JP2012084061A - Blood vessel authentication terminal apparatus and blood vessel authentication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood vessel authentication terminal apparatus and a blood vessel authentication system which can stably acquire more clear images compared to a conventional apparatus in performing personal authentication by using blood vessel authentication.SOLUTION: A blood vessel authentication terminal apparatus takes an blood vessel image of an authentication target finger with a light transmitting through the finger. The apparatus comprises: a base table 150 for setting an authentication target finger 190; a light source 110 which is arranged on a fore side of a fingertip in the base table 150 and radiates light in a direction from the fore side of the fingertip to a dorsal surface of the finger on the authentication target finger 190 set on the base table 150 from the fingertip to a bottom of the finger; and an imaging device 120 which is installed just under a ventral surface of the authentication target finger 190 in the base table 150, and takes the blood vessel image obtained when the light radiated on the dorsal surface of the finger transmits through the finger.

Description

  The present invention relates to a blood flow authentication terminal device for performing personal authentication by extracting a blood vessel pattern and a blood flow authentication system including the blood flow authentication terminal device.

  There is a technique for identifying an individual to be inspected from another individual, that is, a technique called biometric authentication, based on determination whether the biological information acquired from the individual to be inspected is equal to biometric information set in advance. . Examples of the biological information include information based on the iris of a human pupil, information based on a vein pattern such as a human finger, and information based on a fingerprint pattern of the finger.

  Among such biometric authentications, those based on vein patterns are called blood flow authentication. This blood flow authentication is excellent in that it is difficult to forge because the vein patterns are independent of each other and the same shape does not exist, and the veins are difficult to judge from the appearance, and high authentication accuracy can be obtained. In such an authentication system using blood flow authentication, blood vessels or veins are imaged, vein shapes are extracted from the captured images, image processing is performed, and blood flow authentication is performed using feature point extraction and feature point matching. It is executed (see, for example, Patent Document 1). Such a blood flow authentication system is already applied to, for example, entrance management.

  In addition, when adopting a configuration in which multiple persons can access electronic devices such as computers that store a large amount of information, the security of each information can be improved by authenticating individuals who can access each information. Is strongly demanded. The blood flow authentication system is also useful for accessing such electronic devices.

Japanese Patent No. 4236214

  On the other hand, in blood flow authentication based on a vein pattern such as a finger, the following problem occurs. That is, as a feature of the constituent elements of the human body, moisture occupies 70% or more, so that when the finger is irradiated with LED light, halation occurs in the finger, and the entire captured image becomes whitish. For this reason, there is a problem that it is difficult to obtain a clear blood vessel image, particularly when the blood vessel is thin.

  In addition, the conventional blood flow authentication device adopts a configuration in which a blood vessel image is captured by irradiating light from above or from the side of a finger. Therefore, some components constituting the authentication device, such as a light source and an image sensor, are arranged around the finger to be authenticated, due to the size and thickness of the subject's finger for physical reasons. There were also situations where finger detection itself was impossible.

  Furthermore, in the blood flow authentication device using a finger, as described above, blood flow authentication is executed using feature point extraction and feature point matching of a blood vessel image. Therefore, from the necessity of obtaining an image of the same condition, the finger placement state when registering the blood vessel image and the finger placement state when performing blood flow authentication are set to the same placement state for the finger for authentication. There is a need. Therefore, the finger blood flow authentication device is provided with a guide member for positioning the finger.

  However, in the conventional guide member, the arrangement of the fingers is unstable, and it may be difficult to capture a stable image. Furthermore, from the relationship of the irradiation direction of the LED light from the upper side or the side with respect to the finger, the irradiation light can easily enter the imaging element, and as a result, the captured image may become whitish. In either case, there arises a problem that a clear blood vessel image cannot be obtained.

  The present invention has been made in order to solve the above-described problems. In the case of performing personal authentication using blood flow authentication, the blood flow authentication can stably obtain a clearer image compared to the conventional art. An object of the present invention is to provide a blood flow authentication system including a terminal for blood flow and the terminal for blood flow authentication.

In order to achieve the above object, the present invention is configured as follows.
That is, the blood flow authentication terminal device according to the first aspect of the present invention is a blood flow authentication terminal device that captures a blood vessel image of the finger with light transmitted through the finger to be authenticated,
A base on which the finger to be authenticated is placed;
A light source that emits light that passes through the finger to be authenticated, is located at one end of the base and is placed in front of the fingertip of the finger to be authenticated placed on the base, from the front of the fingertip toward the back of the finger to be authenticated A light source that emits light from the fingertip to the fingertip,
The blood vessel of this finger that is placed on the base corresponding to directly below the finger on the ventral side of the finger to be authenticated placed on the base, and the irradiation light emitted from the light source is transmitted through the finger to be authenticated And an image pickup device for picking up an image.

  Further, the base has a finger guide portion, and the finger guide portion places a finger to be authenticated, curves the placed finger to be authenticated from the fingertip to the fingertip in a streamlined shape, and places the belly of the finger. May be configured to block the incidence of the irradiation light from the belly of the finger to the imaging device.

  In addition, the fingertip detection is performed at one end of the finger guide unit at a position corresponding to the fingertip of the finger to be authenticated placed on the finger guide unit, and the fingertip is positioned by contact of the fingertip and detects the fingertip contact. You may further provide a sensor and the finger-tip detection sensor installed in the position corresponding to a finger-tip part in the other end part of the said finger guide part, and detecting the contact of a finger-tip part.

