GB2565446A

GB2565446A - Biometric authentication device

Info

Publication number: GB2565446A
Application number: GB1814817.1A
Authority: GB
Inventors: Kitane Keiji
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2016-06-06
Filing date: 2016-06-06
Publication date: 2019-02-13
Anticipated expiration: 2036-06-06
Also published as: GB201814817D0; GB2565446B8; JP6638067B2; CN108780563B; JPWO2017212513A1; CN108780563A; WO2017212513A1; GB2565446B

Abstract

There are differences in finger width among individuals, and it has been difficult to positionally control both thin and thick fingers by means of a guide or the like in such a way that these fingers are always positioned at the same position, with the result that it has been impossible to avoid a degradation in authentication accuracy due to a displacement in the position of a positioned finger. The biometric authentication device according to the present invention performs authentication on the basis of biometric information, and is provided with a finger tip positioning portion configured from: a finger tip bottom surface portion which is in contact with the ball of a positioned finger; a finger tip surface portion which is connected substantially perpendicular to the finger tip bottom surface portion and which has a surface that meets the tip of said finger at a predetermined angle; and finger tip side surface portions which are connected to the finger tip surface portion and the finger tip bottom surface portion and which each have a surface facing a side surface of said finger.

Description

[DESCRIPTION]

[Title of Invention] BIOMETRIC AUTHENTICATION DEVICE

[Technical Field] [0001]

The present invention relates to biometric authentication devices .

[Background Art] [0002]

Biometric authentication devices that use biometric information to authenticate users have been used in various apparatuses and systems. For authentication of personal identification with a biometric authentication device, the user takes an action of holding a specified body part, such as a finger or eye, over the authentication device or an action of peeping into the authentication device (authentication operation) . With this action, the authentication device reads biometric information, verifies feature amounts extracted from the biometric information against feature amounts of biometric information that the user has registered beforehand, and calculates the matching level of the verification. The authentication device determines whether the user is authentic depending on whether the matching level exceeds a specified threshold.

[0003] A background technique of the present invention is Japanese

Patent Application Publication No . 2011-2988 (Patent Literature 1). This publication describes a technique that "provides a finger vein authentication device capable of performing authentication processing on a short and thin finger of a child without preparing another dedicated finger vein authentication device in addition to one for adults" (see the abstract) . Another background technique is Japanese Patent Application Publication

No. 2013-149115. This publication describes a technique that "provides a finger vein authentication device capable of reducing degradation in authentication rates caused by pressed veins in a finger base portion" (see the abstract).

[Citation List] [Patent Literature] [0004] [PTL 1] Japanese Patent Application Publication No. 2011-2988 [PTL 2] Japanese Patent Application Publication No. 2013-149115 [Summary of Invention] [Technical Problem] [0005]

For biometric authentication devices that acquire biometric information with various sensors such as cameras or electrostatic sensors from a finger placed at a specified position, for example, fingerprint authentication devices and finger vein authentication devices, it is difficult to place a finger at a specified position at every authentication. Due to a difference between biometric information acquired at a registration and that acquired at authentication, this causes a problem of degradation in authentication accuracy.

[0006]

To solve this problem, conventional biometric authentication devices have configurations in which a recess similar to the shape of fingertips, as illustrated in Fig. 7, is formed at a position where a fingertip is to be placed, to restrict the movement of the fingertip back and forth and right and left, and to enable one to place a finger at the same position every time. However, there are variations among individuals in finger thickness. When a finger thinner than the recess is placed, the recess cannot restrict deviation of the finger in the right-left direction.

[0007]

In addition, Japanese Patent Application Publication No. 2011-2988 proposes a device having an intermediate guide to be capable of dealing with both long fingers and short fingers.

However, this device deals with such a wide variety of lengths of fingers that the device cannot prevent a short finger that does not reach the front guide from moving in the front-rear direction.

Thus, it is difficult to restrict the deviation in the front-rear direction.

[0008]

In addition, Japanese Patent Application Publication No. 2013-149115 proposes a device that has a finger rest in a V shape to restrict deviation in the right-left direction regardless of the finger thickness. However, the distance from an imaging device is different between a thin finger and a thick finger. If the focal distance is adjusted to one of these, the other would be out of focus. Thus, a correct image may not be captured.

