WO2015003415A1

WO2015003415A1 - Magnetic sensor, method for quantitatively identifying magnetic hysteresis loop characteristics of magnetic code, automatic teller machine and currency detector

Info

Publication number: WO2015003415A1
Application number: PCT/CN2013/080676
Authority: WO
Inventors: 赵彰武
Original assignee: 广州纳龙智能科技有限公司
Priority date: 2013-07-06
Filing date: 2013-08-02
Publication date: 2015-01-15
Also published as: CN103366438B; CN103366438A

Abstract

A magnetic sensor, a method for quantitatively identifying magnetic hysteresis loop characteristics of a magnetic code, and an automatic teller machine and a currency detector which are provided with the magnetic sensor. The magnetic sensor is provided with a magnet (5) and a magnetic sensitive element (4). The magnetic sensitive element (4) responds to the magnitude and direction of a magnetic-code magnetic field which is generated by a magnetic code in a paper currency which is magnetized by the magnet (5), the whole or part of a magnetic hysteresis loop process is completed when the magnetic code is magnetized by the magnet (5) while passing through the surface of the magnetic sensor, the magnetic sensor reads a signal of a corresponding magnetizing process, and then, identification is carried out. The magnetic sensor can distinguish the properties of the magnetic code and quantitatively define the magnetic hysteresis loop characteristics of the magnetic code independent of intensity of signals of the magnetic code, and is not sensitive to detection clearances accordingly and consequently has the characteristics of high identification accuracy and good identification stability.

Description

Magnetic sensor, method for quantitatively identifying magnetic code hysteresis loop characteristics, automatic teller machine and money detector

The present invention relates to the field of financial magnetic authentication technology, and in particular to a magnetic sensor and a method for quantitatively identifying a magnetic hysteresis loop characteristic of a magnetic code, and an automatic teller machine and a money detector having the magnetic sensor. This application is based on the Chinese patent application No.: 2013102814705, and the filing date of the Chinese invention patent application dated July 06, 2013.

Background technique

Currency is one of the essential elements of the circulation market. In order to ensure the stability of the financial circulation order, it is necessary to identify the authenticity of the currency.

Since the currency is printed, a plurality of magnetic codes are distributed. The currency authenticity test is performed by examining these magnetic code features. In the prior art, the methods for detecting magnetic code features include magnetic detection and optical characteristic detection.

Magnetic identification is widely used in currency detection because of its advantages such as easy and fast inspection. At present, financial magnetic authentication has become one of the indispensable means to maintain the stability of financial circulation.

The principle of magnetic discrimination is to detect the magnetic code set in the currency, including the characteristics of magnetic field strength and position distribution. With the advancement of technology, financial magnetic authentication technology has experienced the development of more advanced Hall magnetoresistance by induction coils that are too sensitive to the speed of detection and detection. However, the Hall magnetoresistance weak magnetic field has a very low magnetic reluctance rate, and its identification procedure needs to rely on the magnetic code signal strength. Therefore, it requires a minimum detection gap, usually less than 0.1. The signal changes with the gap and other influences on the signal strength. The factors are unstable, and it is prone to a series of problems such as high card rate, high wear rate, and easy to break due to high pressure.

In addition, Hall magnetoresistance cannot be easily and easily distinguished between soft magnetic and hard magnetic due to its symmetrical response to the direction of the magnetic field. As shown in Fig. 1, it is impossible to identify the complete hysteresis loop characteristic. Can only be based on magnetic one-sided The geometric mechanical properties of the code and the attempt to judge the absolute value or ratio of the strength of the different magnetic code signals lead to a strong dependence on the signal strength of the magnetic code and uncertainty in the judgment of the signal strength. The magnetic characteristics of the magnetic code are completely anti-counterfeiting. It turns out that Hall magnetoresistance cannot identify the new version of counterfeit banknotes that have appeared in recent years.

Furthermore, Hall-magnetoresis, which is currently dominated by the market, cannot avoid the superposition of magnetic code signals with small adjacent pitches, which complicates the authentication process.

