JP2002304653A - Method and device for deciding genuiness of article by visualizing ruggedness pattern by using photosensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device, with which the genuiness of an article can be accurately determined in an extremely short time. SOLUTION: The surface of the article to be decided, with which a deciding area is characterized by a ruggedness pattern, is irradiated with almost collimated parallel beams in the direction vertical to the surface, a lightness/darkness pattern visualizing ruggedness on the article surface is provided by forming the image of reflected light from the article surface in the direction of illumination by using a lens, the lightness/darkness pattern is made into one-dimensional video signal group by at least one circle image sensor or radial image sensors of a prescribed number arraying pixels on a circumference while sharing a circle center with the center of the deciding area on the article surface, and the genuiness of the article is decided from the degree of matching between the one-dimensional video signal group and a one-dimensional video signal group in respect to a genuine article.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vending machine, a ticket vending machine, a coin counting device, and the like, which determines the authenticity of an article, such as a coin inserted, whose determination target region is characterized by an uneven pattern. Method and apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, in a vending machine, a ticket vending machine, an ATM (automatic cash withdrawal depositing device), etc., the authenticity of coins is determined by utilizing the difference in electric conductivity and weight of inserted coins. Was to be determined. JP-A-60-201247 and JP-A-3-18.
Japanese Patent Application Publication No. 0992 discloses a technique for accurately detecting the material of a coin using a magnetic sensor. However, there are many foreign coins that are very similar in shape and material to Japanese coins, and there is a problem that these coins are erroneously recognized as domestic coins.

[0003]

In order to solve such a problem, a coin discriminating apparatus using both a magnetic sensor and an optical sensor is disclosed in, for example, JP-A-8-36660. In this prior art, a frame of a pattern represented by a circle or a series of dots near the outer periphery on the concave / convex pattern of the coin is a target for discrimination, but such a frame is often used for foreign coins. is there. Therefore, it is not preferable to select such a frame as a target representing a feature of a coin.
It is the concavo-convex pattern on the inside of the frame that the characteristics of each coin often appear. When the authenticity is determined after visualizing the uneven pattern inside the frame and converting it into a video signal with an image sensor, as in this prior art, when illuminating from a direction inclined with respect to the coin surface, When the coin rotates (displaces in the circumferential direction) about an axis perpendicular to the coin surface, the light and dark pattern obtained by visualizing the concavo-convex pattern changes, making it difficult to determine the authenticity. Further, in the above-described prior art, since the coin surface is viewed from a direction inclined with respect to the coin surface, a circular coin looks like an ellipse, and the light and dark pattern is distorted, and it is necessary to correct this.

Japanese Patent Application Laid-Open No. H11-288777 discloses a technique in which unevenness on a coin surface is directly measured by a displacement sensor or the like and compared with a separately prepared reference unevenness pattern. . In this prior art, it is assumed that the displacement sensor is integrated, but it is difficult with the current state of the art. In addition, since mechanical scanning such as rotation is used, there are drawbacks in that not only long time is required for determination but also accuracy is hardly obtained.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and performs highly accurate discrimination of an article, such as a coin, whose surface to be judged is characterized by an uneven pattern in a very short time. And a device therefor.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a substantially collimated parallel light beam; and a determination target surface in which a determination region is characterized by a concavo-convex pattern is perpendicular to the surface. From the direction, the reflected light from the article surface in the illumination direction is imaged by a lens to obtain a light and dark pattern in which an uneven pattern on the article surface is visualized, and the light and dark pattern is concentric with the center of the determination area on the article surface. And a one-dimensional video signal group with one or more circle image sensors having an arbitrary radius in which pixels are arranged on a circle, and the one-dimensional video signal group and the one-dimensional video signal group for a true article The gist is that the authenticity of the article is determined based on the degree of coincidence.

