JP2005128936A - Finger authentication device and its finger placement guide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a finger authentication device and its finger placement guide for naturally guiding a finger's position to a specific position and enabling the stable matching of images without the necessity of positioning and rotation for correction, while increasing matching accuracy without the possibility of a blood-vessel pattern becoming deficit due to pressure on the finger, etc. <P>SOLUTION: The finger authentication device includes a guide part for setting a finger's position; a light source part for applying transmitted light to the finger; an imaging part for imaging the transmitted light; and an authenticating part for authenticating the image taken by the imaging part. The guide part includes an authenticated finger placement guide part for setting the finger to be authenticated and a non-authenticated finger placement guide part for setting fingers that are not to be authenticated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a finger authentication device using a living body for identifying an individual, and more particularly to a novel finger authentication device based on a blood vessel pattern of a finger and a finger placement guide thereof.

  Expectations for personal authentication technology are increasing for the purpose of safe management of property and information. In particular, biometric authentication technology that uses a part of the human body as a key has attracted attention because it is less likely to be illegally exercised due to loss or theft, compared to the conventional management using a personal identification number or key. As biometric authentication technology, various methods using a fingerprint, a face and an iris, a blood vessel pattern of a hand and a finger, and the like have been studied. Among them, the authentication method using the blood vessel pattern of the finger has little psychological resistance because it does not associate a crime like a fingerprint or irradiates light directly on the eye like an iris. Since the internal features are read instead of the surface, there is an advantage that counterfeiting is difficult.

  Specifically, the near infrared light emitted from the light source is transmitted through the finger, and the transmitted light is photographed by the camera. The camera is equipped with an optical filter that passes only wavelengths in the near-infrared region. The image of the finger by the camera during authentication absorbs near-infrared light well because the components in the blood absorb the near-infrared light. It appears dark without passing through. The blood vessel pattern image photographed in this way and the registered blood vessel pattern image are collated to perform personal authentication.

  Conventionally, as disclosed in Patent Document 1, as personal authentication, an apparatus that performs personal authentication using personal biometric data always has a part for inputting personal biometric data, and uses the input data to identify the personal information. Characteristic points are extracted, stored and registered, and personal authentication is performed by collating personal biometric data input during the personal authentication operation with previously registered data.

  Further, in Patent Document 2, as an authentication device using the blood vessel pattern of the back of the hand, it is essential to hold the guide bar with four fingers so that the position of the back of the hand to be imaged becomes constant for each individual. An authentication device to correct is shown.

JP 2003-30632 A JP 2001-184507 A

  However, in Patent Document 1, in order to correctly detect the coincidence of blood vessel patterns, images must be acquired under the same imaging conditions at the time of registration and at the time of authentication. There is a problem that the patterns are greatly different. Movement and rotation that does not change the surface of the finger to be photographed can be corrected by simple image processing, but rotation that causes the finger surface to reverse the back and back is unknown, so correction by image processing is not possible. Can not.

  Although this point is shown in Patent Document 2, in the case of a blood vessel of a finger, when a tension such as grasping is applied, the blood vessel is compressed as described above, and the blood vessel pattern may be lost. In addition, it is possible to provide a guide rail and place the finger at a specific position. However, it is necessary to learn how to place it correctly, and it cannot be used easily by anyone.

  The obtained blood vessel pattern also changes depending on the posture of the finger when inserted into the authentication apparatus. For example, in a finger that is excessively stretched with force, a blood vessel pattern may be partially lost due to the blood vessel being compressed by the tension of the epidermis. Furthermore, even if the external light that illuminates the entire authentication apparatus changes, the brightness and contrast of the obtained image change, which affects the authentication accuracy. This is because normal sunlight or illumination light also includes near-infrared light, and the light wraps around and affects the blood vessel pattern.

  The object of the present invention is that the finger position is naturally guided to a specific position, and it is possible to perform stable collation on the captured image without the need for alignment and rotation correction, as well as by finger compression or the like. It is an object of the present invention to provide a finger authentication device and a finger placement guide that can improve the accuracy of authentication without missing a blood vessel pattern.

