JP2001118108A - Device and method for judging coins - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely judge the kind, the denomination, authenticity, etc., of coins, by accurately recognizing the surface shape of the coins through the use of a detection unit having simple constitution. SOLUTION: An inclined carrying path 2 where a coin 1 is rolled and traveled is inclined at a prescribed angle θ in the longitudinal direction of its rolling surface 2a, and a reference guide surface 2b with which the coin 1 is in slidable contact is formed from nonmagnetic and insulated substance. A detection unit 3 consisting of serially-connected drive coils 11a and 11b and a sensor coil 12 across the path 2 is arranged. An AC magnetic field is generated between them to generate induced current on the surface of the nonmagnetic and electrically conductive coil 1 and the coil 12 detects this induced current. The potential variation of a detection signal received by the coil 12 includes two components being the variation of a phase difference and amplitude with respect to AC to be supplied, executes phase shift detection with respectively different shift quantities and recognizes the diameter of the coil 1 from the shifting of the phase and the recessed and projecting shape of the surface of the coil 1 from the variation of the amplitude, so that the kind, the denomination, authenticity, etc., of the coin are judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for determining coins such as coins and coins.

[0002]

2. Description of the Related Art In a machine into which coins are inserted, such as a vending machine, the type and authenticity of the inserted coins are determined, only regular coins are accepted, and the inserted amount is calculated. , Except for regular coins. Here, coins roll along a predetermined transport path, and during this rolling, coins must be judged. In addition, the structure of the coin judging device is as small and simple as possible. Must be done.
For this reason, conventionally, the outer diameter size, thickness,
The material and the like are detected to determine the type and authenticity of the coin. However, in recent years, a situation has frequently occurred in which a foreign currency or the like having substantially the same outer diameter and material is intentionally remodeled to erroneously determine a coin in a vending machine.

[0003] From the above viewpoint, in order to more accurately determine a coin, a method of detecting a shape pattern on the surface of the coin and determining the counterfeit coin is disclosed in, for example, JP-A-6-162309. It is proposed in the gazette. This known judging device is provided with a pair of coils having a ferrite core as a pair in the middle of a coin transport path.
This coil sensor is used as a sensor coil, the coil sensor is oscillated at a high frequency of about 100 kHz, and a change in electromotive force generated when a coin conveyed along the conveyance path crosses the coil sensor is detected. Is configured to recognize the shape pattern.

[0004]

By the way, since coins are circular and roll along the transport path,
The position of the coin in the rotation direction when crossing the sensor coil is not constant. Therefore, the scanning line of the sensor coil relative to the coin surface is constantly changing. For this purpose, a large number of standard waveforms must be set, and the signal waveform obtained from the sensor coil must be compared with a large number of reference waveforms. This comparison becomes extremely complicated, so that the coin can be quickly and reliably identified. Cannot be performed.

The present invention has been made in view of the above points, and an object of the present invention is to make it possible to recognize the surface shape of coins very accurately with a simple configuration. An object of the present invention is to improve the accuracy of coin type determination.

[0006]

In order to achieve the above-mentioned object, a coin judging apparatus according to the present invention comprises a reference guide surface on which one side of a coin is slidably contacted. An inclined conveyance path for rolling and running, an AC power supply circuit for supplying a predetermined high-frequency current, and a predetermined frequency so as to penetrate the approximate center position of the rolling trajectory of the coins in a direction orthogonal to the reference guide surface. A detection unit that generates an AC magnetic field and detects a change in potential when coins traveling along the reference guide surface cross the AC magnetic field, and a change in the amplitude of an output signal from the detection unit,
And a signal analyzing means for analyzing a phase shift with respect to a reference frequency signal output from the AC power supply circuit.

As described above, the type of coins is detected by analyzing the phase shift with respect to the reference frequency signal and the amplitude change of the detection signal.
The surface irregularities are important clues. The surface of the coins is minute, and therefore, in order to accurately recognize the unevenness, the coins rolling along the inclined conveyance path and the detection unit must maintain an accurate positional relationship. For this purpose, the reference guide surface of the inclined conveyance path is made of a non-magnetic material and is made of an insulator. The rolling surface, which is provided continuously with the reference guide surface and on which coins roll, faces the reference guide surface. With the inclined surface falling down, coins always roll while sliding on the reference guide surface.

