JPS62164190A - Coin identifier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a coin identification system that places a coin in an alternating magnetic field and determines the authenticity of the coin based on the degree of change in the magnetic field.

(cO Conventional Technology) As such a coin identification device, the
There is a technology shown in Publication No. 96, in which the oscillation frequencies are significantly different (for example, a high frequency of 400 KHz and a high frequency of 10 KHz).
The coins are identified by utilizing the fact that the two types of alternating current magnetic fields (low frequency of z) have greatly different dimensions in which the magnetic field penetrates into the coin.

However, because the magnetic field due to low frequency penetrates or penetrates deep into the coin, it changes depending on the material of the coin.
Also, since the magnetic field due to high frequency penetrates only a few percent of the thickness of the coin at most, is it affected by the dimensions of the coin? Focusing on the fact that coins change depending on the amount of time they receive, the coin's authenticity is determined by separately measuring the characteristics of the coin's material and dimensions at two significantly different frequencies. Furthermore, Japanese Patent Publication No. 39-11680 discloses that an oscillating magnetic field is formed by an oscillator having relatively harmonic components, and the influence on the oscillating magnetic field of the coin is determined. It is disclosed that the test equipment is sensitive to the surface characteristics of the coin by including higher frequencies in the oscillating magnetic field.

Problems to be Solved by the Invention However, the above-mentioned prior art has disadvantages in that high-grade elements are required to accommodate two frequencies that differ considerably in height, and the circuit is complicated.

Therefore, the present invention provides a coin identification device that can perform multiple measurements of coins using electromagnetic fields having frequencies in the same frequency band.

B.) Means for Solving the Problems The present invention provides a first coin detector having a coin path in which a coin to be an identifier rolls, a first oscillation coil that induces a first alternating current magnetic field in the coin path, a first measuring device for detecting the oscillation amplitude of the first oscillation coil when a coin rolls on a passage; and a second measuring device for inducing a second alternating current magnetic field in the same frequency band as the first alternating current magnetic field; A coin detector, a second measuring device that measures the oscillation frequency of the second oscillating coil when a coin rolls on the coin path, and distance values measured by the first measuring device and the second measuring device are preset. Effects of certain correspondences With the above configuration, two types of characteristics of a coin can be measured depending on the degree of influence exerted on the coin by two electromagnetic fields in the same frequency band.

(f) Embodiment FIG. 1 schematically shows the structure of a coin identification device according to the present invention. Coins inserted through the coin slot +11 roll through a coin passage (4) formed by a rail (2) and a pair of opposing side walls (3). In the coin passage (4), a coin detector (51 (61t71) is installed along the coin transfer direction.
These coin detectors +
5061 (its authenticity is identified at 71), and a coin gate αa is arranged below the coin passage (4).
The coin gate α4 appears or disappears from the side wall (3) depending on the result of identifying the authenticity of the transfer coin, and guides the coin to the receiving passage 0a or the return passage σS (the coin detector (5) is inserted into the side wall (3)). A set of oscillation coils are arranged facing each other, and each oscillation coil is wound around FF3h of a ferrite bot core.This coin detector (5) is mainly used to detect the material and thickness of the coin. The diameter of the oscillation coil has been miniaturized to reject counterfeit coins and to accommodate all coin diameters that are mechanically possible to insert.The coin detector (6) also mainly detects the material and thickness of the coin. In order to However, since the coin detector (7) mainly detects the diameter of coins, the diameter of the oscillation coil is large.

Next, regarding the oscillation frequency of the oscillation coil, using an oscillation magnetic field means that compared to the case where a countersunk magnetic field is used, there is no adhesion of the a surrounding body, and there is no effect on the transfer of coins. There are many advantages. Diameter 2 from Figure 2 to Figure 4
t! when measuring each rod coin material under each oscillation frequency of 5 KHz, 100 KHz, and 500 KHz with a coin detector consisting of a coil wound around a 2 mm Bot core.
! jNote diagram? It shows. Each characteristic diagram shows the thickness of the coin material.
The inductance L and loss are shown when they are changed, but in this case the diameters are all constant. The inductance and loss values are shown for convenience and may vary depending on the number of turns of the oscillation coil, the magnetic permeability of the ferrite that is the material of the bot core, the dimensions of the coin passage, etc. However, these characteristic diagrams are based on measurements taken under the same conditions. It is. Further, in the characteristic diagram, the symbol Cu indicates copper, Bs indicates brass, and Cu/Ni indicates cupronickel, and the value indicated by the double circle is the loss value at no load when no coin is present.