In today's highly developed technology, it is not difficult to forge the magnetic field size and position distribution of real magnetic codes, and the uncertainty as described above in traditional technology judgments poses a challenge to the identification of magnetic codes.

Therefore, it is necessary to provide an authentication technique capable of identifying more technical features of the currency. In fact, unless you know the magnetic code formula and manufacturing process of the printing bank, it is very difficult to completely imitate the full hysteresis loop characteristics of all the multiple real magnetic codes. Therefore, it is not necessary to simply compare the size and position distribution of the magnetic code magnetic field, and it is necessary to qualitatively and quantitatively identify the soft and hard magnetic properties and hysteresis loop characteristics of the magnetic code to ensure the stability of the signal judgment and reduce the identification method. Uncertainty.

Therefore, in view of the deficiencies of the prior art, it is necessary to provide a magnetic sensor and a method for quantifying the hysteresis loop characteristics of the magnetic code, and an automatic teller machine and a money detector using the technology to overcome the deficiencies of the prior art.

Summary of the invention

One of the objects of the present invention is to provide a magnetic sensor capable of completely discriminating the characteristics of hysteresis loops possessed by a plurality of magnetic codes of a currency setting, avoiding the deficiencies in the prior art.

Another object of the present invention is to provide a method for quantitatively identifying the characteristics of a magnetic code hysteresis loop using the above-described magnetic sensor while avoiding the deficiencies in the prior art.

Another object of the present invention is to provide an automatic teller machine which avoids the deficiencies in the prior art, and which is capable of completely discriminating the characteristics of the hysteresis loops possessed by the plurality of magnetic passwords of the money setting and accurately identifying the currency true. Pseudo. Still another object of the present invention is to provide a money detector which can accurately distinguish the characteristics of the hysteresis loops possessed by the plurality of magnetic passwords of the money setting and avoid the deficiencies in the prior art. True or false.

The above object of the present invention is achieved by the following technical measures.

A magnetic sensor is provided, the magnetic sensor being provided with a magnet and a magnetic sensitive element, the magnetic sensitive element responding to a magnetic code magnetic field generated by a magnetic code in the magnetized banknote and a direction of a magnetic code magnetic field, the magnetic code When passing through the surface of the magnetic sensor, the magnet is magnetized to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the signal of the corresponding magnetization process and then performs identification;

The magnetic sensitive element is composed of two or four magnetic sensitive units having the same specifications and the same response to the direction of the magnetic field. When the magnetic sensitive elements are two, the two magnetic sensitive elements constitute a benefit Stone half bridge circuit; when the magnetic sensitive elements are set to four, four of the magnetic sensitive units constitute a Wheatstone full bridge circuit;

The Wheatstone half bridge circuit or the Wheatstone full bridge circuit is symmetrically distributed on both sides of the magnet center line in the magnetic induction direction.

The magnetic field response of the magnetic sensitive unit is the same as the direction of the magnetic field, and the magnetic sensitive unit arranged on one side of the magnet center line has the same response to the same magnetic field direction on the other side of the magnetic sensitive unit; each of the magnetic sensitive units detects The direction of the magnetic field is the same or opposite to the direction in which the magnetic code moves laterally along the magnet.

The magnetic sensitive unit is configured as an induction coil, a giant magnetoresistance, a tunnel magnetoresistance, an isomagnetoresistive film or device having a barbershop type conductive stripe, a fluxgate or a superconducting heterojunction.

The magnets are arranged in an elongated shape, the north and south poles of the magnet being perpendicular to the magnetic induction direction of the magnetic sensor and the magnetic sensor plane, and the transverse magnetic field strength enables the magnetic code to undergo a partial or full hysteresis loop process while passing the magnetic sensor in the lateral direction.

The invention provides a method for quantitatively identifying magnetic code hysteresis loops by using the above magnetic sensor a method in which a magnetic code is magnetized by the magnet while passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and a magnetic sensor reads a magnetic field magnitude and a magnetic field direction signal of a magnetization process of the magnetic code and then The hysteresis loop characteristics of the magnetic code are then identified.

The above identification of the hysteresis loop characteristics of the magnetic code includes the identification of the magnetic code hard and soft magnetic characteristics and the quantitative definition of the coercive force of the magnetic code.