  The fingertip detection sensor has a height at which the fingertip of the finger to be authenticated contacts and a fingernail of the finger does not contact, and the light source is installed in front of the fingertip at a predetermined distance from the fingertip detection sensor. The prescribed distance may correspond to a distance exceeding the length of the nail extending beyond the fingertip detection sensor.

  Further, the base has a base surface on which a finger next to the finger to be authenticated is placed to suppress rolling of the finger to be authenticated, the light source is disposed above the base surface, and the imaging device is from the base surface. You may comprise so that it may be arrange | positioned below.

  Further, the finger guide portion is composed of a pair of plate members erected on the base surface so as to face each other, and each plate member extends along a finger to be authenticated arranged along one direction on the base plate. Are located opposite each other at a support interval that enables the belly of the finger to be authenticated to be supported, and supports the belly by touching the belly of the finger to be authenticated, and then climbs up and tilts toward the base surface from the fingertip toward the fingertip. It can comprise by the wedge shape which has the support edge used as follows.

  Also, each plate member has a chamfered portion for placing the finger pad inside each support edge, and the chamfering angle of the chamfered portion changes from the fingertip of the finger to be authenticated to the fingertip according to the finger outline. You may comprise.

  The fingertip detection sensor may be provided within a support interval between the pair of plate members, and may have a depression provided with a curved surface that follows the shape of the fingertip of the finger to be authenticated.

The base has a base surface on which a finger next to the finger to be authenticated is placed to suppress rolling of the finger to be authenticated.
The finger guide portion is composed of a pair of plate members erected on the base surface,
The fingertip detection sensor is sandwiched between the plate members and arranged at right angles to each plate member,
In the base, light from the light source that enters from a gap between the plate material and the fingertip detection sensor and the fingertip of the finger to be authenticated enters the imaging device in an area adjacent to the plate material and the fingertip detection sensor. It is also possible to further include a light shielding portion for preventing the above.

  Furthermore, the blood flow authentication system according to the second aspect of the present invention is the blood flow authentication terminal device according to the first aspect and an authentication control device connected to the blood flow authentication terminal device, wherein the blood flow authentication is performed. And an authentication control device that performs personal authentication by blood flow authentication using a light source and an imaging device that are provided in the terminal for use, and a captured image supplied from the imaging device.

  The authentication control device may be a personal computer, and may further include a USB (Universal Serial Bus) cable for electrically connecting the personal computer and the blood flow authentication terminal.

  According to the blood flow authentication terminal in the first aspect of the present invention and the blood flow authentication system in the second aspect, the light source is arranged in front of the fingertip of the finger to be authenticated, from the fingertip of the finger to be authenticated to the back of the finger. A blood vessel image is captured by irradiating light from a light source. Therefore, there are no components such as a light source and an image sensor on the side and upper side of the finger to be authenticated, and the side and upper side of the finger to be authenticated are open spaces. Therefore, blood flow authentication for all people is possible regardless of the size and thickness of the finger.

  Further, according to the blood flow authentication terminal device in the first aspect of the present invention and the blood flow authentication system in the second aspect, light is irradiated from the fingertip front to the back of the fingertip from the front of the fingertip. Since the blood vessel image is picked up by the image pickup device arranged immediately below the authentication finger, the wraparound of the light from the light source to the image pickup device can be reduced as compared with the conventional case. Therefore, the occurrence of halation in the captured image is suppressed as compared with the conventional case, and a clear blood vessel image can be stably obtained.

It is a schematic sectional drawing which shows one structural example of the terminal device for blood-flow authentication in embodiment of this invention. It is a top view of the finger guide part vicinity of the terminal device for blood flow authentication shown in FIG. It is a figure which shows a part of cross section in the AA part of the finger guide part shown in FIG. It is a figure which shows a part of cross section in the BB part of the finger guide part shown in FIG. It is a perspective view of the terminal for blood flow authentication shown in FIG. It is a block diagram which shows the structure of the blood flow authentication system in embodiment of this invention provided with the terminal device for blood flow authentication shown in FIG. It is a figure which shows the modification of the finger guide part shown in FIG. It is a photograph which shows the blood vessel image imaged with the conventional blood-flow authentication apparatus. It is a photograph which shows the blood-vessel image imaged with the terminal device for blood-flow authentication shown in FIG. It is a flowchart which shows the blood flow authentication operation | movement performed with the blood flow authentication system shown in FIG. It is a schematic sectional drawing which shows the modification of the terminal for blood-flow authentication shown in FIG.

  A blood flow authentication terminal device according to an embodiment of the present invention and a blood flow authentication system including the blood flow authentication terminal device will be described below with reference to the drawings. In each figure, the same or similar components are denoted by the same reference numerals.

In the terminal for blood flow authentication and the blood flow authentication system of the present embodiment, blood flow authentication is performed by imaging a vein pattern on the subject's finger to be authenticated.
As shown in FIG. 6, the blood flow authentication system 300 according to the present embodiment includes a blood flow authentication terminal device 100 and an authentication control device 200 connected to the blood flow authentication terminal device 100. The connection between the two may be wired or wireless. In this embodiment, they are electrically connected by wire. In the present embodiment, the blood flow authentication system 300 can access a computer that can be used or accessed by a plurality of workers, and user authentication to the computer and information stored in the computer. Take a system that authenticates an individual as an example. Here, the blood flow authentication terminal device 100 irradiates light to the subject's finger to be authenticated to access information, and captures a blood vessel image of the finger with the light transmitted through the finger. The authentication control device 200 is a device that is connected to the blood flow authentication terminal device 100 and makes an authentication judgment on the acquired blood vessel image and controls the operation of the blood flow authentication terminal device 100. The computer corresponds to a so-called personal computer or a large computer such as a server.

