JP2003196700A - Coin discriminating method, and coin discriminating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coin discriminating method and a coin discriminating device to enable discrimination of coins at high speed and with high precision by discriminating coins based on irregularity patterns formed in coins rolling or dropping along a coin passage. <P>SOLUTION: Light 103 from illumination 102 is radiated to the surface of the coin C, and part of reflection light 104 from the coin C is taken into a line sensor 105, so that a line image of the coin C is obtained. A coin line position detecting part 107 detects a coin line position of the line image, and when the coin line position is at an outer circumferential end part, an interval between protruded patterns is detected by a protruded pattern interval detecting part 109. When the coin line position is at a center part, distance between the protruded pattern and a coin center position is detected by a protrusion pattern position detecting pattern 110. A discrimination part 111 discriminates the coin C based on the detected interval between the protruded patterns and the distance between the protruded pattern and the coin center position. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin discriminating method and a coin discriminating apparatus, and more particularly to discriminating coins based on an uneven pattern formed on the surface of a coin rolling or falling in a coin passage. A method and a coin identification device.

[0002]

2. Description of the Related Art Generally, it is necessary to identify the type and authenticity of inserted coins in vending machines and currency exchange machines that use coins including medals, tokens and IC coins.

Conventionally, a coin discriminating apparatus of this type has one or a plurality of magnetic sensors arranged in a coin passage through which a coin inserted from a coin insertion slot passes to discriminate the material, material, size, etc. of the coin. It has been proposed that the type and authenticity of coins are discriminated based on the discrimination result, and that the thickness, size, etc. of coins are detected using an optical sensor such as an image sensor.

However, in recent years, modified coins made by processing foreign currency, which is similar in material and shape to domestic genuine coins, so as to match the pattern of the optical sensor or magnetic sensor obtained with domestic genuine coins have come around, and the modified coins. As the processing accuracy of No. 1 has increased, there has been a problem that it becomes difficult to determine whether the conventional magnetic sensor or optical sensor is true or false. Especially 50
Since 0 yen coins are high-value coins, they have become a big problem due to illegal use of foreign currencies.

Therefore, in order to discriminate this kind of modified coin, it is necessary to discriminate the coin with higher accuracy, and a two-dimensional image of the surface of the coin is used by using an image area sensor or a line sensor. Has been proposed, and a method of identifying a coin based on the acquired two-dimensional image has been proposed.

[0006] For example, as a conventional technique for identifying a coin based on a projection pattern formed in the outer peripheral edge of the coin at equal intervals in a concentric pattern, in a configuration in which the coin is rotatably conveyed (rolls in an oblique passage), Japanese Unexamined Patent Publication No. 10-83471 discloses a method of detecting the presence or absence of a protrusion pattern on a coin with a sensor fixed at a position separated by a certain distance.

However, according to the method of Japanese Patent Laid-Open No. 10-83471, it is difficult to discriminate coins which the coins orbits are not constant and which freely fall while rotating.

Therefore, a sensor having a relatively wide imaging range such as an area sensor is used to simultaneously image the outer periphery of the coin and the projection pattern, and the distance between the outer periphery of the coin and the projection pattern and the distance between the projection patterns are calculated. The method of doing is proposed.

[0009]

However, when a coin is imaged by the area sensor, the area sensor itself is large, and the illumination necessary for acquiring the image is kept within the imaging range of the area sensor. Since it is necessary to irradiate light from the outside, there is a problem that it is difficult to downsize the device.

Further, in order to find the center of the coin based on the image of the coin acquired by the area sensor, it is necessary to image the edge of the outer periphery of the coin with an area sensor having a large number of pixels, and the acquired image has a large number of pixels. Then, there is a problem that the processing time of data transfer performed pixel by pixel becomes enormous and it becomes difficult to speed up the processing.

On the other hand, when a coin is picked up by a line sensor, there is no problem with downsizing of the apparatus, but since the whole coin cannot be picked up at one time, the whole coin is divided and a line-shaped image is sequentially obtained. The line-shaped images that have been acquired and divided must be combined into one to acquire an image of the entire coin. However, since the passing speed of coins is not constant and some coins also rotate, the image of the whole coin that combines the divided line-shaped images into one deforms,
Even if coins are identified using the deformed image, there is a problem in that highly accurate identification cannot be performed.

Therefore, according to the present invention, coins are sequentially picked up by using a line sensor, and the discrimination processing is performed based on the projected pattern in which the picked-up line-shaped images are concentrically engraved on the outer peripheral edge of the coin at equal intervals. It is an object of the present invention to provide a coin discriminating method and a coin discriminating device capable of performing miniaturization of the device and highly accurate discrimination by performing the above.

