JP2006331441A - Image capturing device or personal authentication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape of a personal authentication device capable of easily authenticating fingers of both left and right hands and achieving authentication accuracy of a high practical level in personal authentication utilizing vein images of the fingers. <P>SOLUTION: The personal authentication device includes a case on which one finger can be placed downward, a light source part for generating transmission light to the finger from the side face, an interference filter part having light transmittivity for an arbitrary wavelength, an imaging part for capturing an image through a mirror for the transmission light transmitted through the interference filter part, and an image processing part for the vein image data of the finger output from the imaging part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for biometric authentication, and more particularly to an apparatus for personal authentication or identification using finger vein image data.

  Personal authentication using human biometric information includes information that uses information (data) such as fingerprints and irises, but finger vein authentication technology that uses images of veins inside human fingers is the focus of attention. Has been. Patent Document 1 discloses a method for performing personal authentication using finger vein image data, and a case provided with an insertion portion that allows a fingerprint of one finger to be inserted toward the lower surface and the finger transmitted through the upper surface. A light source unit that generates light, an interference filter unit that transmits light with respect to an arbitrary wavelength, an imaging unit that captures transmitted light that has passed through the interference filter unit, and the finger vein output from the imaging unit Disclosed is a personal authentication device including an image processing unit that creates collation data that can collate image data with image data stored in advance.

  The finger to be authenticated is positioned by inserting the finger to be authenticated into the insertion portion, the depth is abutting the tip of the finger against the finger abutting portion, and the left and right direction is guided by the upper finger base abutting portion. The left / right rotation is to make visual adjustment so that the center of the back of the finger is aligned with a triangular mark provided at a visible position.

JP 2004-049705 A

  In patent document 1 mentioned above, since the light source part is arrange | positioned above the recognition object finger, the height of a housing | casing becomes high and there exists a problem of the enlargement of an apparatus. Moreover, since the light source part covers the insertion part, the user feels uneasy about putting a finger into the insertion part where the inside cannot be seen. In addition, there is a drawback in that the finger vein image data cannot be obtained with high reproducibility, and the personal authentication accuracy is lowered because the finger rotation is visually adjusted to prevent the finger from rotating in the left-right direction.

  An object of the present invention is to solve any one or more of the above-described problems. For example, finger vein authentication that can easily set finger collation for pre-stored data for both left and right fingers and can acquire finger vein images with high reproducibility (or high authentication accuracy) It is to provide a device, provide a customer with a sense of security, or provide a small finger vein authentication device.

  The present invention includes a case provided with an open finger installation portion that can be placed with the belly surface of the finger facing down, a light source portion that generates transmitted light from both sides of the finger, and an arbitrary wavelength. An interference filter unit having a light transmission property only, an imaging unit that images the transmitted light that has passed through the interference filter unit, and image data that stores vein image data of the finger output from the imaging unit in advance. It exists in the imaging device or personal authentication device to be collated.

  The finger installation unit includes a finger tip guide unit that regulates the tip position of the finger, a left and right guide unit that regulates the left and right position of the finger, and a guide unit that regulates rotation of the finger in the left and right direction. The interference filter unit separates the transmitted light and other light emitted from the light source unit, and the finger tip guide unit has a second joint from a first joint which is a central portion in the longitudinal direction of the finger. It is desirable to arrange so as to be located immediately above the interference filter section. In addition, the vein to be imaged is provided with a finger receiving portion for floating the finger from the interference filter portion so that the vein of the finger does not touch the interference filter portion to deform the vein in order to image the vein close to the abdominal side of the finger.

  That is, when the finger is placed on the finger placement unit of the authentication device, the finger long axis shift, the finger short axis shift (finger left / right shift), the rotation shift around the finger long axis, and finger vein image capture Therefore, it is necessary to improve the reproducibility of reading finger vein data by making the imaging surface of each finger the same. Therefore, in order to prevent displacement in the finger long axis direction, a wall where the tip of the finger abuts is provided at the innermost part of the finger installation part, and in order to prevent displacement in the finger short axis direction, a wall is provided on both sides of the finger. In order to prevent rotation about the long axis, a palm guide portion for restricting rotation of the palm is provided.

