JP3281084B2 - Coin identification device - Google Patents

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 for magnetically detecting a coin (for example, a coin) to identify the type of the coin.

[0002]

2. Description of the Related Art Conventionally, in coin processing apparatuses,
A coin identification device is provided for identifying a coin denomination, authenticity, and the like. This coin identification device generally uses a magnetic sensor or the like to detect the amount of magnetism of a coin passing therethrough, and a differential transformer type magnetic sensor has been conventionally used.

[0003] In this differential transformer type magnetic sensor, two secondary coils are arranged so as to sandwich the primary coil around a core around which the primary coil is wound, and the two secondary coils output each other. Are connected so as to negate each other. And, due to the eddy current generated on the surface of the coin as the coin approaches,
The flow of the magnetic flux is obstructed and the output of the secondary coil is out of balance, so that a differential output is obtained at the secondary coil.

Such a differential transformer type magnetic sensor is usually used for detecting the shape of a coin, that is, the hole of the coin. The diameter of a cylindrical core and the diameter of a cylindrical core are each 50 yen. The size was set to about 4.5 mm and 6.5 mm corresponding to the hole diameters of coins and 5-yen coins, and the sensor itself had a relatively small outer shape of 10 to 13 mm.

[0005]

Conventionally, as described above, a small magnetic sensor detects a hole in a coin and another large magnetic sensor detects the material of the coin. Therefore, two magnetic sensors are used. I had to.

Therefore, it has been considered to detect the hole of the coin and the material using a single small magnetic sensor. However, when a small magnetic sensor is used, the output is determined depending on the direction of the coin. There is a problem that if the direction of the front and back of the conveyed coin is not constant, the accuracy of coin identification is reduced.

[0007]

Accordingly, the present invention provides a coin discriminating apparatus which can easily discriminate between the front and back of a coin, and can perform reliable discrimination without deteriorating the discrimination accuracy of the coin even if the front and back of the coin fluctuate. The purpose is to provide.

[0009]

According to the present invention, there is provided a coin identifying apparatus comprising: a conveying means for conveying coins; a magnetic sensor disposed opposite to the conveying means for magnetically detecting a coin to be conveyed; Detecting means for detecting the number of times that the amount of change in the output signal of the magnetic sensor that changes with the transport of the coin is within a predetermined amount range; and Identification means for identifying, storage means for storing a determination reference value for determining the type of coin for each type of coin and front and back of the coin, front and back orientation of the coin identified by the identification means Selecting means for selecting a judgment reference value stored in the storage means, and judging the type of the coin based on the judgment reference value selected by the selection means and the output of the magnetic sensor. It has and a constant section.

[0010]

[0011]

According to the present invention, a coin type is determined.
The judgment reference value for each coin type and coin orientation
And store it on the front and back of the coin identified by the identification means.
Select the stored judgment reference value according to the direction and
In order to determine the type of in, the coin on the front and back
Even if the direction changes, reliable identification can be performed.

[0012] According to the invention, the coin is transported.
Change of the output signal of the magnetic sensor
The number of times the
In order to identify the front and back of the coin, change the coin surface.
Specially distinguish between digit faces with little change and picture faces with many changes
Can be reliably identified without providing
You.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration of a differential transformer type magnetic sensor 1. That is, the columnar internal magnetic body (core) 2 has four flange-shaped protrusions 2 in its length direction.
a, 2b, 2c, and 2d, and the projections 2a and 2c are provided.
b, a primary coil 3b is wound between the projections 2b and 2c, and a secondary coil 3c is wound between the projections 2c and 2d.

Note that a sine wave signal of a predetermined frequency is input from the oscillator to the primary coil 3b. The secondary coils 3a and 3c are electromagnetically induced by the primary coil 3b, and the secondary coils 3a and 3c are disposed so as to sandwich the primary coil 3b.
a, 3c are connected to cancel each other's output,
It constitutes a differential transformer.

The cylindrical internal magnetic body (core) 2 is positioned on a cylindrical external magnetic body (core) 5 via a positioning ring 4, and the external magnetic body 5 is covered by a cylindrical case 6. ing. P below the cylindrical case 6
A C fixing base 7 and a PC board (printed circuit board) 8 fixed by the PC fixing base 7 are provided, and are integrated by a mold resin 9. The magnetic sensor 1
Is output to the outside through a lead wire 10.