  The present invention relates to a finger placement guide for setting a finger position, a light source unit for irradiating the finger with transmitted light, an imaging unit for capturing the transmitted light, and an authentication process for images captured by the imaging unit. An authentication unit that performs authentication, and the guide includes an authentication target finger placement guide unit in which a finger to be authenticated is set, and a non-authentication finger placement guide unit in which a finger that is not authentication target is set. It is in the characteristic finger authentication device. It is preferable to have a switch portion that is turned on and off by the tip portion of the finger. According to the present invention, it is possible to naturally guide the finger position to a specific position, and because it does not compress the blood vessel, it is possible to perform a stable verification on the captured image, as a result, The accuracy of authentication can be remarkably improved.

  The authentication target finger placement guide part has an opening corresponding to the optical opening where the authentication target finger is set and authentication is performed, and the base part of the authentication target finger has a concave shape along its outer shape. And the authentication target non-finger placement guide unit is provided on the left and right of the authentication target finger placement guide unit via an optical shielding unit that blocks external light entering the imaging unit. It is preferable to have a concave shape along the outer shape.

  Further, the present invention provides a finger placement guide for a finger authentication device that sets the position of a finger and performs authentication processing of an image photographed by the transmitted light that is transmitted by irradiating the set finger with transmitted light. The guide includes an authentication target finger placement guide unit in which an authentication target finger is set, and an authentication target external finger placement guide unit in which a non-authentication target finger is set. The authentication target finger placement guide part and the authentication target non-finger placement guide part are preferably those described above.

  The fingers to be authenticated are 10 fingers, and it is preferable to authenticate any finger with the vein information of one finger, but the authentication with a plurality of fingers complicates the device itself, but more accurate authentication It is preferable when performing. The location of finger authentication is preferably performed between the first and second joints. Further, authentication with the middle finger is preferable because finger rolling can be reduced in finger setting.

  The light source part has a rounded shape that draws an arc, and the optical opening of the part where the authentication target finger is installed has a rounded shape that draws an arc, and the curvature of the arc of the light source part Is larger than the curvature of the arc of the optical aperture, and the distance between the light source and the optical aperture in the height direction of the part corresponding to the base of the finger is greater than the distance of the part corresponding to the tip of the finger. It is preferable to form a large distance.

  The present invention is based on the result of the measurement means having a measuring means for measuring the thickness of the finger, that the shape of the part of the switch part touched by the finger is formed by forming a dent indicating the position of the fingertip. Controlling the amount of light of the light source unit, having a coating of an anti-reflective agent applied to the side wall surface region other than the optical opening, and having a reflected light source unit that emits reflected light that reflects the finger, It is preferable that when the imaging unit includes an optical filter, the transmission wavelength range of the optical filter is switched when switching between the transmitted light and the reflected light.

  According to the present invention, the position of a finger is naturally guided to a specific position, and it is possible to perform stable matching on a captured image without the need for alignment and rotation correction, and finger compression, etc. Therefore, the finger authentication apparatus and its finger placement guide that can improve the accuracy of authentication can be provided. In addition, according to the present invention, it is possible to make the photographing conditions for each authentication, which cannot be guaranteed by the conventional technology, uniform in an operation system that does not burden the user.

  Hereinafter, the best mode for carrying out the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples.

  FIG. 1 is a schematic diagram of a finger authentication apparatus according to the present invention. The main body is roughly divided into two parts, a light source unit 102 and an imaging unit 104 that are configured by the authentication device casing 100. A space is provided between the light source unit 102 and the imaging unit 104, and a finger is inserted into the space during authentication. The light source unit 102 covers the upper part of the space where the finger is inserted like a roof, and plays a role of shielding light so that illumination from the ceiling or the like does not directly enter the imaging unit 104. Here, an example in which there is no side wall in the space is shown, but a side wall may be provided to prevent intrusion of external light from the side. In this case, in order to improve the authentication accuracy, it is desirable to apply a coating such as an anti-reflective agent for preventing irregular reflection of near infrared rays on the side wall, or to configure the side wall with the anti-reflection agent.

