JP4729353B2 - Imaging device - Google Patents

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 root pressing 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 described above, the light source unit is arranged on the upper part of the recognition target finger and covers the insertion unit, so that the external light can be blocked, but the user inserts the finger into the insertion unit where the inside cannot be seen, The finger tip must be aligned with the protrusion by groping. Moreover, inserting a finger into the opening where the inside cannot be seen gives the user anxiety. 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, the finger vein image can be obtained with high reproducibility (or high authentication accuracy) by making it possible to easily set the finger collation for the left and right fingers with respect to the data stored in advance. The object is to provide a small finger vein authentication device that does not give anxiety.

  The present invention provides a case provided with an open finger installation portion that can be placed with the abdominal 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 only light transmittance, an imaging unit for imaging the transmitted light that has passed through the interference filter unit, and further, the vein image data of the finger output from the imaging unit is collated with previously stored image data Located in the imaging device or personal authentication device.

  In addition, the finger installation part includes a finger tip guide part that regulates the tip position of the finger, a protrusion part (first) that holds the finger tip part and is provided with a depression so that the center part of the finger can be easily disposed, There are left and right guide portions for restricting the left and right positions of the finger, and a protrusion (second) that holds the base portion of the finger and has a height sufficient to block external light from the user back.

  It is desirable that the finger tip guide portion is arranged so that the first joint, which is the central portion in the longitudinal direction of the finger, and the second joint are located directly above the interference filter portion.

  In addition, the veins to be imaged have a height that prevents the veins of the fingers from touching the interference filter part to deform the veins in order to image the veins close to the ventral side of the fingers, and the finger holding protrusions at the base of the fingers ing.

  Further, when the finger is placed on the finger placement unit of the authentication device, the finger long axis shift, the finger short axis shift (left / right shift of the finger), and the finger's vein image capturing unit are prevented from being displaced, It is necessary to increase 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 major axis direction, a wall against which the finger tip abuts is provided at the innermost part of the finger installation portion, and a projection (first first) that holds the finger tip portion in order to prevent displacement in the finger minor axis direction. ) And a protrusion (second) for holding the base of the finger has a round shape similar to the finger shape.

  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 view of the image pickup unit viewed from the front side with the finger placed on the personal authentication device of FIG. 1, and FIG. 3 is a view of the personal authentication device of FIG. The figure which looked at the image pick-up part from the upper surface in the state which put it is illustrated. In addition, this personal authentication device is placed on the operation side of an automated teller machine (ATM) that performs deposit / withdrawal transactions installed in financial institutions, etc., especially on the side of the touch panel and used in combination with or substitute for a PIN, It is desirable to install it in a place where it is necessary to prevent unauthorized entry and exit such as a safe entrance and a residence entrance, and use it in the form of authenticating 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 device covers the mounted devices with the upper case 1 and the lower case 2, and the light source mounting portion 3 protrudes from the upper case 1 at two places on the left and right, that is, a pair protrudes upward from the surface of the upper case 1. To do. And the light source mounting part 3 has the light source irradiation window 4 opened 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 abdomen 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. On the other hand, if the upper part has an open structure, in addition to the light source necessary for imaging, the influence of external light that causes disturbances in imaging, such as fluorescent lights in financial stores, and when installed near the store entrance, such as West Japan There is concern about a decline in the recognition rate. Since the authentication target finger (middle finger in the figure) 15 is arranged on the upper surface of the interference filter 5, the personal authentication device shown in the figure is not easily affected by disturbance light from the upper surface of the interference filter 5. The mounting portion 3 is disposed with a height sufficient to block disturbance light.

  Further, a fingertip abutting guide (finger tip guide portion) 7 to be abutted is provided along the light source mounting portion 3 and integrally formed on the distal end side of the finger. This is also referred to as a first protrusion. Since the abutting portion needs to have a height that is easy to use even for users with long nails, the height is set lower than that of the light source mounting portion 3. However, assuming that it is installed at an automatic teller machine, various entrances, etc., it is on the back side with respect to the user, that is, on the side of the device or the wall, so that it is difficult for ambient light to enter.

  There is also concern about the influence of the western sun, which is ambient light with higher brightness than fluorescent lamps, especially from the outside of the store on the finger base side. Therefore, along the light source mounting portion 3, a finger base support guide 6 that supports the finger base and is integrated with a shape without a gap into which light is inserted is disposed so as to protrude from the guide surface. This is also referred to as a second protrusion.

  As described above, with respect to the guide protruding from the guide surface on the part where the finger is placed, by adopting the above-mentioned structural features, the user is not disturbed by inserting the finger into a part that cannot be seen by the disturbance light. Decrease in recognition rate can be suppressed.

  Next, 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 capable of transmitting 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 The support guide 8 is positioned, and a fingertip center guide 9 having a depression indicating the center position of the fingertip in the finger short direction is positioned at the center of the fingertip support guide 8 in the finger short direction. 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. The finger tip abutment guide 7 has an R shape reminiscent of the tip of a finger. Further, since the finger tip abutment guide 7 has an R shape, the fingerprint side of the finger tip is in close contact with the R shape portion, which may cause discomfort to the user, so that the contact area of the fingertip is reduced as much as possible. There is a need. Therefore, the fingertip support guide 8 is configured to hold the finger tip portion, and the fingertip center guide 9 is configured so that the user can easily arrange the finger tip in the short direction.

  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 8 regulate the finger diameter so as to regulate the left / right displacement of the finger. R-shaped dents (dents) are provided in accordance with the above. Further, each guide 6 and 8 has a function of floating the middle finger so that the belly of the finger does not contact the interference filter 5, but the finger base support is provided so that the finger can be placed on each guide 6 and 8 in a naturally bent shape. The guide 6 has a higher guide position than the fingertip support guide 8.

