CN101513348B - Vein authentication device - Google Patents

Abstract

The vein authentication device of the present invention includes an interface for placing a living body to be photographed, a light source emitting infrared light, an imaging unit for imaging a blood vessel image of the living body with light from the light source, and an image of the blood vessel captured by the imaging unit. An image computing unit for processing blood vessel images; the interface is provided with an opening opening in the imaging direction of the imaging unit; the light source irradiates infrared light to the living body from the imaging side of the living body; Among the radiated infrared light, at least the light proceeding in the direction intersecting with the above-mentioned imaging direction is shielded so that the infrared light emitted from the light source does not face the above-mentioned imaging direction; The light shielding member is provided between the opening and the light source along the imaging direction, and the light shielding member has a shape covering a part of an upper portion of the light source on the side of the opening.

Description

Vein authentication device

This application is a divisional application of an invention patent application with the title of "vein authentication device" and application number 20058000279.3 that entered the Chinese national phase on July 20, 2006.

technical field

The present invention relates to an authentication device for authenticating an individual, and in particular relates to a technique for authenticating by using vein information of a living body.

Background technique

In recent years, the security of personal information has become important. Biometric authentication is attracting attention as a personal authentication technology for securing security. Biometric authentication is a technology that uses human biological information for authentication, and has the advantages of convenience and confidentiality.

Existing biometric authentication technologies utilize fingerprints, iris, voice, face, veins on the back of the hand or finger veins for authentication. In particular, biometric authentication using veins enables a user to authenticate by presenting a part of a biological body such as a hand or a finger to an authentication device. Therefore, the use of vein biometric authentication (vein authentication device) reduces the psychological resistance of the user. In addition, since the internal information of the living body is used, the anti-counterfeiting property is good.

In the following, the finger vein authentication device will be described in particular.

First, the finger vein authentication device irradiates the finger with infrared light. In this way, the infrared light is scattered outside the finger after being scattered. Then, the finger vein authentication device takes an image of the infrared light transmitted from the palm side of the finger.

At this time, the hemoglobin in the blood also absorbs infrared light from the surrounding tissues, so that in the image taken by the finger vein authentication device, the blood vessels (finger veins) distributed under the skin on the palm side of the finger can be seen as dark graphics (finger vein pattern) ).

The finger vein authentication device has pre-registered the features of the finger vein pattern.

The finger vein authentication device captures an image of the finger presented by the user during authentication. Then, the finger vein authentication device performs personal authentication by finding the correlation between the finger vein pattern of the captured image and the pre-registered features.

However, the existing finger vein authentication device takes an image of the finger inserted into the device. For this reason, since the user has to insert his finger into the closed internal space of the finger vein authentication device, he feels resistance.

Then, a finger vein authentication device that solves this problem is described in (Japanese) Unexamined Patent Application Publication No. 2004-265269. In the finger vein authentication device, an infrared light source for illuminating the finger is arranged on both sides of the finger. In this way, users only need to place their fingers on the device to authenticate.

However, since this finger vein authentication device needs a space for installing a light source on the side of the finger, there is a problem that it cannot be miniaturized.

In addition, a vein authentication device having a planar structure is described in International Publication No. 2002/099393.

However, in this vein authentication device, the light source is provided on the same surface as the imaging element for the photographed vein.

Contents of the invention

However, a vein authentication device that has a light source provided on the same surface as the imaging element also captures light reflected from the skin surface of a finger. Therefore, this vein authentication device has a problem in that it cannot clearly capture vein patterns.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vein authentication device capable of capturing a clear pattern of veins and capable of being miniaturized.

A vein authentication device of the present invention is characterized in that it includes an interface for placing a living body to be photographed, a light source emitting infrared light, an imaging unit for taking a picture of a blood vessel image of the living body by light from the light source, and An image calculation unit for processing blood vessel images captured by the imaging unit; the interface is provided with an opening opening in the imaging direction of the imaging unit; the light source irradiates the living body with infrared light from the imaging side of the living body; a light shielding member is provided to block the light emitted from the light source. In the infrared light, at least the light proceeding in the direction intersecting with the imaging direction is shielded so that the infrared light emitted from the light source does not face the imaging direction; on the side of the opening, between the opening and the light source Between them, a light shielding member is provided along the imaging direction, and the light shielding member has a shape that covers a part of the upper part of the light source on the opening side.

Another vein authentication device of the present invention is characterized in that it includes an interface for placing the photographed living body, a light source emitting infrared light, an imaging unit for taking a picture of the vein image of the living body through the light from the light source, and The image calculation unit for processing the vein image captured by the imaging unit; the interface is provided with an opening opening in the imaging direction of the imaging unit; the light source is arranged on the side of the opening, and emits light with the imaging direction as the optical axis, so The imaging side irradiates the living body with infrared light; it has a light-shielding member for shielding at least light that advances in a direction intersecting with the imaging direction among the infrared light radiated from the light source; the light-shielding member is arranged between the opening and the imaging direction. The space between the light sources has a shape extending along the imaging direction, and has a shape covering more than half of the upper part of the light source on the side of the opening.

Another vein authentication device of the present invention is characterized in that it includes an imaging unit for capturing vein images, an image computing unit for processing the vein images captured by the imaging unit, an interface for placing the captured living body, and an A light source of infrared light; the interface is provided with an opening opening in the imaging direction of the imaging unit; the light source is arranged on the side of the opening, and emits light from the imaging direction toward the direction inclined to the opposite side of the opening as the optical axis, from the biological The imaging side of the body irradiates infrared light to the biological body; a light shielding member is provided, and the light shielding member is arranged between the opening and the light source, has a rectangular parallelepiped shape extending along the imaging direction, and covers the upper part of the opening side of the light source Dimpled shape.

The vein authentication device of the present invention can capture clear vein patterns and can be miniaturized.

Description of drawings

FIG. 1 is a configuration diagram of an authentication system according to a first embodiment of the present invention.

Fig. 2 is a memory block diagram of an authentication processing unit according to the first embodiment of the present invention.

Fig. 3A is a side view of the input device according to the first embodiment of the present invention.

3B is a front view of the input device according to the first embodiment of the present invention.

3C is a plan view of the input device according to the first embodiment of the present invention.

Fig. 4A is an explanatory diagram showing the effect of the shape of the finger rest according to the first embodiment of the present invention.

Fig. 4B is an explanatory diagram showing the effect of the shape of the finger rest according to the first embodiment of the present invention.

Fig. 5A is an explanatory diagram showing the effect of the shape of the finger rest according to the first embodiment of the present invention.

Fig. 5B is an explanatory diagram showing the effect of the shape of the finger rest according to the first embodiment of the present invention.

Fig. 6 is an explanatory diagram of the relationship between the distance from the light source and the brightness value of the image of the finger vein pattern according to the first embodiment of the present invention.

7 is a flow chart of authentication processing by the authentication processing unit according to the first embodiment of the present invention.

Fig. 8A is an explanatory view of finger veins captured by the imaging device according to the first embodiment of the present invention.

FIG. 8B is an explanatory diagram of an image captured by the imaging device according to the first embodiment of the present invention.

8C is an explanatory diagram of characteristic data transformed by the authentication processing unit according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram of characteristic data pasting processing of the authentication processing unit according to the first embodiment of the present invention.

Fig. 10 is a side view of an input device according to a second embodiment of the present invention.

11A is a plan view of an input device according to a third embodiment of the present invention.

11B is an explanatory diagram of a light source of the input device according to the third embodiment of the present invention.

Fig. 11C is a front view of an input device according to a third embodiment of the present invention.

Fig. 12 is a front view of an input device according to a fourth embodiment of the present invention.

Fig. 13 is a side view of an input device according to a fifth embodiment of the present invention.

Fig. 14 is a side view of an input device according to a sixth embodiment of the present invention.

Fig. 15 is an explanatory diagram of the relationship between the distance from the light source and the brightness value of the image of the finger vein pattern according to the sixth embodiment of the present invention.

16A is an explanatory diagram of an image captured when the light source is strong on the side of the base of the finger according to the sixth embodiment of the present invention.

16B is an explanatory diagram of an image captured when the light source on the fingertip side is strong according to the sixth embodiment of the present invention.

Fig. 16C is an explanatory diagram of images synthesized by the authentication processing unit according to the sixth embodiment of the present invention.

17A is an explanatory diagram of a portable information terminal according to a seventh embodiment of the present invention.

17B is a side view of an input device mounted on a portable information terminal according to a seventh embodiment of the present invention.

18A is an explanatory diagram of a portable information terminal according to an eighth embodiment of the present invention.

18B is a front view of the input device mounted on the portable information terminal according to the eighth embodiment of the present invention.

Fig. 19A is an explanatory diagram of a door handle according to a ninth embodiment of the present invention.

Fig. 19B is a side view of the input device attached to the door handle according to the ninth embodiment of the present invention.

Fig. 20A is a probe-type authentication device according to a tenth embodiment of the present invention.

Fig. 20B is a side view of the input device used in the probe type authentication device according to the tenth embodiment of the present invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a finger vein authentication device is particularly described, but it is also applicable to other living bodies such as palms.

(first embodiment)

FIG. 1 is a configuration diagram of an authentication system according to a first embodiment of the present invention.