The detection units are provided on both sides of the inclined conveyance path, and generate an AC magnetic field so as to penetrate coins which are basically non-magnetic and conductive, thereby detecting coins. An induced current is generated on the surface of the device, and the frequency and amplitude of the induced current are detected. Therefore, as a specific configuration of the detection unit, it can be configured by a pair of drive coils connected in series to the AC power supply circuit, and a sensor coil disposed between one drive coil and the reference guide surface. In this case, it is desirable that the sensor coil be connected to a temperature correction unit.
This temperature correction means can be constituted by a coil, a resistor or the like. Further, the sensor coils may be arranged on both sides of coins together with the drive coils.

As an example of a specific configuration of the signal analyzing means, at least the phase of the reference frequency from the AC power supply circuit is shifted by a predetermined time, and a switching rectangular wave is generated from the shifted phase. A configuration is used in which a detection signal of the detection unit is switched at the rise and fall to detect a change in amplitude of the detection signal of the detection unit and a phase shift detection unit for surface shape recognition is provided. Further, the phase of the reference frequency from the AC power supply circuit is shifted by a time different from that of the phase shift detecting means for surface shape recognition, and a switching rectangular wave is created from the shifted phase. By switching the detection signal of the detection unit, a phase shift detecting means for recognizing the outer diameter for detecting a phase shift in the detection signal of the detection unit is also provided. Can be detected. Then, in order to actually recognize the surface shape of the coin, for example, in the output signal from the phase shift detection means for surface shape recognition, the height difference, the peak value, and the approximate central portion of one side surface of the coins are equivalent. Recognition means is provided which uses the signal level at the position as a criterion and compares the criterion with a preset standard value.

Here, the detection unit scans coins along the surface of the coins while rolling on the inclined conveyance path. Therefore, in order for the signal analysis means to recognize coins with higher accuracy, it is necessary to increase the resolution in the scanning line. For this purpose, it is desirable to reduce the diameters of the drive coil and the sensor coil constituting the detection unit as much as possible, and to increase the output frequency from the AC power supply circuit as much as possible. Although it depends on the running speed of coins, for example, if the diameter of the drive coil and the sensor coil is about several millimeters and the power supply frequency is about several megahertz, sufficient recognition accuracy for practical use can be obtained, This is desirable from the viewpoint of simplification of signal processing and the like.

By the way, the phase shift detecting means for recognizing the outer diameter and the phase shift detecting means for recognizing the surface shape recognize the outer diameter and the surface shape of coins rolling on the inclined conveyance path as clues. Means for obtaining a signal waveform in which the outer diameter and the surface shape are most easily recognized by shifting the phase of the reference frequency. That is, a signal whose outer diameter dimension is most emphasized and a signal whose surface shape is most emphasized are created by phase-shift detection of the signal detected by the detection unit. However, in recognizing the types, denominations and authenticity of a plurality of types of coins,
For example, depending on the material of the coin, in particular, the difference in electric conductivity, etc., a change may occur more clearly when the phase shift amount is changed. Therefore, when coins of different materials are included,
Further, a third phase shift detecting means is provided, and the third phase shift detecting means is made different from the phase shift amounts of the two phase shift detecting means described above, and the fourth phase shift detecting means having a different phase shift amount is provided. , A fifth phase shift detection means, etc. may be provided. In short, the signal analysis means is provided with a plurality of phase shift detection means using the output frequency signal from the AC power supply circuit as a reference frequency for the signal detected by the detection unit, and based on the output signal from each of these phase shift detection means. Recognizing the outer diameter and surface shape of coins rolling and running on the inclined conveyance path, the type, denomination and authenticity of the coins are determined.

[0012] In addition, as a method of judging coins according to the present invention, coins rolling on an inclined conveyance path provided with a reference guide surface on which one side of the coins are slidably contacted. In a direction perpendicular to the direction, generates an AC magnetic field of a predetermined frequency so as to penetrate the approximate center position of the rolling trajectory of the coins, and the coins roll while sliding on the reference guide surface. When crossing the AC magnetic field, the frequency and amplitude of the induced current generated on the surface of the coins are detected, and the phase shift detection is performed, so that the AC current for generating the AC magnetic field is set as the reference frequency, and the phase with respect to this reference frequency is determined. The type of the coins is determined by recognizing the outer diameter of the coins based on the deviation and the surface shape based on the amplitude change.

