JPH02167490A - Device for discriminating sheets of paper - Google Patents

Abstract

PURPOSE:To improve discriminating accuracy by discriminating sheets of paper based on the ratio value of every area classified by the characteristic of the sheets of paper. CONSTITUTION:A CPU 17 performs integration to entire magnetic information read by magnetic sensors 10a and 10b and stored in a memory 18 so as to obtain the sum of magnetic quantity. Next, the CPU 17 reads out area classification data stored in the memory 18 corresponding to the kind of a bank note P to be discriminated and performs the integration in area to the respective areas 1-5 based on the read data so as to obtain the magnetic quantity. Moreover, the magnetic quantity of the respective areas is divided by the sum of the magnetic quantity previously obtained and the obtained value is taken as the partial ratio value of the area (i). Then, the entire integration value and each partial ratio value are compared with an upper limited value and a lower limited value previously prepared in the memory 18 in order to judge whether or not they are within a specified range, whereas the truth or falsehood of the bank note P of the kind thereof is discriminated.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention is intended to detect the authenticity of banknotes based on magnetic information contained in the banknotes being inspected, for example in automatic banknote inspection machines. Alternatively, the present invention relates to a paper sheet discriminating device for discriminating types.

(Prior Art) Conventionally, in this type of automatic banknote inspection machine, banknotes to be inspected are conveyed along a conveyance path, and various detection means provided at each point of this conveyance path detect a predetermined number of banknotes. Detection is performed, and based on the detection results, various information contained in banknotes is obtained and inspected.

One of these inspection items includes detecting magnetic information contained in banknotes and determining the authenticity, type, etc. of banknotes based on this magnetic information. In other words, the magnetic information is read from the banknote, and the read magnetic information is integrated over the whole using hardware to find the total amount of magnetism, and this total is within the range of the upper and lower limit values prepared in advance. A device that determines the authenticity or type of a banknote by determining whether or not it is a banknote, or a device that performs pattern matching by comparing read magnetic information with a standard pattern prepared in advance.
There is a known method that determines the authenticity or type of banknotes by determining the degree of similarity.

However, the method that distinguishes banknotes by calculating the sum of the magnetic quantities as described above does not depend on the frequency of use of banknotes,
Because the amount of magnetism fluctuates greatly due to variations in the amount of ink during printing, and because the output of the magnetic head decreases due to changes over time, the discrimination accuracy is low.As a result, for example, the authenticity or type may be incorrectly determined. There was a problem. In addition, in the case where banknotes are identified by performing pattern matching and calculating similarity, since the pattern matching process takes time, special hardware such as a microprocessor is added, for example. It is necessary to incorporate software into this to configure the device.
The device of the present invention is complicated and expensive, and as described above, the method that performs the discrimination by calculating the total amount of magnetism contained in paper sheets has low discrimination accuracy, so it is possible to make mistakes in determining authenticity or type. This was developed to solve the problem that most paper sheets are distinguished by pattern matching, which requires the use of dedicated hardware, making the device complex and expensive.It has a simple configuration. It is an object of the present invention to provide a paper sheet discrimination device that can improve discrimination accuracy despite this.

[Structure of the Invention] (Means for Solving the Problem) The paper sheet discriminating device of the present invention includes a reading means for reading magnetic information contained in the paper sheets, and a reading means for reading the magnetic information read by the reading means. an overall integrating means for calculating the sum of the magnetic quantity by integrating the whole, and a magnetic information for each area by integrating the magnetic information read by the reading means for each area of the paper sheet divided into a plurality of parts; and a discriminating means for discriminating the paper sheet by determining the ratio of the amount of magnetism for each region obtained by the partial integration means to the sum of the amount of magnetism obtained by the total integration means. It is characterized by what it did.