The authentication device includes an input device 2 , an authentication processing unit 10 , a storage device 14 , a display unit 15 , an input unit 16 , a speaker 17 and an image input unit 18 .

The input device 2 will be described in Fig. 3A, Fig. 3B and Fig. 3C. In addition, the input device 2 includes a light source 23 and an imaging device 29 .

The light source 23 is, for example, an infrared LED, and irradiates the finger 1 presented on the input device 2 with infrared light. The imaging device 29 images the finger 1 presented on the input device 2 .

The image input unit 18 inputs the image captured by the imaging device 29 of the input device 2 to the authentication processing unit 10 .

The authentication processing unit 10 includes a CPU 11 , a memory 12 and an interface (IF) 13 .

CPU 11 performs various processing by executing programs stored in memory 12 . The memory 12, which will be described in FIG. 2, stores programs executed by the CPU. In addition, the memory 12 temporarily stores the image input by the image input unit 18 .

The interface 13 is connected to an external device of the authentication processing unit 10 . Specifically, the interface 13 is connected to the input device 2, the storage device 14, the display unit 15, the input unit 16, the speaker 17, the image input unit 18, and the like.

The storage device 14 pre-stores the comparison data of the user. The collation data is information for collation of the user, for example, an image of a finger vein pattern and the like. The image of the finger vein pattern is an image in which blood vessels (finger veins) distributed subcutaneously on the palm side of the finger are captured in a shaded pattern.

The display unit 15 is, for example, a liquid crystal display or the like, and displays information received from the authentication processing unit 10 .

The input unit 16 is, for example, a keyboard or the like, and sends information input by the user to the authentication processing unit 10 . The speaker 17 transmits the information received from the authentication processing unit 10 by voice.

The authentication processing of the authentication system of this embodiment will be described below.

First, the user requesting authentication shows the finger 1 to the input device 2 , and at this time, the light source 23 provided on the input device 2 irradiates the finger 1 with infrared light. This infrared light is scattered in all directions inside the finger 1 .

The imaging device 29 provided on the input device 2 captures infrared light emitted from the palm side of the finger. Then, the imaging device 29 inputs the captured image to the authentication processing unit 10 through the image input unit 18 .

At this time, the authentication processing unit 10 stores the input image in the memory 12 . Then, feature data is extracted from the image stored in the memory 12 .

Then, the authentication processing unit 10 acquires the authentication data previously stored in the storage device 14 from the storage device 14 . The authentication processing unit 10 may acquire only the authentication data corresponding to the information input from the input unit 16 (for example, user ID, etc.) from the storage device 14 . Then, the acquired authentication information is stored in the memory 12 .

Then, the authentication processing unit 10 compares the extracted feature data with the authentication data acquired from the storage device 14 . Specifically, by calculating the correlation value between the characteristic data and the authentication data, the person who showed the finger on the input device 2 is identified.

Then, the authentication processing unit 10 performs processing corresponding to the specified person.

Through the above steps, the authentication system of this embodiment authenticates the user.

FIG. 2 is a block diagram of the memory 12 of the authentication processing unit 10 according to the first embodiment of the present invention.

The memory 12 is used to store a finger detection program 121 , a light control program 122 , a feature extraction program 123 , a feature data fitting program 124 , a feature comparison program 125 , and the like.

The finger detection program 121 judges whether or not the finger 1 is placed on the input device 2 .

The light quantity control program 122 controls the light quantity of the light source 23 .

The feature extraction program 123 extracts feature data from images captured by the imaging device 29 .

The characteristic data joining program 124 performs joining of the characteristic data extracted by the characteristic extraction program 123 and the characteristic data extracted in the past.

The feature matching program 125 compares the feature data combined by the feature data combining program 124 with the authentication data stored in the storage device 14 .

Fig. 3A is a side view of the input device 2 according to the first embodiment of the present invention. Fig. 3B is a front view of the input device 2 according to the first embodiment of the present invention. FIG. 3C is a plan view of the input device 2 according to the first embodiment of the present invention.

The input device 2 of this embodiment will be described by taking a scanning finger vein authentication device as an example. The scanning finger vein authentication device takes an image of the entire finger 1 when the user moves the finger 1 .

On the upper part of the input device 2, two finger rests 25 are provided as interfaces for setting the living body to be photographed. In addition, the two finger rests 25 are provided with openings 30 .

The opening 30 may be just a space as long as it is transparent to infrared light, or may be a member transparent to infrared light. The opening 30 makes the width of the finger 1 in the longitudinal direction shorter than the length of the finger 1 . In this way, the input device 2 can be miniaturized.

The finger rest 25 may be configured integrally with the input device 2 or may be configured separately from the input device 2 . The placing table 25 is made of opaque material to infrared light.

In addition, the stand 25 has a curved shape matching the shape of the finger 1 (for example, refer to FIG. 3B ). The finger rest 25 is in the shape of a central depression.

In this way, the user can place the finger at a prescribed position. Also, the user can move the finger 1 stably. As a result, the authentication accuracy of the authentication system of this embodiment can be improved.

The finger rest 25 may not have a curved concave shape, but a flat shape. At this time, the finger rest 25 has no unevenness. In this way, the upper part of the input device 2 can be made into a planar structure. The finger rest 25 is an example of an interface for presenting a finger during authentication. The interface may be of any shape as long as it is a place where the finger 1 is presented for authentication.

A light source 23 is provided under the finger rest 25 . The light source 23 irradiates the finger 1 with infrared light. The light source 23 emits light with a direction substantially parallel to the imaging direction 320 of the imaging device 29 serving as an optical axis 231 . The imaging direction 320 is the direction of the optical axis for imaging by the imaging device 29 .

In this explanatory drawing, four light sources 23 are arranged in a row in a direction substantially perpendicular to the longitudinal direction of the finger 1 at the lower portion of each placing stand 25 . As long as the light source 23 irradiates the finger 1 with sufficient intensity, any number can be used.

However, by arranging a plurality of light sources 23 in a direction substantially perpendicular to the longitudinal direction of the finger 1 , it is possible to illuminate the entire finger 1 with the same brightness. It is also possible to reduce the lengthwise width of the finger 1 of the input device 2 . Instead of arranging a plurality of light sources 23 in a row, one elongated light source 23 may be arranged in a direction substantially perpendicular to the longitudinal direction of the pair of fingers.

In addition, the CPU 11 of the authentication processing unit 10 controls the amount of infrared light emitted by the light source 23 by executing the light amount control program 122 . For example, when the joint part is placed on the finger stand 25, the authentication processing unit 10 dims the light intensity. On the other hand, when the thick part of the finger is placed on the finger rest 25, the intensity of the light is adjusted.

The authentication processing unit 10 may control all the light sources 23 to have the same light intensity. In this case, the authentication processing unit 10 only needs to control the light source 23 with one current. Therefore, an authentication system can be produced at low cost.

In addition, the authentication processing unit 10 may control the respective light sources 23 to have different light quantities. At this time, the authentication processing unit 10 controls the light source 23 with a plurality of different currents. Thus, the cost of the authentication system becomes large. However, since each light source 23 emits light with an appropriate amount of light, the imaging device 29 can capture a sharp image with uniform brightness.

In addition, the authentication device 10 may be controlled to have different amounts of light by the light source 23 provided on the finger rest 25 at the base of the finger and the light source 23 provided on the finger rest 25 at the fingertip side. In this case, the authentication processing unit 10 only needs to control the light source 23 with two currents. In this way, an authentication system can be produced at low cost. The imaging device 29 can also capture sharp images with uniform brightness.

In addition, a plurality of light sources 23 may be arranged in a row in the longitudinal direction of the finger 1 .

A plurality of light sources 23 may be arranged in a planar shape. At this time, the authentication processing unit 10 increases the light intensity of the light sources 23 farther from the opening 30 and weakens the light intensity of the light sources 23 closer to the opening 30 . In this way, the imaging device 29 can capture a sharp image with uniform brightness.

An acrylic plate 34 is provided on the opening 30 . The acrylic plate 34 is a material transparent to infrared light. The acrylic plate 34 is used to prevent fingers and foreign matter including dust from entering the input device 2 .

On both sides of the upper portion of the opening portion 30 , light shielding members 32 are provided. The light shielding member 32 is used to prevent external light from entering the opening 30 . For example, the light shielding member 32 is provided to cover both sides of the finger 1 .

When the influence of external light is small, the light shielding member 32 is unnecessary. In addition, when the upper portion of the input device 2 requires a planar structure, the light shielding member 32 is also unnecessary.

Inside the input device 2, an imaging device 29 and an infrared transmission filter 27 are provided.

The infrared transmission filter 27 is provided between the acrylic plate 34 and the imaging device 29 . The infrared transmission filter 27 transmits only infrared light.

The imaging device 29 captures infrared light passing through the opening 30 , the acrylic plate 34 , and the infrared transmission filter 27 from the outside of the input device 2 . The imaging device 29 is provided directly below the opening 30 and facing upward.

A mirror or the like may be provided inside the input device 2 . In this case, the imaging device 29 may be installed at any position and any direction. At this time, the input device 2 can lower the height. The reason for this is that the distance between the opening 30 and the imaging device 29 can be adjusted by changing the path of the infrared light entering from the opening 30 by the reflector.