Next, the flow of the magnetic flux generated from the primary coil 3b will be described with reference to FIG. Primary coil 3
The magnetic flux generated from b mainly concentrates on the four protrusions 2 a to 2 d of the internal magnetic body 2 and reaches the external magnetic body 5,
At that time, the secondary coils 3a and 3c are linked.

When no coin is present above the magnetic sensor 1 and no coin is detected, the amount of magnetic flux linked to the secondary coils 3a and 3c is equal, and the differential output is a value close to "0" ( Offset value).

As the coin approaches, the output of the secondary coil 3a on the detection surface side starts to decrease. This is because an eddy current is generated in the coin in a direction that obstructs the magnetic flux by the magnetic flux linking from the internal magnetic material 2 to the external magnetic material 5 (the magnetic flux shielding effect is, of course, the material, thickness, and diameter of the coin). This is because the magnetic flux linked to the secondary coil 3a decreases.

The magnetic sensor 1 configured as described above is disposed, for example, in a coin recognition unit of a coin processing device as shown in FIG. That is, a transport path for transporting coins C by the transport belt 12 is formed above the feeding belt 11, and a sensor fixing block 13 is provided below the transport belt 12. Is fixed to the magnetic sensor 1.

On the right side of the sensor fixing block 13, a coin sorting device 15 for sorting coins C by type based on the identification result of the coins C is provided.
Are fixed to a coin sorting device 15 by screws 14.

FIG. 4 shows a configuration of a processing circuit for processing an output signal of the magnetic sensor 1. In the figure, a differential output of the magnetic sensor 1 is input to an amplifier circuit 16 and amplified. The amplification factor of the amplifier circuit 16 can be adjusted by a variable resistor (not shown). After the output of the amplifier circuit 16 is rectified by the rectifier circuit 17, it is converted into a DC signal through a low-pass filter (LPF) 18.

The output of the low-pass filter 18 is input to an A / D converter 19, where it is converted into a digital signal and then sent to a CPU (Central Processing Unit) 20. The CPU 20 controls the A / D converter 1
9 is sampled at fixed time intervals, the maximum value is detected from the sampled data, and a random access memory (RAM) is detected.
(Access memory) 21.

The maximum value is detected by sequentially comparing the sampling data to detect the maximum value and to determine the maximum value.
The error is caused by noise or the like by storing the data in the memory 21 and determining the maximum value when the value falls by a predetermined width (amount) from the current maximum value and terminating the process.

ROM (Read Only Memory) 22
Is stored with firmware (control program) for operating the CPU 20, and is sequentially read and executed by the CPU 20.

Next, changes in the output signal of the magnetic sensor 1 due to the front and back of the coin C will be described with reference to FIGS. 5 to 8, the output signal a is a waveform when the number surface of the coin C is downward, and the output signal b is a waveform when the picture surface of the coin C is downward. 5 is an output waveform of a 1-yen coin, FIG. 6 is an output waveform of a 10-yen coin, and FIG.
FIG. 8 shows an output waveform of a 00 yen coin, and FIG. 8 shows an output waveform of a 500 yen coin.

As is clear from FIGS. 5 to 8, when each coin has its numeral surface facing downward, the output signal is little changed because the numeral surface is relatively flat, and the pattern is flat. When the surface is downward, the shape of the pattern changes to a gentle mountain shape due to a change in the pattern surface, and there is no flat portion.

FIG. 9 shows a distribution surface of coins C and a maximum output value when 100 coins are detected as a sample. The white bar indicates when the design surface is facing down, and the black bar indicates when the numeric surface is facing down. For almost all coins, the output is large when the design surface is down and when the numeric surface is down. While the relationship exists, the output distribution peaks are different. In particular, in the case of white copper coins that are difficult to judge, the output doubles are remarkable.

Therefore, conventionally, the reference value for determining the type of coin C based on the maximum value is a wide range (upper limit) so as to cover both the case where the picture surface is downward and the case where the numeral surface is downward. Value, lower limit value), but in the present apparatus, the determination reference value table of the coin C is limited to a range in which the range of the determination reference value is limited depending on whether the picture surface is downward and the numeral surface is downward. Is set.

As described above, by setting the range of the determination reference value in accordance with the direction of the coin C, the range of the determination reference value of each denomination does not overlap, and the determination of the coin C can be performed accurately. Become.

Next, the operation of discriminating the coin C according to the above configuration will be described with reference to the flowchart shown in FIG. The output of the A / D converter 19 is sampled at regular time intervals by the CPU 20, and the A / D converter 1
When the output of No. 9 rises by a predetermined level from the offset value, identification of the front and back sides is started.