Recognition of the surface shape of coins is based on a phase difference detection signal obtained by detecting a change in amplitude, a height difference, a peak value, and a position corresponding to the approximate center of one side surface of the coins. It is desirable to compare the criterion with a preset standard value, using the signal level at the criterion as a criterion.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a schematic configuration of a coin type determination device. In the drawing, 1 is a coin, 2 is an inclined conveying path on which the coin 1 rolls, 3 is a detection unit, and 4 is a signal analyzing means.

First, the inclined transport path 2 for transporting coins 1
Basically, a rolling surface 2a on which the coin 1 rolls and a side surface 2b on which a sensor coil 12 of the detection unit 3 to be described later faces.
And As shown in FIG. 2, the inclined conveying path 2 is inclined at a predetermined angle θ toward the longitudinal direction of the rolling surface 2a, and the coin 1 rolls under its own weight along the inclined direction. The vehicle travels in the direction indicated by the arrow in the figure. The side surface 2b serves as a reference guide surface when the coin 1 rolls and runs along the inclined conveyance path 2. The reference guide surface 2b is a non-magnetic material, is made of an insulator, and the coin 1 In order to slide smoothly when rolling and running, at least the inner surface side is a sliding surface. The rolling surface 2a is an inclined surface that falls toward the side of the portion connected to the reference guide surface 2b, so that the coin 1 always comes into sliding contact with the reference guide surface 2b when the coin 1 runs. In order to make the coin 1 travel stably,
In addition to the rolling surface 2a and the reference guide surface 2b, it is desirable to provide a wall on the other side surface and the upper surface, but these wall surfaces are not necessarily provided. When the reference guide surface 2b is slightly inclined outwardly with respect to the rolling surface 2a, the state of the coin 1 sliding on the reference guide surface 2a is further stabilized.

Next, as a configuration of the detection unit 3, a pair of primary coils 11a connected to the high-frequency power supply circuit 10,
11b and the secondary coil 12. The pair of primary coils 11a and 11b are drive coils,
These are arranged so as to face each other, and the high-frequency power supply circuit 1
By passing a high-frequency current of, for example, 0 to several MHz, an AC magnetic field is generated during the high-frequency current. The secondary coil 12 is a sensor coil. The sensor coil 12 has a ferrite 12a as an iron core and a winding 12b provided around the core. Preferably, the sensor coil 12 has a diameter of about 1/20 to 1/10 of the outer diameter of the coin 1. Shall be.

A pair of drive coils 11a, 11
b is connected in series so that the directions of the lines of magnetic force coincide with each other, and is arranged such that the lines of magnetic force act in a direction exactly perpendicular to the coin 1 traveling on the inclined conveyance path 2. The sensor coil 12 is disposed between one of the drive coils 11a and the reference guide surface 2b of the inclined conveyance path 2, and is disposed so as to be exactly coaxial with the drive coils 11a and 11b. Coin 1
It is located at a position close to the surface. Further, the axes A of the drive coils 11a and 11b and the sensor coil 12 are arranged so as to be orthogonal to the locus of the coin 1 traveling on the inclined conveyance path 2 at the approximate center. Here, when there are a plurality of types of coins traveling on the inclined conveyance path 2, the coins are arranged in a direction orthogonal to the locus through which the center of the most expensive coin or the most likely counterfeit coin passes. Further, a temperature correction unit 13 is connected to the sensor coil 12. The temperature compensating means 13 can be constituted by a resistor, a coil, or the like. When the temperature compensating means 13 is constituted by a coil, the position and direction thereof do not cause any particular problem, but the temperature compensating means 13 can be made to face the sensor coil 12. The correction based on the temperature change can also be performed at the signal processing stage.

FIG. 3 shows the structure of the signal analyzing means 4. As is apparent from FIG. 1, the high-frequency power supply circuit 10 includes an oscillation circuit 20 that performs high-frequency oscillation of several MHz and an output circuit 21 thereof.
When a high-frequency current is passed through the
An alternating magnetic field in a direction orthogonal to the inclined conveyance path 2 is generated between the a and 11b. When the coin 1, which is a nonmagnetic material and a conductor, crosses the alternating magnetic field, the individual inductance of the drive coils 11a and 11b changes due to the induced current generated on the surface of the coin 1, and this potential change occurs. The sensor coil 12 captures the detection signal. The potential change of the detection signal received by the sensor coil 12 is
Two components are included: a phase difference with respect to the supplied alternating current and a change in amplitude.