(Function) The present invention reads the magnetic information contained in the paper sheet with a reading means and performs overall integration to obtain the total amount of magnetism, and also calculates the total amount of magnetism for each area divided based on the characteristics of the paper sheet. Find the magnetic amount for each region by performing partial integration, and then find the ratio of the magnetic amount in each region to the sum of the previously determined magnetic amounts, and check whether this ratio is within a predetermined value range. By examining this, the authenticity or type of the paper sheet can be determined. As a result, even if there is a variation in the detected amount of magnetism, the characteristics of the paper sheet can be detected and more accurate discrimination can be made.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, timing sensors 1a and 1b are arranged at the same interval on a line perpendicular to the direction of conveyance of the bank note P (in the direction of the arrow in the figure) when magnetic sensors 10a and 10b, which will be described later, are arranged. , a significant signal is output while the bank note P being conveyed blocks this. The outputs of the timing sensors 1a and 1b are input to the exclusive OR gate 2, and the output of the exclusive OR gate 1-2 is input to the input terminal of the programmable timer 3. This programmable timer 3 performs a counting operation only while the output signal (input signal to the enable terminal) of the exclusive OR gate 2 is significant due to the tarlock synchronized with the conveyance lock that causes the banknote P to be conveyed. The count value is the bus 19 which will be described later.
is output to.

Further, the outputs of the timing sensors la and lb are also input to the OR gate 4, and one of the outputs of the OR gate 4 is input to the timing delay circuit 5. This timing delay circuit 5 delays the input output signal of the OR gate 4 by a certain period of time, and the delayed output signal is outputted to a bus 19, which will be described later, via a photo 6.

Furthermore, the output of the timing sensor 1a is input to the data input terminal of the flip-flop 7a, and the output of the timing sensor 1b is input to the pig input terminal of the flip-flop 7b. The output signal of gate 4 is manually input. The outputs of these flip-flops 7a and 7b are output to a node 19, which will be described later, via ports 8 and 9, respectively.

Magnetic sensors 10a and 10b (reading means) are arranged at regular intervals on a line perpendicular to the direction of conveyance of banknotes P, and detect magnetic information on banknotes P being conveyed. These magnetic sensors 10a and 10b use AC bias type differential magnetic heads. This magnetic head applies alternating current to the primary coil, detects it with the secondary coil, and sends this output to preamplifiers 11a, 1l.
By performing differential amplification in b and extracting the signal component, an output signal that is faithful to the magnetic amount of the banknote P is obtained without depending on the conveying speed of the banknote P. These preamplifiers
. The V/F converters 13a, 13b convert the voltages output by the amplifiers 12a11, 2b into frequency signals corresponding to the voltages. The frequency signals output by the v/F converters 13a and 13b are sent to the counter 14.
a, 14b, and at the counter 4a114b,
This frequency signal is counted for a certain period of time. The outputs of these counters 4a and 14b are also output from port 1, respectively.
5 and 16 to a bus 19, which will be described later.

17 is a central processing unit (hereinafter referred to as "cPUJ").

) receives information from each port 6,8,9,15,16, programmable timer 3, etc., performs predetermined processing, and also performs bank note P discrimination processing.

Reference numeral 18 denotes a memory, which includes a program for controlling the CPU 17, data handled by the program, discrimination standard data for the bank note P, that is, data such as a reference value of the magnetic amount of the entire detection area and a reference value for each area, or data read from the bank note P. It stores magnetic information, etc. These CPU 17, memory 8, programmable timer 3 and each port 6.8.9.15
．． 16 are connected by a bus 19, and various data are exchanged between them.

Next, the operation in such a configuration will be explained.

First, the bank note P, which has been conveyed while being held in the transverse direction by a conveyor belt (not shown), is transferred to the timing sensor 1a.
By reaching the installation position of % l b and blocking these timing sensors 1 a s 1 b, significant signals are output from each of the timing sensors 1 a and 1 b. Here, if the bank note P is conveyed in a skewed state, a difference will occur in the times at which the timing sensors 1a and 1b are interrupted, and two significant signals with an interval equal to this time difference will be excluded one after another. is input to logical OR gate 2.

As a result, the output signal of the exclusive OR gate 2 becomes a significant signal only while the time difference occurs, and this signal is supplied to the enable terminal of the programmable timer 3. The programmable timer 3 performs a counting operation only while the signal applied to the enable terminal is significant. Note that the clock supplied to this programmable timer 3 is
Since the count value of the programmable timer 3 is proportional to the amount of skew of the banknote P, the count value of the programmable timer 3 is proportional to the amount of skew of the banknote P.