[0009]

In light of the above points, the present invention provides a biometric authentication device that makes placement of fingers stable even if there are variations among individuals in finger thickness .

[Solution to Problem] [0010]

Provided as a means to solve the above problems is a biometric authentication device that performs authentication using biometric information, including a fingertip rest including a fingertip bottom surface portion that comes into contact with a ball of a finger, a fingertip surface portion coupled with the fingertip bottom surface portion approximately perpendicularly and having a surface that comes into contact with a tip of the finger at a specified angle, and a fingertip side surface portion coupled with the fingertip surface portion and the fingertip bottom surface portion and having a surface that is opposed to a side surface of the finger.

[Advantageous Effects of Invention] [0011]

For a biometric authentication device that acquires biometric information from a finger placed at a specified position, the present invention makes it possible to reduce positional deviation of the finger regardless of the thickness of the finger when the finger is placed. This makes it possible to acquire the same biometric information both at the registration and authentication, improving authentication accuracy in biometric authentication.

Problems, configurations, and effects other than those described above will be apparent by the following description of an embodiment.

[Brief Description of Drawings] [0012] [Fig. 1] Fig. 1 is an outline view of the overall shape of a finger vein authentication device.

[Fig. 2] Fig. 2 is a block diagram illustrating the device configuration of the finger vein authentication device.

[Fig. 3] Fig. 3 is a diagram illustrating the shape of a fingertip rest.

[Fig. 4] Fig. 4 is a diagram illustrating the shape of the fingertip rest.

[Fig. 5] Fig. 5 is a flowchart illustrating transaction using the finger vein authentication device.

[Fig. 6] Fig. 6 is a diagram illustrating screens displayed on a display unit of the finger vein authentication device.

[Fig. 7] Fig. 7 is a diagram illustrating the shape of a fingertip rest of a conventional finger vein authentication device.

[Description of Embodiments] [0013]

Hereinafter, an embodiment of the present invention will be described using the drawings. Note that in this embodiment, a finger vein authentication device will be described as an example of a biometric authentication device.

[Example 1] [0014]

Fig. 1 is an outline view of the overall shape of a finger vein authentication device 100 to which this embodiment is applied.

Part (a) of Fig. 1 is a top view of the finger vein authentication device 100 viewed from the above. Part (b) of Fig. 1 is a right cross-sectional view taken along line A-A indicated in the top view of part (a) of Fig. 1. Part (c) of Fig. 1 is a perspective view of the finger vein authentication device 100 viewed from the obliquely above.

[0015]

Fingertip surface portions 101 are surfaces that come into contact with the distal end portion of a finger 116 placed on the finger vein authentication device 100. Fingertip side surface portions 102 are surfaces that come into contact with the side surfaces of the distal end portion of the finger 116 . A fingertip bottom surface portion 103 is a surface that comes into contact with the bottom surface of the distal end portion of the finger 116 (also referred to as the ball of the finger). A fingertip guide 104 is a semicircular guide that indicates the position at which a finger is to be placed to a person who uses the finger vein authentication device 100. The fingertip surface portions 101, the fingertip side surface portions 102, and the fingertip bottom surface portion 103 may be collectively called a fingertip rest 105. The fingertip rest 105 may be collectively called including the fingertip guide 104. Details of the fingertip rest 105 will be described later. Note that here description is provided assuming that the distal end portion of the finger 116 is the tip portion of the finger 116 from the distal interphalangeal joint. However, depending on variations among individuals, the distal end portion of the finger 116 may include portions around the distal interphalangeal joint.

[0016] A finger-base rest 106 is a support portion that supports the base of the finger 116 presented to the finger vein authentication device 100. A near infrared light emission unit 109 emits near infrared light toward the upper portions of the side surfaces of the finger 116 place on the fingertip rest 105 and the finger-base rest 106 from the both sides of the finger.