According to a second aspect of the present invention, there is provided a collimator for collimating light from a light source, and an optical system for illuminating the collimated light from a direction perpendicular to the surface of the article to be determined, in which a determination area is characterized by an uneven pattern. An optical system that forms an image of reflected light from the illuminated article surface in the illumination direction, and a center of a determination area of the article surface, wherein a light-dark pattern of an image of the article surface obtained by the optical system is used as a one-dimensional video signal. One or more circle image sensors having an arbitrary radius in which pixels are arranged on the circumference and sharing a circle center, and a one-dimensional image signal group obtained by the circle image sensor and a true article are obtained. Signal processing means for calculating and calculating the degree of coincidence with the obtained one-dimensional video signal group; and authenticity judgment processing means for judging the authenticity of the article based on the output signal of the signal processing means and outputting an authenticity judgment signal. Yes An authenticity determination apparatus of the article by visualization of the concavo-convex pattern using the optical sensor comprising Te.

According to a third aspect of the present invention, the surface of the article to be determined, in which the determination area is characterized by a concavo-convex pattern, is irradiated with a substantially collimated parallel light from a direction perpendicular to the surface, and reflected from the article surface in the illumination direction. A light-dark pattern is obtained by visualizing an uneven pattern on the article surface by imaging light with a lens, and the light-dark pattern is one-dimensionally formed by a predetermined number of radial image sensors sharing the center of the circle with the center of the determination area on the article surface. Visualization of a concavo-convex pattern using an optical sensor, wherein a video signal group is used, and the authenticity of the article is determined based on the degree of coincidence between the one-dimensional video signal group and the one-dimensional video signal group for a true article. Is a method of determining the authenticity of an article by using

According to a fourth aspect of the present invention, there is provided a collimator for collimating light from a light source, and an optical system for illuminating the collimated light from a direction perpendicular to the surface of the article to be determined in which the determination area is characterized by an uneven pattern. An optical system that forms an image of reflected light from the illuminated article surface in the illumination direction, and a light / dark pattern of an image of the article surface obtained by the optical system as a one-dimensional video signal group, a determination area of the article surface Obtained from a plurality of radial image sensors in which pixels are arranged linearly in the radial direction while sharing the center and the center of the circle, and a one-dimensional video signal group obtained by the radial image sensors and a true article. Signal processing means for calculating and calculating the degree of coincidence with the one-dimensional video signal group; and authenticity judgment processing means for judging the authenticity of the article based on the output signal of the signal processing means and outputting an authenticity judgment signal. Tena An authenticity determination apparatus of the article by visualization of the concavo-convex pattern using the optical sensor.

According to a fifth aspect of the present invention, there is provided a method for judging the authenticity of an article by visualizing an uneven pattern using the optical sensor according to the first or third aspect. It is.

According to a sixth aspect of the present invention, there is provided a device for judging the authenticity of an article by visualizing an uneven pattern using the optical sensor according to the second or fourth aspect, wherein the article is a coin.

[0012]

According to the present invention, an article surface such as a coin is illuminated from a vertical direction with substantially collimated light,
Since the image is formed in the illuminated direction, the same light and dark pattern is obtained despite the rotation (circumferential displacement) about the perpendicular line of the center of the circle of the article as the rotation axis, and the image of the article surface does not have distortion. In addition, since the light / dark pattern is converted into a one-dimensional video signal group by an image sensor and then subjected to signal processing for true / false determination, scanning is performed by electronic technology, and true / false determination can be performed at high speed and with high accuracy. .

According to the first and second aspects of the present invention, an image of an article surface, which is a light and dark pattern obtained by visualizing a concavo-convex pattern on the article surface, is optimal for sharing the center of gravity with the center of the image. A one-dimensional video signal group is formed by a circle image sensor with a large radius (the radius of the circle that best represents the characteristics of the light and dark patterns). It is possible to cope with the rotation (displacement in the circumferential direction) of the light / dark pattern as the rotation axis. The change of the scan start position may be performed by the sensor, or may be realized by changing the position of the first pixel when the video signal is called to obtain the degree of coincidence.