While the coin 1 passes through the position of the detection unit 3, the phase shift is substantially constant, and the amplitude changes according to the distance between the sensor coil 12 and the surface of the coin 1. Therefore, by processing the output signal from the sensor coil 12 and detecting the presence or absence of a phase shift, the time during which the coin 1 is passing, that is, the diameter of the coin 1 can be detected. Also, the change in the amplitude depends on the sensor coil 1 of the coin 1.
The uneven shape on the surface on the side facing 2 will appear.

Therefore, the signal analyzing means 4 includes a phase change detecting section 22 and an amplitude change detecting section 23. Basically, the phase change detecting section 22 and the amplitude change detecting section 23
Are the same, and both are phase-shift detection means.
The degree of phase shift differs. After the phases of the alternating current supplied from the high-frequency power supply circuit 10 to the drive coils 11a and 11b are shifted by the delay circuits 22a and 23a, the rectangular waves are converted by the binarization circuits 22b and 23b. Generate. On the other hand, a detection signal relating to an induced current on the surface of the coins 1 from the sensor coil 12 is amplified by the amplifier circuit 24 and taken into the switching circuits 22c and 23c in the phase change detection unit 22 and the amplitude change detection unit 23, respectively. By switching at the rise and fall of the signals from the binarization circuits 22b and 23b, the potential difference of the detection signal from the sensor coil 12 using the output signal of the high-frequency power supply circuit 10 as the reference frequency signal is detected. The signal related to the potential difference is flattened by the low-pass filter circuits 22d and 23d, and is output as a voltage signal. Further, these low-pass filter circuits 22d, 2d
The output voltage signal from 3d is supplied to A / D converters 22e and 23e.
The digital signal is converted into a digital signal by the
This data and ROM (Read Only Memory) 2
By comparing the coin 1 with the data recorded in advance in the coin 6, the denomination, the authenticity, and the like of the coin 1 passing through the detection unit 3 are determined. Therefore, the microcomputer 25 and the ROM 26 constitute coin 1 recognizing means.

Therefore, the phase shift detection will be specifically described below with reference to FIG. Now, it is assumed that the fundamental frequency signal output from the high-frequency power supply circuit 10 has a waveform as shown in FIG. 4A, and that when the coin 1 crosses the position of the detection unit 3, the sensor coil 12 (B)
It is assumed that a signal having the waveform shown in FIG. In (b), the phase of the left waveform and the waveform of the right waveform do not change, but the amplitude changes.

FIGS. 4C and 4D show that the phase of the reference frequency signal is changed by delaying the reference frequency signal by delay circuits 22a and 23a in the phase change detection unit 22 and the amplitude change detection unit 23, respectively. FIGS. 7E and 7F show a shifted phase-shifted frequency signal, which is a switching signal obtained by binarizing the frequency signal into a rectangular wave. Therefore, when the detection waveform signal of the sensor coil 12 obtained in FIG. 4B is switched by the signals of FIGS. 4E and 4F, the waveforms of FIGS. 4G and 4H are obtained. . This is applied to the low-pass filter circuit 22
Those flattened by d and 23d are shown by dotted lines in (g) and (h), specifically, voltage levels.

When the coin 1 passes through the position of the detection unit 3, the output signal of the sensor coil 12 is shifted by a predetermined amount with respect to the phase of the reference frequency signal due to an induced current generated on the surface of the coin 1. This phase shift is caused by coin 1
Does not substantially change while passing through the position of the sensor coil 12. However, the amplitude changes according to the unevenness on the surface of the coin 1.

Therefore, the phase change detecting section 22 operates so that the phase shift of the detection signal of the sensor coil 12 with respect to the reference frequency signal can be most remarkably detected.
At 2a, the phase of the reference frequency signal is shifted. As a result, it is possible to detect whether or not the coin 1 has passed. In other words, this phase change detection section constitutes a phase shift detection means for outer diameter dimension recognition. Further, the amplitude change detection unit 23 gives a phase shift amount with respect to the reference frequency signal so that the change in the amplitude of the sensor coil 12 can be detected most remarkably. As a result, the irregular shape of the surface of the coin 1 can be detected. Therefore, the table amplitude change detecting section 23 constitutes a phase shift detecting means for surface shape recognition. Specifically, for example, in FIG. 4C, the phase of the reference frequency signal is shifted by 90 ° in FIG. 4C, and the phase is further shifted by 45 ° in FIG. 1 for
By shifting by 35 °, a change in amplitude is emphasized most. However, the phase shift amounts in the phase change detection unit 22 and the amplitude change detection unit 23 do not necessarily need to be 90 ° and 135 °, and the coin 1 is actually detected according to the oscillation frequency, the number of turns of the coil, and the like. In this case, an optimal phase shift amount may be selected.

