WO2018151547A1

WO2018151547A1 - Biometric information recognition apparatus and biometric information recognition method using same

Info

Publication number: WO2018151547A1
Application number: PCT/KR2018/001965
Authority: WO
Inventors: 방창혁
Original assignee: 주식회사 베프스
Priority date: 2017-02-16
Filing date: 2018-02-14
Publication date: 2018-08-23

Abstract

The present invention relates to a biometric information recognition apparatus. The biometric information recognition apparatus according to the present invention may comprise: a piezoelectric sensor array including a plurality of piezoelectric sensors which are arranged in an array in a two-dimensional plane and each of which has a predetermined height; and a control unit for applying a plurality of different frequency signals to the piezoelectric sensors and receiving a plurality of ultrasonic signals reflected from the piezoelectric sensors, so as to acquire a surface image of an object which touches or approaches the piezoelectric sensors and an internal image of the object.

Description

Biometric Information Recognition Apparatus and Biometric Information Recognition Method Using The Same

The present invention relates to a biometric information recognition device and a biometric information recognition method using the same, and more particularly, a biometric information recognition device capable of recognizing not only the epidermis of a fingerprint but also dermis and finger vein information using multiple frequencies, and a biometric using the same It relates to an information recognition method.

User authentication is a necessary procedure for all financial transactions. In particular, as the interest in mobile finance has increased due to the development of networks and portable terminals, the demand for fast and accurate user authentication devices and authentication methods is increasing.

On the other hand, the user's finger fingerprint is one of the authentication media that can meet the above demand, many operators and developers continue to develop devices and methods that can be authenticated using the user's fingerprint.

Recently, researches on the so-called ultrasonic method for identifying the shape of the fingerprint by generating ultrasonic waves have been actively conducted in connection with the fingerprint recognition device.

In the case of a fingerprint recognition device using ultrasonic waves, there are various advantages over conventional optical methods and capacitive methods, such as distinguishing fake fingers from conventional optical systems.

However, the conventional ultrasonic fingerprint recognition device has a problem that it is difficult to recognize a variety of biometric information such as finger vein or bone.

An object of the present invention is to provide an apparatus and method for recognizing a biometric information capable of applying a plurality of different frequencies to a piezoelectric sensor.

In addition, an object of the present invention is to provide a biometric information recognition apparatus and method capable of simultaneously recognizing not only the fingerprint but also the blood vessel information inside the finger.

Biometric information recognition apparatus according to an embodiment of the present invention comprises a piezoelectric sensor array including a plurality of piezoelectric sensors arranged in an array in a two-dimensional plane and having a predetermined height; And a controller configured to apply a plurality of different frequency signals to the piezoelectric sensor and to receive a plurality of ultrasonic signals reflected from the piezoelectric sensor to obtain a surface image of an object in contact with or in proximity to the piezoelectric sensor and an internal image of the object. It may include.

In addition, in the biometric information recognizing apparatus according to the embodiment of the present invention, the controller may control the plurality of frequencies to be alternately input to a column or a row of the piezoelectric sensor array.

Further, in the biometric information recognizing apparatus according to the embodiment of the present invention, the control unit includes a signal generator for generating a plurality of frequency signals applied to the piezoelectric sensor; A signal detector configured to detect a signal generated by the plurality of frequency signals and reflected by the piezoelectric sensor; And an image generator for analyzing the reflected signal to generate a fingerprint image and an image inside the living body.

In addition, in the biometric information recognizing apparatus according to the embodiment of the present invention, the controller may generate and apply a first frequency signal having a low transmittance and a second frequency signal having a high transmittance.

Further, in the biometric information recognizing apparatus according to the embodiment of the present invention, the plurality of frequency signals may be applied to the piezoelectric sensor in different directions.

In addition, in the biometric information recognition apparatus according to the embodiment of the present invention, the surface image of the object may be a fingerprint image, and the internal image of the object may include at least one or more of a dermal image, a blood vessel image, and a bone image.