In addition, a planar photosensitive element may be provided in the opening 30 . The photosensitive element is used to detect infrared light. In this case, since the input device 2 can omit the acrylic plate 34, the infrared transmission filter 27, and the imaging device 29, it can be flattened.

Next, the processing of the input device 2 will be described.

First, the user requesting authentication presents the finger 1 on the top of the finger rest 25 . At this time, the light source 23 irradiates the finger 1 with infrared light. This infrared light is scattered in all directions inside the finger. For this reason, part of the infrared light scattered inside the finger reaches the vicinity above the opening 30 . Part of the infrared light that reaches the vicinity above the opening travels to the outside of the finger 1 .

Then, the infrared light traveling outside the finger 1 passes through the opening 30 , the acrylic plate 34 , and the infrared transmission filter 27 to reach the imaging device 29 . The imaging device 29 images the arriving infrared light.

The infrared light captured by the imaging device 29 is transmitted from the inside of the finger 1 to the palm side surface of the finger 1 . Therefore, the infrared light captured by the imaging device 29 includes a weak portion that is attenuated due to transmission through the finger vein and a strong portion that is not attenuated due to transmission through a portion without the finger vein. That is, the infrared light captured by the imaging device 29 includes a difference in contrast due to finger veins.

Accordingly, the imaging device 29 can acquire an image of a finger vein pattern of a partial area (imaged portion) of the finger 1 located directly above the opening 30 by imaging the infrared light.

The opening 30 of the input device 2 according to the present embodiment has a narrow width in the longitudinal direction of the finger. Therefore, the user moves the finger 1 in the longitudinal direction of the finger 1 while placing the finger 1 on the upper portion of the finger rest 25 . At this time, the imaging device 29 of the input device 2 continuously captures the imaged portion. Furthermore, the authentication processing unit 10 obtains an overall image of the finger vein pattern of the finger 1 by combining a plurality of images captured by the imaging device 29 .

The imaging device 29 of the input device 2 desirably satisfies the following optical conditions in order to clearly capture an image of the finger vein pattern of the imaged portion.

First, the imaging device 29 does not capture infrared light reflected from the skin surface of the finger 1 . Next, the imaging device 29 does not capture infrared light scattered at a depth that does not reach the finger veins.

When the optical condition is not satisfied, the infrared light that does not contain the information of the finger vein pattern reduces the contrast of the finger vein pattern. Furthermore, the image of the finger vein pattern may contain unnecessary information such as the texture of the skin surface of the finger 1, making it unclear.

In order to satisfy this optical condition, the finger rest 25 is provided between the light source 23 and the opening 30 . In addition, the finger rest 25 is made of a material opaque to infrared light.

The light source 23 has expansibility (directivity) and emits infrared light. Therefore, when the finger rest 25 is made of a material transparent to infrared light, the infrared light emitted from the light source 23 will directly reach the portion to be imaged above the opening 30 . In addition, the infrared light that directly reaches the imaged part does not satisfy the optical condition because it is reflected by the skin surface of the imaged part and reaches the imaging device 29 . Therefore, the finger rest 25 must be made of an opaque material to infrared light.

In addition, the inner wall of the input device 2, the optical filter 27, the imaging device 29, and the acrylic plate 34 are desirably made of materials that do not reflect infrared light. This is because the infrared light traveling from the inside of the finger 1 to the outside is reflected by the inside of the input device 2 and does not reach the surface of the finger 1 again.

Furthermore, in order to satisfy this optical condition, the finger rest 25 covers more than half of the upper part of the light source 23 on the side of the opening 30 . In this way, the imaging device 29 can take an image of the finger vein pattern without being affected by infrared light scattered at the depth where the finger veins exist (for example, infrared light scattered near the surface of the finger 1).

The reason for this will be explained below.

Fig. 4A is an explanatory diagram showing the effect of the shape of the finger rest 25 according to the first embodiment of the present invention.

In this explanatory drawing, the finger rest 25 covers more than half of the upper part of the light source 23 on the side of the opening 30 . In this way, the infrared light emitted from the light source 23 is directed to the side opposite to the opening 30 .

The finger rest 25 may be installed so that the spread of the infrared light emitted from the light source 23 does not include the imaging direction 320 . That is, the finger rest 25 is installed so that all components of the infrared light emitted from the light source 23 are directed to the side opposite to the opening 30 . The infrared light emitted from the light source 23 extends only in the range between the boundary lines 322 . The imaging direction 320 is the direction of the optical axis in which the imaging device 29 performs imaging.

In the present embodiment, the light source 23 emits light with a direction substantially parallel to the imaging direction 320 as an optical axis.

Next, the infrared light path at this time will be described.

First, infrared light emitted from the light source 23 reaches the finger 1 . At this time, part of the infrared light reaching the finger 1 is reflected by the skin surface of the finger 1 . Part of this infrared light travels inside the finger 1 .

Infrared light reflected from the skin surface of the finger 1 is blocked by the finger rest 25 and therefore does not reach the upper portion of the opening 30 .

Part 326 of the infrared light traveling inside the finger 1 is scattered before reaching the depth at which the finger vein 62 exists. In addition, a part 324 of this infrared light reaches the depth where the finger vein 62 exists, and is scattered.

The infrared light 326 scattered before reaching the depth where the finger vein 62 exists changes its direction of travel. However, very little infrared light reaches the upper portion of the opening 30 among the infrared light 326 . The reason for this is that almost all components of the infrared light traveling to the finger 1 are directed toward the side opposite to the opening 30 .

Part of the infrared light 324 scattered after reaching the depth at which the finger vein 62 exists is absorbed by the finger vein 62 . Part of this infrared light 324 reaches the upper portion of the opening 30 . In this way, the infrared light 324 reaches the upper portion of the opening 30 while retaining the finger vein pattern information.

Therefore, the imaging device 29 can capture an image of the finger vein pattern by capturing the infrared light 324 . At this time, the imaging device 29 is less affected by the infrared light 326 scattered before reaching the depth of the finger vein 62 and the infrared light reflected by the skin surface of the finger 1, and can capture an image of the finger vein pattern.

FIG. 4B is an explanatory diagram showing the effect of the shape of the finger rest 25 according to the first embodiment of the present invention.

In this explanatory drawing, the finger rest 251 is different from the finger rest 25 of this embodiment in that no light shielding member is provided above the light source 23 . By describing the path of infrared light when this finger rest 251 is used, it will be compared with the finger rest 25 of this embodiment.

At this time, the spread of the infrared light emitted from the light source 23 is the range between the boundary lines 327 , including the imaging direction 320 . That is, the infrared light emitted from the light source 23 includes a component directed toward the opening 30 .

Next, the path of the infrared light at this time will be described.

The path of the infrared light is the same as the path of the infrared light when the finger is placed on the table 25 ( FIG. 4A ), except for the path of the infrared light 326 scattered before reaching the depth where the finger vein 62 exists. For the same path as infrared light, its description is omitted.

In this explanatory drawing, the infrared light emitted from the light source 23 includes a component directed toward the opening 30 . Therefore, part of the infrared light 326 scattered before reaching the depth where the finger vein 62 exists reaches the upper portion of the opening 30 .

That is, when the finger rest 251 does not cover the upper part of the light source 23, the imaging device 29 will be affected by the scattered infrared light 326 before reaching the depth where the finger vein 62 exists when the imaging device 29 captures an image of the finger vein pattern. Therefore, the imaging device 29 cannot clearly capture an image of the finger vein pattern.

In contrast, when the finger rest 25 covers more than half of the upper half of the opening 30 side of the light source 23, the imaging device 29 is hardly affected by the scattered infrared light 326 before reaching the depth where the finger vein 62 exists, so it can clearly accurately capture images of finger vein patterns.

The input device 2 of this embodiment is a scan-type authentication device. The user moves the finger 1 in the longitudinal direction of the finger 1 while placing the finger 1 on the upper portion of the finger rest 25 . However, when the user moves the finger 1, the finger 1 will leave the finger resting platform 25. At this time, the finger resting platform 25 covers more than half of the upper part of the opening 30 side of the light source 23, and the imaging device 29 can clearly photograph the finger. An image of vein graphics.

The reason for this will be described below.

Fig. 5A is an explanatory diagram showing the effect of the shape of the finger rest 25 according to the first embodiment of the present invention.

In this explanatory drawing, the finger rest 25 covers more than half of the upper part of the light source 23 on the side of the opening 30 . In this way, the infrared light emitted from the light source 23 is directed to the side opposite to the opening 30 .

The finger rest 25 may be installed so that the spread of the infrared light emitted from the light source 23 does not include the imaging direction 320 . That is, the finger rest 25 is installed so that all components of the infrared light emitted from the light source 23 are directed to the side opposite to the opening 30 . The infrared light emitted from the light source 23 extends only in the range between the boundary lines 322 . The imaging direction 320 is the direction of the optical axis in which the imaging device 29 performs imaging.

Next, the infrared light path at this time will be described.

First, infrared light emitted from the light source 23 reaches the finger 1 . At this time, part 342 of the infrared light reaching the finger 1 is reflected by the surface of the finger 1 . A part 342 of this infrared light travels to the inside of the finger 1 .

The path of the infrared light 324 traveling inside the finger 1 is the same as the path of the infrared light described in FIG. 4A , so its description is omitted.