Although the finger 116 is radiated from both sides in this embodiment, the finger 116 may be radiated from one side by adjusting the arrangement of the near infrared light emission unit 109. An image capturing window 107 is located between the fingertip rest 105 and the finger-base rest 106, and the position of the image capturing window 107 corresponds to the position of a portion between the distal interphalangeal joint and the proximal interphalangeal joint of the placed finger 116. The image capturing window 107 has a step so that the finger does not touch the image capturing window 107 directly. In addition, a near-infrared pass filter which passes only light with wavelengths longer than or equal to those of near infrared light is provided for the image capturing window 107 . The near-infrared pass filter reduces the influence of outside light, such as sun light, that radiates the finger 116, besides the near infrared light emission unit 109. For the filter, a bandpass filter that blocks light with wavelengths shorter than and longer than those of near-infrared-light and passes only near infrared light may be used instead of the near-infrared-light pass filter which passes light with wavelengths longer than or equal to those of near infrared light. Below the image capturing window 107 (at the bottom surface side of the device) is provided an image capturing unit 108 that captures an image of the transmitted light emitted from the near infrared light emission unit 109 and transmitted through the finger 116.

[0017]

Input units 110 receive input from the operator when the operator operates the finger vein authentication device 100. In this embodiment, four input units 110-1 to 110-4 are provided and assigned respective functions—the button 110-1 (SELECT) for selecting display contents, the buttons 110-2 and 110-3 (marked with triangular figures) for changing the display contents, and the button 110-4 (ENTER) for determining input. Note that the number of input units 110 is not limited to four, and for the functions assigned to the input units 110, functions other than those described in this embodiment may be assigned.

[0018] A display unit 111 is a display unit that displays information such as "authentication successful" or "authentication failed" when biometric authentication is performed. The display unit 111 is composed of a display device such as an LCD or an organic EL. Screens and other information displayed on the display unit 111 will be described later. Note that the display unit 111 and the input units 110 can be integrated into one unit, such as a touch panel.

[0019] A SIM card slot 112 has a shape of a cover. When the cover is opened, an unillustrated slot can be accessed, and a SIM card is inserted into/taken out of the slot. The SIM card to be inserted into the slot can store information such as templates of biometric information used for authentication, which are utilized in the authentication. Note that the SIM card may include a control chip, which may be used to perform authentication on card by using the control chip.

[0020] LEDs 113 are light emitting units capable of indicating the state of the finger vein authentication device 100. For example, in the case of charging the finger vein authentication device 100 by coupling it with an unillustrated external device, using an external coupling I/F 114 described later, the LEDs may emit red light to show that charging is in progress. In addition, when biometric authentication is failed, the LEDs may emit light with a color indicating the authentication failure.

[0021]

The external coupling I/F 114 is a coupling unit used to couple the finger vein authentication device 100 with an unillustrated external device. In this embodiment, description will be provided assuming that the external coupling I/F 114 is

a USB (Universal Serial Bus) . However, the external coupling I/F 114 is not limited to USB, but it may be one conforming to another communication standard. Note that the external device is a computer or the like, including an I/F capable of being coupled with the external coupling I/F 114, such as USB. The external coupling I/F 114 may be referred to as a wired communication unit to be distinguished from a wireless communication unit 203 described later.

[0022] A switch unit 115 is a switch unit that switches ON/OFF of the power of the finger vein authentication device 100 and also switches the coupling between the finger vein authentication device 100 and external devices . In this embodiment, description will be provided assuming that the finger vein authentication device 100 includes two kinds of couplings with external devices, a coupling using the external coupling I/F 114 and a coupling using wireless communication. The switch unit 115 can be switched to three positions—left (the direction indicated by arrow B) , center, and right (the direction indicated by arrow C) as illustrated in part (c) of Fig. 1. For example, when the switch unit 115 is switched to the left (the direction indicated by arrow B) , coupling by USB may be selected, and when the switch unit 115 is switched to the right (the direction indicated by arrow C), coupling by wireless communication may be selected. When the switch unit 115 is switched to the center, powering off is selected.

Note that in this embodiment, description will be provided assuming that Bluetooth (registered trademark) is employed for the wireless communication. However, a wireless communication standard other than Bluetooth (registered trademark) may be implemented for the wireless communication.

[0023] A step 119 is a step formed between the fingertip bottom surface portion 103 and the image capturing window 107. A step 120 is a step formed between the finger-base rest 106 and the image capturing window 107. The portions indicated by the circles of broken lines correspond to the steps, and the details will be provided later.

[0024]

Fig. 2 is a block diagram for explaining the device configuration of the finger vein authentication device 100 in this embodiment. Note that description of the configuration described above is omitted because it would be redundant.