FIG. 2 is a characteristic diagram for an oscillating magnetic field of 5 KHz, and when the inductance L increases the thickness t, only Cu changes. Therefore, it can be said that the inductance L is slightly influenced by the thickness of Cu only, and the degree of influence of other materials is small. Similarly, the loss is also affected by the thickness of Cu (although it is affected to a lesser extent by other materials.This is because when the oscillation frequency is low, the specific resistance of Bs and Cu/Ni is higher than that of Cu). This is because the target is so thick that the magnetic flux penetrates and has little effect on the coin detector.Figure 3 shows the frequency of 100KHz.
This is a % chart in the oscillating magnetic field, and the inductance L changes accordingly with the change in the thickness t.On the other hand, regarding the loss, Cu/Ni and Bs intersect, which is due to the change in magnetic flux. It can be seen that the penetration is sufficient (penetration) to a degree close to penetration in the case of thin Cu/Ni plates, and shallow in the case of thick ones (the ratio is large).

In addition, for Cu, the influence of the thickness is smaller (compared to the case of 5 KHz mentioned above), and the absolute value is also lower than for Bs and Cu/Ni (at a frequency of 100 KHz, the penetration of magnetic flux is shallow. Bs indicates this intermediate custom order. In the characteristic diagram of 500 KHz oscillating magnetic field in Figure 4, the tendency of the characteristic diagram in Figure 3 is even stronger. Focusing on the characteristics, Bs and Cu/Ni with a thickness of about 1.7 ynx exhibit approximately the same loss Da'.

Therefore, even if a coin is identified by detecting only losses, C.
U/Ni coins with a thickness of 1.7 mm and Bs coins with the same thickness cannot be separated. However, the inductance L in Figure 3
In terms of the characteristics, the inductance of a 1.7n thick Cu/Ni coin is 1.43 mH, while a Bs coin of the same thickness shows a difference of 1.33 mHk. Also regarding the characteristic diagram in Figure 4.

Regarding loss characteristics, 1.2 mm thick B coins and 2
, the loss value is the same as that of a 2 mm thick Cu coin.

Regarding the characteristics of the inductance L, there are differences in its value. Therefore, when an oscillating magnetic field with a frequency sufficiently higher than 5 KHz is applied to a coin, different characteristics of the coin can be measured by changing the types of data to be detected to inductance and loss. Both of these characteristics are composite characteristics of the coin's material and plate thickness, but they are characteristics that have different degrees of influence depending on the thickness of the coin. Therefore, if the oscillation frequency of each oscillation coil of the coin detector (5 bars 6) is set to a high frequency in the range from around 1oOKHz to above, the type of data detected will be determined by inductance and loss even if the frequencies of both are the same. B or Cu/N i
For coins the different properties mentioned above can be measured particularly markedly.

By the way, when considering the material of coins, the coins of many countries are made of materials having substantially the same resistivity as Cu/Ni and B. In Japan, the 5 yen coin is made of brass and 10
Yen coins are made of bronze, whose volume resistivity is approximately the same as brass, and all other high-value coins of 50 yen or more are made of cupronickel. On the other hand, countries such as the United States, Australia, and France have high-performance coins that are close to the volume-specific resistivity of brass, and these coins have to be measured with high accuracy (measurement requires a large change from brass or cupronickel). In terms of loss characteristics, at frequencies above approximately 100 KHz, there is a large difference in the measured values for brass and cupronickel coins when there is no load and when coins are present, so identification processing is not necessary. Therefore, it can be seen that it is better to set the oscillation chest wave number of each oscillation coil of the coin detector (51+61) to a frequency above the range of approximately 100 KHz.In this example, the coin detector (51 + 61) ) is used to measure the loss, and the coin detector (6) is used to measure the inductance II'.In some cases, a coin detector (7) that detects the diameter of the coin is also used in combination for even more powerful discrimination. However, in order to detect the diameter of the coin, the appropriate frequency is such that the magnetic field does not penetrate deep into the coin.Therefore, the coin detector (7) is similar to other coin detectors. It is sufficient to set the frequency to a relatively high frequency, which is preferable in terms of commonality and stability.Then, by detecting the inductance with the coin detector (7), the combined characteristics of the coin's material and diameter can be measured. ing.