[0013]

In order to achieve the above object, the invention of claim 1 is a coin identifying method for identifying a coin moving in a coin passage, wherein an image of the surface of the coin is displayed in a plurality of lines. Acquired as a line image, the line image of the line position including the outer peripheral end of the coin and the line image of the line position including the central portion of the coin are detected from the acquired line images of the plurality of lines, and the detected outer periphery While detecting the interval of the protrusion pattern scattered on the outer peripheral edge of the coin from the line image including the end portion, the feature amount is detected from the line image including the detected center portion, and the detected interval of the protrusion pattern And identifying the coin based on the characteristic amount.

According to a second aspect of the invention, in the first aspect of the invention, the position of the protrusion pattern is the distance between the center of the coin and the protrusion pattern, or the outer peripheral end of the coin and the protrusion pattern. Is characterized by a distance of.

According to a third aspect of the present invention, in the first aspect of the present invention, the relationship between the distance between both ends of the outer periphery of the coin captured in the line images of the plurality of lines and the line position is prepared in advance, and the relationship is provided. The line image at the line position including the outer peripheral end portion of the coin and the line image at the line position including the central portion of the coin are detected based on the above.

The invention of claim 4 is a coin discriminating apparatus for discriminating a coin moving in a coin passage, and an image obtaining means for obtaining an image of the surface of the coin as a line image of a plurality of lines. Line image detection means for detecting a line image at a line position including the outer peripheral end of the coin and a line image at a line position including the central portion of the coin from the line images of a plurality of lines acquired by the image acquisition means, and the line Includes a protrusion pattern interval detecting unit that detects an interval of protrusion patterns scattered on the outer peripheral edge of the coin from a line image including the outer peripheral edge detected by the image detecting unit, and a central portion detected by the line image detecting unit. Based on the feature amount detecting means for detecting the feature amount from the line image, the protrusion pattern interval detected by the protrusion pattern interval detecting means, and the feature amount detected by the feature amount detecting means. Characterized by comprising the identifying means for identifying the coin Te.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, the projection pattern position detecting means is configured such that the distance between the center of the coin and the projection pattern, or the outer peripheral end of the coin and the projection pattern. It is characterized by further comprising a projection pattern distance detecting means for detecting the distance.

The invention according to claim 6 is, in the invention according to claim 4, storage means for storing in advance the relationship between the distance between both ends of the outer periphery of the coin imaged in the line image of the plurality of lines and the line position. The line image detecting means detects a line image at a line position including an outer peripheral end of the coin and a line image at a line position including a central portion of the coin based on the relationship stored in the storage means. It is characterized by

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a coin discriminating method and a coin discriminating apparatus according to the present invention will be described in detail below 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, the coin discriminating apparatus according to the present invention has a coin passage 101 for dropping a coin C to be inspected (hereinafter referred to as coin C) in the direction of the arrow in the figure, and a traveling direction of the coin C. Light 1 is placed vertically on the surface of coin C
03, a line sensor 105 for inputting the reflected light 104 reflected on the surface of the coin C to obtain a linear image of the coin C, and a line image output from the line sensor 105 for digital signal Convert to A /
D conversion unit 106, memory 107 that holds the relationship between the distance between the outer edges of the coin in the line image obtained in advance and the coin line position, and the distance between the outer edges of the line image converted into a digital signal Calculate the distance, memory 1
Coin line position detection unit 108 for detecting the coin line position of the line-shaped image acquired by the line sensor 105 based on the relationship between the distance between both ends of the outer periphery of the coin held in 07 and the coin line position, coin line position detection When the coin line position of the line-shaped image is detected by the unit 108 as the outer peripheral end of the coin C, the protrusion pattern interval detection unit that detects the interval between the protrusion patterns concentrically engraved on the outer peripheral edge of the coin C 109, a protrusion pattern position detection unit 110 that detects the distance between the protrusion pattern of the coin C and the coin center position when the coin line position detection unit 108 detects the coin line position of the line image as the center of the coin C. An identification unit 111 that identifies the coin C based on the interval between the protrusion patterns detected by the protrusion pattern interval detection unit 109 and the distance between the protrusion pattern detected by the protrusion pattern position detection unit 110 and the coin center position. Equipped and are configured.

Next, a processing procedure for coin identification performed by the coin identification device according to the present invention will be described.

In the above structure, when the coin C is inserted into the coin discriminating apparatus according to the present invention, the coin C is transferred to the coin passage 10
Free fall 1 downward. Then, the surface of the coin C that freely falls in the coin passage 101 is irradiated with light 103 from the illumination 102, and part of the reflected light 104 reflected from the surface of the coin is input by the line sensor 105, and a line-shaped image of the coin C is input. To get. Here, it is desirable to use a contact-type sensor module in which the illumination and the line sensor are integrated, because the size can be further reduced.