On the other hand, the output signals of the two timing sensors 1a and 1b are inputted to the OR gate 4, and are logically summed and supplied to the clock terminals of the flip-flops 7a and 7b.
and 7b are also supplied to data input terminals, respectively. The flip-flops 7a and 7b can be set when the rising edge of the detection signal of the timing sensor 1a%1b is input. As a result, either one of the flip-flops 7a or 7b connected to the timing sensor 1a or 1b which detected the banknote P first and generated a significant signal is set, and later detects the banknote P and generates a significant signal. The flip-flop 7 connected to the timing sensor 1a or 1b that generated
The other of a and 7b remains unset, thereby detecting the direction of skew.

The above operations are performed in parallel, and upon completion of these operations, the CPU 17 reads the contents of ports 8 and 9 to which the programmable timer 3 and flip-flops 7a and 7b are connected, and reads the contents of the transferred bank. Recognition processing is performed to recognize in which direction and by how much the ticket P is skewed, and is stored as skew state information for later processing.

Note that if the bank note P that has been conveyed is not skewed, the output signal of the exclusive OR gate 2 will not become significant, and therefore the programmable timer 3 will operate and the count value will remain. Never. Also, since both flip-flops 7a and 7b are set, CP
By reading and examining any of the above, U17 can recognize that there is no skew in the bank note P that has been conveyed.

On the other hand, in parallel with the above-described operation, the magnetic sensor 10
The timing of the start of reading by a and 10b is determined. That is, the output signal of the OR gate 4 is output after being delayed for a certain period of time by the timing delay circuit 5, and this certain delay time is determined by whether either the timing sensor 1a or 1b is connected to the bank. The time is adjusted to be the time from when the ticket P is detected until it is conveyed to the position where the magnetic sensors 10a and 10b are installed. The CPU 17 finishes the recognition process for recognizing the skew state of the bank note P during this fixed delay time.

In this manner, the CPU 17 performs the above-described skew state recognition process and monitors whether a significant signal indicating that a certain period of time has elapsed is output from the timing delay circuit 5 via the port 6. When it is detected through this monitoring that a significant signal has appeared at port 6, it is assumed that the banknote P has reached the position where the magnetic sensors la and lb are installed, and the banknote P is read at predetermined intervals from ports 15 and 16. , starts sampling the magnetic information on the banknote P. At the start of this sampling, the previously recognized and stored skew state information is referred to. That is, if the skew state information indicates that the banknote P that has been conveyed has a skew, the programmable timer 3 first starts sampling the output signal of the magnetic sensor 10a or 10b that arrives later. It is suppressed by the count value counted in , and magnetic information is skipped during this time. Then, processing is performed to start sampling the magnetic information after this skipped reading. Thereby, the magnetic information on the bank note P can be read accurately.

The operation until the magnetic information detected by the magnetic sensors 10a and 10b is taken into the CPU 17 is as follows. That is, the banknote P is connected to the magnetic sensors 10a and 10b.
When the outputs of the magnetic sensors 10a and 10b reach the installation position, the alternating current components are removed by the differential amplification of the preamplifiers lla and llb, as described above, and only the signal components are extracted.

This signal component is sent to amplifiers 12a and 12b, where it is amplified to a constant value and output. This amplified signal is sent to V/F converters 13a and 13b, where it is converted from voltage to frequency and output. This output signal is sent to counters 14a, 14b, where it is counted for a certain period of time, and then sent to ports 15 and 16, where it is latched.

When the count value (magnetic information) is latched in this way, the CPU 17 transfers the contents of ports 15 and 16 to the bus]
At the same time, the counters 14a and 14b are cleared. Immediately after this clearing, counting of the next magnetic information is started. By repeating the above operations, the magnetic information on the bank note P is sequentially read and stored in the memory 18.

The magnetic information stored in the memory 18 as described above is
This is used for recognition processing such as authenticity determination or type determination by the CPU 17. In other words, first the CPU 17
calculates the total amount of magnetism by integrating the entire magnetic information obtained from the bank note P stored in the memory 18 as shown in FIG. 2 (total integration means)
. This total magnetic amount is stored in the memory 18 for later processing.

Next, the memory 1 corresponds to the type of bank note P to be determined.
The area division data stored in 8 is read out. This area division data provides information for dividing the banknote P into small sections such as A, B, CSD, and E shown in FIG. 2, which most clearly represent the magnetic distribution state of the banknote P. In FIG. 2, banknote P is divided into areas 1 to 5 according to the area classification data.
It shows that the area is divided into five areas.