The above-mentioned magnetic code soft and hard magnetic characteristic identification is specifically determined whether the magnetic code is a soft magnetic whose coercive force is smaller than the magnetic field of the magnet according to whether the signal of the single magnetic code is a single-sided peak;

The quantification defines the coercive force of the magnetic code to specifically measure and quantify the ratio of the peak, the width, or the half-peak time width between different peaks of each single magnetic code signal sensed by the magnetic sensitive unit. Defining the magnitude of the coercivity of the magnetic code; or

The quantification defines the coercive force of the magnetic code by specifically calculating a difference between a peak, a wave width, or a half-peak time width between different peaks of each single magnetic code signal sensed by the magnetic sensitive unit. Quantization defines the magnitude of the coercivity of the magnetic code.

The specific process of identifying the above-mentioned magnetic code soft and hard magnetic characteristics is:

When the signal displayed by a single magnetic code only shows a single-sided signal peak, the magnetic code is identified as a soft magnetic whose coercive force is smaller than the magnetic field of the magnet;

The specific process of quantifying the coercivity of a magnetic code is:

When two single-sided peaks appear, it is determined that the coercive force is zero;

When two bilateral peaks appear, it is determined that the coercive force is greater than the magnetic field of the magnet;

When more than two bilateral peaks appear, the coercive force is less than the magnetic field of the magnet, and the ratio of the peak of the first peak to the peak, the width of the wave, or the width of the half-peak of the second peak defines the magnitude of the coercive force;

Quantifying the difference between the peak of the first peak and the peak, the width of the wave, or the width of the half-peak of the second peak defines the magnitude of the coercive force;

When more than two bilateral peaks appear and the ratio is less than 1.0, the closer the ratio is to zero, the more The closer the coercive force is to the magnetic field of the magnet; when more than two bilateral peaks appear, and the ratio is greater than 1.0, the closer the ratio is to 1.0, the closer the coercive force is to the magnetic field of the magnet.

The invention provides an automatic teller machine, which is provided with an inspection unit for discriminating and detecting the authenticity of the banknote, the inspection unit is provided with a sensor, a processing unit and a display unit, and the sensor collects the magnetic code signal of the banknote and transmits the collected information to The processing unit is processed by the processing unit and sent to the display unit for display. The sensor is configured as the magnetic sensor described above, and the magnetic sensor uses the above method for quantitatively identifying the hysteresis loop characteristics of the magnetic code for authenticity identification.

The invention also provides a money detector, which is provided with an inspection unit for discriminating and detecting the authenticity of the banknote, the inspection unit is provided with a sensor, a processing unit and a display unit, and the sensor collects the magnetic code signal of the banknote and collects the information. It is sent to the processing unit, processed by the processing unit and sent to the display unit for display. The sensor is set as the magnetic sensor described above, and the magnetic sensor uses the above method for quantitatively identifying the hysteresis loop characteristics of the magnetic code for authenticity identification.

The magnetic sensor of the invention and the method for quantitatively identifying the hysteresis loop characteristics of the magnetic code, the magnetic code being magnetized by the magnet when passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and being read by the magnetic sensor The signal of the corresponding magnetization process is then characterized by the hysteresis loop characteristics of the magnetic code. The invention can distinguish the soft and hard magnetic properties of the magnetic code and can quantify the hysteresis loop characteristic of the defined magnetic code, and does not depend on the strength of the magnetic code signal, so as to be insensitive to the detection gap, so the identification accuracy is high and the identification stability is good. specialty.

The automatic teller machine of the invention performs authenticity identification of the banknote, and the magnetic code is magnetized by the magnet when passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the signal of the corresponding magnetization process and then The hysteresis loop characteristics of the magnetic code are then identified. The automatic teller machine of the invention can distinguish the soft and hard magnetic properties of the magnetic code and can quantify the hysteresis loop characteristic of the defined magnetic code, and is not sensitive to the detection gap, independent of the strength of the magnetic code signal, so the identification accuracy is high and the identification is performed. Good stability.