  First, the blood flow authentication terminal device 100 will be described. FIG. 1 shows a schematic configuration of a blood flow authentication terminal device 100 according to the present embodiment. On the other hand, FIG. 5 shows a perspective view of an example of the blood flow authentication terminal 100. Such a blood flow authentication terminal device 100 is a blood flow authentication terminal device that captures a blood vessel image of the finger with light transmitted through the finger 190 to be authenticated. A light source 110 and an imaging device 120 are provided. Further, the blood flow authentication terminal device 100 according to the present embodiment further includes a finger guide unit 130 and a finger detection sensor 140 in addition to the above basic components.

First, a schematic form of the blood flow authentication terminal device 100 will be described. As shown in FIG. 5 as an example, the blood flow authentication terminal device 100 according to the present embodiment includes a casing base 150 having a shape similar to a mouse connected to a personal computer. A flat base surface 151 is formed. A light source storage portion 152 storing the light source 110 is provided on the base surface 151 so as to protrude from one end portion in the longitudinal direction 158 corresponding to one direction of the base 150. On the other hand, the imaging device 120 is stored in the base 150 below the base surface 151. Further, a finger guide portion 130 is provided in the center portion of the base surface 151 along the longitudinal direction 158 of the base 150. A fingertip detection sensor 141 constituting the finger detection sensor 140 protrudes from one end portion of the finger guide portion 130, and a fingertip detection sensor 142 constituting the fingertip detection sensor 140 protrudes from the base surface 151 at the other end portion. Installed. As will be described in detail later, a near-infrared transmission filter is installed in the optical path of the light emitted from the light source 110 in the base 150 and the light source storage unit 152, but the base 150, the light source storage unit 152, the finger guide unit other than that are installed. 130 is made of a material that blocks visible light and near-infrared light.
Each component in the above schematic configuration will be described in detail below.

  The finger guide unit 130 is a part on which a single finger to be authenticated 190 for performing blood flow authentication is placed. As shown in FIG. 1, the placed finger 190 to be authenticated is a streamline from the fingertip 191 to the fingertip 192. It extends in a length corresponding to almost the entire length of the finger to be authenticated 190 so as to bend into a shape, supports the belly 194 of the finger to be authenticated 190, and positions the finger to be authenticated 190 with respect to the imaging device 120. It is a part to do. Furthermore, the finger guide unit 130 supports the antinode 194 of the finger 190 to be authenticated, thereby blocking the irradiation light from the light source 110 from the antinode 194 to the imaging device 120.

  Specifically, in this embodiment, the finger guide part 130 is configured by a pair of plate members 131 that are opposed to each other and are erected in the vertical direction with respect to the base surface 151 as shown in FIGS. 1 and 2. . The plate members 131 extend in parallel along the longitudinal direction 158 of the base 150 in a length corresponding to almost the entire length of the finger 190 to be authenticated, and as shown in FIGS. The authentication fingers 190 are disposed to face each other at a support interval 138 that can support the belly 194 of the authentication finger 190. Further, as shown in FIG. 1, each plate member 131 has a support edge 132 that is located on the opposite side of the base surface 151 and supports the belly 194 in contact with the belly 194 of the finger to be authenticated 190. The support edge 132 is inclined upward with respect to the base surface 151 from the fingertip 191 of the finger 190 to be authenticated toward the fingertip 192. Therefore, each plate 131 has a wedge shape along the longitudinal direction 158 as shown in FIG. The climbing slope may be an arc shape or a straight line shape. Preferably, the support edge 132 has a large inclination change from the fingertip 191 of the finger to be authenticated 190 to the vicinity of the second joint so that it follows the form when the finger is naturally bent slightly, and the finger 192 from the vicinity of the second joint. Decrease the slope change to the vicinity.

  By setting the finger guide portion 130 to the shape as described above, the finger guide portion 130 is caused to have a synergistic effect with the arrangement relationship of the light source 110, which will be described in detail later, that is, light irradiation from the front of the fingertip. It is possible to irradiate light from the light source 110 over almost the entire finger to be authenticated 190 from the fingertip 191 to the fingertip 192 around the second joint of the finger to be authenticated 190 placed. As a result, it is possible to image the entire to-be-authenticated finger 190, and the amount of blood vessel (vein) information obtained can be dramatically increased as compared to the case where only a part of the finger has been conventionally imaged. Therefore, the blood flow authentication terminal 100 enables blood vessel authentication with higher accuracy than in the past.

  In order to make the blood flow authentication terminal 100 applicable to everyone, the support interval 138 is based on the measurement result by the applicant and the like, in the present embodiment, about 7 to about 9 of the width of the finger 190 to be authenticated. Appropriate intervals are set within the range. That is, the authentication target finger 190 does not enter the support interval 138. By arranging the plate members 131 to face each other at such a support interval 138, it is possible to place the finger 190 to be authenticated between the plate members 131 and 131 as shown in FIGS. Become. Therefore, for example, it is possible to prevent a phenomenon that the finger 190 to be authenticated is sandwiched between the plate members 131 and the blood flow is stagnated and blood flow authentication cannot be performed. Furthermore, it is possible to prevent the light from the light source 110 from entering the imaging apparatus 120, and it is possible to stably obtain a clearer image as compared with the conventional art. In the present embodiment, the dimension between the plate members 131 and 131 is set to an appropriate value within about 16 mm to about 20 mm as an example.

  Further, each plate member 131 has a wedge shape, and has a support edge 132 that is inclined upward with respect to the base surface 151 from the fingertip 191 of the finger to be authenticated 190 to the fingertip 192, so that the finger to be authenticated 190 is straightened. The finger 190 to be authenticated can be placed on both the support edges 132 in a natural manner without applying any special force to the finger, such as stretching or conversely bending the finger. This makes it possible to easily perform authentication operations not only for normal healthy people but especially for people who have difficulty in extending their fingers due to illness or who have trembling on their fingers. This is preferable.