[0025]

The finger vein authentication device 100 includes a CPU 201, a memory 202, the wireless communication unit 203, the external coupling I/F 114, a power unit 204, the SIM card slot 112, a fingertip sensor 205, a finger-base sensor 206, the display unit 111, the image capturing unit 108, the near infrared light emission unit 109, the input units 110, the LEDs 113, the switch unit 115, and a sound output unit 207, which are coupled by buses or electrical circuits.

[0026]

The CPU 201 is a control unit that controls components of the finger vein authentication device 100. The memory 202 is a storage unit that stores programs (an authentication program 202-1, a control program 202-3) executed by the CPU 201 and information necessary for the control (wireless coupling information 202-2).

[0027]

The wireless communication unit 203 is a communication unit that wirelessly couples the finger vein authentication device 100 to an external device. The power unit 204 is a battery that supplies power to the finger vein authentication device 100 . When the external coupling I/F 114 is coupled to an external device, the power unit 204 can charge the battery.

[0028]

The fingertip sensor 205 is a sensor that is provided at the fingertip bottom surface portion 103 and detects whether a fingertip is placed. The finger-base sensor 206 is a sensor that is provided at the finger-base rest 106 and detects whether a finger-base is placed. In this embodiment, description is provided assuming as an example that the fingertip sensor 205 and the finger-base sensor 206 are electrostatic sensors. However, sensors other than electrostatic sensors may be used.

Alternatively, these sensors may be sensors that detect that a finger is held over the sensors when the physical switches are pressed. The sound output unit 207 is a device such as a buzzer that outputs error sound when biometric authentication is failed, or outputs electronic sound when the finger vein authentication device 100 is powered on, or other occasions.

[0029]

Note that in this embodiment, there is some explanation that mainly programs perform control, to make explanation simple.

Actually, hardware resources such as CPU described above are used to execute the programs.

[0030]

Fig. 3 is an enlarged view of the fingertip rest 105, the finger-base rest 106 and their vicinities of the finger vein authentication device 100 when viewed from obliquely above. In addition, part (a) of Fig. 4 is an enlarged top view of the fingertip rest 105, and part (b) of Fig. 4 is a right cross-sectional view taken along line A-A in part (a) of Fig. 4.

Part (c) in Fig. 4 is a diagram illustrating the state when a thin finger 117 is placed at the fingertip rest 105. Part (d) in Fig. 4 is a diagram illustrating the state when a thick finger 118 is placed at the fingertip rest 105. Now, description will be provided in detail for the fingertip rest 105 of this embodiment using Figs. 3 and 4.

[0031]

The fingertip rest 105 in this embodiment includes the fingertip surface portions 101, the fingertip side surface portions 102, and the fingertip bottom surface portion 103, as described above.

[0032]

The fingertip surface portions 101, which are surfaces formed to be approximately perpendicular to the fingertip bottom surface portion 103 in the vertically upward direction, come into contact with a fingertip with two surfaces and support the finger.

As illustrated in part (a) of Fig. 4, the fingertip surface portions 101 look like two sides of a triangle from above.

The angle a formed by the two sides of the triangle is obtuse, and it is desirable that angle a be around 120 degrees so that when a thin finger is stuck to the fingertip surface portions 101, the tip end of the finger comes into contact with the two sides of the triangle, naturally guiding the fingertip to the center portion, and so that when a thick finger is placed, the finger does not interfere with the fingertip surface portions 101 and does not affect capturing of a biological image. It is also desirable that the height b of the fingertip surface portions 101 be a height that prevents the nail from interfering with the fingertip surface portions 101 and is not so low for the finger 116 to get over the wall surfaces when the finger 116 is stuck to the fingertip surface portions 101. In contrast, if height b is large, although the finger does not get over the wall surfaces, the nail comes into contact with the fingertip surface portions 101, preventing the finger from being placed at a right position.

In this embodiment, height b is about 5 mm from the fingertip bottom surface portion 103.

