KR102009000B1 - Anti-spoofing method and system of a device having a fingerprint sensor - Google Patents

Abstract

According to one disclosure the present invention discloses an anti-spoofing method using a device including a fingerprint sensor, and more particularly, by arranging the optical properties of a portion of the cut filter layer of the optical fingerprint sensor to measure the oxygen saturation, The present invention can provide an anti-spoofing method and device that can enhance the security of a device by simultaneously measuring a degree of oxygen saturation while recognizing a fingerprint of a user.

Description

ANTI-SPOOFING METHOD AND SYSTEM OF A DEVICE HAVING A FINGERPRINT SENSOR}

The present invention relates to a method and system for preventing spoofing of a mobile device using a user's body information using a fingerprint sensor. More specifically, the present invention relates to a method and apparatus for efficiently supporting anti-spoofing by measuring oxygen saturation of a user using a PPG sensor module (optical sensor module) mounted on a mobile terminal.

Because of the widespread use of satellite positioning systems by fixed and mobile communication systems, including mobile terminals such as cellular telephones, "spoofing", the use of counterfeit positioning signals that provide a false location to a device, has increased interest. have.

For example, WLAN access point (AP) spoofing attacks the other system by tricking the sending IP address when sending a packet, so that an attacker can hide his information and avoid detection. In other words, WLAN AP spoofing is a deception between two systems in a trusted relationship by replacing an unauthorized one with an IP address of a host in a trusted relationship, and can easily disable a service that authenticates only with the IP address. .

On the other hand, the fingerprint is a unique feature in the human body has invariability, uniqueness and convenience that does not change for a lifetime. Currently, fingerprint identification technology has been widely applied to equipments such as collection systems, access control systems, and smart phones, and capacitive fingerprint identification technology has been steadily spreading in application functions such as unlocking mobile phone fingerprints and paying online fingerprints for mobile phones. There is an increasing demand for the safety of fingerprints. Capacitive-based fingerprint identification technology is at risk of cracking and can take a fingerprint image and use it to print fake fingerprints using special materials to break down the fingerprint identification capabilities of many cell phone models. Therefore, a more secure fingerprint identification technique is needed.

One type of portable biosignal measuring apparatus is a photoplethysmograph (PPG) measuring apparatus. Since the optical volume pulse wave reflects information about the degree of contraction of the peripheral blood vessels and the increase and decrease of the cardiac output, the physiological state associated with the arterial blood vessels can be grasped or used mainly as a diagnostic aid for a specific disease.

In general, the PPG signal can be measured from a user's finger or ear ball. That is, the detector may detect the PPG signal of the user by detecting the light transmitted from the light source to the finger, the earlobe, or the like.

Japanese Patent Laid-Open Publication No. 2006-074104 (released March 16, 2006)

The technical problem of the present invention may provide a method for anti-spoofing using fingerprint information, which is biometric information of a user, in order to prevent wrong authentication due to a user who is incorrectly recognized by spoofing.

According to one disclosure, a device for executing anti-spoofing through a fingerprint sensor may be provided, and the device may be included in one surface of a device and simultaneously detect a plurality of biometric information of a user, and a fingerprint image obtained from the biometric sensor. And a security information generating unit for generating user security information by combining oxygen saturation, a memory for storing information on biometric information of a pre-registered user, and comparing the user security information with biometric information of a pre-registered user. Including a forgery determination unit for determining, the biometric sensor may be characterized in that the fingerprint sensor for sensing the fingerprint image of the user and the PPG (Photo-plethysmography) sensor for measuring the oxygen saturation of the user is combined.

According to one disclosure, the present invention may provide an anti-spoofing method using a device including a fingerprint sensor, and the method may simultaneously sense a plurality of biometric information of a user using a biometric sensor included in one surface of the device. The method may include generating user security information by combining a fingerprint image and oxygen saturation obtained from the biometric sensor, and comparing the user security information with biometric information of a pre-registered user to determine whether the user is authentic. The sensor may be a combination of a fingerprint sensor for sensing a fingerprint image of a user and a photo-plethysmography (PPG) sensor for measuring oxygen saturation in the blood of the user.

In another embodiment, the present invention may include a recording medium that records a program necessary to carry out the method of the present invention.

