JP2015217013A - Blood flow authentication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood flow authentication system which does not need installation of a special operation part, can clearly confirm whether the finger used in the authentication is a finger of a living body or a fake finger, reduce physical elements in the device, and reduce the risk of malfunctions without complication of the device.SOLUTION: The system includes: an imaging part 1 which images arteries and veins of a finger; a luminous source 2 which sends light to the imaging part 1 through the finger and has two or more kinds of different peak wavelengths; a loading part 3 which allows the finger to be loaded thereon; a recording part 4 which stores data of blood flow of the finger; and a control part 5 which makes the blood flow data according to the images imaged in the imaging part 1 and checks them against registered blood flow data. The control part 5 has living body detection means to confirm whether it is a living body by comparing a plurality of images imaged with different wavelengths from the luminous source 2 in a chronological order.

Description

  The present invention relates to a blood flow authentication system that controls the operation of an external device such as locking and unlocking a door using biometric authentication based on blood flow that is an artery or vein of a finger.

  2. Description of the Related Art Conventionally, a system is known in which an individual is identified using a finger vein pattern, and the use of a personal account is permitted at a bank ATM or entry into a building is permitted.

  Because finger veins are personal information inside the body, unlike biometric information that appears on the body surface such as fingerprints, forgery, imitation, duplication, etc. are inherently difficult even in biometric authentication. Very good biological information. However, in the conventional capacitance method, switch method, and the like, there is a possibility that a fake finger is made and registration becomes possible. Therefore, a personal authentication device is also known that determines whether a finger used for authentication is a biometric finger or a forged finger based on a finger vein.

  As various personal authentication systems including such an entry / exit control system, for example, as shown in FIG. 6, FIG. 7, and FIG. Whether the finger used for authentication is a biometric finger or a forged finger by detecting increase or decrease in blood volume due to vein compression or release when the authentication switch 8 is pressed with a finger Means for determining are disclosed.

JP 2005-71118 A

  However, in the personal authentication device described in the prior patent document 1, on the assumption that there is an operation part that is the authentication switch 8, the user can unconsciously increase or decrease the blood flow by compressing and releasing the vein. In a device without such an operation site, the user needs to intentionally increase or decrease blood flow by squeezing and opening a vein, and if the purpose of performing such an operation is known, the security of the authentication device is reduced. Since it was damaged, it could not be used for general purposes.

  In the first place, the amount of blood flow is small in the finger vein, and even if the operation part of the authentication switch 8 is used, the difference in increase / decrease in blood flow due to the compression and release of the vein is minute, and in an environment where the personal authentication device is installed It was difficult to determine whether the finger was a living body finger or a forgery finger.

    Further, in the personal authentication device of the prior art document 1, it is necessary to install the light receiving element 50 and the living body detection light source 51 separately from the light source 3 and the imaging unit 2 for imaging the vein pattern. Furthermore, when the personal authentication device is downsized and slimmed, the light receiving element 50 and the light source 51 for living body detection are limited.

  Therefore, in the present invention, whether the finger used for authentication is a living body finger or a forged finger, without using a special operation unit, and is personal authentication using blood flow. Furthermore, an object of the present invention is to provide a blood flow authentication system that can reduce the possibility of failure without complicating the apparatus by reducing physical elements in the apparatus and reducing the possibility of failure.

  Separately, the blood flow of the finger of a living body fluctuates in summer and winter, and in particular, in Japan, blood vessels may contract in the winter and affect the authentication accuracy. Another object is to provide a blood flow authentication system.

  [1] That is, according to the present invention, an imaging unit for imaging a finger artery and vein, a light transmitted through the finger to the imaging unit, two or more light sources having different peak wavelengths, and a finger are placed. A placement unit, a recording unit in which finger blood flow data is stored, and a control unit that creates blood flow data based on an image photographed by the photographing unit and compares the blood flow data with the registered blood flow data A blood flow authentication system, characterized in that the control unit has a living body detection means for confirming that the image is a living body by comparing a plurality of images taken at different wavelengths of the light source in time series. is there.

  [2] The system according to [1], wherein the living body detection means confirms that the body is a living body by changing at least one of a shape of a blood vessel and / or a shading.

  [3] The blood flow authentication system according to [1] or [2], wherein a magnet is provided in the mounting portion.

  According to the blood flow authentication system of the present invention, it is personal authentication using blood flow, and it is clear that a finger used for authentication is a biological finger, without installing a special operation unit. It is possible to confirm whether or not the finger is a finger, and further, it is possible to reduce the physical elements in the device and reduce the possibility of failure without complicating the device.