[0033]

The fingertip side surface portions 102 are support portions that are connected to the fingertip surface portions 101 and formed to be approximately perpendicular to the fingertip bottom surface portion 103 in the vertically upward direction, and support the placed finger from both right and left sides. It is desirable that the distance c between the fingertip side surface portions 102 be about 15 to 20 mm so as not to interfere with a thick finger. Note that when the placed finger is a thin finger, the fingertip side surface portions 102 do not come into contact with the finger, or only part of the fingertip side surface portions 102 comes into contact with the finger. Thus, it can also be said that the fingertip side surface portions 102 are surfaces located at positions opposed to the side surfaces of the finger. The fingertip side surface portions 102 themselves are also located at positions opposed to each other. The fingertip bottom surface portion 103 looks like the shape of a pentagon when viewed from above, because of the fingertip surface portions 101 and the fingertip side surface portions 102, to which the fingertip bottom surface portion 103 is connected, and the step 119.

[0034]

Note that in this embodiment, it is assumed that the fingertip rest 105 is produced as an integrally molded part made from resin to improve productivity. For this reason, the fingertip surface portions 101 and the fingertip side surface portions 102 are formed to be approximately perpendicular to the fingertip bottom surface portion 103. The coupling portions between the fingertip surface portions 101 and the fingertip bottom surface portion 103 are not perpendicular corners but have gentle curves. The coupling portions between the fingertip side surface portions 102 and the fingertip bottom surface portion 103 are also the same. However, each of these surface portion may be produced as a separate part, and then, these surface portions may be assembled into one fingertip rest 105. In this case, coupling portions of these surface portions may be perpendicular corners .

[0035]

Here, before the effect of the fingertip rest 105 in this embodiment is described, description will be provided for problems on conventional fingertip rests. Part (a) of Fig. 7 is a diagram illustrating the shape of a fingertip rest 701 of a finger vein authentication device which has conventionally been used.

Part (b) of Fig. 7 is a right cross-sectional view taken along line D-D in part (a) of Fig. 7. Part (c) in Fig. 7 is a diagram illustrating the state when the thin finger 117 is placed at the fingertip rest. Part (d) in Fig. 7 is a diagram illustrating the state when the thick finger 118 is placed at the fingertip rest.

[0036]

The shape of the conventional finger rest illustrated in

Fig. 7 (hereinafter referred to as a conventional shape 701) has a round shape adapted to the shape of fingers and typically has a width of about 15 mm adapted to thick fingers. The conventional shape 701 has an advantage that the user can determine where to place the user's finger intuitively because the shape is reminiscent of a fingertip. However, when the thin finger 117 having a fingertip width of about 10 mm is placed as illustrated in part (c) of Fig. 7, the finger can be placed with a deviation 702 of the center of the finger because there are gaps between the portions where the finger is placed and the side surfaces of the finger in the conventional shape 701. In addition, since the portion to which the finger is stuck has a semicircular shape, which is not a shape that limits the movement of the finger in the right-left direction, the user can place the finger at a deviated position without receiving any restriction.

[0037]

If positional deviation of the finger occurs between at the times of registration and authentication, there is a difference in the image of the finger captured by the image capturing unit 108 between at the times of registration and authentication, increasing the possibility that an authentic person may be recognized as another person and that another person may be recognized as the authentic person. Thus, there arises a problem the authentication accuracy of the conventional shape 701 is low.

[0038]

In order to prevent the thin finger 117 from being deviated when the thin finger 117 is placed, the width of the portion where the finger is placed needs to be narrower. However, if the width is narrower to be adapted to the thin finger 117, there arises a problem that when the thick finger 118 is placed, the fingertip cannot enter the portion where the fingertip is to be placed.

[0039]

As described above, the conventional shape 701 has a problem that it is difficult to place correctly fingers having individual variations, such as the thin finger 117 and the thick finger 118.

[0040]

With the shape in this embodiment, when the thin finger 117 is placed, the finger is guided naturally to the center portion by angle a formed by the two sides of the fingertip surface portions 101, when the finger 117 is stuck to the two sides of the triangle portion of the fingertip surface portions 101 as illustrated part(c) of Fig. 4. This makes it possible to place the finger at the same position in the center every time.

[0041]

In addition, when the thick finger 118 is placed as illustrated in part (d) of Fig. 4, with the shape in this embodiment, the movement of the thick finger 118 back and forth and right and left is restricted by the fingertip surface portions 101 and the fingertip side surface portions 102. This makes it possible to place the finger at the same position every time.