  Further, as shown in FIGS. 3 and 4, a chamfered portion 133 is provided on the inner side of each support edge 132 of each plate member 131 so as to contact and place the belly 194 of the finger to be authenticated 190. The chamfer angle of the chamfer 133 is changed from the fingertip 191 to the fingertip 192 of the finger to be authenticated 190 in accordance with the outer shape of the finger. Here, the chamfering angle is an angle θ (FIG. 3) formed by a surface perpendicular to the base surface 151 and the inclined surface of the chamfered portion 133. In the present embodiment, as shown in FIG. 4, the inclination angle of the chamfered portion 133 is large on the fingertip 192 side and is small on the fingertip 191 side as shown in FIG. 3. Further, the chamfer angle is gradually changed gradually from the fingertip 191 to the fingertip 192. Particularly on the fingertip 191 side, since the finger width is gradually reduced compared to the fingertip 192, the chamfer angle is changed more finely so that the chamfered portion 133 can follow this.

  By providing such a chamfered portion 133, the contact area between the support edge 132 of the plate 131 and the finger 190 to be authenticated can be increased. As a result, generation of a gap between the support edge 132 and the finger 190 to be authenticated can be suppressed, and in combination with the light irradiation from the front of the fingertip by the light source 110 described below, the penetration of the irradiation light into the imaging device 120 is efficient. Therefore, it is possible to contribute to the stable acquisition of a clearer blood vessel image.

  In the present embodiment, as described above, the finger guide portion 130 is configured by the pair of plate members 131, but is not limited to this form. For example, as shown in FIG. 7, the finger guide part 130-1 which filled both the board | plate material 131 and the space between the board | plate materials 131 with the translucent member may be sufficient. However, in such a finger guide part 130-1, the part on which the abdomen of the finger is placed is made of a material capable of transmitting near-infrared light, while the part corresponding to the plate 131 is made of visible light and Both near-infrared light has light shielding properties.

  In addition, as described above, one finger 190 to be authenticated is placed on the finger guide unit 130. On the other hand, in the present embodiment, the base 150 has base surfaces 151 on both sides of the finger guide portion 130 in the width direction 159 of the base 150 orthogonal to the longitudinal direction 158, as shown in FIG. In this way, by forming the base surface 151 on both sides of the finger guide part 130, another finger adjacent to the finger 190 to be authenticated can be placed on the base surface 151. Since the subject's hand usually has another finger adjacent to the finger 190 to be authenticated, the base surface 151 is further provided on both sides or one side of the finger guide unit 130 so that the other finger can be placed on the base surface 151. Supported by Therefore, so-called rolling in which the finger 190 to be authenticated placed on the finger guide unit 130 rotates in the direction around the axis of the finger can be suppressed. In this way, by suppressing the rolling of the finger 190 to be authenticated, it is possible to make the captured image constant and contribute to stably obtaining a clearer blood vessel image.

  In the base 150, the finger guide portion 130 and the like are installed on the base surface 151, but no components are installed above the base surface 151 as shown in FIG. Therefore, the path of entry of the finger to be authenticated 190 for placing the finger to be authenticated 190 on the finger guide unit 130 is free. Also in this respect, the blood flow authentication terminal device 100 has a finger width of the subject. It has become a specification for everyone not related to.

  Further, as shown in FIG. 1, a concave groove 153 that is dug down from the base surface 151 is formed in the base 150 so as to correspond to the inside of the pair of plate members 131 constituting the finger guide portion 130. The groove 153 extends along the longitudinal direction 158 with substantially the same length as the plate 131. Further, a near-infrared light transmission filter 154 capable of transmitting near-infrared light transmitted through the finger 190 to be authenticated with near-infrared light from the light source 110 described below is attached to the bottom of the groove 153, and the groove 153 constitutes a bottom plate. The near infrared light transmission filter 154 blocks light other than near infrared light.

  Further, the groove 153 has a light shielding portion 155 as shown in FIGS. 2 and 5 at one end of the groove 153 in the longitudinal direction 158. The one end corresponds to the fingertip 191 side of the finger 190 to be authenticated placed on the finger guide unit 130. The light shielding portion 155 is a portion in which the one end wall surface 153a of the groove 153 is formed in a semicircular shape or a semi-elliptical shape in the present embodiment. As a result, the base surface 151 corresponds to the shape of the one end wall surface 153a. Is also recessed in an arc. That is, an arcuate region corresponding to the roundness of the fingertip 191 is formed on the base surface 151 in the base surface portion corresponding to the one end wall surface 153 a of the groove 153. This arc-shaped region corresponds to the light shielding portion 155. By providing the light shielding portion 155 having such a shape, the following effects can be obtained.

  That is, when the one end wall surface of the groove 153 is simply a flat surface, the flat one end wall surface is formed between the pair of plate members 131 along the width direction 159. Therefore, each corner of the flat one end wall surface and each side wall along the longitudinal direction 158 of the groove 153 intersects each other at a right angle. Therefore, the shape of each corner does not match the shape of the fingertip 191 having roundness, and a gap is generated at each corner. Therefore, light enters from this gap.