Therefore, from these two types of signals, coin 1
By recognizing the diameter of the coin and the shape of the surface irregularities, it is possible to determine the type of coin, whether the coin is a regular coin, or something else. To further improve the accuracy of these determinations, the output frequency from the high-frequency power supply circuit 10 is at least 1 MHz, preferably about 4 MHz, and the outer diameters of the drive coils 11a, 11b and the sensor coil 12 are made as small as possible. This is desirable from the viewpoint of improving the resolution and resolution. At least the sensor coil 12 is arranged at a position as close to the surface of the coin 1 as possible.

Since the coin 1 traveling along the inclined conveying path 2 rolls, when passing through the position of the detection unit 3, the coin 1 is projected on the coin 1 of the sensor coil 12 constituting the detection unit 3. The trajectory, that is, the scanning line, changes depending on the rotational position of the coin 1 when it enters. Thus, when the coin 1 moves at a constant speed, the sensor coil 12
Scans the line indicated by the arrow in FIG.
The pattern on the surface of the coin 1 is represented by unevenness, and since the unevenness pattern is formed on the entire surface, the sensor coil 1
The scan line by 2 will usually pass at least once through the most protruding part and the most depressed part. Further, since the sensor coil 12 is arranged at a position where the center of the coin 1 passes, the information about the center position on the surface of the coin 1 is always included.
At about the midpoint during the passage of.

From the above, the time required for the coin 1 to pass through the position of the detecting unit 3 detected by the phase change detecting unit 22, that is, the passing time data and the surface irregularities detected by the amplitude change detecting unit 23 Among the signals related to the shape, the denomination and authenticity of the coin 1 are determined on the basis of the peak value, the height difference of the signal, and the like, and the surface shape data based on the signal level at the center position. This makes it possible to quickly and extremely accurately identify the type and authenticity of the coin 1 rolling and running. Therefore, the ROM 26 stores standard values for the passing time data and the surface shape data, and the microcomputer 25 outputs the passing time data and the amplitude change detecting unit 23 obtained from the phase change detecting unit 22. Surface shape data and ROM 26
And compare with the data. However, if the standard value is set too strictly, it is judged that it is not a legitimate coin, but it is not legitimate, and the acceptance of the coin will be rejected more frequently. It is desirable to make the width of the standard value as large as possible without making an error in the judgment.

In an actual vending machine, coins to be inserted 1
There are four kinds of denominations, usually 500 yen, 100 yen, 50 yen, and 10 yen, which have different outer diameters and weights, and the 50 yen coin is a perforated coin. However, the coins 1 transported along the inclined transport path 2
It is assumed that there is substantially no friction with respect to the rolling path 2a and that there is no slip when rolling along the rolling surface 2a. The speed of a coin is constant irrespective of its type, that is, its weight and outer diameter. Therefore, the outer diameter of each coin can be detected only by the time when the coin passes through the position of the detection unit 3. On the other hand, as the surface shape data, the inserted coin is
When rolling, the front side faces the reference guide surface 2b and the rear side faces.
From the above, it is necessary to store the standard data on the front and back sides for each denomination in the ROM 26. The detection unit 3 is disposed to face the locus through which the center of the coin passes, but the position cannot be changed according to the denomination of the inserted coin. Therefore, the detection unit 3 is disposed to face the center locus of the most expensive coin. When the highest coin is difficult to forge and other coins are frequently forged, the detection unit 3 may be disposed at a position where the center of the easily forged coin passes. .

