JPS6236592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a coin sorting method for determining suitability based on the degree of influence of a test coin on an oscillating magnetic field.

(B) Conventional technology In general, such coin sorting involves measuring the characteristics of coins by capturing the degree of influence caused by placing the test coin in an oscillating magnetic field by changes in inductance, frequency, phase, induced voltage, etc. It is. As a conventional coin sorting device, there is a configuration disclosed in Japanese Patent Publication No. 52-6200, in which coin measuring devices are installed in two ways, one for inspection and one for reference, and for the reference, real coins are placed in advance for inspection. When a coin to be inspected has passed, the suitability of the coin is determined by comparing the two measurement results. Further, as for setting the reference, there is also a configuration shown in Japanese Patent Publication No. 48-799, in which a variable resistor or a variable capacitor is used to make the electrical conditions the same as those of the reference coin. However, recently, as disclosed in Japanese Patent Application Laid-Open No. 49-95692, a semiconductor memory is used instead of such standard coins and standard setting parts to store standard information such as acceptance range information of appropriate coins and tolerance range. I'm starting to set it up.

However, when the standard information is used to discriminate between coins with significantly different information, it is possible to expand the acceptance tolerance range, and there is no problem in practical use.
If the coin inspection information is very similar depending on the type of coin, or if sophisticated counterfeit coins are inserted, the acceptance rate of genuine coins will be greatly reduced because the acceptance range will be differentiated from other genuine coins or counterfeit coins. It is necessary to keep the range as narrow as possible to the extent that it does not cause In this case, the measurement information from the coin measuring device due to the stable rolling of the coin is not affected by external changes such as the frequency of the alternating magnetic field, voltage, temperature, or various electrical elements in the measurement circuit, but is always kept under stable conditions. In order to achieve this, circuits, elements, and mechanisms must be devised, making the device complicated. For this reason, Japanese Patent Application Laid-Open No. 48-29499 discloses a coin sorting method in which the influence of the variation is canceled by adding or subtracting the variation in the inspection conditions from the measured value of the coin. However, such correction is not necessarily perfect, which will become clear from the description below.

(c) Problems to be Solved by the Invention Before describing the problems, the specific structure of the coin sorting device will be explained with reference to FIGS. 1 to 3. In FIG. 1, the coins inserted from the upper socket 2 of the coin sorting device form one side of the coin passage 16 at an angle of about 10
The coins roll through a passageway 16 formed by the board A2 having an angle of 20° and the board B9 on the other side on the rail located below, and the coins are sent to the material sensor 4, plate thickness sensor 5, and diameter sensor 6 arranged in sequence. When the coin passes through each section and the information of the plurality of testers matches the predetermined reference value information, the receiving gate 7 is sucked and the genuine coin is introduced into the passage 8. The plate thickness sensor includes a pot-shaped core 10 made of ferrite material embedded in the walls of each of the substrates 3 and 9, and a coil 1 wound inside the core 10.
1 and core 12 and coil 1 wound inside it
3, and its passage dimension A is set to have a slight margin for the maximum thickness of the coins used. In the configuration of this example, the thickness of the inserted coin 18 is equal to the thickness T of the recessed portion approximately in the center of the coin.
will be measured, and this dimension will indirectly detect the thickness T of the center portion of the coin by measuring the dimension B from the substrate 9 side sensor and the dimension C from the substrate 3.

Figure 3 shows each coil 11, 1 shown in Figure 2.
This is the connection method of No. 3 and its circuit configuration. In this circuit, only the board thickness inspection circuit is shown for the sake of explanation, and other inspection circuits are omitted. The coils 13 and 11 enter the oscillation circuit 19 by making a series anti-phase connection so as to mutually cancel out the oscillating magnetic fields so that the mutual inductance becomes negative. The series anti-phase connection is used when the passage dimension A changes, for example when it becomes wider.
The total inductance of coil 3 and coil 11 increases, lowering the oscillation frequency, and acts to compensate for the decrease due to the increase in path size.

The oscillation circuit 19 is configured to oscillate at an oscillation frequency determined by the built-in capacitor, the coil 13, and the inductance obtained by the coil 11, and further includes a built-in waveform shaping circuit to change the oscillation waveform from a sine wave to a logic circuit level. are doing. The output of the oscillation circuit 19 is input to a judgment calculation circuit 21, which stores the value of the oscillation frequency, which is the degree of influence of the oscillation magnetic field when the coin passes between the coils 13 and 11, and the storage device 22. If the set standard information is checked and they match within the allowable error range, the measurement result by the plate thickness sensor 5 is a signal 23 indicating that the coin is a genuine coin, or a specific type among a plurality of coin types. It outputs a signal 23 indicating that.