  Next, the index finger and the ring finger that are not to be authenticated are arranged outside the light source mounting unit 3, and the thumb and the little finger are arranged so as to be sandwiched from the left and right outer surfaces of the upper cover 1. That is, a finger other than the authentication target (reference numeral 16) is attached to the case surface that is shielded from the finger installation portion 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 fixed with the index finger and the ring finger (see FIGS. 2 and 3).

  However, the middle finger to be authenticated regulates the front and rear and the left and right with the above-mentioned guides, the index finger, and the middle finger, but there is some instability only with the restriction of the finger. That is, if the middle finger is placed with the palm tilted in the left-right direction, the middle finger rotates in the left-right direction. Therefore, fingers other than the authentication finger are arranged so as to cover the upper cover 1 so that the palm does not tilt in the left-right direction. The upper cover 1 has an R shape that conforms to a shape in which fingers are naturally placed so that fingers other than the authentication finger can be easily placed. 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 FIG. 4, the internal structure of the apparatus is insulated by first mounting a plurality of light source LEDs (light emitting diodes) 11 in a row inside the light source mounting portion 3 that is paired on the left and right of the finger to be authenticated. An LED substrate 10 is mounted. Light 17 emitted from the light source LED 11 through the light source irradiation window 4 strikes from the side of the recognition target finger 15. Specifically, as shown in FIGS. 1 and 3, the light 17 is irradiated from the first joint in the longitudinal direction of the finger to the second joint. The light source LED 11 is positioned at a height equivalent to the center height of the finger, and the irradiated light 17 exits the finger while being reflected inside the finger. That is, the light source LED 11 is positioned on both sides of the finger placement unit (reference numerals 6, 7, 8) and irradiates light 17 from the lateral direction of the recognition target finger 15 toward the recognition target finger 15.

  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. Further, when the light source LED 11 irradiates the transmitted light 17 from a position as high as possible in the lateral direction with respect to the finger 15 to be recognized, reflection of the abdominal surface of the finger is less and the image of the vein can be captured more clearly. The light source mounting portions 3 on both sides of the light source have protruding light source protrusions (projecting upward from the upper surface of the upper case 1) so as to incorporate the light source LEDs 11, and the light source mounting portion 3 has an authentication target finger 15 and a finger adjacent thereto. The authentication target finger 15 and the other fingers do not overlap with each other in a shape that falls between 16.

  The light 18 (light in the downward direction in the figure) emitted from the finger's ventral side is transmitted through the interference filter 5 that transmits only near-infrared rays, is changed in direction by the reflecting mirror 12, and is imaged by the camera (imaging unit) 13. To do. That is, the interference filter unit 5 causes the transmitted light 17 emitted from the light source LED 11 to diffusely reflect inside the finger, and transmits only near-infrared light having an arbitrary wavelength of the transmitted light 17 emitted from the ventral side of the finger. Since near infrared rays are easily absorbed by hemoglobin in the blood, the veins are dark and the other veins are brightly imaged. 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 a user (not shown), or stored in a transaction device such as an automatic cash transaction apparatus or a branch office terminal, or a storage unit of a host / server, and the control unit 14 The registration data may be received and collated with the imaging data, or the collation function is provided outside the imaging apparatus, and the control unit 14 transmits the captured data outside the apparatus and collates outside. But you can. The verification result is displayed on the terminal connected by the external connection connector 19. That is, these are collectively referred to as (finger vein) authentication device. Note that the imaging unit 13 automatically detects that the authentication target finger 15 has been placed in comparison with the previous imaging and starts imaging of the veins. Since it is not necessary to press the manual switch for starting imaging, the authentication target finger 15 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 15 of the authentication target is placed on the finger receiving portions 6, 8, and 9 with the fingertip abutting against the finger tip guide portion 7 located at the innermost part of the finger installation portion. At the same time, the finger other than the authentication target is naturally arranged on the upper cover 1 to suppress the front / rear / left / right positional deviation, the rotational deviation about the finger long axis, and the distance deviation from the imaging unit 13.

  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 the authentication target finger 15.

It is an external appearance perspective view of a personal authentication device. It is the figure which looked at the personal authentication device from this side. It is the figure which looked at the personal authentication device from right above. It is sectional drawing which looked at the personal authentication apparatus from this side.

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 ... Finger tip butting guide, 8 ... Finger tip support guide, 9 ... Finger tip Central guide, 10 ... light source LED substrate, 11 ... light source LED, 12 ... reflecting mirror, 13 ... camera, 14 ... control unit, 15 ... authentication target finger, 16 ... finger adjacent to authentication target finger, 17 ... emitted from light source Light, 18 ... Imaging light, 19 ... External connector

Claims (4)

A case provided with a portion for placing the abdominal surface of a finger downward, a pair of protrusions protruding from the case surface and spaced apart by a predetermined distance, and light from its side with respect to the finger between the protrusions A light source unit that irradiates light, an interference filter unit that is disposed between the protrusions and on the case surface and has a light transmission property with respect to an arbitrary wavelength of light, and is disposed below the interference filter unit and the interference filter unit An imaging unit that captures the transmitted light that has passed through, a first protrusion that holds the tip of the finger and has a depression at the position of the tip of the finger, and the finger integrated with the pair of protrusions And a second protrusion having a recess adapted to the diameter of the finger.   The imaging apparatus according to claim 1, further comprising a guide portion that regulates a tip position of the finger.   3. The imaging apparatus according to claim 1, wherein a height of the second protrusion is high enough to block disturbance light. 4.   The imaging apparatus according to claim 1, wherein a height of the second protrusion is higher than that of the first protrusion.

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