  In the invention [3], even if the blood vessel is contracted particularly in a cold time, the authentication can be performed stably without affecting the authentication accuracy.

It is a block diagram which shows the system configuration | structure in the blood-flow authentication system of this invention. It is a flow which shows an example of the process sequence of the blood flow authentication in the blood flow authentication system of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments relating to a blood flow authentication system according to the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is intended to limit the invention particularly in the following description. Unless specifically stated, the present invention is not limited to this form. In addition, about the expression which shows a numerical range, an upper limit and a lower limit are included.

  As shown in FIG. 1, in one embodiment of the blood flow authentication system according to the present invention, an imaging unit A that images a user's blood flow, a recording unit 4 in which a blood flow pattern and the like are stored in advance, and imaging An external device such as a control unit 5 that creates blood flow data based on an image captured by the unit A and collates with blood flow data registered in the recording unit 4, and a door electronic lock that performs door opening / closing control 6 is provided.

  The imaging unit A is installed outside a building such as a front door, and as shown in FIG. 1, the imaging unit 1 that images the blood flow of the finger artery and vein to be collated and the light source 2 have peak wavelengths. Different first light sources 21 and second light sources 22 are provided, and a placement unit 3 for placing a finger between the imaging unit 1 and the first light source 21 and the second light source 22 is further provided. The imaging unit A uses the imaging unit 1 to capture a pattern of blood flow in a finger vein or an artery when light emitted from the first light source 21 and the second light source 22 passes through the finger to be verified. . Unlike the fingerprint on the surface of the finger, the blood flow of the finger is data unique to the individual inside the finger. For this reason, there is no problem of being duplicated from a residual fingerprint in fingerprint authentication. Furthermore, in fingerprint authentication, it is difficult to determine whether or not a fingerprint to be authenticated is a living body, but it is difficult to determine whether it is a living body by checking not only the blood flow pattern but also the actual blood flow. The system that authenticates blood flow can realize living body detection with higher accuracy than the system that authenticates fingerprints in that it can be determined whether or not.

  The imaging unit 1 is a member that captures a pattern image of blood flow of arteries and veins obtained by transmitting a finger out of light emitted from the first light source 21 and the second light source 22. As the imaging unit 1, a photoelectric conversion element such as a CCD, CMOS, or CIGS is preferably used. The imaging unit 1 captures a plurality of blood flow patterns at predetermined time intervals according to an instruction from the control unit 4, and transmits the captured blood flow pattern image data to the control unit 4.

As the 1st light source 21 and the 2nd light source 22, LED (Light Emitting Diode) which is the red light whose peak wavelength which is the wavelength used as the peak of light quantity is the range of 620-750 nm, and the infrared light of the range of 800-1000 nm. preferable. By using two types of light sources having different peak wavelengths, not only veins but also arteries can be appropriately imaged. Specifically, when red light in the range of 620 to 750 nm is used, oxyhemoglobin (HbO ₂ ) transmits light of about 660 nm well, so that an arterial image can be taken, and red in the range of 800 to 1000 nm. When external light is used, reduced hemoglobin (Hb) transmits light of about 880 nm well, so that a vein image can be taken. Thus, by photographing the finger by alternately emitting two different types of light sources, it is possible to detect a state such as a finger artery and vein pulsation. The 1st light source 21 and the 2nd light source 22 are located in the other side to the imaging | photography part 1 with respect to the finger | toe image | photographed, and each one or two or more plurality is provided. In this embodiment, two types of light sources having different peak wavelengths are used. However, in order to clearly image arteries and veins, a plurality of light sources having two or more different peak wavelengths are used. You may use 2 or more types, such as 3-5 types of light sources from which a wavelength differs.

  The placement unit 3 is a member on which a finger to be authenticated is placed. The member in contact with the finger of the placement unit 3 is irradiated with light from the first light source 21 and the second light source 22 and passes through the finger to be authenticated to reach the photographing unit at least in the red region and the near infrared region. It is made of a transparent member. A finger detection sensor such as a surface-type or projection-type electrostatic capacitance method using the fact that electrostatic coupling is generated when the finger approaches is provided at a position where the fingertip touches the placement unit 3. When the detection sensor detects the finger, the placement unit 3 or the processing unit connected to the placement unit 3 and installed in the imaging unit A transmits information about the placement of the finger on the placement unit 3 to the control unit 4. Send.