According to one disclosure, a fingerprint and an oxygen saturation degree, which are biometric identification information, may be detected to detect a fake fingerprint, thereby enhancing security of a mobile terminal.

According to one disclosure, the mobile device may be provided with a function for simultaneously measuring oxygen saturation and user authentication, and measuring the oxygen saturation using the mobile device, and performing fingerprint authentication by recognizing a fingerprint of a finger. Therefore, the oxygen saturation level can be measured simply and conveniently, without requiring a separate oxygen saturation meter, and at the same time, the user can be authenticated, thereby realizing more efficient and stable user authentication.

In addition, according to the present invention, the accuracy of confirming the correspondence between the registered fingerprint and the recognized fingerprint of the user is increased, thereby preventing spoofing attacks through fingerprint recognition.

According to the present invention, the security of the device can be enhanced by using the fingerprint as well as the security of the user using oxygen saturation. In addition, by mounting a filter having two optical characteristics in one filter, it is possible to complexly sense user biometric information, which is economical and efficient.

1 is a view for explaining a device including a fingerprint sensor of the present invention by way of example.
2 is a view for explaining the configuration of a device for implementing anti-spoofing of the present invention according to an embodiment.
3 is a view for explaining the structure of the biosensor of the present invention according to an embodiment.
4 is a diagram for describing a configuration of a device including a pinhole layer, according to an exemplary embodiment.
5 is a diagram comparing characteristics of a red signal and characteristics of a near infrared signal according to an exemplary embodiment.
6 is a diagram illustrating a change in oxygen saturation according to a signal ratio according to an embodiment.
7 is a graph illustrating a change in light absorption coefficient according to a wavelength according to an embodiment.
8 is a diagram for describing a method of detecting a forged fingerprint, according to an exemplary embodiment.
9 is a diagram for describing characteristics of a pixel of a fingerprint sensor, according to an exemplary embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In addition, in order to clearly disclose the present invention, parts not related to the present invention are omitted, and the same or similar reference numerals denote the same or similar elements in the drawings.

The objects and effects of the present invention may be naturally understood or more apparent from the following description, and the objects and effects of the present invention are not limited only by the following description.

The objects, features and advantages of the present invention will become more apparent from the following detailed description. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a device including a fingerprint sensor of the present invention by way of example. The device 100 includes a touch panel assembly that includes a biometric sensor. Device 100 includes another sensor 21, such as a camera. The device 100 may also include various buttons, such as side buttons that accept a user input. The touch panel assembly 10 can include a reinforcement cover glass 50 disposed over the support glass 54. A colored epoxy material layer 52 can be used to attach the cover glass 50 to the support glass 54. An ITO pattern 56 may be printed on the bottom or back side of the support glass 54. The support glass may be arranged such that a hole 58 is formed to receive the fingerprint sensor module or device 20.

In the recognition of a fingerprint, in applying an optical sensing technique, a light sensor such as a photodiode and a light source such as a light emitting diode (LED) and laser diodes (LD) are fingerprint sensors. The device may be integrated in other ways.

Biometric sensors for fingerprint recognition may be designed to be applied to the front of the display or to a specific location of the device.

2 is a view for explaining the configuration of a device for implementing anti-spoofing of the present invention according to an embodiment.

One disclosure may provide a device 100 for executing anti-spoofing through a fingerprint sensor.

In addition, the biometric sensor 110 included in one surface of the device 100 and simultaneously sensing a plurality of biometric information of the user may be provided.

According to one disclosure, a security information generation unit 120 may generate a user security information by combining a fingerprint image and an oxygen saturation degree obtained from a biometric sensor.

According to one disclosure, a memory 130 that stores information about biometric information of a user registered in advance may be provided.

According to one disclosure, a forgery determination unit 140 may be provided to determine whether a user is authentic by comparing user security information with biometric information of a user registered in advance.

The biometric sensor 110 may be combined with a fingerprint sensor 111 for sensing a fingerprint image of a user and a photo-plethysmography (112) sensor for measuring oxygen saturation in the blood of the user.

In addition, the present invention provides a differential CV amplifier for amplifying a PPG signal through a PPG sensor, a sample amplifier for separating a PPG signal into an IR signal and a RED signal, and removing an ambient noise signal and an amplified IR signal and a RED signal. It may include a measurement unit for measuring the oxygen saturation of the user by analyzing the.