Further, in the biometric information recognizing apparatus according to the embodiment of the present invention, the plurality of frequency signals may be an integer multiple of the resonance frequency of the piezoelectric sensor.

In addition, the biometric information recognition method according to the embodiment of the present invention is a biometric information recognition method for recognizing the biometric information by applying a predetermined frequency signal to the piezoelectric sensor array consisting of a plurality of piezoelectric sensors, different from the piezoelectric sensor array Applying a plurality of frequency signals; Sensing a plurality of ultrasonic signals reflected from the piezoelectric sensor; And analyzing each of the plurality of frequency signals to generate a surface image and an in vivo image of the object.

Further, in the biometric information recognition method according to an embodiment of the present invention, the plurality of frequency signals may be alternately input to a column or a row of the piezoelectric sensor array.

Further, in the biometric information recognition method according to an embodiment of the present invention, the plurality of frequency signals may be applied to the piezoelectric sensor in different directions.

Further, in the biometric information recognition method according to an embodiment of the present invention, the plurality of frequency signals may include a first frequency signal having a low transmittance and a second frequency signal having a high transmittance.

In addition, in the biometric information recognition method according to an embodiment of the present invention, the surface image of the object is a fingerprint image, the internal image of the object may include at least one or more of the dermal image, blood vessel image, and bone image.

According to the present invention, not only the fingerprint image but also other biometric information inside the finger can be recognized simultaneously.

In addition, according to the present invention, an epidermal fingerprint and a dermal fingerprint may be obtained to generate a 3D fingerprint image.

In addition, according to the present invention, security can be enhanced by using not only the fingerprint but also other biometric information.

In addition, according to the present invention, forgery fingerprint can be prevented by recognizing not only the fingerprint image but also biometric information such as blood vessels or bones such as the finger vein.

1 conceptually illustrates a biometric information recognition apparatus according to an embodiment of the present invention.

2 is a block diagram schematically illustrating an apparatus for recognizing biometric information according to an exemplary embodiment of the present invention.

3 illustrates a piezoelectric sensor array of a biometric information recognition apparatus according to an embodiment of the present invention.

4 shows an example of generating biometric information according to an embodiment of the present invention.

5 illustrates a biometric information recognition method according to an embodiment of the present invention.

Details of the object and technical configuration of the present invention and the resulting effects will be more clearly understood by the following detailed description based on the accompanying drawings. With reference to the accompanying drawings will be described in detail an embodiment according to the present invention.

The embodiments disclosed herein should not be interpreted or used as limiting the scope of the invention. It will be apparent to those skilled in the art that the description, including the embodiments herein, has a variety of applications. Accordingly, certain embodiments described in the detailed description of the present invention are illustrative for better understanding of the present invention and are not intended to limit the scope of the present invention to the embodiments.

The functional blocks shown in the figures and described below are only examples of possible implementations. Other functional blocks may be used in other implementations without departing from the spirit and scope of the detailed description. Also, while one or more functional blocks of the present invention are represented by separate blocks, one or more of the functional blocks of the present invention may be a combination of various hardware and software configurations that perform the same function.

In addition, the expression including any configuration sensors merely refers to the presence of the configuration sensors as an open expression, and should not be understood as excluding additional configuration sensors.

Furthermore, when a component sensor is referred to as being connected or connected to another component sensor, it should be understood that there may be another component sensor in between, although it may be directly connected or connected to the other component sensor.

In addition, an expression such as 'first' and 'second' is used only for distinguishing a plurality of components, and does not limit the order or other features between the components.

When a part is said to be "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with the other member in between. In addition, when a part is said to "include" a component sensor, this means that it is possible to further include other component sensors, without excluding the other component sensors unless otherwise stated.

1 schematically shows a biometric information recognition apparatus 100 according to an embodiment of the present invention.

The biometric information recognition apparatus 100 according to the present invention includes a plurality of piezoelectric sensors 110, a controller 120 electrically connected to the plurality of piezoelectric sensors to detect a fingerprint, and a filler 112 provided between the plurality of piezoelectric sensors. ) May be included. The plurality of piezoelectric sensors 110 may form an m × n array on a two-dimensional plane together with the filler 112.