  On the other hand, by providing the light shielding portion 155, the light shielding portion 155 blocks light that enters the groove 153 from the fingertip 191, that is, light that wraps around, as compared with a configuration in which the wall surface of the one end portion is simply a flat surface. be able to. More specifically, the fingertip portion, specifically, the portion from the vicinity of the first joint of the finger to the tip of the fingertip is a location where there are many capillaries and a location where a large amount of blood flow information can be obtained. Therefore, the fact that a clearer blood vessel image can be stably obtained at the fingertip portion enables blood vessel authentication with higher accuracy than before. In other words, the formation of the light shielding portion 155 can contribute to blood vessel authentication with higher accuracy than in the past.

  Further, the groove 153 of the base 150 including the finger guide part 130, the base surface 151 of the base 150, and the light shielding part 155 described above is a paint that suppresses, preferably prevents, near-infrared light reflection. Painted. Of course, the paint color is black. In addition, instead of such coating, surface treatment or surface processing for suppressing or preventing reflection of near-infrared light includes the finger guide part 130, the base surface 151 of the base 150, and the light shielding part 155. You may give to the groove | channel 153 which the base 150 has.

  Next, the light source 110 is a light source that irradiates the finger to be authenticated 190 that performs blood flow authentication with light having a predetermined wavelength that can be transmitted through the finger. The LED 111 that emits light having the predetermined wavelength and the LED 111 And a mounted substrate 112. The light having a predetermined wavelength emitted from the LED 111 is light in an orange to near-infrared region in the present embodiment, and is light having a wavelength of 580 nm to 1000 nm, more preferably 600 nm to 860 nm. As shown in FIG. 1, such a light source 110 is located in front of one end of the finger guide part 130 in the longitudinal direction 158, that is, in front of the fingertip 191 of the finger 190 to be authenticated placed on the finger guide part 130. It arrange | positions above the base surface 151. FIG.

  In this embodiment, two light sources 110, here LEDs 111, are used, and are symmetrical with respect to the central axis located along the plate 131 at the center between the pair of plates 131 constituting the finger guide part 130, and the width described above. They are installed at the same height from the base surface 151 along the direction 159. As an example, each LED 111 is located at a position of about 17 mm above the base surface 151 with a gap of about 10 mm, and the beam center is not parallel to the base surface 151 and is slightly inclined toward the base surface 151 side. The substrate 112 is disposed so as to be inclined. The direction of the beam center is the direction along the longitudinal direction 158, that is, the extending direction of the finger 190 to be authenticated. The LEDs 111 and 111 of the light source 110 arranged in this way are such that the beam center is located at and near the second joint of the finger 190 to be authenticated placed on the finger guide unit 130, and the beam extends from the fingertip 191 to the fingertip 192. The light is irradiated from the front of the fingertip 191 so that the back 193 of the to-be-authenticated finger 190 is irradiated.

  As shown in FIGS. 5 and 1, a near-infrared light transmission filter 113 is provided in front of the LED 111 in the light traveling direction so as to form one side surface of the light source storage unit 152. The near infrared light transmission filter 113 blocks light other than near infrared light.

  As described above, the light source 110 is configured so that light can be emitted from the fingertip 191 to the fingertip 192 from the front of the fingertip 191 of the finger to be authenticated 190 placed on the finger guide unit 130 toward the back 193 of the finger to be authenticated 190. By arranging the following effects can be obtained. That is, when blood flow authentication is performed, the problem with the blood vessel image used for this is the occurrence of halation. Since the finger joint has a depression on the finger surface, it is a place where halation is likely to occur.In the form of irradiating light from above or from the side of the finger as in the conventional authentication device, the depression is not provided. However, it was difficult to prevent halation at the joint part. Therefore, as shown in FIG. 8, halation 410 occurs, the entire image becomes whitish, and blood vessel recognition becomes difficult.

  In contrast, in the present embodiment, as described above, from the front of the fingertip 191 of the finger 190 to be authenticated placed on the finger guide unit 130 toward the back 193 of the finger 190 to be authenticated, from the fingertip 191 to the fingertip 192. It comprised so that light might be irradiated. Thereby, the wraparound of light can be reduced also in the joint part, and the occurrence of halation can be suppressed. Therefore, a clearer blood vessel image can be obtained compared to the conventional art. For example, as shown in FIG. 9, it can be seen that blood vessel recognition is easier than in the prior art due to the reduction of halation. In FIGS. 8 and 9, a portion denoted by reference numeral 400 corresponds to a part of a blood vessel (vein).

  Furthermore, due to the irradiation from the front of the fingertip 191 and the synergistic effect with the finger guide unit 130 described above, it is possible to image from the fingertip 191 to the fingertip 192 in this embodiment. As a result, the blood vessel information obtained is increased as compared to the conventional art, which can contribute to the improvement of authentication accuracy.

  Next, the fingertip detection sensor 141 is disposed so as to protrude from the base surface 151 at one end portion of the finger guide portion 130 as described above. That is, the fingertip detection sensor 141 is installed at a position corresponding to the fingertip 191 of the finger 190 to be authenticated placed on the finger guide unit 130, is formed of a strip-shaped metal plate, and contacts the tip of the fingertip 191. By this contact, the fingertip detection sensor 141 positions the fingertip 191 and electrically detects that the fingertip 191 is in contact. Specifically, contact is detected by a change in capacitance.

  As shown in FIGS. 1 and 5, the fingertip detection sensor 141 has a curved surface that follows the shape of the tip of the fingertip at the upper end portion thereof, and has a recess 141 a that receives the tip of the fingertip 191. By providing such a depression 141a, the tip of the fingertip can be fitted to the fingertip detection sensor 141, and a gap can be prevented from being formed between the tip of the fingertip and the fingertip detection sensor 141. Thereby, it can prevent that the irradiation light from the light source 110 penetrate | invades into the imaging device 120 from the fingertip 191, and can contribute to obtaining a clearer blood vessel image stably.