  Furthermore, the mounting part 3 can be provided with a magnet at the edge of the member that contacts the finger. By attracting the iron component contained in the bloodstream to the magnet, it is possible to collect the bloodstream and stabilize the authentication accuracy even in the winter season in Japan, where blood vessels contract and it is difficult to photograph the bloodstream. As the magnet, a ferrite magnet, a samarium cobalt magnet, a permanent magnet such as a neodymium magnet, an electromagnet, or the like is preferable.

  The recording unit 4 is a member that stores a blood flow pattern of a finger of a user who is going to be authenticated as blood flow data. As the recording unit 4, a storage device such as a hard disk drive (HDD), a solid state drive (SSD), or a flash ROM is preferably used alone or in combination. Although the recording unit 4 may be incorporated in the imaging unit A, it is preferable that the recording unit 4 is not incorporated in the imaging unit A and is located in another housing because of the importance of blood flow data.

  The control unit 5 is located inside or outside the imaging unit 1, determines whether or not the finger imaged by the imaging unit A is a living body, and the finger registered in advance from the imaged blood flow pattern image It is a member that determines whether or not. Specifically, as to whether or not the finger is a living body, a change in shape such as a blood vessel width at an arbitrary blood vessel location from a blood flow pattern image taken at a predetermined time interval, or a change in shading due to passage of red blood cells Judgment is made by comparing one or a plurality of changes caused by pulsations in time series. Whether or not the finger is a registered finger is determined by setting a plurality of arbitrary blood vessel locations and determining whether or not the blood flow pattern image matches a pre-registered finger blood flow pattern image. .

  As shown in FIG. 2, the process in the control unit 5 is performed as follows. That is, the control unit 5 stands by in the activated state, and first acquires information that a finger is placed on the finger detection sensor provided in the placement unit 3 (step S101). Then, the imaging unit A is instructed to image the arterial and venous blood flow patterns (step S102). Then, acquisition of shooting data by the first light source 21 (step S103) and acquisition of shooting data by the second light source 22 (step S104) are performed. Then, it is determined whether the imaging unit A has taken a predetermined number of times (step S105). If the required number of times has not been reached, the imaging unit A is again instructed to image the blood flow pattern of the artery and vein (step S102). When the required number of times has been reached, these image data are compared in time series (step S106), and it is determined whether or not the imaged object is a living body (step S107). Then, when the imaged target is a living body, a composition process for superimposing a plurality of images of the photographed blood flow pattern, an emphasis filter process for emphasizing local shading changes in the synthesized image, and an image after enhancement An image such as a noise removal filter process for removing fine noise is processed (step S108), and it is determined whether the finger is a registered finger (step S109). And when it is a registered finger | toe, the door electronic lock which is the external apparatus 6 is unlocked or locked (step S110). Note that the process ends when the object to be photographed is not a living body, or when the object is not a blood flow of a registered finger even if it is a living body.

  The external device 6 is connected to the control unit 4 and can operate when the control unit 4 is authenticated as a pre-registered finger. For example, a door electronic lock installed at the entrance. A lock provided on the door electronic lock locks the door and locks it, and unlocks the door and unlocks it. Also, when the blood flow is not verified due to an unexpected failure such as a power failure and the standby power supply not working, the door electronic lock lock and the lock provided on the front door are locked. Can be locked and unlocked by operating with a key.

DESCRIPTION OF SYMBOLS 1 ... Image pick-up part 2 ... Light source 21 ... 1st light source 22 ... 2nd light source 3 ... mounting part 4 ... recording part 5 ... control part 6 ... external apparatus 7 ..Magnet A ... Imaging unit

Claims (3)

An imaging unit for imaging the arteries and veins of the finger;
Two or more types of light sources having different peak wavelengths, and transmitting light through the finger to the photographing unit,
A placement unit for placing a finger;
A recording section in which finger blood flow data is stored;
A blood flow data is created on the basis of an image photographed by the photographing unit, and a control unit that performs collation with the registered blood flow data is provided.
The blood flow authentication system, wherein the control unit includes a living body detection unit that confirms a living body by comparing a plurality of images taken at different wavelengths of the light source in time series. 2. The system according to claim 1, wherein the living body detection unit confirms that the body is a living body by a change in at least one of a blood vessel shape and shading. The blood flow authentication system according to claim 1, wherein a magnet is provided in the mounting portion.

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