The money detector machine of the invention performs authenticity identification of the banknote, and the magnetic code is passed through the surface of the magnetic sensor The magnet is magnetized to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the signal of the corresponding magnetization process and then identifies the hysteresis loop characteristics of the magnetic code. The money detector of the invention can distinguish the soft and soft magnetic properties of the magnetic code and can quantify the hysteresis loop characteristic of the defined magnetic code, and is not sensitive to the detection gap, independent of the strength of the magnetic code signal, so the identification accuracy is high and Identification of good stability characteristics.

DRAWINGS

The invention is further described with reference to the drawings, but the contents of the drawings do not constitute any limitation of the invention.

Figure 1 is a schematic diagram of hard magnetic and soft magnetic signals read by a Hall magnetoresistive sensor that is indistinguishable from the direction of the magnetic field.

Fig. 2 is a view showing the configuration of a magnetic sensor embodiment 1 of an automatic teller machine of the present invention. Fig. 3a shows a comparison of the soft magnetic code with zero coercive force and the signal obtained when the hard magnetic code having a coercive force greater than the magnetic field of the magnet passes through the magnetic sensor.

Figure 3b shows the signal obtained when the magnetic code whose coercive force is smaller than the magnetic field of the magnet passes through the magnetic sensor.

Figure 4 is a schematic illustration of the path of the magnetization process experienced by a hard or soft magnetic code as it passes transversely through the magnet.

In Figure 2, it includes:

Module 1, housing 2, Wheatstone bridge circuit interface 3, magnetic sensor 4 and magnet 5. detailed description

The invention is further described in conjunction with the following examples.

Example 1.

A magnetic sensor, as shown in Fig. 2, is provided with a base 1, a casing 2, a Wheatstone bridge circuit interface 3, a magnetic sensing element 4, and a magnet 5.

The base body 1 is used to carry other components, and the base body 1 is usually a plastic block or is mechanically strong by other components. The composition of the object. The magnetic sensing element 4 responds to the magnitude of the magnetic code magnetic field generated by the magnet 5 when magnetizing the magnetic code and the direction of the magnetic code magnetic field. When the magnetic code passes through the surface of the magnetic sensor, it is magnetized by the magnet 5 to complete a complete or partial hysteresis loop. The process, and the signal of the corresponding magnetization process is read by the magnetic sensor and then identified.

The magnet 5 is arranged in an elongated shape, and the magnet 5 may be a single or a plurality of permanent magnets, a direct current or alternating current coil, or other electromagnets.

The north and south poles of the magnet 5 are perpendicular to the magnetic induction direction of the magnetic sensor and the magnetic sensor plane, and the transverse magnetic field strength allows the magnetic code to undergo some or all of the hysteresis loop process as it passes laterally through the magnetic sensor.

Specifically, the magnetic field response of the magnetic sensitive unit is the same in the same magnetic field direction, and the magnetic sensitive unit arranged on one side of the center line of the magnet 5 has the same response to the same magnetic field direction on the other side.

The direction of the magnetic field detected by each of the magnetic sensing units is the same as or opposite to the direction in which the magnetic code moves laterally along the magnet 5.

The magnetically sensitive unit is configured as an induction coil, giant magnetoresistance, tunnel magnetoresistance or an exo magnetoresistive film or device with barbershop-style conductive stripes. It should be noted that the magnetic sensing unit is not limited to the above form, and may be a fluxgate, a superconducting heterojunction or the like.

Among them, the magnetic sensitive component 4 has different or opposite responses to magnetic fields in different directions, and may be magnetic induction coils, giant magnetoresistance, tunnel magnetoresistance or an outer magnetoresistive film chip or device with a barber lamp type conductive strip.

The magnet 5 can be a single or multiple permanent magnets, a direct current or alternating current coil or other electromagnet. The magnetic code is magnetized by the magnet 5 as it passes over the surface of the magnetic sensor to complete a partial or a complete hysteresis loop process, and the magnetic sensor reads the signal of the magnetization process.

The magnetic sensor of the present invention, when the magnetic code passes through the surface of the magnetic sensor, is magnetized by the magnet to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the letter of the corresponding magnetization process. The number is then identified. Through the magnetic sensor, the hysteresis loop characteristic can be read for each magnetic code of the currency, so that the currency counterfeiting is more comprehensive and more accurate.

