JPH1091836A - Device for identifying coin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the discriminating performance of a coin by exactly extracting the rotation angle of the coin. SOLUTION: This device is provided with a dictionary storage part 9 for primary matching which has comparison data constituted of only patterns aperiodic in a coin circumferential direction, and a primary matching part 8 which operates the rotation matching of the multilevel picture data of a coin 1 to be identified with the comparison data of the dictionary storage part 9 for the primary matching, and extracts the rotation angle of the coin 1. Also, the device is provided with a rotation correcting part 10 which corrects the rotation angle of the multilevel picture data so as to be turned into a preliminarily decided desired angle based on the rotation angle of the coin 1. Then, secondary matching is operated after the rotation angle is corrected, and the authenticity of the coin 1 is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin discriminating apparatus, and more particularly to a coin discriminating apparatus for discriminating the authenticity of coins and medals.

[0002]

2. Description of the Related Art Conventionally, in this type of apparatus, the material and
Coins were identified based on their characteristics such as thickness, presence or absence of holes, and outer diameters.In recent years, however, foreign coins with similar materials and outer diameters have become more likely to be mixed in. The likelihood of recognition is high.

[0003] Accordingly, a technique has been proposed for identifying coins based on the features of the pattern on the coin surface. Among them,
There are some coin patterns that match a pattern on the coin surface with a pattern registered in advance.

[0004]

However, since coins are circular objects, when performing pattern matching, it is necessary to match the pattern on the coin surface or the registered pattern while rotating based on the center of the coin. Was. When the pattern on the coin surface is matched, the pattern on the coin surface contains a pattern with periodicity in the circumferential direction of the coin, so even if the rotation angle of the coin is different, And the pattern with periodicity matches,
Even when the rotation angles are different, there is a problem that the matching rate increases and the coin recognition performance decreases.

[0005]

SUMMARY OF THE INVENTION The present invention provides a pattern reading unit for capturing a surface pattern of a coin as an image signal, an A / D conversion unit for converting the image signal into multi-valued image data, and a multi-valued image data. And a pattern memory unit for storing coins based on the multi-valued image data. A dictionary storage unit for next matching is provided, and rotational matching between the multi-valued image data stored in the pattern memory unit and the dictionary data stored in the dictionary storage unit for primary matching is performed.
A primary matching unit for extracting a rotation angle of a coin is provided. Based on the rotation angle of the coin output from the primary matching unit, a rotation angle of the multi-valued image data stored in the pattern memory unit is determined in advance. A rotation correction unit for correcting the angle to a desired angle is provided, a dictionary storage unit for secondary matching storing comparison data for secondary matching for coin authenticity determination is provided, and the dictionary storage unit for secondary matching is provided. , And a secondary matching unit for determining the authenticity of the coin is provided.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 1 denotes a coin to be recognized. Reference numeral 2 denotes a pattern reading unit which captures a surface pattern of the moving coin 1 as an image signal. For example, a two-dimensional sensor such as a CCD camera or a one-dimensional sensor such as a CCD linear sensor is used.

Reference numeral 3 denotes an A / D converter, which uses an A / D converter for converting an image signal into multi-valued image data. Reference numeral 4 denotes a pattern memory unit, and the A / D conversion unit 3
Is a memory for temporarily recording the multi-valued image data output from. Reference numeral 5 denotes a center / diameter extracting unit,
From the image data stored in the pattern memory unit 4,
The center and outer diameter of the coin 1 are calculated by a known method.
For example, the sum of the values of the image data in the specific direction is obtained, and the center and the diameter of the coin 1 are calculated from the change point.

A coin type discriminating unit 6 discriminates the type of the coin 1 based on the outer diameter data of the coin 1 output from the center / diameter extracting unit 5. For example, the outer diameter of an existing coin is recorded in a coin diameter storage unit (not shown) in advance, and the coin type is determined by comparing the outer diameter with the outer diameter. Numeral 7 denotes a position correcting unit which, based on the data of the coin center position outputted from the center / diameter extracting unit 5, determines the position of the multi-valued image data stored in the pattern memory unit 4 and the center of the coin and the center of the image data. Correct so that the positions are equal.

Reference numeral 8 denotes a primary matching unit, which performs rotational matching between the data stored in the pattern memory unit 4 and the dictionary data stored in the primary matching dictionary storage unit 9 to determine the rotation angle of the coin and the primary rotation. Output next output. 10
Is a rotation correction unit that uses the rotation angle of the coin 1 output from the primary matching unit 8 to change the rotation angle of the multi-valued image data stored in the pattern memory unit 4 to an arbitrary predetermined angle. Make corrections so that

Reference numeral 11 denotes a secondary matching unit. When the matching result of the primary matching unit 8 is determined to be true, 2
Secondary matching is performed using the dictionary pattern stored in the dictionary storage unit 12 for next matching, and the authenticity of the coin 1 is determined. The operation of the present embodiment will be described below. The coin 1 to be authenticated is transported to the pattern reading unit 2 by a coin transport unit (not shown).

The pattern reading unit 2 reads a pattern on the surface of the conveyed coin 1 as an image, and passes the output to an A / D conversion unit 3. The A / D converter 3 converts the pattern image on the surface of the passed coin 1 into image data,
It is stored in the pattern memory unit 4. The center / diameter extraction unit 5
Coins 1 based on the image data stored in the pattern memory unit 4
And outputs the outer diameter of the coin 1 to the coin type discriminator 6 and the center of the coin to the position corrector 7.