Then, the line image of the obtained coin C is converted into a digital signal and the coin line position detecting unit 10 is operated.
8 is input, the coin line position detection unit 108 detects which position of the coin C the linear image acquired by the line sensor 105 is based on the linear image. This coin line position detecting method detects the outer peripheral portion of a coin C from a linear image, calculates the distance between the outer peripheral ends of the two detected locations, and calculates the distance between both ends of the outer peripheral and the coin line that are held in memory in advance. The coin line position is detected by the conversion table of the relationship with the position.

Next, FIG. 2 shows a processing procedure from the detection of the coin line position of the line image to the identification of the coin C by detecting the interval between the projection patterns or the distance between the projection pattern and the central position of the coin. This will be described with reference to the flowchart shown.

A line-shaped image is input to the coin line position detection unit 108 (step S201), and the coin line position of the line-shaped image is detected (step S202).

When the coin line position is the center of the coin C (YES in step S203), the protrusion pattern position detection unit 110 determines the distance between the protrusion pattern of the coin C and the coin center position based on the line image. Detected (step S20
4) The detected distance is stored in the identification unit 111 (step S205).

When the coin line position is the outer peripheral end of the coin C (YES in step S206), the projection pattern interval detection unit 109 detects the projection pattern interval of the coin C based on the line-shaped image (step S206). S207), the detected interval is accumulated in the identification unit 111 (step S208).

When the coin line position is a position other than the central portion and the outer peripheral end portion of the coin C (step S206)
No), the line-shaped images other than the central portion and the outer peripheral edge portion are not used for identifying the coin C, and thus these line-shaped images may be deleted or accumulated.

Then, it is confirmed whether or not the line-shaped image remains (step S209). If the line-shaped image remains (YES in step S209), the step S209 is performed.
Returning to step 201, the remaining line-shaped image is processed.

When no line-shaped image remains (NO in step S209), the coin C is accumulated based on the distance between the protrusion pattern of the coin C and the coin center position accumulated in the identification unit 111 and the interval of the protrusion pattern. Is identified (step S2
10).

FIG. 3 is a diagram showing an example of an image in which the line-shaped images of the coin C captured by the line sensor 105 are put together.

FIG. 3 (a) is an example of an image of the coin C without rotation, and FIG. 3 (b) is an example of an image of the coin C with rotation. Here, in order to simplify the explanation, the passing speed of coins is constant.

Here, in the image of FIG. 3A and the image of FIG. 3B, the distance 303 between the protrusion pattern and the coin center position in the line-shaped image 301 in which the center of the coin C is imaged.
Does not change. That is, it can be seen that the distance 303 between the protrusion pattern and the coin center position is not affected by the image deformation due to the rotation.

Further, in the image shown in FIG. 3A and the image shown in FIG. 3B, the projection pattern spacing 304 in the line-shaped image 302 in which the outer peripheral edge of the coin C is imaged does not change.
That is, it can be seen that the protrusion pattern spacing 304 is not affected by the image deformation due to rotation.

Therefore, in the coin discriminating apparatus according to the present invention, the distance 303 between the protrusion pattern and the coin center position which is not affected by the deformation of the image due to the rotation and the interval 304 of the protrusion pattern.
The coin is identified based on.

Next, a method for detecting the interval between the projection patterns performed by the projection pattern interval detection unit 109 and a method for detecting the distance between the projection pattern and the coin center position performed by the projection pattern position detection unit 110 will be described.

FIG. 4 is a diagram showing an example of the grayscale intensity waveform (line-shaped image) acquired from the line-shaped image.

FIG. 4A is a diagram showing an example of an image in which the line-shaped images of the coin C captured by the line sensor are put together. Here, the grayscale intensity waveform in the range of (b) of FIG. 4 (a) is shown in FIG. 4 (b), and FIG.
The grayscale intensity waveform in the range (c) is shown in FIG.

As described above, the projection pattern spacing 304 in the line-shaped image of the outer peripheral edge of the coin C is captured.
Is not affected by the deformation of the image due to rotation,
It is only necessary to extract the edges showing the projection pattern from the grayscale intensity waveform of the outer peripheral edge of the coin C shown in (b) and detect the interval between the extracted edges.

Further, as described above, the distance 303 between the projection pattern in the line image obtained by imaging the central portion of the coin C and the coin center position is not affected by the deformation of the image due to the rotation, and therefore, FIG. The edge showing the protrusion pattern and the coin center position may be extracted from the gray intensity waveform of the central portion of the coin C shown in (c), and the distance between the extracted edge and the coin center position may be detected.