According to the third and fourth aspects of the present invention, an optimal radial grating that shares a center of gravity of a light and dark pattern obtained by visualizing a concavo-convex pattern on an article surface with a center of a determination area on the article surface. A true / false determination of the article is performed by obtaining a one-dimensional video signal group using a line image radial image sensor and obtaining the degree of coincidence of the true article with the one-dimensional video signal group.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to a preferred embodiment of the present invention, taking as an example the determination of the authenticity of a coin.

FIG. 1 shows the basic principle of a coin authenticity determining method and apparatus for converting a coin image by visualizing an uneven pattern into a one-dimensional video signal group using a special image sensor according to the present invention. Figure 2 shows the circle and the circle on the visualized image of the coin.
FIG. 3 is a plan view showing a detection area (represented by a thick line) by an image sensor, and shows a case where there is one circle. FIG. 3 is a plan view showing a detection area (represented by a thick line) of the radial image sensor on the visualized image of the coin, where there are 12 linear image sensors in which pixels are linearly arranged in a radial direction. Is shown. FIG. 4 is a front view showing an apparatus according to an embodiment of the present invention. FIG. 5 is a plan view showing an example of an image sensor using two circles having different radii as a circle image sensor. FIG. 6 shows a case where a two-dimensional radial grid line sensor (a linear image sensor) constituting a radial image sensor is used to generate a one-dimensional video signal group for a true coin using two radial grid line sensors. FIG. 4 is a plan view illustrating an example of an image sensor when detecting.

An uneven pattern is imprinted on the surface of an article such as a coin, an impression, and an engraving. If the article surface is recognized using this uneven pattern as a feature of the article surface, the accuracy of the article authenticity determination can be improved. However, it is difficult to detect the concavo-convex pattern directly at high speed and with high accuracy by the current technology. In the present invention, the uneven pattern is visualized and converted into a light-dark pattern, and is converted into a one-dimensional video signal group by an image sensor. ADVANTAGE OF THE INVENTION According to this invention, visualization of a concavo-convex pattern can be performed instantaneously and conversion of a light-dark pattern into a one-dimensional video signal group can also be performed at high speed and with high precision.

FIG. 1 shows the principle of a method and an apparatus for judging the authenticity of an article by visualizing a concavo-convex pattern using an optical sensor according to the present invention. As shown in FIG. 1, an article surface, for example, a coin 1 surface is illuminated vertically with substantially collimated parallel light 4, and in this illumination direction, reflected light 6 from the article surface is simply imaged by a lens to form an uneven pattern on the article surface. Is obtained. The light / dark pattern 7 representing the article surface, for example, a coin image, is converted into a one-dimensional video signal group by the image sensor 8. The degree of coincidence between the one-dimensional video signal of the surface of the article to be determined and the one-dimensional video signal of the true article is checked to determine the authenticity. In the present invention, the article surface, for example, the coin surface is illuminated from a direction perpendicular to the surface. However, if it is almost vertical including the inclination of the error range from the vertical line with respect to the coin surface, there is no practical problem, and these are included. .

As described above, if the coin surface is illuminated with parallel light from a direction perpendicular to the coin surface and an image is formed in the illumination direction, rotation (circumferential displacement) about the vertical line of the coin center of rotation as a rotation axis is obtained. Even so, the same light and dark pattern without distortion can be obtained. However, the light / dark pattern is also rotated by the rotation of the coin. However, in a general image sensor, a light-dark pattern is converted into a time-series signal, so it is difficult to recognize that the rotated pattern is the same even for the same pattern.