  In the light source unit 102, a light source 106 that emits near-infrared light having a wavelength of about 810 nanometers is installed so as to emit light toward the camera 114 side of the imaging unit 104. By inserting a finger between the light source 106 and the camera 114, near-infrared light is transmitted through the finger, and a blood vessel pattern image of the finger is obtained by photographing it with the camera 114. The guide groove 112 has a structure that presents the correct insertion position and orientation of the finger in a form that is intuitively easy to understand. When a finger is placed in accordance with the guide groove 112, the button switch 108 is provided at the portion corresponding to the fingertip, and the optical opening 110 is formed at the portions before and after the first and second joints of the finger. The optical opening 110 is covered with a transparent glass or acrylic plate, and prevents light from entering the authentication apparatus while allowing light to pass through. Since the camera 114 requires an optical filter that transmits only light in the near-infrared wavelength region, the optical filter plate is used instead of glass or an acrylic plate, so that two functions are formed by a single plate. You can also.

  Authentication starts by pressing the button switch 108 with a finger inserted by the user. The operation itself of pressing the button switch 108 is an action frequently performed by many people in daily life, and can be blended naturally even in a series of operation systems for authentication. When the button switch 108 is pressed, the position of the fingertip when the finger is placed very naturally is almost constant depending on the person, or at least can be reproduced without difficulty. When the position of the fingertip is determined, the finger is guided to the guide groove 112, and the orientation of the finger as a whole is inevitably determined. Therefore, the part of the finger located on the optical opening 110 is almost uniquely determined, and the finger to be photographed. The range of the image is similarly determined. In addition, when the button switch 108 is pressed, the direction in which the joint bends is determined, so that the finger pad naturally faces so as to be a vertical plane with respect to the direction in which the button switch 108 is recessed. Therefore, the surface of the finger to be imaged does not change due to the rotation of the finger circumference, such as taking the back side of the finger or taking the abdomen side.

  Further, when the button switch 108 is pressed, the finger is naturally bent and the epidermis is not unnecessarily tensioned except for the fingertip, so that pattern loss due to blood vessel compression hardly occurs. Further, in a naturally bent state, the finger does not touch the glass surface of the optical opening 110, and the blood vessel is not pressed by the contact with the glass surface, and dirt is not attached.

  Furthermore, if the finger position can be made substantially constant by these, the area of the optical opening 110 is made small enough to be covered with the finger to avoid the incidence of external light, thereby preventing changes in brightness and contrast due to external light. be able to. Conventionally, since the finger position cannot be made constant, it has been necessary to search for a portion having the same pattern as that at the time of registration from the image of the finger captured over a wide range with the optical aperture 110 being large. For this reason, there is a problem that high-cost calculation hardware is required for searching for the pattern and the optical aperture 110 is large, so that it is easy for external light to enter and it is vulnerable to noise. It will be resolved.

  In addition, since the conventional finger blood vessel pattern authentication technology does not provide a user-initiated authentication start request means using a switch or the like, the time when the authentication process starts is determined by the authentication device and may cause confusion to the user. There was also sex. Thus, the installation of the button switch 108 is very effective as a means for improving operability by itself. The guide groove 112 is provided with a finger placement guide 402 shown in FIG.

  FIG. 2 is a block diagram showing a system configuration for realizing the present invention. A finger of the hand 200 is inserted between the light source 106 and the camera 114, and an image signal of the blood vessel pattern is acquired in accordance with the pressing of the button switch 108. An image signal from the camera 114 is converted into digital data by the image input unit 202 and stored in the memory 210 via the input / output interface 206 of the computer 204. Similarly, the button switch 108 is also connected via the input / output interface, and the on / off state is stored in the memory 210, or an interrupt signal is generated to the CPU 208 at the same time as being turned on. When the CPU 208 confirms that the button switch 108 is turned on or detects an interrupt signal that is turned on, the CPU 208 activates and executes a software program for authentication. Then, based on the processing result of the program, various kinds of control are performed such as displaying the result on the display 212 or sending and receiving an appropriate signal to the control target 216 to open and close the door. The keyboard 214 is used, for example, for inputting auxiliary information related to authentication such as a password.