The light emitting unit may include at least one of an internal light source positioned in the display panel of the device 100 to emit light and an external light source positioned in the display cover glass of the device 100 to emit light.

In addition, the biometric sensor is composed of a touch sensor grouped into a plurality of pixels of the fingerprint sensor 111, the forgery determination unit 140, the data obtained from each of the plurality of pixels of the fingerprint sensor 111 for the user's authenticity determination It may be characterized by using the user security information generated by.

In addition, the forgery determination unit 140 compares the fingerprint image of the user with a pre-registered fingerprint image to derive a first forgery determination value of whether the matching ratio of the fingerprint pattern is higher than a predetermined criterion, and the blood oxygen saturation degree and the pre-stored blood of the user. By comparing the oxygen saturation in the blood to derive the second counterfeit determination value whether the error value corresponds to a predetermined reference value, and to determine the authenticity of the user using the first counterfeit determination value and the second counterfeit determination value. have.

Therefore, in the present invention, after determining whether or not the first forgery using the fingerprint first to reveal the authenticity, it is possible to determine whether or not the second forgery using the oxygen saturation of other user information. In addition, the fingerprint and the oxygen saturation information can be determined at a time by combining the information. By using complex information, security can be strengthened.

Therefore, device security can be efficiently implemented using user information registered in advance.

Further, according to one disclosure, a fingerprint image quality evaluation unit for dividing a fingerprint image of a user into blocks to determine an image quality evaluation value, a filtering unit obtaining a filtered fingerprint image by filtering a fingerprint image of the user, and a filtered fingerprint The apparatus may further include a fingerprint comparator configured to compare the image with a pre-registered fingerprint image to determine a similarity value, and a fingerprint authenticity determiner to determine whether the user's fingerprint is forged based on the determined image quality evaluation value and the similarity value.

The configurations can be implemented integrally by the control unit. The controller may mean a module for collectively controlling the device 100 of the present invention.

According to one disclosure, when the fingerprint is in contact with the biometric sensor, further comprising a finger recognition sensor for sensing the user's finger and the real user determination circuit for determining whether the obtained fingerprint image is the fingerprint of the user's actual finger. Can be.

By using the finger recognition sensor, it is possible to determine whether the person who contacts the fingerprint is a real person or another item forging the fingerprint, thereby enhancing security.

3 is a view for explaining the structure of the biosensor of the present invention according to an embodiment.

According to one disclosure, the biometric sensor 110 may be a combination of a portion for recognizing a fingerprint and a portion for measuring oxygen saturation in the blood of the user.

According to an exemplary embodiment, the fingerprint sensor 111 may emit light of a specific frequency reflected from a fingerprint of a user by photodiodes formed by a plurality of light emitting units emitting light of a specific frequency to a fingerprint area of a user. And a light receiver configured to sense and output an electrical signal having a fingerprint image, and a fingerprint image generator to generate a fingerprint image through signal processing of the electrical signal.

The PPG sensor 112 is a color filter that selectively passes light of the same color to selectively sense light having the same color and wavelength band for some of the photodiodes included in the light receiving portion of the fingerprint sensor 111. (Color Pass Filter) and an IR Pass Filter for selectively passing light having the same wavelength band in the infrared region to selectively sense light having the same wavelength band in the infrared region. have.

According to an exemplary embodiment, the fingerprint sensor 111 includes an optical filter (Red-IR Cut Filter) that blocks light above the infrared band on the remaining photodiodes except for photodiodes equipped with color filters and infrared filters among photodiodes of the light receiving unit. It may be characterized by including.

Referring to FIG. 3, the structure of the biometric sensor 110 may be confirmed.

In the case of an optical fingerprint sensor, in order to secure authentication performance in outdoor light, an optical filter layer capable of removing a near infrared band or more needs to be secured at the top of the fingerprint sensor.

In addition, in order to perform the complex user authentication pursued by the present invention, it should be able to measure blood oxygen saturation at the same time. In this case, in order to sense blood oxygen saturation or HRM, light of a red color and a near infrared band is required. Therefore, there is a need for a filter capable of transmitting red color and near-infrared light inside an optical filter layer serving as a cut filter.