Next, a procedure for determining the denomination and authenticity of the inserted coin will be described with reference to FIG. First, when it is detected that a coin has been inserted, detection of the coin is started by the sensor coil 12 of the detection unit 3 (step 1). Here, the insertion of the coin can be detected by a signal from the detection unit 3, but a passage sensor is disposed at a position on the inclined conveyance path 2 upstream of the position where the detection unit 3 is disposed. Can also be detected. The signal obtained by the sensor coil 12 is subjected to signal processing by a phase change detection unit 22 and an amplitude change detection unit 23 that constitute the signal analysis unit 4, and is processed by a microcomputer 25.
Are taken in as the passage time data and the surface shape data (step 2). Then, the denomination and the authenticity of the inserted coin are compared with the standard data stored in the ROM 26, and the denomination is first estimated from the passing time data. Since the diameters of the 100-yen coin and the 50-yen coin are not so different from each other, and the sensor coils 12 constituting the detection unit 3 do not pass through their center positions, neither is specified at this stage. Therefore, from the passing time data, specifically, it is determined whether the coin is equivalent to a 500 yen coin (step 3), whether it is equivalent to a 100 yen coin or a 50 yen coin (step 4), and is equivalent to a 10 yen coin. A determination is made as to whether or not to perform (step 5), and if neither of them is a valid coin, the coin is rejected (step 6).
Is done.

When it is determined that the coin is equivalent to a 500 yen coin, the surface shape data is compared with the standard data of the 500 yen coin to determine whether or not the coin is valid (step 7). This comparison is made between the detected surface shape data and the RO
This is performed with respect to the standard data stored in M26. Specifically, the level of the peak value, the level difference, and the level of the center position are compared. Then, as a result of the comparison, if all of these detected values fall within the range of the standard data, an acceptance registration of 500 yen is made (step 8). If any value is out of the range of the standard data, step 6
Is rejected. Note that the comparison is performed twice since the standard data includes two types of data, the front side and the back side.

When it is determined that the coin is equivalent to a 100 yen coin or a 50 yen coin, the surface shape data is compared with the standard data, and it is determined whether or not the coin is a 100 yen coin (step 8). Otherwise, it is determined whether the coin is a 50 yen coin (step 9). Since it is possible to determine whether the coin is a 100-yen coin or a 50-yen coin based on whether or not the coin is a perforated coin, the presence or absence of a perforated coin may be determined prior to the authenticity determination. When it is determined that the coin is a genuine 100 yen coin, the registration of 100 yen is made (step 10), and when it is determined that the coin is a genuine 50 yen coin, the registration of 50 yen is made (step 11).
Otherwise, it is rejected in step 6.

When it is determined that the coin is equivalent to a 10-yen coin, the surface shape data is compared with the standard data to determine whether or not the coin is a regular 10-yen coin (step 1).
1) When it is determined that the coin is a 10-yen coin, an acceptance registration of 10 yen is made (step 12), and otherwise, the rejection of step 6 is made. When the registration or rejection of the amount is made, the system waits until the next coin is inserted.

Here, data relating to the center position of the coin 1 conveyed along the inclined conveying path 2 is stored in the sensor coil 12.
Is at a position passing through the center position of the 500 yen coin, and for other coins, the sensor coil 12 is data at a position below the center position and after passing through the center. Therefore, in the case of coins other than the 500 yen coin,
If the data at this position converges to a certain range, the range is used as data relating to the center position, otherwise, the comparison of the center position data is not performed.

As described above, the pair of drive coils 11
The type and authenticity of coins traveling while rolling on the inclined conveyance path 2 can be accurately determined by the detection unit 3 having a simple configuration including the sensor coils 10a and 11b and one sensor coil 10. Modified coins will not be mistaken for legitimate coins and will be reliably rejected. In addition, the surface shape of the coin is recognized in three types, that is, a peak value level, a height difference, and a center position level, and the processing for comparison can be significantly simplified, and the judgment is made with extremely high accuracy.

By the way, since the drive coil faces both sides of the coin, an induced current is generated not only on the side facing the sensor coil but also on the opposite side. Therefore,
The change in the amplitude of the detection signal of the sensor coil is affected by the induced current on the back side. To prevent the waveform of the detection signal from being blurred by the influence of the induced current on the back side, as shown in FIG.
0b, the drive coils 31a, 31b and the sensor coils 32a, 32b are wound, and both ferrites 30a,
30b are disposed on the left and right sides of the inclined conveying path 2 on which the coins 1 roll. The drive coils 31a and 31b and the sensor coils 32a and 32b are arranged in series, respectively, and the ferrites 30a and 30b are coaxially arranged at positions substantially the same distance from the front and back surfaces of the coin 1. In the case of such a configuration, the surface shape data of the coin 1 to be obtained is data relating to the difference between the irregularities on the front and back surfaces. By using the difference between the irregularities on the front and back surfaces as the surface shape data, a sharper signal waveform can be obtained.