The piezoelectric sensor 110 may be configured of any one of an ultrasonic piezoelectric ceramic sensor, an ultrasonic piezoelectric film sensor, a CMUT sensor, and a PMUT sensor.

The ultrasonic piezoelectric ceramic sensor is a method using a polycrystalline piezoelectric ceramic capable of generating ultrasonic waves, the ultrasonic piezoelectric film sensor is a method of forming or coating a film in the film form, the CMUT sensor is a method using a semiconductor manufacturing method Capacitive Micromachined Ultrasonic Transducers (CMUTs) are used, and the PMUT sensor is a method using a MEMS process, using a Piezoelectric Micromachined Ultrasonic Transducers (PMUT).

Each sensor configured in the form of an array may be arranged at regular intervals to independently transmit and receive signals, and may be configured so that interference between the sensor and the sensor may not occur chemically, physically, or electrically.

The filler 112 may be composed of a polymer or an epoxy.

The controller 120 is connected to each of the plurality of piezoelectric sensors 110, and in particular, is connected to an electrode provided up and down in the height direction of each piezoelectric sensor 110. The piezoelectric sensor 110 may be 1-3 piezo composites, and may be manufactured by disposing electrodes on upper and lower surfaces of pillars extending in a height direction. The pillar portion may include at least one material of PZT, PST, Quartz, (Pb, Sm) TiO3, PMN (Pb (MgNb) O3) -PT (PbTiO3), PVDF, or PVDF-TrFe.

The controller 120 may generate an ultrasonic signal by applying a voltage having a resonant frequency of the ultrasonic band to electrodes provided on the upper and lower surfaces of the pillar part to vibrate the pillar part up and down. The upper and lower surfaces of each of the plurality of piezoelectric sensors 110 may be a square or a circle having one side or a diameter of 40 to 50 μm. In addition, it can be implemented in various shapes such as triangle, pentagon, hexagon.

The filler 112 provided between the plurality of piezoelectric sensors 110 may block the vibrations of the plurality of piezoelectric sensors 110 from affecting each other. An array structure including the piezoelectric sensor 110 is manufactured by densely arranging a plurality of piezoelectric sensors 110 having a columnar shape and forming a filler 112 therebetween. Accordingly, as the number of piezoelectric sensors 110 is disposed in the same area, problems such as a decrease in yield may occur due to an increase in difficulty of the manufacturing process. However, since the fingerprint can be accurately detected by measuring the difference in acoustic impedance generated from the valley and the ridge of the fingerprint by the ultrasonic signal generated by each piezoelectric sensor 110, in order to accurately detect the fingerprint It is necessary to place as many piezoelectric sensors 110 as possible in the same area.

2 is a block diagram schematically showing the biometric information recognition apparatus 100 according to an embodiment of the present invention.

2, the biometric information recognition apparatus 100 according to the present exemplary embodiment includes a piezoelectric sensor array 210 including a plurality of piezoelectric sensors 110 and a polymer filler 112, and a controller 220. . The controller 220 may include a signal generator 222, a signal detector 224, an image generator 226, and the like.

The piezoelectric sensor array 210 includes a plurality of piezoelectric sensors 110 densely arranged in a matrix form as shown in FIG. 1, and a filler 112 disposed therebetween to insulate the vibration between the piezoelectric sensors 110. ) May be included. Each of the piezoelectric sensors 110 may include a pillar formed of a material that is easy to vibrate, and an electrode provided of a conductive material on upper and lower surfaces of the pillar. As described above, the pillar portion may be formed of a material such as PZT, and the electrode may be formed of a metal having excellent conductivity (Cu, Ag, Ni, Mo, or an alloy thereof).