Therefore, a red-IR cut filter 2020 may be formed on the plurality of photodiodes 2010 constituting the fingerprint sensor, and an IR pass filter is used to measure blood oxygen saturation in the red-IR cut filter 2020. 2030 and Red Pass Filter 2040 may be included.

In other words, by analyzing the light passing through the IR Pass Filter (2030) and the Red Pass Filter (2040) to determine the oxygen saturation in the blood, using the light passed through the other Red-IR cut filter (2020) the user's fingerprint information Can be identified.

Therefore, the present invention doubles the security using the oxygen saturation of the user as well as the fingerprint can enhance the security of the device. In addition, by mounting a filter having two optical characteristics in one filter, it is possible to complexly sense user biometric information, which is economical and efficient.

4 is a diagram for describing a configuration of a device including a pinhole layer, according to an exemplary embodiment.

Referring to FIG. 4, the device 100 may include a display panel 3110 and a fingerprint sensor 2120, and the fingerprint sensor 2120 may include a pinhole layer 3200 and a biometric sensor 110. According to one embodiment, the fingerprint sensor 2120 may be packaged and attached to one surface of the display panel 3110.

The pinhole layer 3200 may include a plurality of pinholes, and each pinhole may form a focal point of light reflected and transmitted by the fingerprint. In addition, the display panel 3110 may include LEDs that emit light of a plurality of colors. In addition, LEDs emitting light of at least some of the plurality of colors among the LEDs may be used for a fingerprint sensing operation.

The biometric sensor 110 may include a plurality of sensor pixels corresponding to the plurality of pin holes, and each sensor pixel may include one or more photo diodes PD. In addition, according to an embodiment, a filter may be formed corresponding to each of the plurality of sensor pixels, and the same color filter (or a filter for passing light of the same wavelength) may be formed in correspondence to the sensor pixels. have. 4 illustrates an example in which a red color filter CF_R is formed above the photodiode in the image sensor corresponding to the sensor pixel.

Also shown is an example of a sensor pixel in which a near infrared filter IF is formed that efficiently passes near infrared rays. In addition, an optical filter may be applied to the remaining photodiodes, which may block light having an abnormal wavelength in the near infrared band.

According to the embodiment shown in FIG. 4, even if light from all the LEDs of the display panel 3110 is reflected on the fingerprint, the same color (or, Since only light of a wavelength) can be selectively provided to the photodiodes PD in the sensor pixel, the sharpness of the fingerprint sensing result can be improved similarly to the above-described embodiment.

Meanwhile, in FIG. 4, the oxygen saturation of the user may be measured using light in the infrared region passing through the near infrared filter and light passing through the red filter. In addition, the present invention provides a differential CV amplifier for amplifying a PPG signal through a PPG sensor, a sample amplifier for separating a PPG signal into an IR signal and a RED signal, and removing an ambient noise signal and an amplified IR signal and a RED signal. It may include a measurement unit for measuring the oxygen saturation of the user by analyzing the.

According to one disclosure, the pinhole layer may be positioned between the display panel and the biosensor. In addition, the pinhole layer may include a plurality of pinholes that form a focal point in order to deliver the light reflected by the user's fingerprint to the biometric sensor.

The plurality of pinholes may be arranged to correspond one-to-one with a plurality of biosensor pixels included in the biosensor.

5 is a diagram comparing the characteristics of the red signal and the characteristics of the near infrared signal.

Referring to FIG. 5, the components of the red signal and the near infrared signal that pass through the skin are shown. Both the red and near-infrared signals that pass through the skin consist of DC and AC components. In particular, the DC component of the near infrared signal is larger than the DC component of the red signal, and the AC component of the near infrared signal is larger than the AC component of the red signal. Oxygen saturation is based on the difference in the reaction of oxygen hemoglobin and hemoglobin for red and near-infrared signals.

Where R is the ratio of the red signal to the near infrared signal, S _R is the red signal, S _IR is the near infrared signal, AC _R is the AC component of the red signal, DC _R is the DC component of the red signal, and AC _IR is the AC of the near infrared signal. Component, DC _IR is the DC component of the near infrared signal)

6 is a view showing a change in oxygen saturation according to the ratio of signals.