  Further, the stray light blocking portion is configured by the chamfered portion 133 in the plate member 131 constituting the finger guide portion 130, the light shielding portion 155 formed in the base 150, and the depression 141a formed in the fingertip detection sensor 141 described above. That is, the light from the light source 110 that enters through the gap formed by the fingertip 191 of the finger 190 to be authenticated supported by the plate 131 of the finger guide 130 and the plate 131 and the fingertip detection sensor 141 by the stray light blocking unit. Can be prevented from entering the imaging device 120.

  Further, in the fingertip detection sensor 141, the finger side surface 141b in which the recess 141a is formed is the same surface or substantially the same surface as the central portion of the one end wall surface 153a in the groove 153 formed in the base 150, as shown in FIG. It arrange | positions so that it may become. By adopting such an arrangement, the irradiation light from the light source 110 enters the imaging device 120 from the fingertip 191 due to a synergistic effect of the light shielding portion 155 having the one end wall surface 153a and the depression 141a of the fingertip detection sensor 141. And can contribute to stably obtaining a clearer blood vessel image.

  Further, as shown in FIG. 1, the fingertip detection sensor 141 has a height 143 from the base surface 151 at which the fingertip 191 of the finger to be authenticated 190 abuts and the nail of the finger to be authenticated 190 does not abut. The reason why the height 143 of the fingertip detection sensor 141 is set in this way is to reliably execute detection and positioning of the fingertip 191 and light shielding at the fingertip 191 even for a subject whose nails are elongated.

  Furthermore, in order to be able to cope with a subject whose nails are elongated, a specified distance 156 is set in the longitudinal direction 158 with respect to the near-infrared light transmitting filter 113 that forms one side surface of the light source storage unit 152 that stores the light source 110. A fingertip detection sensor 141 is arranged open. This prescribed distance 156 can prevent the nail from coming into contact with the near-infrared light transmission filter 113 even in a subject whose nail is elongated, and reliably perform detection and positioning of the fingertip 191 and light shielding at the fingertip 191. Can do.

Next, the finger detection sensor 142 is disposed so as to protrude from the base surface 151 at the other end portion of the finger guide portion 130 as described above. That is, the finger detection sensor 142 is installed at a position corresponding to the finger 192 of the finger 190 to be authenticated placed on the other end of the finger guide 130, and is formed of a strip-shaped metal plate. Is placed. By this placement, the finger detection sensor 142 electrically detects that the finger 192 is in contact. Specifically, contact is detected by a change in capacitance. Further, the upper end surface with which the fingertip 192 contacts in the fingertip detection sensor 142 is formed to be recessed in an arc shape as shown in FIG. 5 so as to match the shape of the fingertip 192. By using the concave arc shape, the finger detection sensor 142 can reliably support the finger 190 to be authenticated, and the finger detection operation can be reliably performed.
As will be described later, the blood flow authentication operation can be started when both the fingertip detection sensor 141 and the fingertip detection sensor 142 detect the finger 190 to be authenticated.

  Next, as illustrated in FIG. 1, the imaging device 120 is located between the pair of plate members 131 of the finger guide unit 130 and directly below the finger to be authenticated 190 on the ventral side of the finger 190 to be authenticated supported by the plate member 131. Are stored in the base 150 and fixedly installed. The imaging device 120 is disposed at a position for imaging transmitted light that is bent in a direction perpendicular to or substantially perpendicular to the traveling direction of the center of the irradiation light beam from the light source 110, and the irradiation light is applied to the authentication target finger 190. The blood vessel image obtained by transmitting through the near-infrared light shielding filter 154 is captured.

  Such an imaging apparatus 120 includes an imaging element, an optical system including a lens, and an imaging drive circuit. Further, in this embodiment, the imaging device 120 is arranged so that the optical axis in the imaging device 120 corresponds to the vicinity of the second joint centered on the second joint of the finger 190 to be authenticated. Further, the imaging device 120 is slightly focused on the inside of the finger from the skin on the ventral side of the finger 190 to be authenticated. In the present embodiment, the focal position is fixed. Further, the reason for focusing on the inner side of the finger is to prevent recognition of the fingerprint of the finger skin. Furthermore, the imaging device 120 has a lens surface disposed at a position of about 20 mm or less from the antinode 194 of the finger 190 to be authenticated placed on the finger guide unit 130 as an example in this embodiment. By having a distorted lens, it is possible to image from the fingertip 191 to the fingertip 192 of the finger 190 to be authenticated supported by the finger guide unit 130.

Next, a blood flow authentication system 300 including the blood flow authentication terminal 100 configured as described above will be described.
As shown in FIG. 6 and as already described, the blood flow authentication system 300 includes a blood flow authentication terminal device 100 and an authentication control device 200 connected to the blood flow authentication terminal device 100. Here, the authentication control device 200 corresponds to a so-called personal computer, and the blood flow authentication system 300 is a system for authenticating a user who can access the personal computer and an individual who can access each information stored in the personal computer. Take as an example. The blood flow authentication terminal 100 and the authentication control device 200 are connected by a USB (Universal Serial Bus) 160.

  The authentication control device 200 is a device that performs authentication judgment of the blood vessel image acquired by the blood flow authentication terminal device 100 and controls the operation of the light source 110 and the imaging device 120 provided in the blood flow authentication terminal device 100. Such an authentication control device 200 actually corresponds to an arithmetic processing unit having a CPU or the like provided in a personal computer, but from the functional aspect of executing a blood flow authentication operation, the authentication unit 210, the control unit 220, and the storage unit 230.

