a diagram for explaining a process in which the inter-projection distance detecting section 109 calculates the inter-projection pattern distance 203.

FIG. 5A is an image of the edge of a 500 yen coin. A projection operation in the Y direction is performed on the image in the cut-out projection pattern area 401 to create a one-dimensional waveform.

FIG. 5B shows a one-dimensional waveform created by performing a projection operation in the Y direction on the image in the projection pattern area 401.

As shown in FIG. 5B, since the white pixels concentrate on the portion where the plurality of projections of the 500 yen coin are imaged, the one-dimensional waveform created by performing the projection operation in the Y direction is It has multiple peaks. Then, from the plurality of peaks of the one-dimensional waveform, the inter-projection pattern distance 203 is calculated from the distance between two adjacent peaks.

The discriminating unit 110 detects the outer periphery-projection pattern distance 202 calculated by the outer periphery / projection position detection unit 108 and the projection pattern distance 203 calculated by the interprojection distance detection unit 109.
Is compared with the distance 202 between the outer circumference and the protrusion pattern 203 and the distance 203 between the protrusion patterns of the 500-yen coin set in advance to identify the coin C.

According to the above configuration, for example, even if the outer periphery-projection pattern distance 202 of a genuine coin and a counterfeit coin is the same, the coin C can be identified from the difference in the projection pattern distance 203. Even if the distance 203 between coins is the same, the coin C can be identified from the difference between the outer circumference and the distance 202 between the protrusion patterns.

[0050]

As described above, according to the present invention, noise and uneven illumination can be obtained by using a projection operation to detect the positions of concentric protrusions engraved at equal intervals on the edge of a coin. This makes it less likely to be affected by density unevenness due to gender, for example, and makes it possible to detect, for example, a projecting pattern of a coin that falls freely in a coin path. In addition, by limiting the projection calculation to the projection pattern area including only the projection pattern, a one-dimensional waveform based on only the projection pattern can be obtained, and highly accurate position detection can be performed. Furthermore, the detection of the outer periphery of the coin and the position of the projecting pattern by the projection operation is simple, and has an effect that high-speed processing can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a coin identification device according to the present invention.

FIG. 2 is an explanatory diagram of a projection pattern of a 500 yen coin.

FIG. 3 is a diagram illustrating a process in which an outer periphery / projection position detector calculates a distance between outer periphery projection patterns.

FIG. 4 is a diagram illustrating a process in which an inter-projection distance detection unit obtains a projection pattern area from an image of an edge of a 500 yen coin.

FIG. 5 is a diagram illustrating a process in which an inter-projection distance detection unit calculates an inter-projection pattern distance.

[Explanation of symbols]

 C coin 101 coin passage 102 light source 103 light 104 reflected light 105 area sensor 106 A / D conversion unit 107 image memory unit 108 outer periphery / projection position detection unit 109 inter-projection detection unit 110 identification unit 201 projection pattern 202 outer periphery-projection pattern distance 203 Projection pattern distance 401 Projection pattern area

Continued on front page F-term (reference) 3E002 AA04 BD01 BD05 CA01 CA07 CA20 5B057 AA01 AA20 BA02 BA17 CA08 CA12 CE09 CH11 DA12 DB02 DB09 DC03 DC19 5L096 AA06 BA08 CA02 CA14 EA35 FA38 FA66 JA24

Claims (6)

[Claims] 1. A method for illuminating light from a light source on an edge of a coin to be tested and receiving a reflected light from the edge by an optical sensor to include a protrusion pattern and an outer periphery of the edge of the coin to be tested. Acquiring an image, based on the acquired image, a first distance between an outer peripheral portion of the test coin and a projection pattern and a second distance between adjacent projection patterns.
And comparing the detected first and second distances with the previously measured distance between the outer peripheral portion of the coin to be detected and the projection pattern and the distance between adjacent projection patterns, respectively. A coin identification method, wherein the test coin is identified. 2. The first distance is obtained by performing a projection operation on an image including a projection pattern and an outer periphery of an edge of the test coin in a direction in which the projection patterns are arranged, and obtaining the projection operation result. 2. The coin identifying method according to claim 1, wherein the coin is determined based on a distance between peaks of the obtained one-dimensional waveform. 3. The method according to claim 2, wherein the second distance is obtained by cutting an image including only the protrusion pattern from an image including the protrusion pattern and the outer periphery of the edge of the test coin, and converting the image including only the cut protrusion pattern into an image including the cut pattern. 2. The coin identification method according to claim 1, wherein a projection operation is performed in a direction orthogonal to a direction in which the projection patterns are arranged, and the projection operation is performed based on a distance between peaks of a one-dimensional waveform obtained from the projection operation result. 4. A light source for illuminating the edge of the test coin with light, and a projection pattern and an outer periphery of the edge of the test coin by receiving light reflected from the edge of the test coin. An optical sensor for acquiring an image, first detecting means for detecting a first distance between an outer peripheral portion of the test coin and a projection pattern based on the image acquired by the optical sensor, and an optical sensor for acquiring the first distance. Second detecting means for detecting a second distance between adjacent protrusion patterns of the test coin based on the obtained image, a distance between an outer peripheral portion of the coin to be detected and the protrusion pattern, and a distance between adjacent protrusion patterns. Storage means for measuring and storing the distance in advance; and a coin to be detected in which the first distance detected by the first detection means and the second distance detected by the second detection means are stored in the storage means in advance. The distance between the outer periphery of the Coin discriminating apparatus characterized by comprising the identifying means for identifying the test coin by comparing each distance between patterns. 5. The projection detection means, wherein the first detection means performs a projection calculation on an image including a projection pattern and an outer periphery of an edge of the test coin in a direction in which the projection patterns are arranged; 5. The coin discriminating apparatus according to claim 4, further comprising: first distance detecting means for detecting the first distance based on a distance between peaks of a one-dimensional waveform obtained from a calculation result of the projection calculating means. 6. The position detecting means, wherein the second detecting means detects a position in a direction in which the projecting patterns are arranged from an image including a projecting pattern and an outer periphery of an edge of the test coin, and the position detecting means. Image cutting means for cutting out an image containing only the protrusion pattern based on the detection position of the projection pattern, and projecting the image containing only the protrusion pattern cut by the image cutting means in a direction orthogonal to the direction in which the protrusion patterns are arranged. Projection calculation means for performing calculation, and second distance detection means for detecting the second distance based on the distance between peaks of the one-dimensional waveform obtained from the calculation result of the projection calculation means. The coin identification device according to claim 4.