  FIG. 3 is a flowchart showing the finger authentication process in the present invention. In particular, an example of a processing flow of software executed by the CPU 208 is shown. In process 300, initial values are substituted into temporary variables required for initialization of the entire hardware and program execution. When the transition to the initial state is completed, the program enters an idling state and waits for the button switch 108 to be turned on (302). When the button switch 108 is turned on, the finger image taken by the camera 114 is taken into the memory 210 (304). The captured image data is subjected to image processing, the blood vessel pattern features are extracted (306), and a collation search is performed to see if there is a match with the already registered pattern (308). If there is a matching (310) pattern, a signal indicating that the legitimate access right has been authenticated for the control target such as a device or software program that requires authentication, or for identification of the authenticated individual Data is transmitted (312).

  Then, it waits again until the button switch 108 is turned on next time. It should be noted that turning on / off the power of this hardware can also be used as the button switch 108. The power is turned on by the button switch 108, and the software flow is sequentially executed up to the process 310 except the process 302, to 312 if the authentication is successful, and then the power is turned off again. As a result, power consumption during standby can be reduced. Similarly, a mode in which only on / off of the light source is controlled is also conceivable. The light source is turned on simultaneously with the button switch 108 being turned on, and turned off simultaneously with the end of the authentication process. Depending on the configuration, the entire system may be powered on and off, so that it may take time to start up. Therefore, when convenience is important, only the power saving of the light source is limited. The on / off of the light source may be physically linked to the switch 108, or a switch circuit such as a relay or a transistor may be connected to the input / output interface 206 of the computer 204 to electronically control the switch of the light source. . In such a method using an electronic control circuit, the circuit can be diverted to a power control method by switching on / off of the button switch 108 at high speed, that is, so-called PWM (Pulse Width Modulation) control, and the brightness of the light source is stepped. It becomes possible to control. Because the thickness of the finger varies from person to person, some people may or may not show a blood vessel pattern well with a uniform light quantity, but continuous imaging while controlling the light quantity until the blood vessel pattern appears best Thus, the accuracy of authentication can be improved. Further, if a sensor for measuring the thickness of the finger is added, the optimal blood vessel pattern can be obtained with a smaller number of images by calculating and storing the relationship between the thickness of the finger and the optimum light amount in advance.

  FIG. 4 is a front view (a), a side view (b), and a lower side view (c) of the finger placement guide according to the present invention. The finger placement guide 402 is fixed in the guide groove 112 shown in FIG. 1 along the finger insertion direction shown in FIG. The finger placement guide 402 is provided on the left and right sides of the authentication target finger placement guide unit 403 that guides the insertion operation of the authentication target finger, and the authentication subject non-authentication finger placement guide unit 404 that positions the authentication target non-finger. And an external light shielding unit 405 that prevents the intrusion of external light. The authentication target finger placement guide unit 403 has an opening corresponding to the optical opening 110 where the authentication target finger is set and authentication is performed, and the base of the authentication target finger is a recess-shaped protrusion along its outer shape. Have Further, the authentication target non-finger placement guide unit 404 is provided symmetrically on the left and right of the authentication target finger placement guide unit 403 via an external light shielding unit 405 that blocks external light entering the imaging unit 104. The overall length has a concave shape with a length along the outer shape. The external light shielding portion 405 is larger than the length and height of the finger, and the tip thereof is lowered with a curve.