[0042]

As described above, the shape according to the present invention makes it possible to place the finger at the same position every time for both the thin finger 117 and the thick finger 118. Consequently, it is possible to prevent degradation of authentication accuracy caused by positional deviation of the finger .

[0043]

In addition, the conventional shape 7 01 is a shape with which the finger can be placed at as it is when the finger is placed, and thus it is possible to press the finger against it. If the finger is strongly pressed, it will hinder the blood flows in blood vessels of the finger, which sometimes affects image capturing and authentication of the finger veins. In contrast, the shape of this example has a structure in which two surfaces of the fingertip surface portions 101 support the finger, and thus, this is not a structure against which the finger is strongly pressed.

Consequently, this structure does not hinder the blood flows, and it is less likely that this structure affects image capturing and authentication of finger veins. In particular, suppose that the finger is pressed against the far side of the device (in the direction of arrow B). With the conventional shape, the entire finger including the ball of the finger is pressed. However, with the shape of this embodiment, the surfaces coming into contact with the fingertip surface portions 101 are pressed, and thus, the influence is small.

[0044]

Further, in this embodiment, as illustrated in Fig. 3, outside the fingertip surface portions 101 is formed the step in a semicircular shape as the fingertip guide 104 to indicate the shape of a finger. In the same way as with the conventional shape, this configuration reminds the user, who uses the finger vein authentication device 100, of the shape of a fingertip and makes it easy for the user to understand that this is where the finger is to be placed. Note that the fingertip guide 104 may be indicated, for example, by coloring by painting other than forming the semicircular step. In other words, the semicircular edge may be painted so that the paint is reminiscent of the shape of fingers .

[0045]

Part (b) of Fig. 1 is a right cross-sectional view of the finger vein authentication device 100, taken along line AA. As is apparent from the right cross-sectional view, the step 119 is formed between the surfaces of the fingertip rest 105 and the image capturing window 107. Similarly, the step 120 is formed between the surfaces of the finger-base rest 106 and the image capturing window 107. The steps formed between the fingertip rest 105, the finger-base rest 106, and the image capturing window 107 have effects of not hindering the blood flows in the fingertip and the finger-base. In other words, even if the user unintentionally applies some force to the fingertip or the finger-base and presses the finger 118 against the fingertip rest 105 or the finger-base rest 106, the blood flows are kept because of the steps, making it possible to capture an image of the veins.

[0046]

Without the step 119 and the step 120, when the finger is strongly pressed, the skin of the finger is pulled at the peripheral portions of the image capturing window 107, and the veins maybe pressed and cannot be seen. However, since the steps 119 and 120 are formed away from the image capturing window 107 by certain distances, the portions that are pressed and cannot be seen are outside the image capturing window 107. Thus, even if the finger is strongly pressed, it is possible to capture a vein image normally. Note that even in the case where there is only one of the steps 119 and 120, the step still has the above effect.

[0047]

Next, finger vein authentication processing in this embodiment will be described using Fig. 5. Fig. 5 is a flowchart for explaining the authentication processing and transaction.

[0048]

Note that in this embodiment, description will be provided assuming that templates of biometric information (finger vein) used for authentication have already been prepared. Since methods of creating templates of biometric information have already been publicly known, description of the methods is omitted.

Note that it is assumed that the templates of biometric information are stored in an unillustrated SIM card. In addition, the transaction described herein is settlement transaction of a bank as an example. Specifically, description will be provided for a process in which when settlement operation is performed at a bank, an employee having the authority for the approval places his/her signature using the finger veins.

[0049]

First, the finger vein authentication device 100 receives authorization information from an external device (Sil).

Although the finger vein authentication device 100 receives authorization information from an external device at a timing of authorization in this embodiment, the finger vein authentication device 100 may receive the authorization information in advance from the external device so that settlement operation can be performed at any timing.