On the other hand, the signal analysis means shifts the phase of the detection signal obtained by the sensor coil so that the outer diameter can be more clearly recognized, and shifts the phase so that the surface shape can be clearly recognized. In the end, however, the phase shift detection produces a signal whose outer diameter dimension is most emphasized and a signal whose surface shape is most emphasized. However, in a vending machine or the like, various types of coins are inserted, and not only have different outer diameter dimensions and surface irregularities, but also different electric conductivity and thickness. Therefore, regarding the signal obtained by the sensor coil, the phase shift amount of the reference frequency performed by the phase shift detecting means for outer diameter dimension recognition and the phase shift detecting means for surface shape recognition changes due to a difference in electric conductivity and the like. There may be no or only minor changes. Therefore, in order to improve the determination accuracy due to the difference in the material of the coin, etc., as shown in FIG. 8, a third phase shift detecting means is provided.
The phase shift amounts of the two phase shift detecting means are made different from each other. Note that, if necessary, fourth and fifth phase shift detection means having different phase shift amounts may be provided.

As apparent from FIG. 8, three sets of means for performing phase shift detection including a delay circuit and the like are provided, and one set of these means is used as the phase change detecting unit 22. ,
Another set is the amplitude change detecting section 23, and the remaining one set of the third phase shift detecting means 60 functions as a phase change detecting section or an amplitude change detecting section for coins of a specific material. . Therefore, standard data for the third phase detection means 60 is recorded in the ROM 26. The delay circuit 60a, the binarization circuit 60b, and the switching circuit 60 constituting the third phase shift detection means 60
c and the low-pass filter circuit 60d perform substantially the same signal processing as the phase change detection unit 22 and the amplitude change detection unit 23, but the amount of phase shift in the delay circuit 60a is
It is assumed that each of the detection units 22 and 23 is different. Thereby, the phase change detecting section 22 and the amplitude change detecting section 23
The third phase-shift detection means 6 does not show any change or a small change
A change may be recognized in the output signal waveform from 0.

Thus, in coins of different materials, it is usually desirable to set the phase shift amount so that the surface shape of a high-priced coin appears most prominently. The surface irregularities may not always be clear. Therefore, it is sufficient to set the phase shift so that the surface irregularities appear for the coins of both these materials. However, by further configuring as in this embodiment, the amplitude change detection unit 23 can be configured to use one of the coins. The phase is shifted so that the surface irregularities appear most prominently on coins of the material, and the third phase shift detection means 60 is set so as to shift the phase so as to be optimal for coins of other materials. As a result, even if there is a difference in the material or the like, the determination can be made extremely accurately. As described above, in processing the detection signal obtained by the sensor coil 12 (or the sensor coils 32a and 32b),
Coins having various shapes, materials, and the like can be accurately identified with a simple configuration in which only a predetermined number of phase shift detecting means such as three sets or four sets are connected.

[0039]

Since the present invention is constructed as described above, the surface shape of coins can be recognized very accurately by using a detection unit having a simple structure, and the denomination of coins is thereby improved. This makes it possible to determine the accuracy and the authenticity of the information with extremely high accuracy.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a coin type determination device according to an embodiment of the present invention.

FIG. 2 is a front view of an inclined conveyance path.

FIG. 3 is a circuit configuration diagram of a signal analysis unit.

FIG. 4 is a signal waveform diagram at each part in the signal analysis means.

FIG. 5 is an explanatory diagram showing scan lines of a sensor coil on the surface of a coin.

FIG. 6 is a flowchart illustrating a procedure for determining coins.

FIG. 7 is a configuration explanatory view showing another example of the detection unit.