The coin type discriminating unit 6 compares the outer diameter value of the coin 1 output from the center / diameter extracting unit 5 with a template prepared in advance, discriminates the coin type of the coin 1, and determines the discriminated coin type. Is output to the primary matching unit 8 and the secondary matching unit 11. In the primary matching unit 8, the coin 1
Are obtained from the primary matching dictionary storage unit 9 and two types of front and back comparison data for primary matching according to the type of coin 1 are obtained, and rotational matching is performed.

At this time, as a method of rotation matching, a method of performing rotation matching by rotating data stored in the pattern memory unit 4, a method of performing rotation matching by rotating comparison data for primary matching, and a method of primary matching A method of preparing a number of data obtained by rotating the comparison data for matching in advance and performing matching on it, a method of performing polar matching on image data with respect to a coin center, and a method of performing slide matching, etc. I don't care.

If the matching ratio exceeds a certain threshold value at a certain angle, the result of the matching is determined to be true, and the angle is output to the rotation correction unit 10 as the coin rotation angle, and obtained from the matched comparison data. The information on the front and back of the coin 1 is output to the secondary matching unit 11. If the result of the matching is false for all the candidate comparison data, the authenticity determination of the coin is false and all the operations are stopped.

At this time, the comparison data for the primary matching includes only a non-periodic pattern in the coin circumferential direction. FIGS. 2A and 2B are explanatory diagrams of examples of the primary matching dictionary pattern according to the embodiment.
If such comparison data for primary matching is used,
It does not happen that the matching ratio shows the maximum for a plurality of angles. Note that only the thick line portion in FIG. 2 is the primary matching dictionary pattern, and the thin line portion that is a periodic pattern is not used as the primary matching dictionary pattern.

FIGS. 3A and 3B are comparison explanatory diagrams of the matching result. FIG. 3A is a graph showing the matching result for each angle in the conventional example, and FIG. 3B is a graph showing the matching result for each angle in the embodiment. It is a graph shown. As can be seen from FIG. 3A, conventionally, the coin 1 includes a periodic pattern in the circumferential direction of the coin 1, and the matching ratio increases at a plurality of angles. Although it is difficult to determine the rotation angle of, as can be seen from FIG. 3B, in the present embodiment, the dictionary pattern does not include a pattern that is periodic in the circumferential direction. Only the rotation angle of the coin 1 indicates a sharp rise of the coin 1, and such a sharp rise is unlikely to occur at other angles, so that the rotation angle of the coin 1 can be easily determined.

In the rotation correction unit 10, the primary matching unit 8
The rotation angle of the image data stored in the pattern memory unit 4 is corrected on the basis of the rotation angle of the coin 1 output from.
In the secondary matching unit 11, based on the image data stored in the pattern memory unit 4, the front and back of the coin 1 determined by the primary matching unit 8, and information on the coin type determined by the coin type determining unit 6, Select the corresponding coin comparison data from the secondary matching dictionary storage unit 12, perform pattern matching,
The authenticity of the coin 1 is determined.

When the required recognition rate can be achieved only by the primary matching, the secondary matching can be omitted. As described above, according to the present embodiment, as the primary matching dictionary pattern for one coin, the primary matching is performed using a dictionary pattern composed of only patterns having no periodicity in the coin circumferential direction. Is performed, the rotation angle of the coin can be reliably extracted, and the coin discrimination performance can be improved.

In addition, by performing the kind of discrimination in advance based on the outer diameter of the coin, efficient and high-performance discrimination becomes possible.

[0020]

As described in detail above, a dictionary pattern composed of only patterns having no periodicity in the coin circumferential direction is stored in the primary matching dictionary storage unit, and is used. Since the primary matching is performed in this manner, it is possible to reliably extract the rotation angle of the coin, which has the effect of improving the coin discrimination performance.

In addition, prior to the primary matching, the coin type discriminating section discriminates the type of coin, and the matching dictionary data is selected based on the discrimination result. It also has the effect of improving speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment;

FIG. 2 is a dictionary pattern for primary matching according to the embodiment;

FIG. 3 is a diagram illustrating a comparison of matching results.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coin 2 pattern reading unit 3 A / D conversion unit 4 pattern memory unit 6 coin type discriminating unit 8 primary matching unit 9 primary matching dictionary storage unit 10 rotation correction unit 11 secondary matching unit 12 secondary matching dictionary storage Department

Claims (1)

[Claims] 1. A pattern reading unit for capturing a surface pattern of a coin as an image signal, an A / D conversion unit for converting the image signal into multi-valued image data, and a pattern memory unit for storing the multi-valued image data. A coin discriminating device for identifying coins based on the multi-valued image data, a coin type discriminating unit for discriminating a coin type based on outer diameter data of the coin extracted from the multi-valued image data, A primary matching dictionary storage unit having comparison data composed of only a non-periodic pattern in the circumferential direction; multi-valued image data stored in the pattern memory unit;
A primary matching unit that selects and compares the comparison data stored in the primary matching dictionary storage unit according to the type of the coin, and extracts the front and back and rotation angle of the coin; A rotation correction unit that corrects the rotation angle of the multi-valued image data stored in the pattern memory unit to a predetermined desired angle based on the output rotation angle of the coin; A secondary matching dictionary storage unit for storing comparison data for secondary matching, and selecting the comparison data from the secondary matching dictionary storage unit based on the type of the coin and the front and back of the coin, And a secondary matching unit for determining whether the coin is true or false.