[0050]

The received authorization information is displayed on the display unit 111 (S12). Information displayed on the display unit 111 will be described using Fig. 6. Part (a) of Fig. 6 illustrates a first screen 601 of the authorization operation displayed on the display unit 111, and part (b) of Fig. 6 illustrates a second screen 602 of the authorization operation displayed on the display unit 111. As can be seen from "1/2" on the first screen 601 and "2/2" on the second screen 602, the screen can be switched according to input from the input units 110. This is because the display unit 111 has an upper limit for the number of characters that can be displayed. Here, as illustrated in the second screen 602, description will be provided for authorization on transfer transaction of transferring "2,000,000 USD" to account number "1234567", as an example. In this way, authorization operation can be performed after checking the contents of the transaction on the display unit 111 of the finger vein authentication device 100. Thus, for example, even in the case where a display screen of the external device is altered with malice, and correct information is not displayed on the screen, the correct transaction and the correct transfer destination are displayed on the finger vein authentication device 100, and it is possible to make safe transaction.

[0051]

After the information displayed on the display unit 111 is checked, whether to continue or suspend the transaction is inputted from the input units 110. Specifically, if the transaction is continued, an OK button is pressed, and if the transaction is suspended, a cancel button is pressed (S13). If the cancel button is pressed (cancel at S13), an error message indicating the suspension of the transaction is displayed (S20) , and the operation ends. On the other hand, if the OK button is pressed (OK at S13), the process proceeds to the step of finger vein authentication.

[0052]

At the step of the finger vein authentication, first a display screen prompts the user to present the finger 116 on the display unit 111 (S14) . When it is detected that the finger 116 is placed on the fingertip rest 105 and the finger-base rest 106, from the output of the fingertip sensor 205 and the finger-base sensor 206, the near infrared light emission unit 109 projects near infrared light toward the finger 116 and an image of transmitted light transmitted through the finger 116 is captured by the image capturing unit 108.

[0053]

After the image of the finger veins is captured, it is checked if the image capturing is completed successfully (S15) .

If the image of finger veins is not correctly captured due to influence of external light or other factors (No at S15), a screen requesting the user to present the finger 116 again is displayed on the display unit 111. If the image of finger veins is correctly captured (Yes at S15), the process proceeds to the next finger vein authentication processing (S16) .

[0054]

At the finger vein authentication processing (S16), feature amounts used for finger vein authentication are calculated from the finger vein image captured by the image capturing unit 108, and the feature amounts are matched against the templates of biometric information stored in the SIM card. As a result of matching, it is determined that the authentication is successful if an evaluation result higher than a predetermined threshold is obtained, and it is determined that the authentication failed if the evaluation result is lower than the threshold. Since methods of calculating feature amounts and details of matching are techniques that have already been publicly known, description thereof is omitted. The matching may be performed in the finger vein authentication device 100, or in the SIM card, or the matching may be performed in both. In the case where authentication processing is performed in both the device 100 and the SIM card, the security is higher than the case where the authentication processing is performed in one of them.

[0055]

As a result of authentication processing, if the authentication failed (No at S17), a screen for indicating that the authentication failed and checking if the user performs a retry or not is displayed on the display unit 111. If the user performs a retry (Yes at S19), the process returns to step 14, the same processing is performed. If the user does not perform a retry (No at S19), an error message is displayed, and the processing ends.

[0056]

If the authentication is successful (Yes at S17), information telling that the authorization operation may be executed is transmitted to the external device, and the processing ends (S18).

[0057]

As described above, the finger vein authentication device 100 of this embodiment has the fingertip rest 105 including the fingertip surface portions 101, the fingertip side surface portions 102, and the fingertip bottom surface portion 103, and this makes it possible for the user to place the finger 116 at the same position, even though the finger 116 has variations among individual (thin or thick).

[0058]

In addition, the fingertip guide 104 provided at the fingertip rest 105 indicates where to place the finger more clearly to a person who uses the authentication. In addition, the steps formed between the surfaces of the fingertip rest 105, the finger-base rest 106, and the image capturing window 107 make it possible to obtain finger vein images without hindering the blood flows of the finger 116.

[0059]

In addition, since the display unit 111 displays information on transaction, even if information on a screen of the external device is altered by someone malicious, it is possible to see correct transaction information and perform legitimate transaction.

[Example 2] [0060]

Although in Example 1, information on finger veins is acquired as biometric information, the present invention can be applied to the case of acquiring biometric information other than information on finger veins.

[0061]

For example, if the fingertip bottom surface portion 103 is made of transparent material, and the fingertip sensor 205 at the fingertip bottom surface portion 103 is a sensor capable of capturing fingerprint images, the device can be used as a fingerprint authentication device that performs authentication with fingerprints. In addition, not only authentication with only fingerprints, what is called multimodal operation is possible using both fingerprint information and finger vein information. Use of multiple pieces of biometric information increases the security.