  The storage unit 230 is a storage device such as a hard disk or a semiconductor memory (DRAM or SRAM). Information such as an authentication operation program for executing blood flow authentication, a blood flow authentication program for realizing an image configuration, a pre-registered blood vessel (vein) image used for authentication, and an authentication history are stored in the storage unit 230. Is stored.

  Based on the authentication operation program stored in the storage unit 230, the control unit 220 executes various processes such as information (signal) calculation processing and information transmission. The function of the control unit 220 is realized by sequentially executing the authentication operation program by the arithmetic processing unit. Further, the control unit 220 confirms whether or not the finger to be authenticated 190 is in contact with the fingertip detection sensor 141 and the fingertip detection sensor 142, emits and turns off the LED 111, performs an imaging operation on the imaging device 120, and Control each operation of captured image transfer.

  The authentication unit 210 performs blood flow authentication based on the acquired image based on the blood flow authentication program stored in the storage unit 230 and a registered image registered in advance. A specific blood flow authentication method by the authentication unit 230 is arbitrary, and for example, various methods for determining similarity of blood vessel patterns can be applied.

Next, the blood flow authentication operation executed in the blood flow authentication system 300 will be described with reference to FIG.
First, in step S <b> 10, the subject places the finger 190 to be authenticated on the support edge 132 of the pair of plate members 131 that constitute the finger guide unit 130.

  In the next step S <b> 11, it is determined whether or not the touch of the authentication target finger 190 is detected by both the fingertip detection sensor 141 and the fingertip detection sensor 142 by the placement operation of the authentication target finger 190. This determination is performed by the control unit 220 of the authentication control apparatus 200. When only one of the fingertip detection sensor 141 and the fingertip detection sensor 142 detects the finger 190, the fingertip detection sensor 141 and the fingertip detection sensor When both of the original detection sensors 142 do not detect the finger 190 to be authenticated, and when both the fingertip detection sensor 141 and the finger detection sensor 142 detect that the capacitance value does not satisfy the reference value Do not start blood flow authentication operation. On the other hand, when both the fingertip detection sensor 141 and the fingertip detection sensor 142 detect the contact of the finger 190 to be authenticated and the capacitance value satisfies the reference value, the process proceeds to the next step S12.

  In step S <b> 12, the control unit 220 causes the LED 111 to emit light and irradiates the finger to be authenticated 190 with light. Then, when the illuminance of the LED 111 is stabilized after the lapse of the specified time, the process proceeds to the next step S13.

  In step S <b> 13, the control unit 220 drives the imaging device 120 and images the authentication target finger 190. In the blood flow authentication operation, the number of times of imaging is one. The captured image is supplied from the imaging device 120 to the authentication control device 200. Further, after imaging, the control unit 220 turns off the LED 111.

  In the next step S14, the authentication unit 210 of the authentication control apparatus 200 executes blood flow authentication between the acquired image captured in step S13 and the registered image of the subject read from the storage unit 230 according to the blood flow authentication program. It is determined whether or not the two match. In the present embodiment, blood flow authentication is performed using feature point extraction and feature point matching after pattern extraction of a vein shape and image processing, as in the prior art.

  If the acquired image and the registered image match as a result of the blood flow authentication, the authentication unit 210 determines that the subject is a suitable person, for example, permits the use of the personal computer, or accesses the information in the personal computer. Enable access. On the other hand, when the acquired image and the registered image do not match, the authentication unit 210 determines that the subject is a non-conforming person and does not permit access to the personal computer.

  Here, the imaging and storage of the registered image will be briefly described. After the authentication target finger 190 to be registered is determined, the registration target finger 190 is placed on the finger guide unit 130. For example, by pressing the registration button, the imaging device 120 captures the authentication target finger 190 twice. Only when the two captured images match, this image is stored in the storage unit 230 as a registered image. At the time of blood flow authentication, the registered finger 190 to be registered is imaged once as described above, and blood flow authentication is performed.

  In addition, in the blood flow authentication terminal device 100 in the above-described embodiment, the authentication target finger 190 has been described as one, but by providing a plurality of finger guide units 130 and the imaging device 120 on the base 150, Blood flow authentication may be executed with a plurality of authentication target fingers 190. By adopting such a configuration, it is possible to further improve the authentication accuracy.

  Further, in the blood flow authentication terminal device 100 according to the present embodiment, as described above, the base surface 151 of the base 150 is a flat surface, and the finger guide portion 130 is configured to protrude from the base surface 151. However, the present invention is not limited to such a form. For example, as shown in FIG. 11, a base 150-1 having a groove 153 and a curved base 153 as a whole so as to coincide with the support edge 132 described above is configured. May be. By comprising in this way, the base surface 151 and the finger guide part 130 can be integrated, and the base surface 151 can also have the function of the finger guide part 130. FIG.

  Furthermore, instead of configuring the finger guide portion 130 so as to protrude from the base surface 151, the support edge 132 of the finger guide portion 130 may be formed in a groove recessed with respect to the flat base surface 151. By configuring in this way, the groove can fulfill the function of the finger guide part 130.

In the blood flow authentication terminal device 100 according to the present embodiment, the groove 153 is formed in the base 150 as described above, but the present invention is not limited to this configuration. That is, in this embodiment, the groove 153 is provided to ensure a distance necessary for the imaging device 120 to image the finger 190 to be authenticated. If the necessary distance is ensured, the groove 153 is not necessary. Absent.
Moreover, the shape of each part in the terminal 100 for blood-flow authentication is not limited to the shape shown in figure. Shapes that can be conceived by a person skilled in the art within the scope of the above description and claims are included in the present invention.