On the other hand, the infrared light 342 reflected by the surface of the finger 1 changes the traveling direction. However, very little infrared light reaches the upper portion of the opening 30 among the infrared light 342 . The reason for this is that the infrared light reaching the finger 1 is directed to the side opposite to the opening 30 . That is, almost all components of the infrared light 342 reflected from the surface of the finger 1 travel toward the side opposite to the opening 30 .

FIG. 5B is an explanatory diagram showing the effect of the shape of the finger rest 25 according to the first embodiment of the present invention.

In this explanatory drawing, the finger rest 251 is different from the finger rest 25 of this embodiment in that no light shielding member is provided above the light source 23 . By describing the path of infrared light when this finger rest 251 is used, it will be compared with the finger rest 25 of this embodiment.

At this time, the spread of the infrared light emitted from the light source 23 is the range between the boundary lines 327 , including the imaging direction 320 . That is, the infrared light emitted from the light source 23 includes a component directed toward the opening 30 .

Next, the path of the infrared light at this time will be described.

The path of the infrared light is the same as the path of the infrared light when the finger is placed on the table 25 ( FIG. 5A ), except for the infrared light 342 reflected by the surface of the finger 1 . For the same path as infrared light, its description is omitted.

In this explanatory drawing, the infrared light emitted from the light source 23 includes a component directed toward the opening 30 . Therefore, part of the infrared light 342 reflected from the surface of the finger 1 reaches the upper portion of the opening 30 .

That is, when the finger resting platform 251 does not cover the upper part of the light source 23, the imaging device 29 will be affected by the infrared light 342 reflected from the surface of the finger 1 when capturing the image of the finger vein pattern. Therefore, the imaging device 29 cannot clearly capture an image of the finger vein pattern.

Compared with this, when the finger resting platform 25 covers more than half of the upper part of the opening 30 side of the light source 23, the imaging device 29 is hardly affected by the infrared light 342 reflected from the surface of the finger 1, so the finger vein pattern can be captured clearly. Image.

That is, the finger rest 25 needs to cover the upper part of the light source 23 in order to avoid the spread of the infrared light emitted from the light source 23 from the opening 30 .

The upper portion of the light source 23 may not be covered, and the width of the finger rest 25 may be sufficiently widened. At this time, the input device 2 becomes larger, but the imaging device 29 can make the influence of the infrared light 326 scattered before reaching the depth where the finger vein 62 exists and the infrared light reflected by the skin surface of the finger 1 be very small, and the image of the finger vein pattern can be photographed. image.

Next, an image of a finger vein pattern captured by the imaging device 29 will be described.

FIG. 6 is an explanatory diagram of the relationship between the distance from the light source 23 and the brightness value of the image of the finger vein pattern according to the first embodiment of the present invention.

The curve shown in this explanatory drawing shows the relationship between the distance from the light source 23 and the brightness value of the image of the finger vein pattern.

First, the case where the amount of infrared light emitted by the light source 23 is not changed will be described.

When the distance from the light source 23 is short, the brightness value of the image is high. Moreover, as the distance from the light source 23 becomes farther away, the brightness value of the image decreases. At a position closer to the light source 23 , as the distance from the light source 23 gradually increases, the brightness value of the image drops sharply. On the other hand, at a position farther away from the light source 23 , even if the distance from the light source 23 gradually increases, the brightness value of the image decreases slowly.

The luminance values may be classified into any one of a high luminance area 184 , a visible area 186 or a low luminance area 188 .

When the luminance value is within the range of the high luminance area 184, the authentication processing unit 10 cannot obtain the information of the finger vein pattern from the image. The reason is that the image is already light saturated.

On the other hand, when the luminance value is within the range of the visible area 186, the authentication processing unit 10 can obtain the information of the finger vein pattern from the image.

When the luminance value is within the range of the low luminance area 188, the authentication processing unit 10 cannot obtain the finger vein pattern information from the image. The reason for this is that the light in this image is too weak.

That is, the visible area 186 is a range in which the imaging device 29 can detect the intensity of light. The high-brightness area 184 and the low-brightness area 188 are ranges where the imaging device 29 cannot detect the intensity of light.

Then, when the amount of infrared light emitted by the light source 23 is increased, the curve representing the brightness value of the image shifts to the upper right. That is, when the light intensity of the light source 23 is increased, the position of the visible area 186 is away from the light source 23 .

On the other hand, when the amount of infrared light emitted by the light source 23 is reduced, the curve representing the luminance value of the image shifts to the lower left. That is, when the light intensity of the light source 23 is reduced, the position of the visible area 186 is close to the light source 23 .

This explanatory diagram shows the luminance value of the image generated by the light source 23 on the base side of the finger 1 . The luminance value of the image generated by the light source 23 on the fingertip side is a curve in which the curve in this explanatory diagram is reversed left and right.

Then, the luminance value of the image generated by the light source 23 on the root side of the finger 1 and the light source 23 on the fingertip side becomes a curve in which these two curves are superimposed.

In the present embodiment, the width of the opening 30 is sufficiently narrower than the viewing area 186 . In this way, by adjusting the amount of infrared light emitted by the light source 23 , the entire area of the opening 30 can be included in the visible area 186 .

In addition, the light source 23 may be provided either on the root side of the finger 1 or on the fingertip side. Even in this case, since the width of the opening 30 is sufficiently narrower than the visible area 186 , the entire area of the opening 30 can be included in the visible area 186 . On the side without the light source 23, the finger rest 25 may or may not be provided.

However, by disposing the finger rest 25 also on the side where there is no light source, deviation in movement of the finger 1 can be suppressed. On the other hand, the input device 2 can be further miniaturized by omitting the finger rest 25 and the light source 23 on either the root side or the fingertip side of the finger 1 .

When the width of the opening 30 cannot be included in the visible area 186, the amount of infrared light emitted from the light source 23 is continuously changed. The imaging device 29 then captures images in each light amount, respectively. The authentication processing unit 10 obtains an overall image of the width of the opening 30 by combining these images captured by the imaging device 29 .

FIG. 7 is a flowchart of authentication processing by the authentication processing unit 10 according to the first embodiment of the present invention.

First, the authentication processing unit 10 performs finger detection processing (S100), and determines whether or not the finger 1 is placed on the finger rest 25 (S110).

For example, whether or not the finger 1 is placed on the finger rest 25 is determined by using information output from a contact sensor, a temperature sensor, a resistance sensor, a dielectric constant sensor, and the like. In addition, it may be determined whether or not the finger 1 is placed on the finger rest 25 using an image captured by the imaging device 29 .

Next, the case of using the image captured by the imaging device 29 will be specifically described. In this case, since no sensor is required, an authentication system can be constructed at low cost.

At this time, the light source 23 is turned on at a constant cycle. The imaging device 29 captures images at a cycle shorter than the cycle in which the light source 23 is turned on. Then, the imaging device 29 sends the captured image to the authentication processing unit 10 .

First, the authentication processing unit 10 receives an image from the imaging device 29 . Then, the luminance value of the received image is obtained. Then, by comparing the luminance values of successively received images, the amount of change in the luminance value of the images is calculated. Then, it is judged whether or not the finger 1 is placed on the finger rest 25 based on the obtained change amount of the luminance value of the image.

Specifically, when the amount of change in the brightness value of the image is smaller than the threshold, it is determined that the finger 1 is not placed on the finger rest 25 . This is because the infrared light emitted from the light source 23 does not reach the imaging device 29 when the finger 1 is not placed on the finger rest 25 .

On the other hand, when the amount of change in the luminance value of the image is equal to or greater than the threshold value, it is determined that the finger 1 is placed on the finger rest 25 . This is because when the finger 1 is placed on the finger rest 25 , the infrared light emitted from the light source 23 scatters inside the finger 1 and reaches the imaging device 29 .

When it is judged that the finger 1 is not placed on the finger rest 25, since authentication processing is unnecessary, the process returns to step S100.

On the other hand, when it is judged that the finger 1 is placed on the finger rest 25, light amount control processing is performed (S120).

Specifically, the light intensity of the light source 23 is controlled so that the brightness value of the image captured by the imaging device 29 approaches the target value. The target value is the luminance value at which the difference in contrast between the vein portion and other tissue portions is the largest. The target value is a fixed value regardless of the shape and thickness of the finger.

Next, a case where the authentication processing unit 10 separately controls the light source 23 on the fingertip side and the light source 23 on the base side of the finger 1 will be described.

The authentication processing unit 10 receives an image from the imaging device 29 . Then, the average luminance value of the half surface on the fingertip side of the received image and the average luminance value of the half surface on the root side of the finger 1 of the image are obtained.

Then, the light intensity of the light source 23 is controlled based on the obtained average luminance value. Specifically, the light intensity of the light source 23 on the fingertip side is controlled so that the average luminance value on the opposite side of the fingertip side approaches the target value. In addition, the light intensity of the light source 23 on the side of the base of the finger is controlled so that the average luminance value on the back side of the base of the finger approaches the target value.

The authentication processing unit 10 increases or decreases the light intensity of the light source 23 while feeding back the luminance value of the image, so that the luminance value approaches the target value. At this time, the value for increasing or decreasing the light quantity of the light source 23 may be a fixed value or may be changed according to the state of convergence. In addition, the authentication processing unit 10 may estimate the amount of light that brings the luminance value of the image closer to the target value based on the characteristics of the imaging device 29 , and cause the light source 23 to emit the estimated amount of light.