Figure 4 shows the coin sorting device with the above configuration, when there are no coins and when the thickness is 1.0 mm/1.5 mm.
This shows the frequency change when there are mm and 2.0 mm coins, and this characteristic diagram allows you to understand that the measured value of the coin must be effectively corrected in response to fluctuations in the inspection conditions. That is, in the same figure,
The horizontal axis T represents the thickness of the central part of various inserted coins or equivalent counterfeit coins, etc., and the vertical axis represents the oscillation frequency, which is the output 20 of the oscillation circuit 19 in FIG. 3, and the T ₀ point is This is the oscillation frequency when no coins are inserted, and is the standby frequency. As described above, this standby frequency is determined by the characteristics of the coils 13, 11, the capacitors inside the oscillation circuit 19, and the oscillator. ₁ , ₀ , on the T ₀ line
₂ is the standby frequency, ₀ is the oscillation frequency when reference information is set in the storage device 22 during adjustment at the factory, etc., and ₁ and ₂ are both caused by external factors such as ferrite of pot core 10 or 12. This shows a state in which the standby oscillation frequency changes due to changes in inspection conditions due to changes in magnetic permeability, capacitance of the capacitor inside the oscillation circuit, changes in passage dimension A over time, etc. The relationship between ₂ , ₀ , ₁ is ₂ > in frequency
₀ > ₁ , ₂ indicates an increase in frequency, and ₁ indicates a decrease in frequency. In this example, ( ₂ − ₀ ) = ( ₀ −
₁ ). Under these conditions, if the coin thickness T is varied, the change in the oscillation frequency will be as shown in the graph.For example, if a coin with a thickness of 2.0 mm is inserted, the standby frequency will change to ₀ depending on the standby frequency. ₀ T ₂ . ₀ for , ₁ T _{2 .} for ₁ .
In the case of ₀ and ₂ , it becomes ₂ T ₂ . ₀ , and the difference between them ( ₂ T ₂ . ₀ ) − ( ₀ T ₂ . ₀ ) is ( ₀ T ₂ . ₀ ) − ( ₁ T ₂ . ₀ )
Become bigger. Also, each difference is the difference in standby frequency, that is, ( ₂ ) - ( ₀ ) or (
It can be seen that it is larger than ₀ )-( ₁ ). Also, _the same difference when inserting a 1.0 mm coin shows the same trend, but ( ₂ T _2.0 )−
( ₀ T ₂ . ₀ ), the difference in oscillation frequency in the T ₁ . ₀ part under the same conditions is small. The reason for this is that the change in the standby oscillation frequency when a coin is inserted is a geometric change, and the thicker coin is closer to the sensor on the board 9 side, so the change in the coil 13 becomes larger, and the inductance change becomes exponential. This shows that there is a tendency to increase functionally.

In this way, the change in the measurement frequency is not uniform as the inspection conditions change;
There is a correction method that directly adds or subtracts the variation in the oscillation frequency during standby from the oscillation frequency when coins are inserted, as shown in Publication No. 29499, or a correction method in which the variation in the oscillation frequency during standby is multiplied by a correction coefficient of 1%. This method of correction is incomplete. Therefore, under such correction, it is extremely difficult to set a narrow tolerance range in order to accept only genuine coins.

Therefore, the present invention makes it possible to correct the measurement values obtained from the test coins according to the degree of measurement imbalance resulting from variations in the standby frequency and differences in coin characteristics (e.g., thickness). The present invention provides a method for sorting coins.

(d) Means for Solving the Problems In order to solve the above problems, the coin sorting method according to the present invention is explained using the characteristic diagram of FIG. A first standby value ₀ is set in advance, which is the measured value when the test coin is not present, and a second standby value ₂ is set in advance, which is the measured value immediately before the test coin is present in the oscillating magnetic field when the device is operating.
When detected, the difference ( _2-0 ) between the first standby value and the second standby value is multiplied by a predetermined first correction coefficient α to obtain a first correction value ( _2-0 ) indicating the degree _of variation in the inspection conditions.
₀ )・α is calculated, and if a test coin is present in the oscillating magnetic field during operation _of the device, the difference between the measured value ₂ T _2.0 of the coin indicating the degree of influence at that time and the second standby value ( ₂ T ₂ . ₀ − ₂ ) is multiplied by a predetermined second correction coefficient β to calculate a second correction value ( ₂ T ₂ . ₀ − ₂ ) β indicating the degree of fluctuation caused by changes in the coin characteristics,
Next, the coin measurement value ₂ T ₂ . ₀ is converted to the first correction value ( ₂ −
₀ )・α, the second correction value ( ₂ T ₂ . ₀ − ₂ )・β, and the difference between the first standby value ₀ and the second standby value ₂ ( ₂ −
₀ ), calculate the following formula, x= ₂ T ₂ . ₀ − [( ₂ − _{0 ) ・}α ₊ ( _{2 T 2 .}
... The suitability of the test coin is determined based on the calculated value x resulting from this correction.