First, the CPU 20 stores, in the RAM 21, values obtained by adding and subtracting a predetermined width from the present detection value as an upper limit value and a lower limit value, and determines whether or not the next detection value is within the range between the upper limit value and the lower limit value. Is determined. When the detected value is within the range between the upper limit value and the lower limit value, the CPU 20 counts up a counter (not shown). When the detected value is out of the range between the upper limit and the lower limit, the upper limit described above,
Reset the lower limit again and reset the counter.

The CPU 20 repeats the above operation until the output of the A / D converter 19 reaches a level close to the offset value, thereby determining the direction of the coin based on the contents of the counter.

That is, when the counter has reached a predetermined value, it is determined that the output signal has a flat portion (the number surface is downward), and when the counter has not reached the predetermined value, the flat portion is determined. It was determined that there was no (the pattern surface was facing down).

The CPU 20 selects a reference value from a judgment reference value table (not shown) based on the results of the front and back judgments. As described above, the determination criterion value table of the coin is set to a range in which the range of the criterion value is limited when the picture surface is downward and when the numeral surface is downward.

Then, the CPU 20 compares the reference value of the selected maximum value with the maximum value of the output of the A / D converter 19 stored in the RAM 21 to determine which coin range the maximum value belongs to. , The type of the coin C is determined.

As described above, if the range of the reference value is set in accordance with the direction of the coin, the range of the reference value of each denomination does not overlap, and the coin can be accurately determined.

Further, since it is possible to determine the front and back of a coin with a simple configuration, there is an effect that the cost is greatly reduced as compared with the case where the front and back of the coin are determined by an optical pattern or the like.

In the above embodiment, the case where the type of coin is identified has been described. However, the present invention is not limited to this. For example, the present invention is similarly applied to an identification device for identifying the type of a medal or the like. it can.

[0040]

As described above in detail, according to the present invention, the front and back of a coin can be easily identified, and even if the direction of the front and back of the coin fluctuates, the accuracy of coin identification can be reduced without deteriorating the accuracy of coin identification. And a coin identification device capable of performing accurate identification.

[Brief description of the drawings]

FIG. 1 is a vertical side view showing a configuration of a magnetic sensor.

FIG. 2 is a diagram illustrating the flow of a magnetic flux generated by a primary coil of a magnetic sensor.

FIG. 3 is a diagram showing an arrangement of a magnetic sensor in a coin identification unit of the coin processing device.

FIG. 4 is a block diagram illustrating a configuration of a processing circuit that processes an output signal of a magnetic sensor.

FIG. 5 is a diagram showing an output signal waveform of a magnetic sensor for a one-yen coin.

FIG. 6 is a diagram showing an output signal waveform of a magnetic sensor for a 10-yen coin.

FIG. 7 is a diagram showing an output signal waveform of a magnetic sensor for a 100 yen coin.

FIG. 8 is a diagram showing an output signal waveform of a magnetic sensor for a 500 yen coin.

FIG. 9 is a view for explaining the distribution of the maximum value of the output signal of the magnetic sensor.

FIG. 10 is a flowchart illustrating a coin discriminating operation.

[Explanation of symbols]

 1 Magnetic sensor 2 Internal magnetic body 2a Projection 2b Projection 2c Projection 3a Secondary coil 3b Primary coil 3c Secondary coil 4 Positioning ring 5 External Magnetic body 6 Cylindrical case 11 Feeding belt 12 Conveyor belt 13 Sensor fixing block 14 Screw 15 Coin sorting device 16 Amplifying circuit 17 Rectifying circuit 18 Low-pass filter 19 ... A / D converter 20 ... CPU 21 ... RAM 22 ... ROM

Claims (1)

(57) [Claims] 1. A transporting means for transporting coins, a magnetic sensor arranged opposite to the transporting means for magnetically detecting the transported coins, and a magnetic sensor which changes as the coins are transported. Detecting means for detecting the number of times the change amount of the output signal is within a predetermined amount range; identifying means for identifying the front and back of the coin based on the detection result of the detecting means; determining the type of the coin Storage means for storing a determination reference value for each type of coin and the front and back of the coin, and the determination criteria stored in the storage means according to the front and back orientation of the coin identified by the identification means. Selection means for selecting a value, and determination means for determining the type of the coin based on the determination reference value selected by the selection means and the output of the magnetic sensor. Coin identification device.