The signal generator 222 is electrically connected to an electrode of the piezoelectric sensor 110 included in the piezoelectric sensor array 210, and applies an AC voltage having a predetermined frequency to each electrode. As the pillar portion of the piezoelectric sensor 110 vibrates up and down by an alternating voltage applied to the electrode, an ultrasonic signal having an integer multiple of a predetermined resonance frequency is emitted to the outside.

A predetermined protective layer may be further provided on the piezoelectric sensor array 210, and a specific object may contact one surface of the protective layer. When the object in contact with one surface of the protective layer is a finger of a person including a fingerprint, the reflection pattern of the ultrasonic signal emitted by the piezoelectric sensor 110 is different depending on minute valleys and ridges present in the fingerprint. Is determined.

Assuming that no object is in contact with a contact surface such as one surface of the protective layer, most of the ultrasonic signals generated by the piezoelectric sensor 110 due to the difference between the contact surface and the air do not pass through the contact surface and are reflected. Come back. On the other hand, when a specific object including a fingerprint is in contact with the contact surface, a portion of the ultrasonic signal generated by the piezoelectric sensor 110 directly contacting the ridge of the fingerprint passes through the interface between the contact surface and the fingerprint. Only part of the ultrasonic signal is reflected back. As such, the intensity of the ultrasonic signal reflected back may be determined according to the acoustic impedance of each material. As a result, the signal detector 224 may obtain a fingerprint image by measuring a difference in acoustic impedance generated by an ultrasonic signal at a valley and a ridge of the fingerprint from each piezoelectric sensor 110.

The signal generator generates a plurality of different frequencies. It is possible to generate two or more different frequencies. For example, the apparatus may include a first signal generator for generating a first frequency signal and a second signal generator for generating a second frequency signal. When a signal is applied from the signal generator to the piezoelectric sensor, ultrasonic waves are generated while the piezoelectric element vibrates, and the generated ultrasonic waves generate ultrasonic waves having different frequencies according to the frequency of the applied signal.

Ultrasonic signals have different reflectances and transmittances according to frequency, so when only one frequency signal is applied, a clear image cannot be obtained for both the fingerprint of the epidermis and the body signals such as blood vessels and bones. If the ultrasound signal has a high reflectance and a low transmittance, the finger epidermal fingerprint signal may be clearly obtained, but the biosignal (blood vessel, bone) inside the finger may not be obtained clearly. On the contrary, when the reflectance is low and the transmittance is low, the biosignal inside the finger can be obtained clearly, but the epidermal fingerprint cannot be obtained clearly.

However, when the high transmittance signal and the low signal are simultaneously applied as in the present invention, an image of the epidermal part and a biosignal (dermis, blood vessel, bone, etc.) inside the finger can be obtained at the same time. For example, at a thickness of 1.7 millimeters, 30 MHz provides nearly 100% transmittance and 10 MHz provides approximately 65% transmittance. Therefore, if the first signal generator oscillates at a frequency of 5 MHz, and the second signal generator oscillates at a frequency of 30 MHz, not only an image of the epidermal fingerprint but also an image of a blood vessel in the skin can be obtained.

The epidermal image and the dermis or the finger vein image can be obtained at the same time by applying the first signal to the odd column and the second signal to the even column of the sensor array. For example, when the resonant frequency of the piezoelectric sensor is 5 MHz, when the first signal generator applies a frequency of 10 MHz to the odd column and the second signal generator applies a frequency of 20 MHz to the even column, the ultrasonic waves generated in the odd column are the epidermis. The fingerprint image of the part may be clearly obtained, and the ultrasound generated in the even rows may acquire the dermal fingerprint or the finger vein image clearly.

The image generator 226 analyzes a signal detected by the signal detector 224 to calculate a fingerprint pattern, and generates an image accordingly.

As described above, the piezoelectric sensor 110 generated with low intensity of the reflected signal is the piezoelectric sensor 110 abutting the ridge of the fingerprint, and the generated ultrasonic signal has high intensity-ideally output ultrasonic signal The piezoelectric sensor 110, which is generated approximately equal to the strength of the piezoelectric sensor 110, corresponds to the valley of the fingerprint. Therefore, a fingerprint image may be generated by calculating a difference in acoustic impedance detected by each piezoelectric sensor 110.