(e) Effect In the formula, the conventional correction is to subtract the variation in the oscillation frequency during standby ( ₂ - ₀ ) from _the coin measurement value ₂ T ₂ . The amount of change is corrected. Then, from ₂ T _{2. 0} , the first correction value ( ₂ − ₀ )・α
By subtracting , the part that changes exponentially due to the change in standby frequency is corrected. Moreover, by calculating the first correction value according to the variation ( _2-0 ) of the standby frequency at this time, _the correction becomes effective in all regions of the test frequency. ₂ T ₂ at the same time.
By subtracting the second correction value ( ₂ T ₂ . ₀ − ₂ )·β from ₀ , the imbalance caused by the difference in the characteristics of the coins is corrected.

(F) Embodiment FIG. 5 shows a control circuit for coin sorting, and the configuration of the device and the structure of the plate thickness sensor 5 are the same as those in FIGS. 1 and 2. When a coin is inserted into the socket 2, it first passes through the material sensor 4, and based on the output of the material sensor 4, the material discrimination circuit 15 determines whether the coin is suitable from the viewpoint of the material, but this is not directly related to the present invention. The explanation will be omitted because it is unrelated. At the same time, the material discrimination circuit 15 is connected to the standby frequency acquisition circuit 2.
A coin insertion signal 14 is output to 6. Upon input of the signal 14, the standby frequency acquisition circuit 26 acquires the frequency of the oscillation circuit 19. The state in which the coin passes through the material sensor 4 and the material discrimination circuit 15 outputs the coin insertion signal 14 is a standby state for the plate thickness sensor 5 just before the coin passes, and the standby frequency acquisition circuit 26 is the standby frequency of the plate thickness sensor 5 when the device is in operation. The standby frequency of the plate thickness sensor 5 at the time of adjustment, such as during production of the device, is set in the standby frequency storage section 28 of the storage device 22, and the standby frequency fluctuation calculation circuit 27 stores the standby frequency at the time of adjustment and operation. The change is calculated and the result is output to the correction circuit 30. The coin that has passed through the material sensor 4 reaches the plate thickness sensor 5, and when the peak value detection circuit 29 detects the maximum frequency at that time, it outputs this to the correction circuit 30 as a measured value indicating the degree of influence by the coin. The correction circuit 30 calculates the difference between the standby frequency during adjustment, that is, the first standby value, and the standby frequency during operation, that is, the second standby value, and multiplies the value of the difference by a correction coefficient α for the change in standby frequency. A first correction value is calculated. Further, the correction circuit 30 produces a difference between the measured value and the second standby value, and calculates a second correction value by multiplying the value of the difference by a correction coefficient β for the imbalance due to the difference in the thickness of the coin. Then, the correction circuit 30 corrects the measured value by subtracting the first correction value, the second correction value, and the standby frequency change value from the measured value.
The values of the correction coefficients α and β are constants determined by the sensitivity of the sensor, the size of the passage, the difference due to the thickness of a plurality of coins, etc. In this way, the correction circuit 30
The corrected measurement value is compared with reference information set in the acceptance range information storage section 3 of the storage device 22 in the comparison circuit 32. and verification circuit 32
outputs a signal 23A indicating the specie or denomination for plate thickness measurement if the corrected measured value is within the acceptable range.

In this example, the description has been made using the plate thickness sensor 5, which is most effective when applied, but the same applies to the material sensor 4 and the diameter sensor 6.

(G) Effects of the Invention According to the present invention, since effective correction can be made in all areas according to variations in inspection conditions, the allowable error range can be set narrowly and accurate coin sorting can be performed. Furthermore, in addition to frequency fluctuations, it is possible to perform accurate judgment operations that take into account error ranges in order to compensate for excessive influences due to differences in characteristics due to coin thickness, etc.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the coin sorting device, Figure 2 is
Cross-sectional view of the plate thickness sensor, Figure 3 is the control circuit, Figure 4 is the control circuit.
The figure shows plate thickness characteristics for coins, and FIG. 5 shows a control circuit according to the present invention. 5... Plate thickness sensor, 13, 11... Coil,
29...Peak value detection circuit, 30...Correction circuit.

Claims (1)

[Claims] 1. A coin sorting method in a coin sorting device that forms an oscillating magnetic field and determines the suitability of the test coin by measuring the influence of the test coin on the oscillating magnetic field,
A first standby value, which is a measured value when no coin is present in the oscillating magnetic field, is set in advance when adjusting the device, and a second standby value, which is a measured value immediately before a coin exists in the oscillating magnetic field, is set in advance when the device is operating. When the standby value is detected, a first correction value indicating the degree of variation in the inspection conditions is calculated by multiplying the difference between the first standby value and the second standby value by a predetermined first correction coefficient, and oscillation is detected when the device is operating. When a test coin exists in the magnetic field, the difference between the measured value of the coin indicating the degree of influence at that time and the second standby value is multiplied by a predetermined second correction coefficient to calculate the degree of variation caused by the change in the characteristics of the coin. The coin measurement value is then corrected based on the first correction value, the second correction value, and the difference between the first standby value and the second standby value, and A coin sorting method characterized by determining the suitability of test coins based on calculated values.