  In addition, as described above, in the present embodiment, the blood flow authentication system 300 takes access authentication to the computer and the information in the computer as an example, but the application example is not limited to this. For example, the blood flow authentication terminal 100 and the blood flow authentication system 300 can be used for entrance / exit management. In this configuration, an additional configuration such as a room number input device is required.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a blood flow authentication terminal for performing personal authentication by extracting a blood vessel pattern and a blood flow authentication system including the blood flow authentication terminal.

DESCRIPTION OF SYMBOLS 100 ... Terminal device for blood-flow authentication, 110 ... Light source, 120 ... Imaging device, 130 ... Finger guide part,
131 ... Plate material, 132 ... Support edge, 133 ... Chamfered part, 141 ... Fingertip detection sensor,
141a ... depression, 142 ... finger detection sensor, 150 ... base, 151 ... base surface,
155 ... light-shielding part, 190 ... authenticated finger,
200: Authentication control device, 300: Blood flow authentication system.

Claims (11)

A blood flow authentication terminal device that captures a blood vessel image of a finger with light transmitted through the finger (190) to be authenticated,
A base (150) on which the finger to be authenticated is placed;
A light source that emits light that passes through the finger to be authenticated, is located at one end of the base and is placed in front of the fingertip of the finger to be authenticated placed on the base, from the front of the fingertip toward the back of the finger to be authenticated A light source (110) that emits light from the fingertip to the fingertip;
The blood vessel of this finger that is placed on the base corresponding to directly below the finger on the ventral side of the finger to be authenticated placed on the base, and the irradiation light emitted from the light source is transmitted through the finger to be authenticated An imaging device (120) for capturing an image;
A terminal for blood flow authentication, comprising:   The base includes a finger guide part (130), and the finger guide part places a finger to be authenticated, curves the placed finger to be authenticated from the fingertip to the fingertip in a streamline shape, and The blood flow authentication terminal device according to claim 1, wherein the terminal for supporting the abdomen and blocking the incidence of the irradiation light from the belly of the finger to the imaging device.   A fingertip detection sensor that is installed at a position corresponding to the fingertip of the finger to be authenticated placed on the finger guide portion at one end portion of the finger guide portion, and that positions the fingertip by contact of the fingertip and detects contact of the fingertip ( The blood according to claim 2, further comprising: 141) and a fingertip detection sensor (142) that is installed at a position corresponding to the fingertip portion at the other end of the finger guide portion and detects contact of the fingertip portion. Flow authentication terminal.   The fingertip detection sensor has a height (143) at which the fingertip of the finger to be authenticated abuts and a fingernail does not abut, and the light source is spaced from the fingertip detection sensor by a specified distance (156). The blood flow authentication terminal device according to claim 3, wherein the terminal device is installed in front and the specified distance corresponds to a distance exceeding a length of a nail extending beyond the fingertip detection sensor.   The base has a base surface (151) on which a finger next to the finger to be authenticated is placed to suppress rolling of the finger to be authenticated, the light source is disposed above the base surface, and the imaging device is a base surface The terminal for blood flow authentication according to any one of claims 1 to 4, which is arranged further downward.   The base places the finger to be authenticated, curves the finger in a streamline shape from the fingertip to the fingertip, supports the belly of the finger, and allows the irradiation light to enter the imaging device from the belly of the finger. It has a finger guide part (130) for blocking, and this finger guide part is composed of a pair of plate members (131) erected on the base surface so as to face each other, and each plate member is in one direction on the base plate Extending along the to-be-authenticated finger and disposed opposite to each other at a support interval (138) that can support the torso of the to-be-authenticated finger. The terminal for blood flow authentication according to claim 5, wherein the terminal for blood flow authentication is formed in a wedge shape having a support edge (132) that supports and is inclined upwardly with respect to the base surface from the fingertip to the fingertip.   Each plate member has a chamfered portion (133) for placing the finger pad inside each support edge, and the chamfer angle of the chamfered portion corresponds to the finger outline from the fingertip of the finger to be authenticated to the fingertip. The terminal for blood flow authentication according to claim 6, which changes.   A fingertip detection sensor (141) that is installed at the position of the fingertip of the finger to be authenticated placed on the finger guide portion, positions the fingertip by the contact of the fingertip, and detects the contact of the fingertip, and further includes the fingertip detection. The terminal for blood flow authentication according to claim 6 or 7, wherein the sensor has a recess (141a) provided in a support interval between the pair of plate members and provided with a curved surface along the shape of the fingertip of the finger to be authenticated. The base has a base surface (151) for placing a finger next to the finger to be authenticated to suppress rolling of the finger to be authenticated.
The finger guide portion is composed of a pair of plate members (131) erected on the base surface,
The fingertip detection sensor is sandwiched between the plate members and arranged at right angles to each plate member,
In the base, light from the light source that enters from a gap between the plate material and the fingertip detection sensor and the fingertip of the finger to be authenticated enters the imaging device in an area adjacent to the plate material and the fingertip detection sensor. The blood flow authentication terminal device according to any one of claims 3 to 8, further comprising a light-shielding portion (155) for preventing the blood flow. A blood flow authentication terminal (100) according to any one of claims 1 to 9,
An authentication control device connected to the blood flow authentication terminal device, the operation control of the light source and the imaging device provided in the blood flow authentication terminal device, and blood flow authentication using a captured image supplied from the imaging device An authentication control device (200) for performing personal authentication by
A blood flow authentication system characterized by comprising:   The blood according to claim 10, wherein the authentication control device is a personal computer, and further comprises a USB (Universal Serial Bus) cable (160) for electrically connecting the personal computer and the blood flow authentication terminal. Flow authentication system.