In addition, the image generator 226 may generate an image of blood vessel or bone shape by analyzing signals reflected from blood vessels or bones inside the finger as well as the fingerprint.

3 briefly illustrates the piezoelectric sensor array 310 and the electrode arrangement.

Referring to FIG. 3, a plurality of piezoelectric sensors 110 are arranged in a matrix form in the piezoelectric sensor array 310, and each of the piezoelectric sensors 110 is connected to an upper electrode 310 and a lower electrode 320. have. Any one of the upper electrode 310 and the lower electrode 320 may be used as the transmission electrode Tx. In this embodiment, the upper electrode 310 is a transmission electrode.

The upper electrode 310 and the lower electrode 320 may be disposed to cross each other at right angles. The signal input directions of the

electrodes

310 and 320 may be alternately input in opposite directions. For example, in the case of the upper electrode 310, an electrode may be connected to an odd column of the piezoelectric sensor array in an upward direction, and an electrode may be connected to an even column in a downward direction. Similarly, in the case of the lower electrode 320, an electrode may be connected to an odd row of the piezoelectric sensor array in a left direction, and an electrode may be connected to an even row in a right direction.

That is, the upper electrode 310 includes the first upper electrode 312 and the second upper electrode 314, and the lower electrode 320 includes the first lower electrode 322 and the second lower electrode 324. Can be.

When the upper electrode 310 is used as a transmission electrode, a first frequency signal may be applied to the first upper electrode 312, and a second frequency signal may be applied to the second upper electrode 314.

The first frequency signal may be a signal for recognizing the epidermal fingerprint, and the second frequency signal may be a signal for recognizing a biosignal inside the finger.

The first frequency signal may be 10 MHz, and the second frequency signal may be 15 MHz or 20 MHz. The frequency may vary depending on the resonance frequency of the piezoelectric sensor, and may be variously set within a range that is an integer multiple of the resonance frequency.

In the present embodiment, an example in which different frequencies are alternately input to odd and even columns of the sensor array may be input based on rows. That is, the first frequency may be input to odd rows of the sensor array, and the second frequency may be input to even rows.

4 illustrates an example of simultaneously acquiring a fingerprint and a blood vessel image according to an embodiment of the present invention.

Referring to FIG. 4, a cover substrate 450 is disposed on the piezoelectric sensor array 410, and a finger is positioned on the cover substrate 450. The cover substrate 450 is formed above the plurality of piezoelectric elements, which means a substrate to which a user's finger directly touches. The cover substrate may be embodied as a glass substrate, and may further include reinforced or soft plastics such as polyimide, polyethylene terephthalate, propylene glycol, polycarbonate, and sapphire.

When a finger is positioned above the sensor in the plurality of piezoelectric sensors, the piezoelectric sensor of the portion where the finger is positioned is activated to generate an ultrasonic signal. At this time, the odd-numbered piezoelectric sensors may generate ultrasonic waves of the first frequency, and the even-numbered piezoelectric sensors may generate ultrasonic waves of the second frequency. The first frequency may be 10 MHz and the second frequency may be 20 MHz. Therefore, an odd number of piezoelectric sensors may generate a fingerprint image of the finger epidermis, and an even number of piezoelectric sensors may generate a blood vessel image inside the finger. In addition, the fingerprint image can be generated in three dimensions by generating not only the epidermal fingerprint but also the dermal fingerprint image.

As described above, according to the present invention, by simultaneously applying different frequencies to the piezoelectric sensor to generate ultrasonic waves having different transmittances, it is possible to simultaneously measure not only the image of the epidermal part of the finger but also the bioinformation inside the finger.

Therefore, not only security can be more enhanced than the prior art, but also a 3D fingerprint image can be generated.