Next, feature extraction processing is performed (S130). The feature extraction process will be described later with reference to FIGS. 8A , 8B, and 8C, and feature data is extracted from an image captured by the imaging device 29 .

Then, feature data bonding processing is performed (S140). The feature data matching process will be described later with reference to FIG. 9 , and the extracted feature data is combined with past feature data.

Then, it is judged whether or not the size of the bonded feature data is greater than or equal to a threshold (S150). This threshold is the size of feature data required for comparison.

Specifically, in the feature data pasting process (S140), the movement amount of the finger 1 can be obtained. Then, based on the calculated movement amount of the finger 1, it is judged whether or not the size of the feature data is equal to or greater than a threshold value.

When the size of the characteristic data is smaller than the threshold value, since the characteristic matching process is not performed, it returns to step 120 .

On the other hand, when the size of the feature data is equal to or larger than the threshold value, feature comparison processing is performed (S160).

In step S150, it may also be determined whether the moving speed of the finger 1 is slower than a threshold. At this time, when the size of the feature data is equal to or greater than the threshold and the moving speed of the finger 1 is slower than the threshold, feature matching processing is performed (S160).

Since the length of the finger varies, the movement amount of the finger varies, so even if the size of the feature data exceeds the threshold value, it is sometimes possible to move the finger 1. At this time, the extraction of characteristic data continues until the finger 1 stops or immediately before it stops. Then, when the feature data is acquired up to the maximum size, the feature collation process is started (S160). In this way, the recognition rate can be further improved.

Specifically, the feature data bonded in step S140 is compared with the authentication data stored in the storage device 14 .

For example, the degree of similarity between feature data and authentication data is calculated. And, when the calculated similarity is equal to or greater than the threshold, the person corresponding to the authentication data is authenticated.

Then, the authentication processing ends.

The feature data combined by the feature data combining process (S140) may be distorted. At this time, the authentication processing unit 10 performs feature matching processing using a matching method that takes distortion into account (S160).

The collation method that takes distortion into account includes the method of enlarging or reducing the image while comparing it, the method of dividing the image into multiples, and comprehensively judging the results of the independent collation in each area, etc. In the method of comparing images while enlarging or reducing them, the distortion in the moving direction of the finger 1 is appropriately compensated by increasing the stretch rate in the longitudinal direction of the finger 1 .

Next, the feature extraction process (S130) of the authentication processing unit 10 will be described.

FIG. 8A is an explanatory diagram of a finger vein 62 captured by the imaging device 29 according to the first embodiment of the present invention.

The finger veins 62 are distributed over the entire area of the finger 1 . The imaging device 29 images the finger 1 presented through the opening 30 . That is, the imaging device 29 images the finger veins 62 included in the range of the opening 30 .

FIG. 8B is an explanatory diagram of an image 64 captured by the imaging device 29 according to the first embodiment of the present invention.

The image 64 is an image captured by the imaging device 29 . In the image 64 , the finger 1 and the finger vein 62 included in the range of the opening 30 are reflected.

The authentication processing unit 10 extracts the range of the opening 30 from the image 64 captured by the imaging device 29 .

The range of the opening 30 may be set in advance, or may be automatically determined by the authentication processing unit 10 .

Here, a method in which the authentication processing unit 10 automatically measures the range of the opening 30 will be described.

The authentication processing unit 10 judges the range of the opening 30 from the brightness difference on the image captured by the imaging device 29 . This image is taken in a state where the light source 23 emits light and the finger 1 is placed on the finger rest 25 .

Then, the authentication processing unit 10 extracts an image of a finger vein pattern from the extracted image of the area around the opening 30 .

Specifically, a general image processing method is used to extract an image of a vein pattern. Common image processing methods include a method of tracing dark lines, a method of emphasizing line patterns using filters, or a method of extracting line patterns based on the curvature of the brightness profile curve of an image.

The authentication processing unit 10 may extract an image of a finger vein pattern after performing a finger contour detection process on the extracted image in the range of the opening 30 . The finger outline detection process detects the outline of the finger 1 by distinguishing the finger area from other areas. The authentication processing unit 10 can extract an image of a finger outline pattern with high precision by performing a finger outline detection process in advance.

Specifically, a general image processing method is used to detect the outline of the finger 1 . A general image processing method is edge emphasis processing, contour tracking processing, or the like.

For example, the authentication processing unit 10 controls turning on and off of the light source 23 . At this time, the imaging device 29 captures an image when the light source 23 is turned on and an image when the light source 23 is turned off, and inputs the image to the authentication processing unit 10 .

The authentication processing unit 10 obtains each luminance value from the input image when the light source 23 is turned on and the image when the light source is turned off. Then, a region having a large difference between the luminance value of the image when the light source 23 is turned on and the luminance value when the light source 23 is turned off is detected as the finger region. In this way, the authentication processing unit 10 can stably detect the outline of the finger 1 by comparing the image when the light source 23 is turned on and the image when the light source 23 is turned off.

In addition, the outline of the finger 1 can also be detected by the following method. The imaging device 29 captures an image of a state in which the light intensity of the light source 23 on one side of the finger 1 is high and the light intensity on the opposite side is weak. Then, the imaging device 29 captures an image in which the intensity of the light intensity of the light source 23 is switched. The imaging device 29 inputs these captured images to the authentication processing unit 10 .

The authentication processing unit 10 detects, as a finger area, a region having a large difference in luminance value between the input images.

Next, the authentication processing unit 10 converts the image of the extracted finger vein pattern into characteristic data.

FIG. 8C is an explanatory diagram of characteristic data 66 converted by the authentication processing unit 10 according to the first embodiment of the present invention.

The feature data 66 is information used for collation with collation data stored in the storage device 14 .

The feature data 66 represents the correspondence relationship between the position (x coordinate) on the image and the brightness value. The x-axis is a direction substantially perpendicular to the longitudinal direction of the finger 1 . The feature data 66 of this explanatory diagram is data about the area 65 on the image 64 ( FIG. 8B ).

The feature data 66 has a plurality of minima 68 . The minimum point 68 is the location of the finger vein. The reason for this is that the blood in the finger vein absorbs the infrared light emitted from the light source 23 .

In addition, the feature data may be an image of a finger vein pattern used in template matching, or may be structural information of a line segment. The structure information of the line segment includes the information of the branch point and the end point of the finger vein, which is information about the abstraction of the finger vein information.

Next, the characteristic data pasting process (S140) of the authentication processing unit 10 will be described.

FIG. 9 is an explanatory diagram of the characteristic data pasting process (S140) of the authentication processing unit 10 according to the first embodiment of the present invention.

In this explanatory diagram, the feature data will be described using an image of a finger vein pattern used in template matching as an example. The same applies even if the feature data is other information including line segment structure information and the like.

The authentication processing unit 10 pastes the feature data extracted by the feature extraction process (S130). Here, a case where the authentication processing unit 10 pastes the feature data 80 extracted from the image 64 of frame N to the feature data 82 extracted from the images of frame 1 to frame N−1 will be described. Here, frame N represents the sequence number of the image captured by the imaging device 29 . The first image captured by the imaging device 29 of the finger 1 is defined as frame 1 .

First, the authentication processing unit 10 superimposes the feature data 82 extracted from the image before the frame N−1 while shifting the position of the feature data 80 extracted from the image 64 of the frame N.

Then, the authentication processing unit 10 obtains the coincidence between the feature data 80 of the frame N and the feature data 82 before the frame N−1 at each position of the movement feature data 80 . Then, the amount of deviation of the finger 1 is calculated based on the consistency of the obtained feature data. The position shifted by the amount of deviation from the position of frame N−1 is defined as the position of feature data 80 extracted from image 64 of frame N.

The deviation amount of the finger 1 can also be obtained by using a method of observing the surface texture of the finger 1 or a method of observing the contour of the finger 1 . By using such a method in combination, the amount of deviation of the finger 1 can be obtained with high precision.

Here, the authentication processing unit 10 stores the coordinates 92 of the upper left end of the position 88 pasted with the feature data before the frame N−1. The authentication processing unit 10 moves the position of the characteristic data 80 of the frame N so that the coordinate 90 of the upper left end of the position of the characteristic data 80 of the frame N falls within a predetermined range centered on the coordinate 92 .

At this time, since the authentication processing unit 10 limits the position of the movement characteristic data 80, the burden of calculating the deviation amount of the finger 1 can be reduced.

The image of frame N and the image of frame N−1 are continuously captured images without a large change in position. Therefore, even if the authentication processing unit 10 limits the location of the movement characteristic data 80, no problem will arise.

When the position of the characteristic data 80 of frame N is determined, the authentication processing unit 10 pastes the characteristic data 80 of frame N and the characteristic data 82 before frame N−1.

Specifically, the feature data 80 of the frame N and the feature data 82 before the frame N−1 are pasted using a general image bonding method. The general image bonding method is a method of covering characteristic patterns, a method of taking the average value of characteristic patterns, or a method of taking multiple characteristic patterns, etc.

As described above, the authentication processing unit 10 can acquire the vein pattern of the entire finger 1 by performing the bonding process (S140).

(second embodiment)

In the second embodiment of the present invention, the input device 2 includes a reflective light source.