[0062]

Note that the present invention is not limited to the above examples. For example, the above examples have been described in detail to make explanation of the present invention easier, but the present invention is not limited to the configurations including all the constituents described above. In addition, some of the constituents of an example can be replaced with constituents of another example, and some constituents of an example can be added to the constituents of another example.

Moreover, for some of the constituents of each example, constituents of another example can be added, deleted, or replaced.

[Reference Signs List] [0063] 100 Finger vein authentication device 101 Fingertip surface portion 102 Fingertip side surface portion 103 Fingertip bottom surface portion 104 Fingertip guide 105 Fingertip rest 106 Finger-base rest 107 Image capturing window 108 Image capturing unit 109 Near infrared light emission unit 110 Input unit 111 Display unit 112 SIM card slot

113 LED

114 External coupling I/F 115 Switch unit 119, 120 Step

Claims

[CLAIMS] [Claim 1] A biometric authentication device that performs authentication using biometric information, comprising a fingertip rest including a fingertip bottom surface portion that comes into contact with a ball of a finger, a fingertip surface portion coupled with the fingertip bottom surface portion approximately perpendicularly and having a surface that comes into contact with a tip of the finger at a specified angle, and a fingertip side surface portion coupled with the fingertip surface portion and the fingertip bottom surface portion and having a surface that is opposed to a side surface of the finger. [Claim 2] The biometric authentication device according to claim 1, wherein the fingertip surface portion has a first surface and a second surface, and the specified angle is an obtuse angle formed by the first surface and the second surface. [Claim 3] The biometric authentication device according to claim 1 or 2, wherein the fingertip rest includes a semicircular fingertip guide coupled with the fingertip surface portion. [Claim 4] The biometric authentication device according to any one of claims 1 to 3, further comprising: a finger-base rest that comes into contact with a base of the finger; and an image capturing window through which an image of the finger is captured, wherein a first step is formed between the fingertip bottom surface portion and the image capturing window, a second step is formed between the finger-base rest and the image capturing window, and the first step and the second step are arranged at positions away from the image capturing window. [Claim 5] The biometric authentication device according to any one of claims 1 to 4, further comprising: an external coupling unit that is coupled with an external device by wire and transmits and receives communications; a wireless communication unit that is wirelessly coupled with the external device and transmits and receives communications; a switch unit that turns on and off power of the biometric authentication device; a power unit that supplies power according to input of the switch unit; and a control unit that turns on the power and selects communication via the external coupling unit when detecting that the switch unit receives an input in a first direction, and turns on the power and selects communication via the wireless communication unit when detecting that the switch unit receives an input in a second direction. [Claim 6] The biometric authentication device according to claim 5, further comprising: a display unit that displays information received from the external device; and an input unit that operates a content displayed on the display unit, wherein the control unit causes the display unit to perform display by switching a part of the received information displayed on the display unit to another part of the received information outside the displayed part according to input of the input unit. [Claim 7] The biometric authentication device according to claim 5 or 6, further comprising: a slot for reading and writing information from and into an information storage device that is inserted in the slot; a light emitting unit that projects near infrared light to the finger; and an image capturing unit that captures an image of transmitted light that has been transmitted through the finger, wherein when biometric information is stored in the information storage device, the control unit performs verification of biometric information captured by the image capturing unit against the stored biometric information, the control unit causes the information storage device to perform the verification, or the control unit performs the verification and also causes the information storage device to perform the verification. [Claim 8] The biometric authentication device according to any one of claims 1 to 7, wherein the fingertip side surface portion includes a third surface and a fourth surface opposed to the third surface, the third surface is coupled with the first surface and the fingertip bottom surface portion, and the fourth surface is coupled with the second surface and the fingertip bottom surface portion. [Claim 9] The biometric authentication device according to any one of claims 1 to 8, wherein the fingertip guide includes a semicircular step and/or has a color different from a color of the fingertip rest. [Claim 10] The biometric authentication device according to any one of claims 1 to 9, wherein the fingertip surface portion, the fingertip side surface portion, and the fingertip bottom surface portion are formed integrally.