  FIG. 5 is a front view in which a finger is set on the finger placement guide. As shown in FIG. 5, the finger insertion operation at the time of authentication includes the middle finger of the authentication target finger along the authentication target finger placement guide unit 403, and the index finger and the ring finger that are not the authentication target via the external light shielding unit 405. And inserted along the non-authentication target finger placement guide 404. As a result, the finger insertion operation at the time of authentication can be performed without any tension in the natural operation. Furthermore, since the middle finger of the authentication target is inserted and set along the authentication target finger placement guide unit 403 and the non-authentication index finger and ring finger along the authentication target finger placement guide units 404 on both sides, the authentication target finger of the authentication target finger is set. The setting position on the placement guide unit 403 can be always set constant without the rotation of the finger, and as a result, the authentication accuracy can be remarkably improved.

  In addition, the external light entering the optical opening 110 is shielded by the external light shielding unit 405, and a clear blood vessel pattern image of the finger to be authenticated can be extracted. By positioning with the authentication target finger placement guide unit 403 and the non-authentication target finger placement guide unit 404, rotation of the authentication target finger in the long axis direction can be prevented during natural operation, and stable verification can be performed. As a result, authentication accuracy can be further improved. Further, although the authentication target finger is the middle finger in FIG. 5, the setting can be made in the same manner for any finger in either hand.

  FIG. 6 is an assembled perspective view of the finger authentication apparatus in the present embodiment. FIG. 7 is an enlarged side view of a portion where a finger is inserted as seen from the side. The finger placement guide of FIG. 4 is installed in the guide groove 112 of FIG. 6, but the illustration of the finger placement guide is omitted in FIG. Accordingly, in FIG. 7, the finger opening guide is in contact with the optical opening 110 between the first and second joints, which are the finger authentication portions, but the finger placement guide is a convex portion whose protruding base portion protrudes. Since it is formed, it is a thing which does not touch and can authenticate a vein more correctly.

  As shown in FIG. 6, in the lower portion of the space including the opening, the distance in the height direction of the upper portion of the space is different between the front side and the back side where the finger is inserted. Further, the surface of the light source 106 corresponding to the upper part of the space and the surface of the optical opening 110 corresponding to the lower part of the space are formed so as to draw an arc. Here, between the arc at the top of the space and the arc at the bottom of the space, the former arc has a larger curvature. With this configuration, when inserting a finger, for example, even if the finger's belly is oriented sideways or diagonally, the arc is further narrowed toward the back of the space, so the finger is inserted. As you go, it will be corrected so that the belly of your fingers will face down. Furthermore, near-infrared rays from the light source 106 are evenly radiated, and the distance from the camera 114 to the optical aperture 110 is equalized, so that more accurate authentication can be performed.

  Further, the position of the touch part 1301 is different from that in FIG. In the touch unit 1301 in FIG. 7, unlike the touch unit 400 in FIG. 10, the button switch 108 is operated by an operation of pointing a finger deeply. In this case, pressing the touch unit 1301 is more unnatural than the touch unit 400 in FIG. 10, but for example, by making the touch unit 1301 a switch means that does not involve a click operation such as a touch sensor, a comfortable operation is achieved. A feeling can be obtained.

  In the above, the advantages brought about by the use of the button switch in the finger authentication device have been described. However, the operation of pressing the button means contact with the device, and is not without the possibility of causing a sense of hygiene resistance. This can be mitigated by using an antibacterial material that is generally used recently for the authentication device casing 100 and the button switch 108. In particular, a psychological effect is great even if characters “antibacterial” can be printed on the authentication device casing 100. In the device configuration of the present invention, the sensor unit for acquiring the blood vessel pattern does not need to appear on the surface of the authentication device casing 100, and antibacterial processing of the device surface is very easy. In a biometric authentication method in which a sensor needs to touch a living body directly such as a fingerprint, there are many cases where it is difficult to make the sensor antibacterial, but the present invention has no problem.

  In this embodiment, a mechanical push switch is used as an example of the button switch 108. However, for example, an electrostatic type switch that conducts electricity only by touching may be used instead. Alternatively, a combination of a light source and an optical sensor may be used so that the fingertip comes to a predetermined position and is switched on when the light is blocked. In this case, various sensors such as a human sensor can also be used.