Referring to FIG. 6, a change in oxygen saturation is shown according to a ratio of a red signal and a near infrared signal. That is, the oxygen saturation decreases as the size of the red signal is larger than the near infrared signal, and the oxygen saturation increases as the size of the red signal is smaller than the near infrared signal. On the other hand, oxygen saturation is a criterion for determining cardiac function and lung function, the normal person is close to 100 oxygen saturation. On the other hand, the relationship between the ratio of the red signal and the near infrared signal and the oxygen saturation is as follows.

Where SpO ₂ is the oxygen saturation, A is the y-intercept, B is the slope, and R is the ratio of the signal.

7 is a graph showing the change of the light absorption coefficient according to the wavelength.

Referring to FIG. 7, the change in the light absorption coefficient of oxygen hemoglobin and hemoglobin with respect to wavelength is shown. That is, it can be seen that the light absorption coefficient of oxygen hemoglobin is larger than the light absorption coefficient of hemoglobin for a signal having a small wavelength, and the light absorption coefficient of oxygen hemoglobin is smaller than the light absorption coefficient of a hemoglobin for a signal having a large wavelength. In particular, it can be seen that the difference in the light absorption coefficients of oxygen hemoglobin and hemoglobin varies considerably even if the wavelength is slightly changed for the red signal having 640 to 690 nm.

According to one disclosure it is possible to simultaneously recognize the oxygen saturation and fingerprint of the user using the biometric sensor of the present invention.

Oxygen saturation can be measured with a PPG sensor equipped with a red color filter and an infrared pass filter on the photodiode of the fingerprint sensor. It will be described in more detail below.

A photodiode equipped with a red color filter is called a first light emitting element, and a photodiode equipped with an inpass filter in infrared light is called a second light emitting element.

In the first light emitting device, the light output of the red signal may be performed. Also, photodetection of a red signal may be performed through the red light receiving element. The first photodetection data detected by the light receiving element may be stored in a memory. In addition, the current I ₂ applied to the second light emitting device may be increased by a unit size. In addition, the second light emitting device may perform optical output of the near infrared signal. Photodetection of the near infrared signal can be performed using the light receiving element. The second photodetection data detected by the light receiving element may be stored in the memory. Here, the unit size may be a unit of ㎂.

It is determined whether the current I ₁ applied to the first light emitting device and the current I ₂ applied to the second light emitting device have respectively reached the set values, and if the first current I ₁ and the second current I _{2 are determined,} When) does not reach the set value, the first current I ₁ may be increased by a unit size and the second current I ₂ may be increased by a unit size to further increase the number of times. That is, the first current I ₁ and the second current I ₂ may be continuously increased until the valid data necessary for analyzing the characteristics of the oxygen saturation measuring sensor are obtained.

If the first current I ₁ and the second current I ₂ respectively reach the set values, the first photodetection data and the second photodetection data may be analyzed.

That is, the change rate of the first photodetection data value according to the increase of the first current I ₁ is analyzed (first analysis), and the change rate of the second photodetection data value according to the increase of the second current I ₂ is determined. Analyze (second analysis). In addition, the difference between the rate of change of the first photodetection data value with the increase of the first current I ₁ and the rate of change of the second photodetection data value with the increase of the second current I ₂ is analyzed (third analysis). ). Further, the value of the first photodetection data for the first current I ₁ having a specific magnitude is analyzed (fourth analysis), and the second photodetection data for the second current I ₂ having the same magnitude is analyzed. The value is analyzed (fifth analysis). In addition, the difference between the value of the second photodetection data for the second current I ₂ having the same magnitude as the value of the first photodetection data for the first current I ₁ having a specific magnitude is analyzed. 6 analysis).

Based on the analysis results, the stored oxygen saturation calculation method can be modified. That is, the oxygen saturation measuring algorithms (Equations 1 and 2) are modified to be suitable for the oxygen saturation measuring sensor having a new light output characteristic. Modification of the oxygen saturation measurement algorithm may be comprehensively made based on the first to sixth analysis results. On the other hand, as described above, since the change in the wavelength of the red signal has the greatest influence on the oxygen saturation degree, the oxygen saturation measurement algorithm may be modified based on the first analysis and the fourth analysis. The microprocessor stores the modified oxygen saturation calculation method in a memory, and then calculates the oxygen saturation degree with reference to the modified oxygen saturation calculation method.