The configuration of the authentication system according to the second embodiment of the present invention is the same as that of the authentication system ( FIG. 1 ) according to the first embodiment except for the input device 2 . In addition, the processing of the authentication system of the second embodiment of the present invention is the same as that of the authentication system of the first embodiment (FIG. 7, etc.). The description of the same configuration and processing is omitted.

Fig. 10 is a side view of the input device 2 according to the second embodiment of the present invention.

The input device 2 of the second embodiment has a reflective light source 102 . Other configurations are the same as those of the input device ( FIGS. 3A , 3B, and 3C ) of the first embodiment. The same components are given the same reference numerals, and their descriptions are omitted.

In this explanatory drawing, the reflective light source 102 is provided near the imaging device 29 inside the input device 2 . In addition, the reflective light source 102 is provided in a direction facing the opening 30 . In this way, the reflective light source 102 irradiates the imaged portion of the finger 1 with infrared light.

The reflective light source 102 may be installed anywhere inside the input device 2 as long as it can irradiate infrared light to the imaged portion of the finger 1 . In addition, a plurality of reflective light sources 102 may be provided inside the input device 2 .

When the reflected light source 102 irradiates the imaged part of the finger 1 , the imaging device 29 takes an image of the infrared light reflected by the surface skin of the finger 1 . That is, the imaging device 29 can capture an image of the surface of the finger 1 .

The authentication processing unit 10 can use an image of the surface of the finger 1 captured by the imaging device 29 to acquire various information.

For example, the authentication processing unit 10 obtains the reflectance of an object presented on the finger rest 25 from an image captured by the imaging device 29 . Then, based on the obtained reflectance, it can be judged whether or not the presented object is the finger 1 .

In addition, the authentication processing unit 10 can extract information on the surface texture of the finger 1 from the image captured by the imaging device 29 . Then, the movement amount of the finger 1 can be obtained from the extracted texture information.

When the light source 23 is turned off and the reflective light source 102 is turned on, the camera 29 takes an image of the surface of the finger 1 . And when the light source 23 is turned on and the reflective light source 102 is turned off, the imaging device 29 takes an image of the finger vein pattern.

The input device 2 of this embodiment is a scanning finger vein authentication device. In this way, the finger 1 moves on the finger rest 25 .

In this way, the authentication processing unit 10 turns on the reflective light source 102 and the light source 23 alternately. Then, the imaging device 29 images the finger 1 in accordance with the timing (timing: timing) of turning on the reflective light source 102 and the light source 23 . In this way, the imaging device 29 can alternately capture the image of the surface of the finger 1 and the image of the finger vein pattern.

The reflected light source 102 can also be used in the finger detection process (step S100 of FIG. 7 ). At this time, the reflective light source 102 is turned on at a certain period. On the other hand, the imaging device 29 captures an image at a cycle shorter than the cycle at which the reflective light source 102 is turned on. Then, the imaging device 29 inputs the captured image to the authentication processing unit 10 .

The authentication processing unit 10 obtains the brightness value of the input image. Then, by comparing the luminance values of successively received images, the amount of change in the luminance value of the images is obtained. Then, it is judged whether or not the finger 1 is placed on the finger rest 25 based on the obtained change amount of the luminance value of the image.

Specifically, when the amount of change in the brightness value of the image is smaller than the threshold, it is determined that the finger 1 is not placed on the finger rest 25 .

On the other hand, when the amount of change in the luminance value of the image is equal to or greater than the threshold value, it is determined that the finger 1 is placed on the finger rest 25 .

As described above, the authentication processing unit 10 can perform finger detection processing (step S100 in FIG. 7 ) using the reflected light source 102 .

In the authentication system of the present embodiment, power consumption can be reduced by performing finger detection processing using reflection light source 102 instead of light source 23 . This is because the authentication processing unit 10 can detect the finger by irradiating the finger 1 with infrared light weaker than the light source 23 by the reflective light source 102 .

(third embodiment)

In the third embodiment of the present invention, the light source 23 is installed obliquely.

The configuration of the authentication system according to the third embodiment of the present invention is the same as that of the authentication system ( FIG. 1 ) according to the first embodiment except for the input device 2 . In addition, the processing of the authentication system of the third embodiment of the present invention is the same as that of the authentication system of the first embodiment (FIG. 7, etc.). The description of the same configuration and processing is omitted.

Fig. 11A is a plan view of an input device 2 according to a third embodiment of the present invention. FIG. 11B is an explanatory diagram of the light source 23 of the input device 2 according to the third embodiment of the present invention. Fig. 11C is a front view of the input device 2 according to the third embodiment of the present invention.

The configuration of the input device 2 of the third embodiment is the same as that of the input device of the first embodiment ( FIGS. 3A , 3B, and 3C ), except for the light source 23 and the finger rest 25 . The same components are given the same reference numerals, and their descriptions are omitted.

The light source 23 has expansibility (directivity) and emits infrared light. In addition, the light source 23 is obliquely provided on the opposite side of the opening 30 .

For example, the light source 23 is installed at an inclination of 60 degrees from the imaging direction 320 of the imaging device 29 . That is, the light source 23 emits light with the direction inclined by 60 degrees from the imaging direction 320 of the imaging device 29 as the optical axis 231 . The imaging direction 320 is the direction of the optical axis in which the imaging device 29 performs imaging. In this way, the infrared light emitted from the light source 23 is directed to the side opposite to the opening 30 .

The finger rest 25 is arranged so that the spread of the infrared light emitted from the light source 23 does not include the imaging direction. That is, the finger rest 25 is set so that all components of the infrared light emitted from the light source 23 face the opposite side of the opening 30 , and the spread of the infrared light emitted from the light source 23 is the range between the boundary lines 322 .

The finger rest 25 of this embodiment may not cover the upper half of the light source 23 . The reason for this is that the light source 23 is inclined to the imaging direction. In addition, depending on how the infrared light emitted from the light source 23 spreads, the finger rest 25 may not cover the upper part of the light source 23 .

In the present embodiment, the infrared light emitted from the light source 23 enters the finger 1 at a position farther from the opening 30 than in the first embodiment. In this way, the images captured by the camera 29 also have the advantage of uniform brightness values.

(fourth embodiment)

In the fourth embodiment of the present invention, the finger rest 25 has a recess.

The configuration of the authentication system according to the fourth embodiment of the present invention is the same as that of the authentication system ( FIG. 1 ) according to the first embodiment except for the input device 2 . In addition, the processing of the authentication system of the fourth embodiment of the present invention is the same as that of the authentication system of the first embodiment (FIG. 7, etc.). The description of the same configuration and processing is omitted.

Fig. 12 is a front view of an input device 2 according to a fourth embodiment of the present invention.

The configuration of the input device 2 of the fourth embodiment is the same as that of the input device ( FIGS. 3A , 3B, and 3C ) of the first embodiment except for the finger rest 25 . The same components are given the same reference numerals, and their descriptions are omitted.

The finger resting platform 25 has a depression 142 on the surface contacting with the finger 1 . The depression 142 extends in the length direction of the finger 1 . Since the depression 142 does not press the finger 1, the blood flow inside the finger 1 is smoothed.

The user moves the finger 1 while pressing the finger 1 with more than necessary pressure on the finger rest 25 . At this time, if the finger rest 25 does not have the recess 142, the blood does not flow due to the pressure on the finger rest 25, and the blood on the imaged surface of the finger 1 is exhausted. Therefore, in the images captured by the imaging device 29, the finger vein patterns are not clear.

On the other hand, when the finger rest 25 has a depression 142, the blood flows in the depression 142, so that even if the user presses the finger 1 with more than necessary pressure on the finger rest 25, the imaging device 29 can clearly capture the finger vein pattern. Image.

(fifth embodiment)

In the fifth embodiment of the present invention, a finger rest and a light shielding member are provided separately.

The configuration of the authentication system according to the fifth embodiment of the present invention is the same as that of the authentication system ( FIG. 1 ) according to the first embodiment except for the input device 2 . In addition, the processing of the authentication system of the fifth embodiment of the present invention is the same as that of the authentication system of the first embodiment (FIG. 7, etc.). The description of the same configuration and processing is omitted.

Fig. 13 is a side view of an input device 2 according to a fifth embodiment of the present invention.

The configuration of the input device 2 of the fifth embodiment is the same as that of the input device of the first embodiment ( FIGS. 3A , 3B, and 3C ), except for the light shielding member 22 and the finger rest 28 . The same components are given the same reference numerals, and their descriptions are omitted.

The input device 2 is provided with a light shielding member 22 and a finger rest 28 instead of the finger rest 25 of the first embodiment.

Since the finger rest 25 of the first embodiment is made of a material opaque to infrared light, it also functions as a light shielding member.

In the present embodiment, the light shielding member 22 is provided between the light source 23 and the opening 30 . The light shielding member 22 is a material opaque to infrared light.

The finger rest 28 is provided on the opposite side of the opening 30 with respect to the light source 23 . The finger rest 28 is a stand on which the finger 1 is placed during authentication. At this time, the finger rest 28 may be made of a material transparent to infrared light or an opaque material.

(sixth embodiment)

In the sixth embodiment of the present invention, authentication is performed without moving the finger 1 .

The configuration of the authentication system according to the sixth embodiment of the present invention is the same as that of the authentication system ( FIG. 1 ) according to the first embodiment except for the configuration of the input device 2 . Descriptions of the same configurations are omitted.