  In addition, even if the authentication with the finger fails by using the keyboard 214, it is possible to perform the authentication using a password registered in advance. In addition, more reliable authentication is possible by combining authentication with a finger and authentication with a password. Furthermore, it is possible to apply applications such as changing the operation after authentication depending on whether authentication is performed using a finger or authentication using a personal identification number.

  FIG. 8 is a front view showing a sensor for measuring the thickness of a finger. The sensor in this embodiment is provided in the optical aperture 110 in FIG. Other structures are the same as those in the first embodiment. FIG. 8A shows a surface of the light source that is displayed by a camera facing it. A central infrared light source 106 is surrounded by a surface 1000 coated with a paint that suppresses or absorbs near-infrared reflection. On the surface 1000, on the contrary, a bar-like four-point marking 1002 made of a material that easily reflects near infrared rays is applied. When the light source shines, there is a clear contrast between the surface 1000 and the marking 1002. When shooting with a camera, the brightness difference between the two becomes very large. As shown in FIG. 8B, when the finger 200 is held over the light source, the hidden area of the marking 1002 changes according to the thickness of the finger. In the image area of the finger portion, the luminance difference between the blood vessel and the other portion does not become extremely large. Therefore, when the finger covers the marking 1002 portion, the luminance difference existing in the marking 1002 portion disappears. . In other words, the position coordinates where the portion where the luminance difference is large has been given give the outline position of the finger, and this can be obtained by simple difference processing. In order to obtain the thickness of the finger, it is sufficient if there is a marking of at least two points. However, since the thickness of the finger is not uniform due to a node or the like, the marking of four points 1002 as shown in the figure. Can be used to determine a more accurate thickness. If four points are used, even if the finger is inserted with a slight inclination, the inclination angle can be obtained.

  FIG. 9 is a flowchart of authentication processing for performing light amount control according to the thickness of the finger. In the processing, initial values are assigned to temporary variables necessary for initialization 900 of the entire hardware and program execution. When the transition to the initial state is completed, the program enters an idling state and waits for the button switch 108 to be turned on (step 902). When the button switch 108 is turned on, the thickness of the finger is first measured by the sensor shown in FIG. 8, and a light source is used by using a reference table in which a combination of the thickness and the initial light amount value is registered in advance. An initial light amount 106 is set. Subsequently, an image of a finger is taken by the camera 114 and is taken into the memory 210 (step 906).

  The captured image data is subjected to a blood vessel pattern feature extraction process 908 to check whether or not a blood vessel pattern has appeared (step 912). If not, the amount of light is changed (step 910), and the image is read from the camera again. Capture. The direction of changing the amount of light is that if the image area of the finger part is bright overall, the light amount is strong and the tendency of saturation is predicted. Since the S / N ratio of the transmitted light is predicted to decrease because of weakness, the operation is performed in the direction of increasing the amount of light. The overall brightness of the finger area can be easily measured from the average value of the constituent pixels. Then, a collation search is performed to see if there is a match with the already registered pattern (step 914). If there is a matching pattern (step 916), a device or a software program that requires authentication, etc. A signal indicating that the legitimate access right has been authenticated or data for identifying the authenticated individual is transmitted to the control object (step 918). Then, it waits again until the button switch 108 is turned on next time.

  Also in the present embodiment, as in the first embodiment, the middle finger of the authentication target finger is along the authentication target finger placement guide unit 403, and the index finger and the ring finger that are not the authentication target are authenticated through the external light shielding unit 405. By inserting along the outer finger placement guide 404, it is possible to perform finger insertion operation during authentication without any tension in natural operation, and the middle finger to be authenticated is always kept constant without rotation of the finger. As a result, the authentication accuracy can be remarkably improved.