Referring to FIG. 5, in the method of recognizing biometric information according to the present invention, a plurality of different frequency signals are applied to a piezoelectric sensor array including a plurality of piezoelectric sensors (S510). And sensing (S520), and analyzing each of the plurality of frequency signals to generate a surface image and an in vivo image of the object (S530).

The plurality of different ultrasonic signals may be two or more, and as described above, the ultrasonic signals may include a first frequency signal having a low transmittance and a second frequency signal having a high transmittance.

When the frequency signal is applied to the piezoelectric sensor, the piezoelectric sensor generates an ultrasonic signal, the ultrasonic signal is reflected on the object located above the piezoelectric sensor. In this case, the ultrasonic signal generated by the first frequency signal has a low transmittance and is mainly reflected from the surface of the object, and the ultrasonic signal generated by the second frequency signal has a high transmittance and penetrates to the inside of the object and then may return. have.

The first frequency signal may be input to an odd column of the piezoelectric sensor array, and the second frequency signal may be input to an even column of the piezoelectric sensor array.

That is, the surface image of the object may be generated by analyzing the ultrasonic signals reflected from the odd rows of the piezoelectric sensor array, and the internal image of the object may be generated by analyzing the ultrasonic signals reflected from the even columns of the piezoelectric sensor array.

The surface image of the object may include an epidermal fingerprint image of a finger, and the internal image of the object may include a dermal fingerprint image, a blood vessel image, and a bone image of a finger.

By the above method, a three-dimensional fingerprint image can be generated by synthesizing the epidermal fingerprint image and the dermal fingerprint image. In addition, it is possible to acquire other biometric information simultaneously with the fingerprint.

While preferred embodiments and applications of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments and applications described above, and the present invention may be made without departing from the spirit of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be distinguished from the technical spirit or the scope of the present invention.

Claims

A piezoelectric sensor array including a plurality of piezoelectric sensors arranged in an array in a two-dimensional plane and having a predetermined height; And

And a controller configured to apply a plurality of different frequency signals to the piezoelectric sensor and to receive a plurality of ultrasonic signals reflected from the piezoelectric sensor to obtain a surface image of the object in contact with or in proximity to the piezoelectric sensor and an internal image of the object. Biometric information recognition device.
The method of claim 1,

And the controller controls the plurality of frequencies to be alternately inputted into a column or a row of the piezoelectric sensor array.
The method of claim 1,

The control unit,

A signal generator configured to generate a plurality of frequency signals applied to the piezoelectric sensor;

A signal detector configured to detect a signal generated by the plurality of frequency signals and reflected by the piezoelectric sensor; And

And an image generator configured to analyze the reflected signal to generate a fingerprint image and an image inside the living body.
The method of claim 1,

And the controller generates and applies a first frequency signal having a low transmittance and a second frequency signal having a high transmittance.
The method of claim 1,

And the plurality of frequency signals are applied to the piezoelectric sensor in different directions.
The method of claim 1,

The surface image of the object is a fingerprint image,

The internal image of the object includes at least one or more of the dermal image, blood vessel image, and bone image.
The method of claim 1,

And said plurality of frequency signals is an integer multiple of a resonant frequency of said piezoelectric sensor.
In the biometric information recognition method for recognizing biometric information by applying a predetermined frequency signal to the piezoelectric sensor array consisting of a plurality of piezoelectric sensors,

Applying a plurality of different frequency signals to the piezoelectric sensor array;

Sensing a plurality of ultrasonic signals reflected from the piezoelectric sensor; And

And analyzing each of the plurality of frequency signals to generate a surface image and an inside image of the object.
The method of claim 8,

And a plurality of frequency signals are alternately inputted into columns or rows of the piezoelectric sensor array.
The method of claim 8,

And a plurality of frequency signals are applied to the piezoelectric sensor in different directions.
The method of claim 8,

The plurality of frequency signals includes a first frequency signal having a low transmittance and a second frequency signal having a high transmittance.
The method of claim 8,

The surface image of the object is a fingerprint image,

The internal image of the object includes at least one or more of the dermal image, blood vessel image, and bone image.