Therefore, according to the first and second aspects of the present invention, a circle image sensor in which pixels are arranged in a circle as shown in FIG. 2 is used as the image sensor. Of the light and dark patterns, only the light and dark distribution on a circle having a radius r that best represents the feature is used as a video signal. As a result, a one-dimensional video signal that best represents the characteristics of the light-dark pattern obtained by visualizing the article surface, for example, the coin surface, is obtained. By changing the position of the pixel at which the circle image sensor starts scanning, the rotation of the light and dark pattern can be corrected. Alternatively, when a reference video signal, which is a one-dimensional video signal for a true article surface, for example, a coin surface, is called, the same effect can be obtained only by changing the position of the first pixel. In FIG. 2, reference numeral 21 denotes a detection area by the circle image sensor.

According to the third and fourth aspects of the present invention, a radial image sensor in which the radial grid lines are made of a linear image is used. In a radial image sensor, grid lines of a radial grating are linear image sensors, and are integrated by semiconductor technology.

The radial image sensor is designed and used as follows. A reference signal is a video signal from a radial grid sensor (linear image sensor) in the radial direction that well represents the characteristics of a true coin. When θ is set, the optimal number n of the radial grid line sensors in the radial direction is an integer value satisfying n> 360 / θ. The number of radial grid line sensors is such that the video signal corresponding to any linear sensor of the radial grid line in the radial direction in the video signal group for the determined coin detected by the image sensor having the optimum value is the reference video signal. If they match, it is determined that the coin is a true coin. If the coin to be determined is a true coin, the same video signal as the reference signal is detected by any radial grating sensor in the radial direction, even if the light and dark pattern is rotating around the vertical line of the coin center of rotation. It should be possible. Therefore, the problem of the rotation of the light / dark pattern due to the rotation of the coin can be solved. In FIG. 3, reference numeral 31 denotes a detection area by the radial grid line sensor in the radial direction.

As shown in FIG. 3, assuming that the light and dark distribution in the radial direction (1) best represents the characteristics of this coin, a one-dimensional video signal in this radial direction for a true coin is referred to as a reference signal. And Even if the coin to be determined is true, if it rotates around the vertical line of the center of the circle, the one-dimensional video signal obtained by the radial image sensor will cause The video signal does not match the reference signal. However, as described above, the optimal number (1)
If (12) is adopted, one of the one-dimensional video signal groups by a number of radial grid line sensors matches the reference video signal. Thus, the authenticity can be determined even if the determined coin is rotating.

[0024]

FIG. 4 shows an embodiment of a coin authenticity judging device by visualizing a concavo-convex pattern using an optical sensor according to the present invention. In FIG. 4, 1 is a coin, 2 is a light source,
In this embodiment, the light source is a point light source. Reference numeral 3 denotes a collimator lens, which functions as a means for collimating light from the light source 2. Reference numeral 4 denotes parallel light, which is substantially collimated light. Reference numeral 5 denotes a half mirror, which functions as means for reflecting the collimated light and illuminating the coin 1 surface vertically. Reference numeral 6 denotes reflected light from the coin surface. 7
Is a light / dark pattern (coin image) of a coin, which is made into a one-dimensional video signal group by the image sensor 8.

Reference numeral 9 denotes a video signal pre-processing unit which normalizes, further binarizes, and inverts the one-dimensional video signal obtained by the image sensor 8 as necessary. Reference numeral 11 denotes a correlation processing unit that calculates a correlation between the detected video signal directly or after the image processing and the reference video signal 10 obtained for a real coin. Reference numeral 12 denotes a true / false judgment processing unit, which judges the authenticity of the coin based on the output signal of the correlation processing unit 11 by comparing it with a threshold and outputs the result as a judgment signal.

In this embodiment, when the degree of coincidence between the one-dimensional video signal of the coin to be determined and the one-dimensional video signal of the true coin is obtained, a correlation calculation processing method by the correlation processing unit 11 is employed. I have. A one-dimensional video signal for a true coin by the special image sensor 8 described above is recorded as a reference signal 10. By calculating the correlation between the one-dimensional video signal for the determined coin and the reproduced reference video signal, the degree of coincidence can be obtained.