8 is a diagram for describing a method of detecting a forged fingerprint, according to an exemplary embodiment.

Forgery determination unit 140 according to an embodiment includes a fingerprint sensor 111 for sensing a user's fingerprint. The forgery determination unit 140 may acquire the input fingerprint image 115 in which the user's fingerprint is displayed through the fingerprint sensor 111. The fingerprint image 115 of the user may be obtained in the form of a partial image capturing a part of the user's fingerprint.

The forgery determination unit 140 may recognize the user's fingerprint by comparing the fingerprint (hereinafter, referred to as an “input fingerprint”) shown in the fingerprint image 115 of the user with the registered fingerprints shown in the registered fingerprint images 121 to 123. Can be. The registered fingerprint images 121, 122, and 123 may be previously stored in the registered fingerprint database 120 through a fingerprint registration process. The registration fingerprint database 120 may be stored in a memory (not shown) included in the forgery determination unit 140 or in an external device (not shown) such as a server that can communicate with the forgery determination unit 140. .

8 is a view for explaining a process of comparing the input fingerprint image 115 and the registered fingerprint image 123. Referring to FIG. 8, the forgery determination unit 140 may match the input fingerprint image 115 and the registered fingerprint image 123 to compare the input fingerprint image 115 and the registered fingerprint image 123. have. For example, the forgery determination unit 140 adjusts the size of the input fingerprint image 115 or overlaps the input fingerprint image 115 so that a common area overlaps between the input fingerprint image 115 and the registered fingerprint image 123. ) Can be rotated and translated. The forgery determination unit 140 may calculate the similarity of the fingerprint pattern in the corresponding common area and determine the recognition result based on the calculated similarity.

If the input fingerprint image 115 senses a fake fingerprint and the fingerprint patterns between the input fingerprint image 115 and the registered fingerprint image 123 are similar to each other, authentication of the fake fingerprint may be successful. . In order to solve this misrecognition problem, it is necessary to determine whether the input fingerprint shown in the input fingerprint image 115 is a fake fingerprint or a real fingerprint of a person. According to an embodiment, the forgery determination unit 140 may include a forgery fingerprint detection device (not shown), and may determine whether the input fingerprint is a forgery fingerprint through the forgery fingerprint detection device.

9 is a diagram for describing characteristics of a pixel of a fingerprint sensor, according to an exemplary embodiment.

According to one disclosure, a fingerprint sensor that performs fingerprint sensing may include characteristics of capacitance included in the touch sensor. According to an exemplary embodiment, pixels for sensing a fingerprint may be configured to have a narrower pitch than pixels of a general touch sensor. For example, the pixels constituting the touch sensor may be plural. The fingerprint sensing pixels may be configured in plural, and several fingerprint sensing pixels may be grouped as one. A sensor grouped into a plurality of pixels may be utilized as a touch sensor.

The plurality of pixels for detecting fingerprints can effectively use detailed data of individual pixels to detect a fake fingerprint. Each of the fingerprint sensing pixels senses light to sense an electronic signal having a fingerprint.

The fingerprint sensing pixels may be formed with a pitch of 200 μm or less. In this case, the pitch of the pixels of the touch sensor grouped into a plurality of fingerprint sensing pixels may be 2.0 mm or more.

According to one embodiment, it is necessary to reduce the pitch of the fingerprint pixel to secure additional resolution of the fingerprint image. When the pixels of the fingerprint sensor are reduced, a clear fingerprint image can be obtained. In addition, it is necessary to reduce the diameter of the pinhole of the pinhole layer to reduce the angle of view and to reduce the pitch between the pinholes.

According to one disclosure, the present invention may provide an anti-spoofing method using a device including a fingerprint sensor, and the method may simultaneously sense a plurality of biometric information of a user using a biometric sensor included in one surface of the device. The method may include generating user security information by combining a fingerprint image and oxygen saturation obtained from the biometric sensor, and comparing the user security information with biometric information of a pre-registered user to determine whether the user is authentic. The sensor may be a combination of a fingerprint sensor for sensing a fingerprint image of a user and a photo-plethysmography (PPG) sensor for measuring oxygen saturation in the blood of the user.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Should be regarded as falling within the scope of the above claims.