  FIG. 10 is an enlarged view of a portion where a finger is inserted as viewed from the side, showing another embodiment of the finger authentication device of the present invention. Other structures are the same as those in the first embodiment. There is a near infrared light source 106 at the top, an optical aperture 110 at the bottom, and a camera 114 below it. Reference numeral 400 denotes a touch portion of the button switch. When the finger is directly touched and pressed, the spring-loaded push button switch 108 is turned on. Only when the button switch 108 is being pressed, it is in a conductive state, and when released, it automatically returns to its initial position by a spring and enters an insulated state.

  As shown in FIG. 10, between the optical opening 110 and the touch portion 400, the finger is surely bent when designed so as to bend so that the finger naturally bends. Omissions are less likely to occur. In addition, the glass plate forming the optical opening 110 is disposed below or the finger placement guide 402 is provided so that the base of the finger is lifted with respect to the optical opening 110, thereby the optical opening 110. It is possible to more reliably prevent blood vessel compression due to contact between the finger and the finger. The finger placement guide 402 has a structure in which a protrusion is provided at a portion that comes into contact with the finger base, and the finger authentication unit does not come into contact with the optical opening 119.

  FIG. 11 is a perspective view of a touch portion according to the present invention. The surface touched by the finger is shaped such as a dent so that the finger just fits, so that the position of the fingertip is more sure to be at the same position every time, and the displacement due to pressing the touch part 400 itself Can be avoided. In addition, as shown in FIG. 10, the height of the touch part 400 is limited so that the abdominal part of the fingertip can be accommodated. A touching person 400 can press the touch part 400 without inconvenience.

  Also in the present embodiment, as in the first embodiment, the middle finger of the authentication target finger is along the authentication target finger placement guide unit 403, and the index finger and the ring finger that are not the authentication target are authenticated through the external light shielding unit 405. By inserting along the outer finger placement guide 404, it is possible to perform finger insertion operation during authentication without any tension in natural operation, and the middle finger to be authenticated is always kept constant without rotation of the finger. As a result, the authentication accuracy can be remarkably improved.

  FIG. 12 is a perspective view showing another embodiment of the finger insertion unit in the finger authentication device according to the present invention. Other structures are the same as those in the first embodiment. In the example of FIG. 1, the light source unit 102 is provided in the shape of a roof for shielding light from ceiling lighting or the like, but for the user, conversely, psychological anxiety that a finger is inserted into the shielded space. May be beaten. Therefore, as shown in FIG. 7, by disposing the light source obliquely above the finger, it is possible to eliminate a cover that completely hides the finger from the user's field of view. In the example of FIG. 12, oblique roof-type light source portions are provided on both sides of the opening, and the near-infrared light sources 106 are respectively disposed. The reason why the near-infrared light source is provided at two locations on both sides is that if the location is one location, the transmitted light from the finger is biased and becomes uneven, and a correct blood vessel pattern may not be obtained.

  Also in the present embodiment, as in the first embodiment, the middle finger of the authentication target finger is along the authentication target finger placement guide unit 403, and the index finger and the ring finger that are not the authentication target are authenticated through the external light shielding unit 405. By inserting along the outer finger placement guide 404, it is possible to perform finger insertion operation during authentication without any tension in natural operation, and the middle finger to be authenticated is always kept constant without rotation of the finger. As a result, the authentication accuracy can be remarkably improved.

  FIG. 13 is a configuration diagram of an optical system arrangement showing another embodiment of the finger authentication device according to the present invention. Other configurations are the same as those of the first embodiment. The light source 800 provides a reflected light source for the near-infrared light source 106 of transmitted light. These two light sources can be turned on and off in any combination under the control of the computer 204. For example, visible light may be generated in the reflected light source 800 and the surface of the finger may be imaged by the camera 114. In the above-described embodiment, the optical filter transmits only the near-infrared region. However, instead of this, by providing a variable or switchable optical filter 802, the visible light can be switched as necessary. Make it possible. As a result, it is possible to image biometric features such as a fingerprint pattern on the finger surface, and it is possible to improve authentication accuracy by simultaneously performing biometric features on the finger surface and a blood vessel pattern.