The magnetic sensor of the present invention can distinguish whether the magnetic code belongs to soft magnetic or hard magnetic; the magnetic hysteresis loop characteristic can be quantified, including the coercive force; and the judging method is directed to the hysteresis loop characteristic of each independent magnetic code itself, and never Depending on the strength of the magnetic code signal, it can get rid of the binding of the magnetic field with distance. It solves a series of problems that require minimal detection gap, banknote, roller breakage, banknote wear, wrinkles, angle and temperature drift.

Due to the above beneficial effects, the present invention is accurate. Quantitative judgment standards can be implemented for all magnetic codes in banknotes, which can effectively check and prevent counterfeit banknotes.

In addition, the magnetic sensor of the present invention has a simple structure and is convenient to use, and is not only suitable for authenticity identification of money, but also suitable for authenticity identification of other items such as checks.

Example 2.

A method for quantitatively identifying a hysteresis loop characteristic of a magnetic code by using the magnetic sensor of the first embodiment, wherein the magnetic code is magnetized by the magnet to complete a complete or partial hysteresis loop process when passing through the surface of the magnetic sensor, and The signal of the corresponding magnetization process is read by the magnetic sensor for identification.

Identification includes the identification of magnetic code soft and hard magnetic properties and the quantitative definition of the coercivity of the magnetic code.

Among them, the soft-hard magnetic property identification of the magnetic code is based on whether the signal of a single magnetic code is a single-sided peak to determine whether the magnetic code is hard magnetic or soft magnetic. When only two single-edge signal peaks appear, the magnetic code is soft magnetic which can be reversed by the magnet magnetization; if two bilateral signal peaks appear (positive and negative signal peaks appear simultaneously), it is judged that the coercive force is greater than the magnetic field of the magnet. Hard magnetic.

Quantifying the coercivity of the defined magnetic code is specifically calculating the ratio of the peak, the width, or the half-peak time width between different peaks of each single magnetic code signal sensed by the magnetic sensitive unit; or calculating the magnetic sensitive unit The difference between the peaks, the widths, or the half-peak time widths between different peaks of each individual magnetic code signal sensed, and the magnitude or the difference is used to measure and quantify the magnitude of the coercivity of the magnetic code. When two single-sided peaks appear, the coercive force is zero, as shown by the solid line in Figure 3a. When two bilateral peaks appear, the coercive force is greater than the magnetic field of the magnet, as shown by the dashed line in Figure 3a. When more than two bilateral peaks appear, the coercive force is less than the magnetic field of the magnet. And the ratio of the peak, the wave width or the half-peak time width of the first peak to the second peak (Vl/V2, tl/t2, wl/w2 as shown in Fig. 3b) or the difference (as shown in Fig. 3b) The Vl-V2, t l_t2, wl_w2 ) quantization defines the magnitude of the coercivity.

When more than two bilateral peaks appear and the ratio is less than 1.0, the closer the ratio is to zero, the closer the coercive force is to the magnet magnetic field; when more than two bilateral peaks appear and the ratio is greater than 1.0, the ratio is higher. A close to 1.0 indicates that the coercive force is closer to the magnetic field of the magnet.

The identification method provided by the present invention uses the number of peaks of the same single magnetic code to determine whether the magnetic code belongs to hard magnetic or not according to the read signal; the amplitude coefficient method of the same magnetic code is used to quantitatively identify the magnetic code coercivity independent of The absolute value of the magnetic code magnetic field strength signal is insensitive to factors such as detection gap, banknote condition, banknote angle, temperature drift, and magnetic sensor performance deviation, which ensure the stability and judgment of the judgment parameters. accuracy.

The invention can distinguish whether the magnetic code belongs to soft magnetic or hard magnetic; the magnetic hysteresis loop characteristic can be quantified, including the coercive force; the judging method is directed to the hysteresis loop characteristic of each independent magnetic code itself, and thus does not depend on the magnetic The strength of the code signal can get rid of the binding of the magnetic field with distance attenuation. It has the characteristics of simple operation and accurate results.