Similarly to the distance between the protrusion pattern and the coin center position, the distance between the protrusion pattern and the outer periphery of the coin C is not affected by the image deformation due to the rotation, so that the coin C shown in FIG. A configuration may also be adopted in which an edge showing a projection pattern and an edge showing the outer periphery of the coin C are extracted from the gray intensity waveform of the central portion and the distance between the extracted edges is detected.

In the present embodiment, as a method of detecting the coin line position of a line-shaped image, the relationship between the end-to-end distance on the outer periphery of the coin and the coin line position which has been obtained in advance is referred to. The coin line position of the maximum linear image may be used as the central portion, and the coin line position of the linear image having the minimum distance between both ends may be the outer peripheral end portion.

[0044]

As described above, according to the present invention, line images of coins are sequentially acquired by the line sensor,
From the line image including the central part of the coin and the line image including the outer peripheral edge of the coin from the acquired line image, the protrusion pattern without being affected by the fluctuation or rotation of the passing speed of the coin. Since it is configured to obtain accurate positions and intervals, it is possible to perform high-speed and high-precision identification processing, and further, it is possible to reduce the size of the device as compared with the configuration using an area sensor.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a processing procedure from detecting a coin line position of a line-shaped image to detecting a gap between projection patterns or a distance between a projection pattern and a coin center to identify a coin C.

FIG. 3 is a diagram showing an example of an image in which line-shaped images of a coin C captured by a line sensor 105 are put together.

FIG. 4 is a diagram showing an example of a grayscale intensity waveform (line-shaped image) acquired from a line-shaped image.

[Explanation of symbols]

C coin 101 coin passage 102 illumination 103 light 104 reflected light 105 line sensor 106 A / D conversion unit 107 memory 108 coin line position detection unit 109 projection pattern interval detection unit 110 projection pattern position detection unit 111 identification unit 301 central part of coin C Image 302 of the line image 302 of the line image of the outer peripheral edge of the coin C 303 distance between the protrusion pattern and the center position of the coin 304 distance between the protrusion patterns

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3E002 AA04 AA06 BD01 BD02 BD05                       CA01 CA06 CA15 EA01 EA05                 5B057 DA11 DB01 DB09 DC03 DC05                       DC16 DC22 DC36                 5L096 AA06 BA03 CA16 FA06 FA14                       FA62 FA64 FA66 FA69

Claims (6)

[Claims] 1. A coin identification method for identifying coins moving in a coin passage, wherein an image of the surface of the coin is acquired as a line image of a plurality of lines, and the coin image of the coin is acquired from the acquired line images of the plurality of lines. A line image at a line position including the outer peripheral edge portion and a line image at a line position including the central portion of the coin are detected, and projections scattered on the outer peripheral edge portion of the coin are detected from the detected line image including the outer peripheral edge portion. Detecting the pattern interval, detecting the position of the protrusion pattern from the detected line image including the central portion, and identifying the coin based on the detected interval of the protrusion pattern and the position of the protrusion pattern. A method for identifying coins. 2. The position of the protrusion pattern is the distance between the center of the coin and the protrusion pattern, or the distance between the outer peripheral end of the coin and the protrusion pattern. How to identify coins. 3. A relationship between the distance between both ends of the outer periphery of the coin captured in the line images of the plurality of lines and the line position is prepared in advance, and the line position including the outer peripheral end of the coin is determined based on the relation. The coin identifying method according to claim 1, wherein a line image and a line image at a line position including a central portion of the coin are detected. 4. A coin identification device for identifying coins moving in a coin passage, comprising: an image acquisition unit that acquires an image of the surface of the coin as a line image of a plurality of lines; and a plurality of images acquired by the image acquisition unit. Line image detecting means for detecting a line image of a line position including the outer peripheral end of the coin and a line image of a line position including the central portion of the coin from a line image of a line, and an outer periphery detected by the line image detecting means Projection pattern interval detection means for detecting the interval of the projection pattern scattered on the outer peripheral edge of the coin from the line image including the end portion, and the projection pattern from the line image including the central portion detected by the line image detection means Projection pattern position detection means for detecting the position, projection pattern interval detected by the projection pattern interval detection means, and projection pattern detected by the projection pattern position detection means Coin discriminating apparatus characterized by comprising the identifying means for identifying the coin based on the position. 5. The projection pattern position detection means further comprises projection pattern distance detection means for detecting a distance between the center of the coin and the projection pattern or a distance between an outer peripheral end of the coin and the projection pattern. The coin discriminating apparatus according to claim 4, wherein 6. The storage device further comprises a storage unit that stores in advance a relationship between the line position and the distance between both ends of the outer periphery of the coin captured in the line images of the plurality of lines, and the line image detection unit is stored in the storage unit. The coin discriminating apparatus according to claim 4, wherein a line image at a line position including an outer peripheral end portion of the coin and a line image at a line position including a central portion of the coin are detected based on the stored relationship.