FIG. 8 is a circuit diagram showing another example of the signal analyzing means.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Coin 2 Inclined conveyance path 2a Rolling surface 2b Reference guide surface 3 Detection unit 4 Signal analysis means 10 High frequency power supply circuit 11a, 11b, 31a, 3
1b Drive coil 12, 32a, 32b Sensor coil 13 Temperature correction means 22 Phase change detection unit 23 Amplitude change detection unit 22a, 23a Delay circuit 22b, 23b Binarization circuit 22c, 23c Switching circuit 22d, 23d Low-pass filter circuit 25 Microcomputer 26 ROM 60 Third phase shift detection means

Claims (12)

[Claims] 1. A reference guide surface on which one side of coins slides, an inclined conveyance path on which the coins roll and run, an AC power supply circuit for supplying a predetermined high-frequency current, and a direction orthogonal to the reference guide surface. In such a direction that an alternating magnetic field of a predetermined frequency is generated so as to penetrate the approximate center position of the rolling trajectory of the coins, and the potential when coins traveling along the reference guide surface cross the alternating magnetic field. A detection unit that detects a change, and a signal analysis unit that analyzes a change in amplitude of an output signal from the detection unit and a phase shift with respect to a reference frequency signal output from the AC power supply circuit. Characteristic coin type judgment device. 2. The reference guide surface of the inclined conveyance path is a non-magnetic material and is made of an insulator, and the rolling surface on which the coins roll is a slope surface falling toward the reference guide surface. The coin judging device according to claim 1, wherein the coins are determined. 3. A sensor provided on both sides of the inclined conveyance path, and a pair of drive coils connected in series, and a sensor coaxially arranged between one drive coil and the reference guide surface. The coin judging device according to claim 1, comprising a coil. 4. A coin type judging device according to claim 3, wherein a temperature correction means is connected to the sensor coil. 5. The detection unit according to claim 1, wherein the detection unit includes a pair of drive coils connected in series to the AC power supply circuit, and a pair of sensor coils arranged coaxially with the drive coils. An apparatus for determining coins according to the above. 6. The coin judging device according to claim 3, wherein the AC power supply circuit supplies a high-frequency current of 1 MHz or more. 7. The signal analysis means shifts a phase of a reference frequency from the AC power supply circuit by a predetermined time,
By generating a switching rectangular wave from the shifted phase and switching the detection signal of the detection unit at the rise and fall of the rectangular wave,
2. A coin type judging device according to claim 1, further comprising a phase shift detecting means for surface shape recognition for detecting an amplitude change in a detection signal of said detecting unit. 8. The signal analyzing means further shifts the phase of a reference frequency from the AC power supply circuit by a time different from that of the surface shape recognizing phase shift detecting means, and outputs the switching rectangular wave from the shifted phase. A configuration including an outer diameter dimension recognition phase shift detector for detecting a phase shift in the detection signal of the detection unit by switching the detection signal of the detection unit at the rise and fall of the rectangular wave. The coin judging device according to claim 7, wherein: 9. An output signal from the surface shape recognizing phase shift detecting means, wherein a level difference, a peak value, and a signal level at a position corresponding to a substantially central portion of one side surface of coins are used as determination criteria. The coin judging device according to claim 7, further comprising a recognizing means for recognizing the surface unevenness of the coin by comparing the judgment standard with a preset standard value. 10. The signal analysis means comprises at least three sets of phase shift detection means, each of which shifts the phase of the reference frequency from the AC power supply circuit by a different time, and A switching rectangular wave is generated from the shifted phase, and the type and authenticity of coins are determined based on each signal waveform obtained by switching the detection signal of the detection unit at the rise and fall of the rectangular wave. The coin judging device according to claim 1, wherein the coin is a coin. 11. A coin rolling along an inclined conveyance path provided with a reference guide surface on which one side surface of the coin slides, in a direction orthogonal to the reference guide surface, the coin being rolled. An alternating current magnetic field of a predetermined frequency is generated so as to penetrate the approximate center position of the moving trajectory, and when the coins roll while sliding on the reference guide surface and cross the alternating magnetic field, the coins move on the surface of the coins. By detecting the frequency and amplitude of the induced current that occurs, and performing phase shift detection, the AC current for generating the AC magnetic field as a reference frequency, the outer diameter of coins based on the phase shift with respect to this reference frequency, Also, by recognizing the surface shape based on the amplitude change,
A method of determining coins, wherein the type of coins is determined. 12. The recognition of the surface shape of the coins corresponds to a height difference, a peak value, and a substantially central portion of one side surface of the coins from a phase shift detection signal obtained by detecting the amplitude change. 12. The method for determining coins according to claim 11, wherein the determination is performed by using a signal level at a position where the determination is made as a determination criterion and comparing the determination criterion with a preset standard value.