  In particular, the method of preventing rotation around the long axis of the finger is difficult to prevent rotation even if only one finger is supported. If you rotate it in the direction of rotation, the fingers will also move with you. In other words, this rotation of the finger is solved not by supporting only the finger but by supporting the palm not to rotate. Also, the palm support surface may support the entire palm, but if a plurality of joints at the base of the finger to be imaged and the joints at the base of the finger adjacent to each other are supported simultaneously on a plane, the rotation of the finger can be restricted.

  According to the present invention, in personal authentication using a finger vein image, it is possible to easily set a finger collation with respect to pre-stored data at an accurate position for both left and right fingers. In addition, a personal authentication device with high authentication accuracy can be provided by acquiring finger vein images with high reproducibility.

  Embodiments of the present invention will be described below.

  1 is an external perspective view of the personal authentication device, FIG. 2 is a cross-sectional view of the imaging unit viewed from the front side with a finger placed on the personal authentication device of FIG. 1, and FIG. The cross-sectional view which looked at the image pick-up part from the side in the state which set | placed is shown in figure. In addition, it is desirable that this personal authentication device is placed on the operation surface of an automatic teller machine (ATM) that performs deposit / withdrawal transactions installed in financial institutions, especially on the side of the touch panel, and is used in combination with or replaced with a PIN. It is desirable to use it in a form that is installed in a financial sales office and authenticates an individual. Further, in the following example, there is a control unit that performs image processing on finger vein image data captured by the personal authentication device and collates with registered personal data. However, this control unit may be provided outside the device. Since it is sufficient if the finger vein data can be imaged, it is also simply referred to as an imaging device.

  As shown in FIG. 1, the personal authentication apparatus covers the mounted devices with an upper case 1 and a lower case 2, and the light source mounting unit 3 is located at two locations on the left and right from the upper case 1, that is, one pair is above the surface of the upper case 1. Protruding. The light source mounting part 3 has a light source irradiation window 4 so that both the left and right sides face each other. As shown in the figure, the upper case 1 is open so that the abdominal surface of the finger can be placed downward, so that the user is less anxious than a method in which the finger is inserted into a certain part. There is an interference filter 5 on the surface sandwiched between the light source mounting portions 3, and the interference filter 5 is a glass or resin sheet that can transmit only near infrared rays. A finger base support guide 6 that supports the base of the finger in front of the interference filter 5, a finger tip abutment guide (finger tip guide portion) 7 that abuts the tip of the finger on the back side of the interference filter, and a fingertip that supports the tip of the finger A support guide 8 is positioned, and a palm support guide 9 that supports the palm is positioned in front of the upper case 1. The guides 6, 8, and 9 collectively refer to finger restriction guide portions (also simply referred to as guide portions) because they restrict finger rotation, left / right / front / rear shift, and the like.

  For placing the finger, the tip of the middle finger is abutted against the fingertip abutment guide 7 as shown by a two-dot chain line, and is placed on the fingertip support guide 8 and the finger base support guide 6. On the other hand, an index finger and a ring finger that are not subject to authentication are placed outside the light source mounting unit 3, and the palm is extended and placed on the palm support guide 9. That is, fingers other than those to be authenticated are attached to the case surface that is shielded from the finger placement portion that is authenticated by the light source protrusion 3. As described above, since the pair of light source mounting portions 3 is elongated in the finger longitudinal direction, the middle finger of the authentication finger can be firmly fixed with the index finger and the ring finger. The fingertip abutment guide 7 regulates the position in the longitudinal direction (front-rear direction) of the middle finger to be authenticated, and the finger base support guide 6 and the fingertip support guide 7 are matched to the finger diameter so as to regulate the left / right displacement of the finger. R-shaped recesses (recesses) are provided. Further, each of the guides 6 and 7 has a function of floating the middle finger so that the belly of the finger does not contact the interference filter 5. The middle finger to be authenticated regulates front / rear and left / right by these guides, but there is some instability only by restriction of the finger. In other words, when the middle finger is placed with the palm tilted in the left-right direction, the middle finger rotates in the left-right direction, so the palm is placed on the palm support guide 9 that supports the palm so that the palm does not tilt in the left-right direction. The palm support guide 9 may be a large area that supports the entire palm surface, but for an operator who does not want to touch objects touched by others, it is perpendicular to the optical mounting case 8 as shown in this figure. It is desirable to have a shape that is thin and long in the lateral direction. In FIG. 1, the middle finger is the authentication target finger, but if the finger is a hand, all the left and right fingers can be the authentication target finger.