Is the inductance L in Figure 5? : Shows the configuration for measurement. It forms a kind of Colpitts-type oscillator circuit using a CMOS inverter IC (16). An oscillation coil (lη08) is connected in series, and a capacitor α is connected in series. By constructing a resonant circuit using the oscillation coil Q?) (181), it will oscillate at a frequency determined by the inductance of the oscillation coil Q? The frequency is measured by counting the oscillation output that is amplified and input through the counter (AND gate C31), and the sampling pulse is introduced into one input terminal of the AND gate C31). Then, the oscillation output is output to the counter (3 counters), and the counter G3 is cleared at the rising edge of the sampling pulse. Therefore, the counter 62 measures the oscillation frequency every time the sampling pulse of Ims is generated. Although the excavation coil aη0& is connected in series with reverse phase, it may be connected in series with positive phase.

However, with the reverse phase connection, the ratio of the difference between various coins to the impedance when a coin is not present is larger (it cannot be detected because it is too weak).

Next is the measurement of loss.Does loss affect the amount of feedback in the oscillation circuit? The so-called soft oscillation circuit that gives? It can be measured by detecting the amplitude at the time of oscillation. To explain with reference to FIG. 6, the active element is a CMOS inverter tcry and an oscillation coil (c!) similar to that shown in FIG. 4) is also connected in series with reverse phase. However, the feedback resistor (251) should be made as large as possible to reduce the amount of feedback, and the oscillation coil (c) which is the load (24) should be affected by the equivalent resistance which is the loss of the inverter. The voltage on the input side of (c) is detected.Then, this voltage is amplified by the amplifier circuit 2, and the measuring device (c) then uses the rectifier circuit (b) to identify the level. After rectifying to A/
A D converter (351) samples the signal voltage from the rectifier circuit (b) every 1 m5ec, converts it into a digital value, and outputs it.

By the way, as mentioned above, it is preferable to use the same oscillation station inverse number of each oscillation coil of the coin detector T51 (61 (71) in terms of commonality and stability. However, the coin detector +51161 (power If all (setting the same frequency), mutual interference may occur.To prevent this interference, during standby when no coins pass, set the input side of the CMOS inverter IC of the oscillation circuit to high level or low level. There is a method of fixing it at the level.In other words, as shown in Figure 7, the input side of the CMOS inverter IC (5) is connected to the switch o7) via the restraining diode (1), and the diode (to The connection point between the switch C37) and the switch C37) is connected to the power supply +VCC through the bias resistor -.

When the switch Gη is turned on in this configuration, the CMOS
Since the input side potential of the inverter IC@ becomes a voltage drop across the diode (T) and becomes a low level, oscillation becomes impossible and stops. Such an oscillation control switch C17
) is provided for each coin detector +51 (61 (71), and is controlled to 5' so that only the oscillation circuit of one coin detector is driven.In this example, the oscillation is controlled by a switch,
Does it actually oscillate in response to the passage of coins using a semiconductor switch? This is a control configuration.

In addition, when the identification determination section of the coin identification device is constituted by a microcomputer, such control of oscillation can be achieved by the operation of the microcomputer. However, in the above method, each coin detector (51
In order to start or stop the oscillation of (61(7)), the number of circuit parts increases and the control becomes complicated.Therefore, there is a method that is simplest and sure.In this case, the coin detector (51+61(7) 7) It varies depending on the distance between the leopards, the wiring, etc., but it is generally said that it is sufficient to shift the frequency by 0 to 20%.In that case, set the frequency to the center frequency of the coin detector (6). hand,
Coin detector (517) Y 10 in each high and low direction
It is best to set it in increments of ~20%. For example, the coin detector +51 (61 (71) oscillation frequency during standby of each oscillation coil? 95 KHz, 115 KHz, respectively.
The frequency is set to 140 KHz.

In FIG. 1, the identification determination unit α2 is a coin detector (5) (
The coin detector (5) of this example measures the loss based on the coin measurement data by each measuring device (8) (91αQ) corresponding to 61+71. In order to do this, the measuring device (8) shown in Fig. 6 is used, and the coin detector (61 (7)
1 is a measuring device (9) to measure the inductance LY.
) For each QOI, use the measuring device at■ shown in Fig. 5. In addition, the acceptance condition setting section (131) includes a measuring device t when a specie coin passes through the coin detector +51 +6171'Y.
81 (91αα) The upper and lower limits of the measured peak value are set.