Fig. 14 is a side view of an input device 2 according to a sixth embodiment of the present invention.

The configuration of the input device 2 of the sixth embodiment is the same as that of the input device of the first embodiment ( FIGS. 3A , 3B, and 3C ), except for the size of the opening 30 . The same components are given the same reference numerals, and their descriptions are omitted.

Two finger rests 25 are provided on both sides of the opening 30 . The opening 30 is wider in the longitudinal direction of the finger 1 than the opening of the first embodiment ( FIG. 3A ). The opening 30 has a width enough that the imaging device 29 can capture an image of a finger vein pattern required for authentication.

In the authentication system of the sixth embodiment, since the opening 30 has a wide width, it is not necessary for the user to move the finger 1 . Therefore, the user can authenticate only by placing the finger 1 on the finger rest 25 .

Next, the light amount control processing of this embodiment will be described.

FIG. 15 is an explanatory diagram of the relationship between the distance from the light source 23 and the brightness value of the image of the finger vein pattern according to the sixth embodiment of the present invention.

The curve shown in this explanatory drawing shows the relationship between the distance from the light source 23 and the brightness value of the image of the finger vein pattern. This curve is for the case where the light source 23 exists on the fingertip side and the root side of the finger 1 . Therefore, this curve is synthesized by inverting the curve ( FIG. 6 ) when the light source 23 exists only on one side.

The luminance values can be classified into any one of high luminance area 184 , visible area 186 or low luminance area 188 .

When the luminance value is within the range of the high luminance area 184, the authentication processing unit 10 cannot obtain the information of the finger vein pattern from the image. The reason is that the image is already light saturated. On the other hand, when the luminance value is within the range of the visible area 186, the authentication processing unit 10 can obtain the information of the finger vein pattern from the image. When the luminance value is within the range of the low luminance area 188, the authentication processing unit 10 cannot obtain the finger vein pattern information from the image. The reason for this is that the light in this image is too weak.

In the input device 2 of the present embodiment, the width of the opening 30 is wide. Therefore, the authentication processing unit 10 sometimes adjusts the light intensity of the light sources 23 on both sides. Also, the entire area of the opening 30 cannot be included in the viewing area 186 .

At this time, the authentication processing unit 10 changes the light intensity of the light source 23 on the base side of the finger 1 and the light intensity of the light source 23 on the fingertip side in time sequence. At this time, the imaging device 29 captures images at each light intensity. A part of the captured image becomes the optimum brightness. Then, the authentication processing unit 10 synthesizes the images captured by the imaging device 29 to obtain an image with the overall optimum brightness.

Hereinafter, specific processing will be described.

First, the authentication processing unit 10 increases the light intensity of the light source 23 on the base side of the finger 1 and decreases the light intensity of the light source 23 on the fingertip side.

In this state, the imaging device 29 captures an image. This image becomes the luminance value of the curve shown in (A) of FIG. 15 . Thus, the image becomes as shown in Fig. 16A.

16A is an explanatory diagram of an image captured when the light source 23 on the base side of the finger 1 is strong according to the sixth embodiment of the present invention.

When the light source 23 on the root side of the finger 1 is strong, the image taken by the camera 29 is the best brightness in the area above the half surface of the fingertip side. However, the image is completely saturated with light on a part on the root side of the finger 1 .

Therefore, the authentication processing unit 10 reduces the light intensity of the light source 23 on the base side of the finger 1 and increases the light intensity of the light source 23 on the fingertip side.

In this state, the imaging device 29 captures an image. This image becomes the brightness value of the curve shown in Fig. 15B. Thus, the image becomes as shown in Fig. 16B.

FIG. 16B is an explanatory diagram of an image captured when the light source 23 on the fingertip side is strong according to the sixth embodiment of the present invention.

When the hand tip side light source 23 is strong, the image taken by the camera 29 is the best brightness in the area above the half surface of the finger 1 root side. But the image is fully saturated with light on a portion on the fingertip side.

The authentication processing unit 10 synthesizes these two images ( FIGS. 16A and 16B ) captured by the imaging device 29 .

Fig. 16C is an explanatory diagram of images synthesized by the authentication processing unit 10 according to the sixth embodiment of the present invention.

The authentication processing unit 10 synthesizes the image with the best luminance in the area above the half surface of the fingertip ( FIG. 16A ) and the image with the best luminance in the area above the half surface of the base of the finger ( FIG. 16B ). In this way, the authentication processing unit 10 obtains an image with optimum brightness in the entire area of the explanatory diagram.

In addition, the authentication processing unit 10 may obtain an image with optimum brightness in the entire area by synthesizing two or more images.

At this time, the authentication processing unit 10 gradually increases the light intensity of one light source 23 and gradually decreases the light intensity of the other light source 23 . The imaging device 29 captures images under each light intensity. In this image, slowly move the area of optimum brightness. Then, the authentication processing unit 10 synthesizes the images captured by the imaging device 29 to obtain an image with the overall optimum brightness.

The imaging device 29 of the authentication system according to the sixth embodiment captures an image of the entire finger 1 . Therefore, since the authentication processing unit 10 performs tilt compensation and background removal of the finger 1 , it is necessary to detect the contour of the finger 1 .

The authentication processing unit 10 detects the outline of the finger 1 using a general image processing method. A general image processing method is edge emphasis processing, contour tracking processing, or the like.

In addition, the authentication processing unit 10 may detect the outline of the finger 1 by comparing a plurality of images.

Specifically, the authentication processing unit 10 compares the image in which the light intensity of the light source 23 is enhanced with the image in which the light source 23 is turned off, and detects a region with a large change in luminance value as the finger region. In this way, the authentication processing unit 10 can stably detect the outline of the finger 1 .

The authentication system according to the sixth embodiment can stably obtain a clear finger vein pattern even if the finger 1 is placed on the finger rest 25 in a bent state. This is because even in this case, the principle that the infrared light emitted from the light source 23 scatters inside the finger 1 and travels outside does not change.

However, when the finger 1 is placed on the finger rest 25 in a bent state, the authentication processing unit 10 calculates the distance between the finger and the device based on the detected contour of the finger 1 . Then, the authentication processing unit 10 corrects the magnification using the calculated distance between the finger and the device. In this way, the authentication processing unit 10 can perform the matching process while reducing the influence of bending of the finger 1 . That is, since the finger 1 is allowed to bend to some extent, the user's convenience can be improved.

In addition, the authentication system according to the sixth embodiment can acquire the finger vein pattern even when the finger 1 is not in contact with the finger rest 25 . The reason for this is the same as the reason why a clear finger vein pattern can be obtained when the finger 1 is separated in the first embodiment (FIG. 5A and FIG. 5B).

That is, in the authentication system according to the sixth embodiment, the user can authenticate without touching the finger 1 to the finger rest 25 . In this way, the user's psychological resistance to contact can be alleviated.

The sixth embodiment can also be applied to the second to fifth embodiments by widening the width of the opening 30 .

(seventh embodiment)

In the seventh embodiment of the present invention, an authentication system is installed in a portable information terminal.

FIG. 17A is an explanatory diagram of a portable information terminal 242 according to a seventh embodiment of the present invention.

The information portable terminal 242 is equipped with an authentication system. One of the authentication systems of the first to sixth embodiments may be installed in the portable information terminal 242 .

In addition, the input device 2 of the authentication system, the finger rest 25 is provided to appear on the surface of the information portable terminal 242 . The input device 2 may also be provided on the side of the information portable terminal 242 .

The configuration of the authentication system mounted on the information portable terminal 242 is the same as that of the authentication system ( FIG. 1 ) of the first embodiment except for the input device 2 . In addition, the processing of the authentication system installed in the portable information terminal 242 is the same as that of the authentication system (FIG. 7, etc.) of the first embodiment. The description of the same configuration and processing is omitted.

17B is a side view of the input device 2 mounted on the portable information terminal 242 according to the seventh embodiment of the present invention.

The input device 2 is the same as the input device ( FIG. 3A , FIG. 3B , and FIG. 3C ) of the first embodiment except that it has the light source light window 43 . The same components are given the same reference numerals, and their descriptions are omitted.

The light source light window 43 is provided on the same plane as the surface of the information portable terminal 242 . In addition, the light source light window 43 covers the upper part of the light source 23 and the upper part of the opening part 30, and the light source light window 43 is made of a material transparent to infrared light.

The finger resting platform 25 can be either a curved concave shape or a flat shape. When the finger resting platform 25 is in the shape of a plane, the display position of the finger 1 can be printed on the surface, or the surface can be made of different materials that touch the skin. In this way, the user can grasp the presentation position and movement direction of the finger 1 .

(eighth embodiment)

In an eighth embodiment of the present invention, an authentication system is installed in a portable information terminal.

FIG. 18A is an explanatory diagram of a portable information terminal 242 according to an eighth embodiment of the present invention.

The information portable terminal 242 is equipped with an authentication system. Any one of the authentication systems of the first to sixth embodiments may be installed on the information portable terminal 242 .

In addition, the input device 2 of the authentication system is installed on the side of the information portable terminal 242 in a state where it can be drawn out. This explanatory diagram shows the information portable terminal 242 in a state where the input device 2 is pulled out. Furthermore, the input device 2 is moved to the left by software control or physical control. In this way, the input device 2 can be accommodated inside the portable information terminal 242 .