  Next, as shown in FIGS. 2 and 3, first, a plurality of light source LEDs (light emitting diodes) 11 are mounted in a row inside the light source mounting portion 3 that is paired on the right and left sides of the finger to be authenticated. An insulated LED substrate 10 is mounted. The light emitted from the light source LED 11 through the light source irradiation window 4 strikes from the side of the recognition target finger. Specifically, as shown in FIG. 1, this light source is irradiated from the first joint in the longitudinal direction of the finger to the second joint. The light source is positioned at a height equivalent to the center height of the finger, and the irradiated light 11 exits the finger while being reflected inside the finger. That is, the light source unit is positioned on both sides of the finger installation unit (reference numerals 6, 7, and 8) and irradiates light from the lateral direction of the recognition target finger toward the recognition target finger. A plurality of light emitting diodes 11 are arranged in a row on the insulating substrate 10 and are arranged at equal intervals corresponding to at least the first joint and the second joint of the finger. Also, when the light source unit irradiates transmitted light from a position that is as high as possible in the lateral direction with respect to the finger to be recognized, reflection of the abdominal surface of the finger is less and the vein image can be captured more clearly. The case 3 has a light source projection (projecting upward from the upper surface of the upper case 1) that is projected so as to incorporate the light source, and the light source projection 3 has a shape that fits between the authentication target finger and the adjacent finger. It also has a function that the finger to be authenticated and other fingers do not overlap.

  Light emitted from the abdominal side of the finger (light in the downward direction in the figure) passes through the interference filter 5 that transmits only near-infrared rays, changes its direction with the reflecting mirror 12, and is imaged with the camera (imaging unit) 13. . That is, the interference filter unit diffusely reflects the transmitted light emitted from the light source unit inside the finger, and transmits only near infrared rays having an arbitrary wavelength of the transmitted light emitted from the finger belly side. Since near infrared rays are easily absorbed by hemoglobin in the blood, the veins are dark and the other veins are brightly imaged. The hemoglobin present in the blood absorbs near-infrared rays, so that the blood vessels appear dark, and other than the blood vessels appear bright. The control unit 14 combines the captured data as finger vein image data. That is, the right and left vein image data of the finger obtained through the pair of left and right LED irradiations is edited into one piece of vein image data and collated with registered data registered in advance. The registered data is stored in a bank card (medium) owned by the user, or stored in a transaction device such as an automatic teller machine or a branch terminal, or a storage unit of a host / server, and the control unit 14 The registration data may be received and collated with the imaged data, or the collation function may be provided outside the apparatus, and the control unit 14 may transmit the imaged data outside the apparatus and collate outside. The verification result is displayed on the terminal connected by the external connection connector 19. In addition, the imaging unit 13 detects that the authentication target finger has been placed, compared with the imaging before the placement, and automatically starts vein imaging. Since there is no need to press the manual switch for starting imaging, the authentication target finger does not move. As described above, the positional deviation / rotational deviation can be suppressed only by placing the finger on the authentication apparatus, and the finger vein image data can be acquired with high reproducibility.

  By adopting the above structural features, the authentication target finger of the authentication target is placed on the finger receiving unit 6, 8, etc. while the fingertip abuts against the finger tip guide unit 7 located at the innermost part of the finger installation unit. Put the palm on the palm guide part 9. As a result, positional deviations in the front / rear / left / right direction, rotational deviation about the finger long axis, and deviation in distance from the imaging unit 13 are suppressed.

  Furthermore, since the present invention has an open planar case shape, there is no restriction for specifying a finger, so that any finger on the left and right as long as the hand can be used as an authentication target finger.

  FIG. 4 is an example in which the light source mounting part 20 is different in shape from the light source mounting part 3 of FIG. The authentication target finger is placed in the same manner as in FIG. 1, and the finger adjacent to the authentication target finger is placed on the light source mounting unit 20. If the operator's finger is short, the light source mounting unit 3 in FIG. This can be prevented because it may tear. However, it is desirable that the light source mounting unit 20 is provided with an inclination 21 because the root of the finger to be authenticated is lifted from the finger base support guide 6 if there is an excessive step in the height direction with the finger base support guide 6.