Example 3.

With the magnetic sensor of the present invention, the magnetic code is passed over the magnet to undergo a magnetization process, and the details of the magnetization process are as shown in Fig. 4. The details of the magnetization depend on the soft and hard magnetic properties of the magnetic code and whether it can be reversed for the magnetic field.

A hard magnetic code that cannot be reversed can only undergo a local hysteresis loop magnetization process, as shown in Figure 4a for Path 1 or Path 2. In Figure 4a, Hm is the maximum transverse magnetic field of the magnet. Path 1 is from Mr+3⁄4 A point, then to Mr+, then to point B, and then to Mr+. Path 2 is from Mr- to C, Then go to Mr-, then to point B, then to Mr+. The soft magnetic code that can be inverted is determined by the magnetization direction (Mr+ or Mr-) of the remanence at the start of the magnetic code, as shown in Figure 1b, path 1 or path 2. In Figure 4b, path 1 is from Mr+ to point A, then to Hc_, then to point B, point C, point B, Mr-, point D, point Hc+, point E, point F, point E, and finally to Mr+.

Path 2 is from Mr- to B, then to C, B, Mr -, D, Hc+, E, F, E, and finally to Mr+.

Example 4.

An automatic teller machine is provided with an inspection unit for discriminating and detecting the authenticity of the banknote. The inspection unit is provided with a sensor, a processing unit and a display unit. The sensor collects the signal of the banknote and transmits the collected information to the processing unit, and the processing unit processes Then sent to the display unit display. The sensor is set to the magnetic sensor described in Embodiment 1.

The magnetic sensor, as shown in Fig. 2, is provided with a base 1, a casing 2, a Wheatstone bridge circuit interface 3, a magnetic sensing element 4, and a magnet 5.

The base 1 is used to carry other components, and the base 1 is usually a plastic block or composed of other objects that constitute mechanical strength. The magnetic sensing element 4 responds to the magnitude of the magnetic code magnetic field generated by the magnet 5 when magnetizing the magnetic code and the direction of the magnetic code magnetic field. When the magnetic code passes through the surface of the magnetic sensor, it is magnetized by the magnet 5 to complete a complete or partial hysteresis loop. The process, and the signal of the corresponding magnetic code magnetization process is read by the magnetic sensor and then identified.

Specifically, the magnetic field response of the magnetic sensitive unit is the same in the same magnetic field direction, and the magnetic sensitive unit arranged on one side of the center line of the magnet 5 has the same magnetic field direction as the magnetic sensitive unit on the other side. The same response.

The automatic teller machine of the present invention performs the authenticity verification of the magnetic code by the method as described in Embodiment 3. When the magnetic code is magnetized by the magnet while passing through the surface of the magnetic sensor, a complete or partial hysteresis loop process is completed, and the magnetic sensor is used. The signal of the corresponding magnetization process is read and then identified. The information of the magnetic sensor is sent to the processing unit, and the authenticity result is displayed by the display unit after being processed by the processing unit.

Through the magnetic sensor of the ATM, the hysteresis loop characteristic can be read for each magnetic code of the currency, making the currency counterfeiting more comprehensive and more accurate.

The automatic teller machine of the present invention can distinguish whether the magnetic code belongs to soft magnetic or hard magnetic; the magnetic hysteresis loop characteristic can be quantified, including the coercive force; the judging method is directed to the hysteresis loop characteristic of each independent magnetic code itself, and never Depending on the strength of the magnetic code signal, it can get rid of the binding of the magnetic field with distance. It solves a series of problems that require minimal detection gap, banknote, roller breakage, banknote wear, wrinkles, angle and temperature drift.

Due to the above advantageous effects, the automatic teller machine of the present invention has the characteristics of accurate identification. Paper All the magnetic codes in the currency can be implemented with quantitative judgment standards, which can effectively check and prevent counterfeit banknotes. In addition, the automatic teller machine of the invention has the advantages of simple structure and convenient use, and is not only suitable for authenticity identification of money, but also suitable for authenticity identification of other items such as checks.

Example 5.