Next, on the basis of the area division data read from the memory 18, integration is performed within each of these areas 1 to 5 to determine the amount of magnetism in each area 1 to 5 (partial integration means). Furthermore, each area 1 to 5 found
The magnetic amount is divided by the sum of the previously determined magnetic amounts, and this is taken as the partial ratio value of area i. That is, the partial ratio value of area i is determined by the following formula.

Area i integral/total integral = area i partial ratio where i=l~
5, the region i integral is the sum of the magnetic quantities in region i,
The overall integral is the sum of the magnetic quantities of all regions 1 to 5.

Next, the value of the total integral and the value of each partial ratio obtained as described above are compared with the upper limit value and lower limit value prepared in advance in the memory 18 corresponding to the type of bank note P. That is, it is determined whether the overall integral value is within a predetermined upper limit value and lower limit value, and it is also determined whether the value of each partial ratio is between the upper limit value and lower limit value for each region. (discrimination means). This allows the authenticity or type of bank note P to be determined.

In this way, in addition to identifying banknotes P based on the sum of magnetic quantities determined by global integration, banknotes P can also be discriminated based on the ratio of magnetic quantities in each area divided according to the characteristics of banknotes P. Therefore, even if the amount of magnetism contained in the bank note P decreases overall due to changes over time or deterioration of the bank note P, the ratio with each area hardly changes, making it possible to obtain accurate discrimination results. It has become a thing.

Note that in the above embodiment, banknotes are discriminated by dividing the banknote into five regions and obtaining partial integral values for each region, but the number of divisions is not limited to this.
Even if the banknote is divided into 5 or less or 5 or more for discrimination based on the magnetic distribution state specific to the type of banknote, the same effect as in the above embodiment can be obtained.

In addition, the memory 18 stores area classification pigs corresponding to multiple types of banknotes and corresponding upper and lower limit values for comparison.
By providing a means for selecting these types in the CPU 17, it is possible to distinguish between a plurality of types of banknotes using the same device.

Further, by preparing area classification data in the memory 18 when the bank note is being conveyed in the forward direction and in the reverse direction, and by preparing an upper limit value and a lower limit value for each area, the direction in which the bank note is conveyed is also detected. I can do it.

Further, in the above embodiment, the case where the present invention is applied to a discriminating device for banknotes has been described, but the present invention is not limited to this, and can be applied to a discriminating device for other paper sheets such as securities such as checks. Also applicable to Mori, 9...Bass.

Ru.

[Effects of the Invention] As described in detail above, according to the present invention, the discrimination is made based on the ratio value of each area divided based on the characteristics of the paper sheet, so it is a simple structure. Nevertheless, it is possible to provide a paper sheet discrimination device that can improve discrimination accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining its operation. la, ], b... timing sensor, 2... exclusive OR gate, 3... programmable timer, 4...
・OR gate, 5...timing delay circuit, 6
゜8.9, 15.16-=Port, 7a, 7b...Flip-flop, 10a, 10b...Magnetic sensor (reading means), lla, 1lb-...Preamplifier, 12a
. 12 b-...Amplifier, 13 a, 13 b・=V
/F converter, 14a, 14b-counter, 17-CPU
(Total integration means, partial integration means, discrimination means), 18...
・Patent attorney Kensuke Norichika Patent attorney Sanno

Claims (2)

[Claims] (1) a reading means for reading magnetic information contained in paper sheets; an overall integrating means for calculating the total amount of magnetism by integrating the entirety of the magnetic information read by the reading means; and magnetism read by the reading means. a partial integration means for integrating information for each region of the paper sheet divided into a plurality of parts to obtain the magnetic quantity for each region; and a partial integration means for calculating the sum of the magnetic quantities obtained by the overall integration means. A paper sheet discriminating device comprising a discriminating means for discriminating the paper sheet by determining the obtained ratio of the amount of magnetism for each region. (2) The determination means determines whether each ratio value obtained by the total integration means and the partial integration means is within a range of an upper limit value and a lower limit value specific to the paper sheet. A paper sheet discriminating device according to claim 1.