  FIG. 5 shows an example in which the palm support guide 9 of FIG. 1 is brought close to a finger and the depth of the apparatus is shortened. The control unit 24 can be compactly mounted in the apparatus, or can be another external control unit 24 via the relay cable 23 as shown in the figure. When the palm support guide 22 is close to the finger, it supports three indirect roots of the finger, which is effective in restricting the rotation of the finger in the left-right direction.

It is an external appearance perspective view of a personal authentication device. It is sectional drawing which looked at the imaging part from the near side in the state which put the finger | toe in the personal authentication apparatus of FIG. It is sectional drawing which looked at the imaging part from the side in the state which put the finger | toe in the personal authentication apparatus of FIG. It is an external view which shows the other Example of a personal authentication apparatus. It is an external view which shows the other Example of a personal authentication apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Upper case, 2 ... Lower case, 3 ... Light source mounting part, 4 ... Light source irradiation window, 5 ... Interference filter, 6 ... Finger root support guide, 7 ... Fingertip butting guide, 8 ... Fingertip support guide, 9 ... Palm support guide, 10 ... LED base, 11 ... Light source LED, 12 ... Reflector, 13 ... Camera, 14. ..Control unit, 15... Finger to be authenticated, 16... Finger adjacent to the finger to be authenticated, 17 .. light emitted from the light source, 18... Imaging light, 19. 20 ... finger placement part, 21 ... palm support guide

Claims (10)

  A case provided with a portion for placing the abdominal surface of the finger downward, a pair of protrusions protruding from the case surface and spaced apart by a predetermined distance, and light from the side with respect to the finger between the protrusions A light source unit that emits light, an interference filter unit that is disposed between the protrusions and on the case surface and has light transmittance with respect to an arbitrary wavelength of light, and is disposed below the interference filter unit and the interference filter unit And an imaging unit that images the transmitted light that has passed through the imaging device. The imaging device according to claim 1,
The image pickup apparatus, wherein the light source unit is arranged inside the protrusion and a plurality of light emitting diodes emitting near infrared rays are arranged in a line on a substrate.   A case provided with a part to be placed with the abdominal surface of the finger facing down, a pair of protrusions protruding upward in the case surface and spaced apart by a predetermined distance, and the protrusion placed between the protrusions A light source unit that irradiates light from both sides of the finger, an interference filter unit that is disposed between the protrusions and on the case surface and has light transmittance with respect to an arbitrary wavelength of light, and the interference filter An image capturing unit that images the transmitted light that has been transmitted through the interference filter unit, and a personal authentication device that collates finger vein image data captured by the image capturing unit with pre-registered finger vein image data .   4. The personal authentication device according to claim 3, wherein the protrusion has an elongated shape along a longitudinal direction of the finger. A case with a part to be placed with the abdomen of the finger facing down,
An interference filter unit disposed on the case surface and having optical transparency with respect to an arbitrary wavelength of light;
An imaging unit that is disposed below the interference filter unit and that images the transmitted light that has passed through the interference filter unit, and projects from the case surface and surrounds the periphery of the imaging unit, and restricts the movement of the finger A personal authentication device comprising a guide unit. The personal authentication device according to claim 5,
The personal authentication device, wherein the guide unit includes a finger tip guide for regulating a finger tip and a finger regulation guide having an R-shaped depression for regulating the tip of the finger or the vicinity of the base. The personal authentication device according to claim 5 or 6,
The personal authentication device, wherein the guide unit includes a light source unit that irradiates light from a side surface of the finger. The personal authentication device according to claim 5, wherein
The personal authentication device, wherein the case includes a palm support guide for supporting a palm of a user holding a finger in a predetermined position. The personal authentication device according to claim 8,
The personal authentication device, wherein the palm support guide is arranged in parallel with the finger tip guide and the finger restriction guide. The personal authentication device according to claim 8 or 9, wherein
The width of the palm support guide is wider than the width of the finger tip guide or the finger restriction guide.

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