A money detector, which is provided with an inspection unit for distinguishing the authenticity of the banknote, the inspection unit is provided with a sensor, a processing unit and a display unit, and the sensor collects the signal of the banknote and transmits the collected information to the processing unit, through the processing unit After processing, it is sent to the display unit display. The sensor is set to the magnetic sensor described in Embodiment 1.

The direction of the magnetic field detected by each of the magnetic sensing units is the same or opposite to the direction in which the magnetic code moves laterally along the magnet 5. The magnetically sensitive unit is configured as an induction coil, giant magnetoresistance, tunnel magnetoresistance or an exo magnetoresistive film or device with barbershop-type conductive strips. It should be noted that the magnetic sensing unit is not limited to the above form, and may be a fluxgate, a superconducting heterojunction or the like.

The money detector of the present invention adopts the method as described in Embodiment 3 to perform the authenticity verification of the magnetic code. When the magnetic code is magnetized on the surface of the magnetic sensor, it is magnetized to complete a complete or partial hysteresis loop process, and is magnetically The sensor reads the signal of the corresponding magnetization process and then performs the identification. The information of the magnetic sensor is sent to the processing unit, and after the processing unit processes, the authenticity result is passed through the magnetic sensor of the money detector through the display unit, so that the hysteresis loop characteristic of each magnetic code of the currency can be read, so that Currency forgery is more comprehensive and more accurate.

The money detector of the present invention can distinguish whether the magnetic code belongs to soft magnetic or hard magnetic; the magnetic hysteresis loop characteristic can be quantified, including the coercive force; and the judging method is directed to the hysteresis loop characteristic of each independent magnetic code itself, thereby It does not depend on the strength of the magnetic code signal, and can get rid of the binding of the magnetic field with distance. It solves a series of problems that require minimal detection gap, banknote, roller breakage, banknote wear, wrinkles, angle and temperature drift.

Due to the above advantageous effects, the money detector of the present invention has the characteristics of accurate identification. Quantitative judgment standards can be implemented for all magnetic codes in banknotes, which can effectively check and prevent counterfeit banknotes.

In addition, the money detector of the invention has the advantages of simple structure and convenient use, and is not only suitable for authenticity identification of money, but also suitable for authenticity identification of other items such as checks. It should be noted that the magnetic transmission of the present invention The sensor and the method for quantitatively identifying the characteristics of the magnetic code hysteresis loop are not only applicable to the field of financial technology, but also applicable to other fields requiring signing, such as checks, magnetic bar codes, and anti-counterfeiting marks for articles.

It should be noted that the above embodiments are only for explaining the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, those skilled in the art The technical solutions of the present invention are modified or equivalently substituted without departing from the spirit and scope of the technical solutions of the present invention.

Industrial applicability

The invention utilizes the magnetic code to be magnetized by the magnet when passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the signal of the corresponding magnetization process and then the hysteresis of the magnetic code. Line features were identified. It can distinguish the soft and hard magnetic properties of the magnetic code and can quantify the hysteresis loop characteristics of the magnetic code. It does not depend on the strength of the magnetic code signal and is insensitive to the detection gap. It has the characteristics of high identification accuracy and good identification stability. Has good industrial applicability.

Claims

Claim

A magnetic sensor, characterized in that: the magnetic sensor is provided with a magnet and a magnetic sensitive element, and the magnetic sensitive element generates a magnetic code magnetic field generated by a magnetic code in the magnetic banknote and a direction of a magnetic code magnetic field In response, the magnetic code is magnetized by the magnet while passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and the magnetic sensor reads the signal of the corresponding magnetization process and then performs identification;

The magnetic sensitive element is composed of two or four magnetic sensitive units having the same specifications and the same response to the magnetic field direction. When the magnetic sensitive elements are two, the two magnetic sensitive elements constitute a benefit Stone half bridge circuit; when the magnetic sensitive elements are set to four, four of the magnetic sensitive units constitute a Wheatstone full bridge circuit;

The Wheatstone half bridge circuit or the Wheatstone full bridge circuit is symmetrically distributed on both sides of the magnet center line in a magnetic induction direction.