  Also in the present embodiment, as in the first embodiment, the middle finger of the authentication target finger is along the authentication target finger placement guide unit 403, and the index finger and the ring finger that are not the authentication target are authenticated through the external light shielding unit 405. By inserting along the outer finger placement guide 404, it is possible to perform finger insertion operation during authentication without any tension in natural operation, and the middle finger to be authenticated is always kept constant without rotation of the finger. As a result, the authentication accuracy can be remarkably improved.

It is a perspective view showing a finger authentication device concerning the present invention. 1 is a system configuration diagram of a finger authentication device according to the present invention. It is a flowchart which shows the process of the finger | toe authentication apparatus which concerns on this invention. It is a block diagram which shows the finger placement guide in the finger | toe authentication apparatus which concerns on this invention. It is a front view which shows the finger insertion to the finger placement guide in the finger | toe authentication apparatus which concerns on this invention. It is a perspective view of the finger authentication device concerning the present invention. It is a side view of the finger authentication device concerning the present invention. It is a block diagram which measures the thickness of the finger in the finger | toe authentication apparatus which concerns on this invention. It is a flowchart which shows the process process by the light quantity control of the finger | toe authentication apparatus which concerns on this invention. It is a side view which shows the other example of the finger | toe authentication apparatus which concerns on this invention. It is a perspective view of the touch part of the button switch in the finger authentication device concerning the present invention. It is a perspective view which shows the other example of the finger authentication apparatus which concerns on this invention. It is a block diagram of the optical system which shows the other example of the finger | toe authentication apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Authentication apparatus housing | casing, 102 ... Authentication apparatus light source part, 104 ... Authentication apparatus imaging part, 106 ... Near infrared light source, 108 ... Button switch, 110 ... Optical opening part, 112 ... Guide groove, 114 ... Camera, 200 ... Hand 202 202 Image input device 204 Computer 206 Input / output interface 208 Central processing unit 210 Memory 212 Display 214 Keyboard 216 Control target 402 Finger placement guide 403 Authentication target finger placement guide unit, 404... Non-authentication target finger placement guide unit, 405.

Claims (6)

  A finger placement guide for setting a finger position, a light source unit that irradiates the finger with transmitted light, an imaging unit that captures the transmitted light that has passed through, and an authentication unit that performs authentication processing of an image captured by the imaging unit The finger placement guide includes an authentication target finger placement guide unit in which a finger to be authenticated is set and an authentication target non-authentication finger placement guide unit in which a finger that is not to be authenticated is set. Finger authentication device.   2. The authentication target finger placement guide part according to claim 1, wherein a part corresponding to an optical opening part where the authentication target finger is set and authentication is performed is opened, and a base part of the authentication target finger is formed in an outer shape thereof. A finger authentication device characterized by having a concave shape along.   3. The authentication target finger placement guide unit according to claim 1, wherein the authentication target finger placement guide unit is provided on the left and right of the authentication target finger placement guide unit via an optical shielding unit that blocks external light entering the imaging unit. A finger authentication device having a concave shape along an outer shape of an outer finger.   In a finger placement guide for a finger authentication device that sets the position of a finger and performs authentication processing of an image photographed by the transmitted light that is transmitted through the transmitted light by the transmitted light, the guide is an authentication target A finger placement guide for a finger authentication device, comprising: an authentication target finger placement guide portion for setting a finger; and an authentication subject non-authentication finger placement guide portion for setting a finger that is not subject to authentication.   5. The authentication target finger placement guide portion according to claim 4, wherein a portion corresponding to an optical opening portion where the authentication target finger is set and authentication is performed is opened, and a base portion of the authentication target finger is formed in an outer shape thereof. A finger placement guide for a finger authentication device, characterized by having a concave shape along the shape. 6. The authentication target finger placement guide unit according to claim 4, wherein the authentication target finger placement guide unit is provided on the left and right of the authentication target finger placement guide unit via an optical shielding unit that blocks external light entering the imaging unit. A finger placement guide for a finger authentication device, characterized by having a concave shape along the outer shape of the outer finger.

Images