Then, when the coin moves through the coin path (4), the identification/judgment unit σ2 extracts the peak value of the data measured by each measurement device [1t81(9) αα, and compares it with the setting value of the condition setting unit αJ, If the coin is correct, an opening signal is given to the coin gate Qυ, and the coin is accepted into the receiving passage Q41. At this time, if the oscillation frequencies of the oscillation coils of the coin detector (51t61 (71) are all the same, the identification determination unit Q2+ controls the drive of each oscillation circuit in addition to the above processing. This is an example showing the control of the identification determination unit α in this case.
In the 1 mode, the identification determination unit α2 controls so that only the oscillation coil of the coin detector (5) oscillates intermittently. Then, during each oscillation drive period t11...t, of the coin detector (6), the identification determination section successively compares the data of the oscillation amplitude measured by the measuring device (8) every 1 ms, and determines the peak value. To detect. However, coin detector (6) in period tan
When the measured peak value for is detected, identification judgment sa3
is T, mode, the driving period t of the coin detector (5;
! , ·to...t, n and the drive period t;1·t,',...ttn of the coin detector (6) are repeated alternately. At this time, the coin has left the coin detector (5) and is now approaching the coin detector (6).

Therefore, the discrimination determination section α is t:1·111...ta
In each oscillation drive period of n, data based on the frequency measured by the measuring device (9) every 1 ms? The peak value is detected by sequential comparison, and each oscillation drive period t□・t2ffi...t!
In the U mode, the measurement device (8) successively compares the data of the oscillation width measured every 1 ms, and thereby monitors the additional insertion of coins in the T mode. and period tJ
When the measurement peak (1) is detected for the coin detector (6) in the mode, the identification determination unit α is set to ), the oscillation driving periods of t;, ・t;, ... tl are alternately repeated. At this time, the coin is detected by the coin detector (
6) and then approaching the coin detector (7).

Therefore, the identification determination section Mata 2 is set at t5 and t8. ...In each oscillation drive period of t and y, the measurement device R (81 is also output
Do you compare the measurement data every ms and insert additional coins? In addition to monitoring, in each oscillation drive period of tit-chi;...t;7, the measurement data outputted from the measuring device αl every 1 ms is successively compared, and the coin detector of the transfer coin (measurement of the sword) is The peak value is detected. When the peak value is detected in the period ts'n, the identification determination unit α2 performs the processing in the TI mode.

According to the present invention, strong coin discrimination can be performed to measure different characteristics of coins in two types of electromagnetic fields depending on the same wave number. The coins can be identified with high precision even though the circuit and processing are complicated in order to set the frequencies used to be the same or, at best, to approximate frequencies that are slightly smooth enough to prevent mutual interference.

[Brief explanation of drawings]

FIG. 1 schematically shows the structure of the coin identification device, and the numbers -10,000 on a pair of opposing side walls (3) are omitted. Figures 2, 3, and 4 are diagrams showing the inductance and loss characteristics when frequencies of 5KH2lI100KH2 and 500KHz are applied to the oscillation coil of the coin detector, respectively. FIG. 5 is an example diagram showing inductance measurement, FIG. 6 is an example diagram showing loss measurement, and FIG. 7 is a diagram showing an example circuit for stopping oscillation of the excavation circuit to prevent interference. FIG. 8 is a timing chart for controlling the oscillation of each oscillation circuit in response to passage of a coin when the oscillation frequencies of the coin detectors are made the same. (4+...coin aisle, +51F61(71...
Coin detector, (81 (910a...measuring device) Applicant Sanyo Electric Co., Ltd. and one other representative Patent attorney Mamoru Sano Figure 1 Figure 7 Deaf to Web ＼Beichi Tokiguchi Figure 5 Figure 6 ■ Φ Moxibustion possible Stomach 1

Claims (1)

[Claims] 1. A first device having a coin passage in which coins to be identified roll, and a first oscillation coil that induces a first alternating current magnetic field in the coin passage.
a coin detector; a first measuring device for detecting the amplitude of oscillation of the first oscillating coil when a coin rolls on the coin path; a second coin detector having a second oscillation coil that induces a second alternating current magnetic field with an approximate frequency having a predetermined frequency difference between the two; and oscillation of the second oscillation coil when a coin rolls in the coin path. a second measurement device that measures frequency;
A coin identification device comprising an identification determination unit that compares each measurement value by the first measurement device and the second measurement device with each corresponding reference value.