The magnetic sensor according to claim 1, wherein: the magnetic sensitive unit has the same magnetic field response as the direction of the magnetic field, and the magnetic sensitive unit arranged on one side of the magnet center line and the magnetic sensitive unit on the other side The same magnetic field direction has the same response;

The direction of the magnetic field detected by each of the magnetic sensing units is the same as or opposite to the direction in which the magnetic code moves laterally along the magnet.

The magnetic sensor according to claim 2, wherein: the magnetic sensitive unit is provided as an induction coil, a giant magnetoresistance, a tunnel magnetoresistance, an isomagnetoresistive film or device having a barbershop type conductive stripe, and a magnetic Through the door or superconducting heterojunction.

The magnetic sensor according to any one of claims 1 to 3, wherein the magnet is disposed in an elongated shape, and the north and south poles of the magnet are perpendicular to a magnetic induction direction of the magnetic sensor and a magnetic sensor plane, and a transverse magnetic field The intensity allows the magnetic code to undergo some or all of the hysteresis looping process as it passes laterally through the magnetic sensor.

5. The magnetic sensor according to any one of claims 1 to 4 for quantitatively identifying magnetic A method for characterizing a hysteresis loop, characterized in that: the magnetic code is magnetized by the magnet when passing through the surface of the magnetic sensor to complete a complete or partial hysteresis loop process, and the magnetic code is read by the magnetic sensor. The magnetic field magnitude and magnetic field direction signals of the magnetization process are then identified for the hysteresis loop characteristics of the magnetic code.

6. The method for quantitatively identifying a hysteresis loop characteristic of a magnetic code according to claim 5, wherein: the characterizing the hysteresis loop characteristic of the magnetic code comprises identifying and quantifying magnetic properties of the magnetic code soft and hard magnetic characteristics. The coercivity of the code.

7. The method of quantizing and identifying a magnetic code hysteresis loop characteristic according to claim 6, wherein:

The identification of the soft and hard magnetic characteristics of the magnetic code is specifically determined whether the magnetic code is a soft magnetic having a coercive force smaller than a magnetic field of the magnet according to whether the signal of the single magnetic code is a single-sided peak;

8. A method of quantitatively identifying a magnetic code hysteresis loop characteristic as claimed in claim ,, characterized in that:

The specific process of identification of magnetic code soft and hard magnetic properties is:

The specific process of quantifying the coercivity of a magnetic code is:

When two bilateral peaks appear, it is determined that the coercive force is greater than the magnetic field of the magnet; When more than two bilateral peaks appear, the coercive force is less than the magnetic field of the magnet, and the ratio of the peak of the first peak to the peak, the width of the wave, or the width of the half-peak of the second peak defines the magnitude of the coercive force;

When more than two bilateral peaks appear, and the ratio is less than 1.0, the closer the ratio is to zero, the closer the coercive force is to the magnetic field of the magnet; when more than two bilateral peaks appear, and the ratio is greater than 1.0, the ratio is higher. A close to 1.0 indicates that the coercive force is closer to the magnetic field of the magnet.

9. An automatic teller machine, provided with an inspection unit for discriminating and detecting the authenticity of a banknote, the inspection unit being provided with a sensor, a processing unit and a display unit, the sensor collecting the magnetic code signal of the banknote and conveying the collected information to the processing The unit is processed by the processing unit and sent to the display unit for display, wherein the sensor is provided with the magnetic sensor according to any one of claims 1 to 4, and the magnetic sensor adopts any one of claims 5 to 8. The method for quantitatively identifying the characteristics of the magnetic code hysteresis loop is described for authenticity identification.

10. A money detector, which is provided with an inspection unit for detecting the authenticity of a banknote, the inspection unit is provided with a sensor, a processing unit and a display unit, and the sensor collects the magnetic code signal of the banknote and transmits the collected information to The processing unit is processed by the processing unit and sent to the display unit for display, wherein the sensor is provided with the magnetic sensor according to any one of claims 1 to 4, and the magnetic sensor is any according to claims 5 to 8. A method for quantitatively identifying the characteristics of a magnetic code hysteresis loop is performed for authenticity identification.