Generally, used coins are dirty or have many small scratches. These become noises of a light and dark pattern obtained by visualizing the coin surface. This noise causes an error in calculating the correlation between the one-dimensional video signal for the determined coin and the reproduced reference video signal. Therefore, preprocessing is performed by the video signal preprocessing unit 9. First, normalization and smoothing (smoothing) of one-dimensional video signals
Perform processing to binarize. By these processes, noise due to dirt and scratches can be almost removed, and erroneous determination due to fluctuation in illumination can be avoided. Furthermore, since the light-dark pattern has many bright parts, the accuracy is improved by inverting the light-dark. These pre-processing can be performed by hardware. In other words, the brightness of the entire light and dark pattern is detected by the point image sensor, and the image signal is divided by this to normalize the image. Can be corrected.
Smoothing (smoothing) can be realized by defocusing the imaging lens and blurring the image. Binarization can be realized by using the nonlinearity of the image sensor. Also,
Inversion of light and darkness can be performed by circuit technology.

The reference video signal requires the front and back of the coin. If a circle image sensor having two circles of radii r ₁ and r ₂ made of a set of pixels as shown in FIG. 5 is used, the accuracy of authenticity determination can be increased. In FIG. 5, reference numeral 51 denotes a detection area by the circle image sensor. Similarly, a one-dimensional video signal group by two radial grid line image sensors as shown in FIG. 6 is adopted as a reference signal, and a one-dimensional video signal group for the determined coin and a reproduced reference video signal group are compared. When the degree of coincidence is obtained, the accuracy of the authenticity determination can be increased.
In FIG. 6, reference numeral 61 denotes a detection area by the radial grid line image sensor.

Although the present invention has been described with reference to the embodiment for determining the authenticity of a coin, it is apparent from the above description that the present invention can be applied to an article surface such as an impression or an engraving which is characterized by a concavo-convex pattern. Will.

[0030]

According to the present invention, since the authenticity of an article is determined by using the features of a concave / convex pattern imprinted on the surface of the article, for example, coins, engravings, and impressions, the present invention can be performed in a short time and with high accuracy. The authenticity of the article can be determined. The surface of the article targeted by the present invention is finely stamped, and it is considered very difficult to manufacture a counterfeit article imitating the stamp, and the present invention has a great effect.

According to the first and second aspects of the present invention, an image of a coin, which is a bright and dark pattern obtained by visualizing a concave / convex pattern on the surface of an article, for example, a coin surface, is defined by the center of the image and the center of the circle. Since a one-dimensional video signal is generated by a circle image sensor with the radius of the circle that best represents the characteristics of the shared light and dark pattern, simply changing the start position of the scan, the light and dark with the vertical axis of the coin circle as the rotation axis It can respond to the rotation of the pattern (displacement in the circumferential direction).

According to the third and fourth aspects of the present invention, a light and dark pattern obtained by visualizing a surface of an article, for example, a concave and convex pattern of a coin, is converted into an optimal radial grid line sharing a center of gravity with the center of the coin. The number of radial image sensors is used to generate a one-dimensional video signal group, and by determining the degree of coincidence of the true coin with the one-dimensional video signal group, the authenticity of the coin is determined. It is easy and makes it possible to make a true and false judgment of coins.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the principle of an article authenticity determination method and apparatus by visualizing a concavo-convex pattern using an optical sensor according to the present invention.

FIG. 2 is a plan view showing an example of a detection area by a circle image sensor for converting an image (light / dark pattern) obtained by visualizing an article surface into a one-dimensional video signal in the present invention.

FIG. 3 is a diagram showing a radial image for converting an image (light and dark pattern) obtained by visualizing an article surface into a one-dimensional video signal group according to the present invention.
Plan view showing an example of a detection area by an image sensor

FIG. 4 is a front view showing an embodiment of the apparatus for judging the authenticity of an article by visualizing an uneven pattern according to the present invention;

FIG. 5 is a plan view showing a detection area by an image sensor using two circles having different radii as a circle image sensor in the present invention.

