JP2012088939A - Biometrics authentication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a unit and to improve the authentication accuracy in a finger vein authentication device.SOLUTION: A biometrics authentication device comprises: a finger support base to put a finger on; a light source 31 to irradiate the finger with light; a sensor (imaging part) 34 that receives transmitted light penetrating the finger and images the finger; a feature extraction part 37 to perform arithmetic processing on a blood vessel pictorial image of the finger acquired by the sensor 34 and to perform feature extraction of a vein pattern; a storage part 35 that stores the feature information extracted by the feature extraction part 37; and a check part 38 that compares and collates the feature information extracted from a newly imaged blood vessel pictorial image with the feature information stored in the storage part 35, and determines whether the two pieces of feature information are obtained by imaging the same finger. The sensor 34 has a shape wrapping up the bottom and the right and left side of the finger.

Description

  The present invention relates to a biometric authentication device used in a personal authentication system, and more particularly to a biometric authentication device that performs biometric authentication using an image pattern of a finger vein.

  Conventionally, there are various authentication methods such as a seal, a card, a personal identification number, etc. as a method for authenticating whether or not the person is authentic, but these are accurate but can be copied or forged, and security is not perfect. .

For this reason, recently, biometric authentication devices have become widespread as personal authentication. In particular, fingerprint authentication devices have become quite widespread. For example, they are also used in bank ATM terminals, and an increasing number of terminals can perform fingerprint authentication in addition to passwords. There is also a fingerprint authentication device installed on a personal computer.
Other authentication methods include iris (eye iris pattern) authentication, face authentication, voiceprint authentication, and blood vessel pattern authentication. The present invention relates to a vein authentication apparatus using a blood vessel pattern, particularly a finger vein pattern.

  In general, vein authentication is said to be a universal pattern of blood vessels including veins, and it is said to be stable information that does not change over time, except for the thickness of the blood vessels, unless there is a major injury. . Because of these features, various vein authentication devices have recently appeared and are becoming increasingly popular (Patent Document 1).

  FIG. 4 is an outline of a conventional finger vein authentication device. A lens 42 is assembled to the sensor 41 to capture a finger vein pattern, and a distance 43 is required between the lens 42 and the finger 44. In addition, in order to photograph the vein pattern of the finger 44 three-dimensionally, as shown in FIG. 4A, a plurality of sets of sensors 41 and lenses 42 are required, or as shown in FIG. It is necessary for the sensor 41 and the lens 42 to move in the direction of the arrow 48 (or the opposite direction).

JP 2009-059249 A

In general, the vein authentication apparatus uses a CCD camera or a CMOS sensor as a sensor for displaying a vein pattern. As described above, a predetermined distance is required between the lens and the finger due to restrictions such as the focal length of the lens.
This increases the size of the unit and makes it difficult to adjust the position of the optical system, resulting in increased manufacturing costs.

  In addition, since the finger is three-dimensional, the sensor is flat, so that distortion due to finger rotation or the like cannot be corrected, which causes the authentication rate to deteriorate. In order to acquire a three-dimensional vein pattern, it is necessary to perform imaging using two or three sensors as described above, or to perform imaging by moving one sensor.

  The shape of the sensor that projects the vein pattern is made so as to wrap the finger (for example, a semicircular shape) so that it can be read directly without using a lens or the like.

  By making the shape of the sensor that projects the vein pattern so as to wrap the finger, the vein pattern can be photographed on a wider surface and with one sensor fixed, and image distortion due to finger rotation or the like is eliminated.

To capture the vein pattern directly on the sensor without using a lens by making the shape of the sensor that projects the vein pattern a shape that envelops the finger (for example, a semicircular shape) so that it can be read directly without using a lens. It is not necessary to take a distance from the finger, and the size can be reduced.
In addition, by making the shape of the sensor that displays the vein pattern a shape that the sensor wraps around the finger (for example, a semicircular shape), the vein pattern can be imaged on a wider surface and with one sensor fixed, Image distortion due to finger rotation and the like is eliminated, and high-accuracy authentication is possible.

  Hereinafter, the present invention will be described in detail with reference to the drawings. However, this description does not limit the technical scope of the present invention to the following embodiments.

1 and 2 are schematic views of a finger vein authentication device using the present invention. As shown in FIG. 1 (a), the sensor unit 11 has an inner side of the finger 12 (the side that is the inner side when the finger is bent. The side facing the sensor in FIG. 1 (a)) and its left and right side surfaces. The shape should be covered. FIG.1 (b) shows the shape of the sensor 11 removed from the finger vein authentication apparatus 10 shown to Fig.1 (a).
As shown in FIG. 2, the finger vein authentication device 20 includes a finger placement unit 21 for placing a finger, a light source 22 that irradiates light on the finger, and a sensor that receives and captures transmitted light that passes through the irradiated finger ( An imaging unit) 23 and a feature extraction unit 24 that performs arithmetic processing on the blood vessel image of the finger acquired by the sensor (imaging unit) 23 and extracts features of the vein pattern are provided.
Furthermore, the finger vein authentication device 20 has already stored the storage unit (not shown) that stores the feature information extracted by the feature extraction unit 24, and the feature information and the storage unit that are newly captured and extracted from the blood vessel image. And a collation unit (not shown) for comparing and collating the feature information with each other and determining whether or not the two feature information are feature information obtained by photographing the same finger.