As those skilled in the art to which the present invention pertains, various permutations, modifications, and changes are possible without departing from the technical spirit of the present invention. It is not limited by.

In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks, but the invention is not limited to the order of steps, and certain steps may occur in a different order or concurrently with other steps than those described above. Can be. In addition, those skilled in the art will appreciate that the steps shown in the flowcharts are not exclusive and that other steps may be included or one or more steps in the flowcharts may be deleted without affecting the scope of the present invention.

Claims (11)

A biometric sensor included in one surface of the device and configured to simultaneously sense a plurality of biometric information of a user;
A security information generation unit generating user security information by combining a fingerprint image obtained from the biometric sensor and a blood oxygen saturation level of the user;
A memory for storing information on biometric information of a user registered in advance; and
And a forgery determination unit comparing the user security information with the biometric information of the pre-registered user and determining whether the user is authentic.
The biometric sensor is characterized in that the fingerprint sensor for sensing the fingerprint image of the user and a PPG (Photo-plethysmography) sensor for measuring the oxygen saturation of the user is combined,
The fingerprint sensor,
A light emitting unit for irradiating light of a specific frequency to the fingerprint area of the user;
A light receiver which senses light of a specific frequency reflected by the user's fingerprint by a sensor pixel array formed of a plurality of photo diodes and outputs an electrical signal having a fingerprint image;
And a fingerprint image generator configured to generate a fingerprint image through signal processing on the electrical signal.
The PPG sensor,
Some of the photodiodes included in the light receiving unit of the fingerprint sensor may include a color pass filter and an infrared ray region for selectively passing light having the same color to selectively sense light having the same color and wavelength band. In order to selectively sense the light having the same wavelength band is characterized in that the infrared pass filter (IR Pass Filter) for selectively passing the light having the same wavelength band in the infrared region,
The fingerprint sensor may include an optical filter (Red-IR Cut Filter) to block light above the infrared band on the remaining photodiodes except for the photodiodes equipped with the color filter and the infrared filter among the photodiodes of the light receiving unit. With
The color filter and the infrared filter is characterized in that included in the optical filter,
A differential CV amplifier for amplifying the PPG signal received through the PPG sensor;
A sample amplifier separating the PPG signal into an IR signal and a RED signal, and removing an ambient noise signal; and
Further comprising: a measuring unit for measuring the oxygen saturation of the user by analyzing the amplified IR signal and RED signal,
The light emitting unit,
At least one of an internal light source positioned in the display panel of the device to emit light and an external light source positioned in the display cover glass of the device to emit light;
The biometric sensor,
It consists of a touch sensor grouped into a plurality of fingerprint sensor pixels,
The forgery determination unit,
Characterized by using the user security information generated by the data obtained from each of the plurality of fingerprint sensor pixels for the authenticity of the user,
The forgery determination unit,
Comparing the fingerprint image of the user with a pre-registered fingerprint image to derive a first forgery determination value whether the matching ratio of the fingerprint pattern is higher than a predetermined criterion;
Comparing the blood oxygen saturation level with the blood oxygen saturation degree of the user and deriving a second counterfeit determination value whether the error value corresponds to a predetermined reference value,
The authenticity of the user is determined using the first forgery judgment value and the second forgery judgment value.
A fingerprint quality evaluation unit for dividing the fingerprint image of the user into blocks to determine an image quality evaluation value;
A filtering unit filtering the fingerprint image of the user to obtain a filtered fingerprint image;
A fingerprint comparator for comparing a filtered fingerprint image with a pre-registered fingerprint image to determine a similarity value; and
And a fingerprint authenticity determination unit configured to determine whether the user's fingerprint is forged based on the determined image quality evaluation value and the similarity value.
A pinhole layer disposed between the display panel of the device and the biometric sensor, the pinhole layer including a plurality of pinholes to form a focal point for transferring light reflected by the user's fingerprint to the biometric sensor;
The plurality of pinholes are disposed to correspond one-to-one with a plurality of biosensor pixels included in the biosensor.
A finger recognition sensor sensing a user's finger when a fingerprint is in contact with the biometric sensor; And
And a real user determination circuit configured to determine whether the obtained fingerprint image is a fingerprint of a user's actual finger. delete delete delete delete delete delete delete delete delete delete

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