FIG. 6 is a plan view showing a detection area when a reference image signal group is obtained by adopting two radial grating sensors (linear image sensors) in the radial direction constituting the radial image sensor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coin 2 Light source 3 Collimator lens 4 Parallel light 5 Half mirror 6 Reflected light 7 Coin surface light / dark pattern 8 Image sensor 9 Video signal pre-processing part 10 Reference video signal 11 Correlation processing part 12 True / false judgment part 21 Detection area 31 Detection Area 51 Detection area 61 Detection area

Claims (6)

[Claims] 1. A substantially collimated parallel light illuminates a surface of an article to be determined, in which a determination area is characterized by a concavo-convex pattern, from a direction perpendicular to the surface, and forms an image of light reflected from the article surface by a lens in the illumination direction. To obtain a light and dark pattern obtained by visualizing the concavo-convex pattern on the article surface. The light and dark pattern is formed by sharing one or more circles with the center of the judgment area on the article surface and having at least one arbitrary radius in which pixels are arranged on the circumference. A one-dimensional video signal group by the circle image sensor of claim 1, wherein said one-dimensional video signal group and a one-dimensional video signal group corresponding to a true article are used to judge the authenticity of the article. A method of judging the authenticity of an article by visualizing an uneven pattern using a sensor. 2. A collimator for collimating light from a light source, an optical system for illuminating the collimated light from a direction perpendicular to the surface of an article to be determined in which a determination area is characterized by an uneven pattern, and An optical system that forms an image of the reflected light in the illumination direction, and the center and the circle of the determination area of the article surface, where the center of the determination area on the article surface and the light / dark pattern of the image obtained by the optical system are a one-dimensional video signal. One or more circle image sensors having an arbitrary radius in which the pixels are arranged on a circle sharing the heart, and a one-dimensional video signal group obtained by the circle image sensor and a true article are obtained. Signal processing means for calculating and calculating the degree of coincidence with the one-dimensional video signal group; and authenticity judgment processing means for judging the authenticity of the article based on the output signal of the signal processing means and outputting an authenticity judgment signal. Become A device for determining the authenticity of an article by visualizing an uneven pattern using an optical sensor. 3. A surface of an article to be determined, in which a determination area is characterized by an uneven pattern with substantially collimated parallel light, is illuminated from a direction perpendicular to the surface, and reflected light from the article surface is imaged by a lens in the illumination direction. A radial image sensor comprising a predetermined number of radial radial grid line sensors sharing a center of gravity with the center of the determination area on the article surface, thereby obtaining a light-dark pattern in which the uneven pattern on the article surface is visualized. And a one-dimensional video signal group, and the authenticity of the article is determined based on the degree of coincidence between the one-dimensional video signal group and the one-dimensional video signal group for a true article. A method for determining the authenticity of an article by visualizing the pattern. 4. A collimator for collimating light from a light source, an optical system for illuminating the collimated light from a direction perpendicular to the surface of the article to be determined in which a determination area is characterized by an uneven pattern, and An optical system that forms an image of the reflected light in the illumination direction, and a light-dark pattern of an image of the article surface obtained by the optical system as a one-dimensional video signal group. A plurality of radial image sensors in which pixels are linearly arranged in a radial direction, and a one-dimensional video signal group obtained by the radial image sensor and a one-dimensional video signal group obtained by a true article surface; An optical sensor having signal processing means for calculating and calculating the degree of coincidence and authenticity judgment processing means for judging the authenticity of an article based on an output signal of the signal processing means and outputting an authenticity judgment signal is used. Irregularities A device for judging the authenticity of goods by visualizing turns. 5. The method for judging the authenticity of an article by visualizing an uneven pattern using the optical sensor according to claim 1, wherein the article is a coin. 6. An apparatus for judging the authenticity of an article by visualizing an uneven pattern using the optical sensor according to claim 2 or 4, wherein the article is a coin.