FIG. 3 is a cross-sectional image view of the mechanism of the finger vein authentication device using the present invention. FIG. 3 is a view as seen from the direction indicated by the arrow 13 in FIG. 1 (the direction from the tip of the finger toward the root).
The light source 31 may be installed obliquely above the finger 33 placed on the sensor 34 as shown in FIG. 3 (a), or placed on the sensor 34 as shown in FIG. 3 (b). The light source 31 may be installed next to the finger 33.
3B does not illustrate the storage unit 35, the display unit 36, and the like, the storage unit 35, the display unit 36, and the like are required as in FIG. 3A.

3A and 3B, near infrared light 32 is emitted from the light source 31 to the finger 33 in order to project the vein of the finger 33, and the vein 34 inside the finger 33 is transmitted through the sensor 34 by the transmitted light. Take a picture in a shot. The captured vein image is sent to the feature extraction unit 37, where the vein pattern is analyzed by a unique algorithm, and vein authentication data is extracted. This authentication data is stored in the storage unit 35 as verification data at the time of initial registration. At that time, the display unit 36 displays whether the vein authentication data has been successfully extracted. If authentication registration data cannot be collected successfully, a message to that effect (for example, “Register data again”) is displayed on the display unit 36 to prompt the user to register vein data again.
The matching unit 38 compares the feature information extracted by the feature extraction unit 37 from the newly imaged blood vessel image with the feature information stored in the storage unit 35, and uses the same finger for the two feature information. It is determined whether or not the feature information is obtained by photographing.

In order to eliminate the drawbacks of the conventional finger vein authentication device, the finger vein authentication device of the present invention has a shape that wraps the inside of the finger 12 and the left and right sides of the sensor 34 that displays the vein pattern (for example, the sensor 34). By making the cross-sectional shape perpendicular to the longitudinal direction of the sensor into a semicircular shape, it is not necessary to provide a predetermined distance between the finger 33 and the sensor 34, and the vein authentication device can be downsized.
Further, by forming the sensor 34 so as to wrap the finger 33, the vein pattern can be imaged on a wider surface and with one sensor fixed.

  In addition, a light source control means (not shown) that can turn off the light of the light source is provided during imaging (including immediately after the start of imaging and immediately before the end of imaging) to shorten the exposure time or change the exposure time to A (venous) image may be acquired.

  In addition, as the miniaturization progresses, it becomes unnecessary to adjust the combination of the sensor and the lens, and there is an effect that the cost is reduced and the selling price is lowered due to the mass production effect.

(A) is a general view of a finger vein authentication device according to an embodiment of the present invention, and (b) is a general view of a sensor. Overview of finger vein authentication device according to an embodiment of the present invention It is a mechanism cross-sectional image figure of the vein reading part which reads the finger vein which concerns on embodiment of this invention, Comprising: (a) When installing a light source diagonally upward, (b) When installing a light source sideways It is a schematic diagram of a conventional finger vein authentication device, where (a) is a three-dimensional image using three sensors, and (b) is a three-dimensional image by moving one sensor.

31 ... Light source, 32 ... Light source irradiation light, 33 ... Cross section of finger, 34 ... Sensor, 35 ... Storage part, 36 ... Display part, 37 ... Feature extraction part, 38 ... collation unit, 41 ... sensor (imaging unit), 42 ... lens, 43 ... distance (interval between sensor and lens), 44 ... moving direction

Claims (5)

Arithmetic processing for a finger placement table on which a finger is placed, a light source that irradiates light to the finger, an imaging unit that receives and captures transmitted light that passes through the finger, and a finger blood vessel image acquired by the imaging unit A feature extraction unit for extracting features of a vein pattern; a storage unit for storing feature information extracted by the feature extraction unit; a feature information extracted from a newly imaged blood vessel image; and the storage unit A biometric authentication device comprising a collation unit that compares and collates the feature information stored in the image and determines whether or not the two feature information are feature information obtained by photographing the same finger,
A biometric authentication device, wherein the imaging unit is a sensor shaped so as to wrap the inside of a finger and its left and right side surfaces.   The biometric authentication apparatus according to claim 1, wherein the imaging unit has a semicircular cross section perpendicular to the longitudinal direction.   The biometric authentication apparatus according to claim 1, wherein the light source irradiates the finger with irradiation light from a side or obliquely above the finger.   The light source control means capable of extinguishing light from the light source during imaging is provided, and blood vessel images are acquired by shortening the exposure time or changing the exposure time. The biometric authentication device according to 1.   The biometric authentication device according to any one of claims 1 to 4, further comprising a display unit that displays a comparison result in the collation unit.