In this way, the authentication system can be mounted on the portable information terminal 242 even when the input device 2 of the authentication system cannot be installed on the surface.

The configuration of the authentication system mounted on the information portable terminal 242 is the same as that of the authentication system ( FIG. 1 ) of the first embodiment except for the input device 2 . In addition, the processing of the authentication system installed in the portable information terminal 242 is the same as that of the authentication system (FIG. 7, etc.) of the first embodiment. The description of the same configuration and processing is omitted.

18B is a front view of the input device mounted on the portable information terminal 242 according to the eighth embodiment of the present invention.

The configuration of the input device 2 is the same as that of the input device of the first embodiment (FIG. 3A, FIG. 3B, and FIG. 3C) except for the point that it has the reflector 302, the position of the infrared transmission filter 27, and the position of the imaging device 29. . The same components are given the same reference numerals, and their descriptions are omitted.

A reflection unit 302 is provided inside the input device 2 . The reflection part 302 is, for example, a prism or an optical fiber, and is used to change the traveling route of the infrared light.

In addition, inside the portable information terminal 242 , the imaging device 29 is installed facing the direction of the reflection part 302 . The infrared transmission filter 27 is provided between the imaging device 29 and the reflection part 302 .

The imaging device 29 captures infrared light passing through the opening 30 , the reflective unit 302 , and the infrared transmission filter from the outside of the input device 2 . That is, the imaging device 29 captures an image of the infrared light whose travel route has been changed by the reflection unit 302 .

(ninth embodiment)

In a ninth embodiment of the present invention, an authentication system is mounted on a door handle.

Fig. 19A is an explanatory diagram of a handle 264 of a door 262 according to a ninth embodiment of the present invention. 19B is a side view of the input device 2 attached to the handle 264 of the door 262 according to the ninth embodiment of the present invention.

The handle 264 of the door 262 is fitted with an authentication system. Any one of the authentication systems of the first to sixth embodiments may be attached to the handle 264 .

That is, the handle 264 is provided with the input device 2 , the authentication processing unit 10 , and the communication cable 268 . The communication cable 268 connects the input device 2 and the authentication processing unit 10 .

The configuration of the authentication system attached to the handle 264 is the same as that of the authentication system ( FIG. 1 ) of the first embodiment. In addition, the processing of the authentication system mounted on the handle 264 is the same as that of the authentication system (FIG. 7, etc.) of the first embodiment. The description of the same configuration and processing is omitted.

The user holds the handle 264 when opening the door 262 . At this time, the input device 2 attached to the handle 264 acquires an image of the finger vein pattern, and sends the acquired image to the authentication processing unit 10 .

The authentication processing unit 10 performs authentication processing on the image received from the input device 2 , and when the image matches the authentication data stored in the storage device 14 , the authentication processing unit 10 unlocks the door.

In this way, the user only needs to operate by pulling the handle 264 .

The authentication system according to the present embodiment can improve the user's convenience because authentication can be performed by the user's natural actions.

The authentication system of this embodiment may be mounted on a mobile phone, a steering wheel of a car, a handlebar of a motorcycle, etc., like the handle of the door 262 . The authentication system can be authenticated by the natural movement of the user by installing it on the part held by the user.

In addition, when the user holds the part, the authentication system ends the authentication, so the user's next action can be assisted by using the authentication result.

For example, when the authentication system completes the authentication, it performs an operation of assisting the user to open the door 262 . Specifically, the authentication system can not only make the handle 264 tilt automatically, but also make the door 262 open automatically, and can also control the door 262 to be opened with a small force.

Through the above steps, the authentication system not only authenticates the user, but also assists the user's actions.

(tenth embodiment)

The tenth embodiment of the present invention is applied to a probe-type authentication device.

Fig. 20A is a probe-type authentication device according to a tenth embodiment of the present invention. Fig. 20B is a side view of the input device 2 used in the probe type authentication device according to the tenth embodiment of the present invention.

The probe-type authentication device performs authentication by touching the probe 282 to a part of the body.

Detector 282 is equipped with an authentication system. Any one of the authentication systems of the first to sixth embodiments may be attached to the probe 282 .

The configuration of the authentication system mounted on the probe 282 is the same as that of the authentication system ( FIG. 1 ) of the first embodiment. In addition, the processing of the authentication system mounted on the probe 282 is the same as that of the authentication system (FIG. 7, etc.) of the first embodiment. The description of the same configuration and processing is omitted.

By touching the probe 282 to a part of the body, the authentication system takes an image of the vein pattern of the part. A part of the body includes fingers (palm side, side of the back of the hand, side, fingertips, etc.), palm, back of the hand, wrist, arm, foot, face, ear or cheek, etc., and can also be anywhere on the body.

In the probe-type authentication device, vein patterns at arbitrary locations can be used for personal authentication. Therefore, in the probe-type authentication device, since the information on the body part registered in the authentication system in advance is also a password, the security can be enhanced.

In addition, the probe-type authentication device can also compare vein patterns after judging the identity of body parts.

Specifically, the probe-type authentication device stores body position information corresponding to registered authentication data. Then, the probe-type authentication device specifies the body part to be imaged by the imaging device 29 at the time of authentication.

For example, in a probe-type authentication device, body parts may be input from the input unit 16 for each user. In addition, feature quantities may be calculated from images captured by the imaging device 29, and body parts may be specified based on the calculated feature quantities. In addition, general image processing may be applied to the image around the part captured by the imaging device 29 to specify the part of the body.

Moreover, the probe-type authentication device, only when the determined body part is consistent with the registered body position information, does the comparison of the pattern of the vein, that is, the probe-type authentication device compares the identified body part with the registered body position information. When the position information is different, no matching process is performed.

In this way, the probe-type authentication device can prevent authentication errors caused by comparing vein patterns of different parts, so the accuracy of authentication can be improved.

In Embodiment 1 or 6 of the present application described above, a combination with any of Embodiments 2 to 5 is of course also within the scope of the disclosure of the present application. In addition, Embodiments 7 to 10 may be used in combination as appropriate within a range not inconsistent with the configurations of Embodiments 1 to 6.

(industrial utilization possibility)

The present invention can be used in personal authentication devices installed in PCs, portable terminals, ATMs, automobiles, or room entry and exit management.

Claims (11)

1. A vein authentication device, characterized in that, An interface for placing a living body to be photographed, a light source emitting infrared light, an imaging unit for capturing an image of a blood vessel of the living body with light from the light source, and an image calculation for processing the blood vessel image captured by the imaging unit department; The interface is provided with an opening opening in an imaging direction of the imaging unit; The light source irradiates the living body with infrared light from the imaging side of the living body; A light-shielding member is provided for shielding at least light that travels in a direction intersecting with the imaging direction among the infrared light radiated from the light source so that the infrared light radiated from the light source does not go toward the imaging direction. ; On the side surface of the opening, between the opening and the light source, the light shielding member is provided along the imaging direction, and the light shielding member has a shape covering more than half of an upper portion of the light source on the opening side, Or it has a shape which covers a part of the opening side upper part of the said light source, when the said light source is inclined with respect to an imaging direction. 2. The vein authentication device according to claim 1, characterized in that: The aforementioned organism is a finger. 3. The vein authentication device according to claim 2, characterized in that: There are a plurality of the above-mentioned light sources arranged along the width direction of the fingers placed on the above-mentioned interface. 4. The vein authentication device according to claim 2, characterized in that: The interface has a plurality of depressions extending in a lengthwise direction of a finger placed on the interface. 5. The vein authentication device according to claim 2, characterized in that: The above-mentioned interface is in the shape of a central depression. 6. The vein authentication device according to claim 1, characterized in that: said organism is capable of moving over said interface, The imaging unit captures a plurality of vein images of the living body at different positions; The image computing unit synthesizes the plurality of vein images captured by the imaging unit. 7. The vein authentication device according to claim 6, characterized in that: having a movement amount measuring unit for measuring the movement amount of the living body; The image calculation unit synthesizes the plurality of vein images captured by the imaging unit with reference to the movement amount measured by the movement measurement unit. 8. The vein authentication device according to claim 1, characterized in that: It has a light quantity adjustment part which adjusts the light quantity of the said light source. 9. The vein authentication device according to claim 8, characterized in that: The imaging unit captures the vein image of the living body under different light quantities adjusted by the light quantity adjustment unit; The image computing unit synthesizes the images captured by the imaging unit. 10. The vein authentication device according to claim 1, characterized in that: The above-mentioned interface is integrally formed with the above-mentioned light-shielding member. 11. A vein authentication device, characterized in that, An interface for placing a living body to be photographed, a light source emitting infrared light, an imaging unit for capturing a vein image of the living body with light from the light source, and an image calculation for processing the vein image captured by the imaging unit department; The interface is provided with an opening opening in an imaging direction of the imaging unit; The light source is arranged on the side of the opening, and emits light with the imaging direction as the optical axis, so as to irradiate the living body with infrared light from the imaging side of the living body; A light shielding member is provided for shielding at least light that advances in a direction intersecting with the imaging direction, out of the infrared light emitted from the light source; The light shielding member is disposed between the opening and the light source, has a shape extending along the imaging direction, and has a shape covering more than half of an upper portion of the light source on the side of the opening.

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