JP2007044397A - Light irradiation structure of authentication device using vein pattern - Google Patents

Abstract

In an authentication device using a vein pattern, a light irradiation structure is provided that enables accurate reading of the vein pattern even with a relatively small amount of light.
A first light irradiation structure according to the present invention irradiates a test object (1) with light necessary for imaging a vein pattern in an authentication device using a vein pattern, and emits light having directivity. The light (6) emitted from the body (2) is concentrated in a specific area (3) on the inspection object. Further, the second light irradiation structure according to the present invention irradiates the inspection object (1) with light necessary for imaging the vein pattern in the authentication device using the vein pattern, and has a directional light emitter ( The light (6) emitted from 2) is concentrated at a specific point (5) on the inspection object.
[Selection] Figure 1

Description

  The present invention relates to a light irradiation for irradiating a palm or finger to be inspected with light necessary for vein pattern imaging in an authentication apparatus used for authenticating an individual using a palm or finger vein pattern. Concerning structure.

  In recent years, authentication technology using vein patterns, which is rapidly spreading, has different vein patterns used for authentication, does not change over time, and is an internal structure of the human body. Since it has such characteristics as being possible, it is suitable for personal authentication. However, there are various problems in the authentication technique using the vein pattern, and the arrangement of light sources necessary for imaging is one of such problems.

  For example, for the test object for imaging the vein pattern, simply irradiating the light necessary for imaging from above the test object, if the back of the hand is the test object, the hair growing on the back of the hand becomes an obstacle, When the finger is an inspection target, much of the light transmitted through the finger is blocked by the bone, and the amount of light becomes insufficient, which may prevent accurate reading of the vein pattern.

  Further, when a light source indispensable for reading the vein pattern is arranged above the inspection target, the user cannot confirm the insertion destination of the finger or the back of the hand with his / her own eyes in the authentication device. When the reading device is embedded in the wall, only the insertion opening that cannot confirm the inside of the reading device is formed on the wall surface, which causes the user to feel a sense of fear or disgust.

Therefore, in Japanese Patent Application No. 2004-115033, the present applicant has proposed an authentication apparatus including a light source disposed at a position where the optical axis intersects the visual axis of the imaging unit at a predetermined angle. According to this authentication apparatus, the position at which the light source is arranged is not particularly limited as long as the optical axis intersects the visual axis of the imaging unit at a predetermined angle. Therefore, by appropriately adjusting the position where the light source is arranged according to the installation state or the like, a sufficient amount of light can reach the imaging means, or a viewing window of the installation unit can be provided at an appropriate place. And it becomes possible to read a vein pattern correctly, and when an apparatus is embed | buried under a wall surface, it becomes possible to read a vein pattern, without making a user hold fear and disgust.
Japanese Patent Laid-Open No. 2004-115033

  However, the authentication device has an advantage that the light source is not disposed above the inspection target, but the vein pattern cannot be sufficiently read unless the light amount of the light source is large. Therefore, there is a problem that it takes a lot of cost and time to increase the amount of light, for example, when an LED is used as the light source, a large number of LEDs are used to increase the total amount of light, which increases power consumption. Or there was a problem that the failure frequency may increase.

  Accordingly, an object of the present invention is to provide a light irradiation structure that enables accurate reading of a vein pattern even with a relatively small amount of light in an authentication device using a vein pattern.

  A first light irradiation structure according to the present invention irradiates a test object with light necessary for imaging a vein pattern in an authentication apparatus using a vein pattern, and light emitted from a directional light emitter It concentrates on a specific area on the inspection object.

  The second light irradiation structure according to the present invention irradiates the inspection object with light necessary for imaging the vein pattern in the authentication device using the vein pattern. Light emitted from a directional light emitter is It concentrates on a specific point on the inspection object.

The light emitter may be arranged so that the optical axis thereof is on the same plane as the axis of the inspection object and the visual axis of the imaging unit, and the specific region or the specific point may be on the visual axis.
In the present invention, the axis of the inspection object refers to a virtual line extending in the longitudinal direction through the center of the inspection object. For example, in an authentication apparatus using a vein pattern, the inspection target is generally a finger or palm, but if the inspection target is a finger, the axis of the inspection target is a line passing through the center of the finger bone.

  The illuminator may be disposed at a position near the tip of the inspection object placed in a state where inspection is possible.

  According to the first light irradiation structure according to the present invention, the light emitted from the directional light emitter is concentrated in a specific area on the inspection object, so that the light reaching the inspection object is diffused in the inspection object. Using the phenomenon, the luminance of the inspection object can be efficiently increased. Therefore, the vein pattern can be accurately read with a smaller amount of light than a conventional light irradiation structure that uniformly irradiates light on the entire inspection target.

  In addition, if the directivity of a light-emitting body becomes strong, the area of the specific area | region where the light emitted from there will concentrate will become narrow, and will eventually become 1 point. The second light irradiation structure according to the present invention is obtained by replacing the light emitter in the first light irradiation structure with a light emitter having higher directivity, and obtains the same effect as the first light irradiation structure. Can do. In addition to these effects, by concentrating the light at a specific point, the luminance of the inspection object can be increased more efficiently than when a light emitter with low directivity is employed. Therefore, the number of light emitters can be further reduced from that of the first light irradiation structure that employs a light emitter with weak directivity, and in some cases, the number of light emitters can be reduced to reduce the effort required for maintenance such as adjustment of the optical axis.

  If the light emitter is arranged so that its optical axis is on the same plane as the axis of the inspection object and the visual axis of the imaging means, a large amount of light is scattered in the longitudinal direction of the inspection object within the inspection object and dissipated from the width direction. Less. Furthermore, with this arrangement, it is possible to increase the luminance of only the part to be imaged with the specific region or the specific point on the visual axis. Therefore, the brightness of the inspection object can be increased more efficiently.

  If the light emitter is arranged at a position near the tip of the inspection object placed in an inspectable state, it can also be applied to a type of authentication device in which the upper side of the inspection object is opened.

1-4, the specific example of the 1st light irradiation structure concerning this invention is shown. 1 is a side view showing a schematic configuration of the structure, FIG. 2 is a front view, and FIG. 3 is a plan view. FIG. 4 is a perspective view of an authentication apparatus having the same structure.
This light irradiation structure irradiates the finger, which is the inspection target 1, with light necessary for imaging the vein pattern in the authentication device using the vein pattern, and is arranged toward the placement unit 10 of the inspection target 1. A light emitter 2 having directivity is provided. The mounting unit 10 includes an imaging window 11, and the imaging unit 4 is disposed below the window 11. The inspection object 1 can be placed in the same state for each use by abutting against a positioning projection 12 provided in the vicinity of the light emitter 2 side end of the placement portion 10.

The illuminant 2 is an LED having a directivity of 30 degrees (which can irradiate a conical region having a light emission point as a vertex and an apex angle of 30 degrees), and two LEDs arranged side by side in the visual axis N direction of the imaging unit 4 are used. Yes.
Then, the light 6 emitted from both the light emitters 2, 2 is concentrated in the specific region 3 between the intersections F, F between the optical axes L, L of the light emitters 2, 2 and the inspection object 1. Yes.

  According to this light irradiation structure, the light 6 emitted from the illuminating body 2 having directivity is concentrated on the specific region 3 on the inspection object 1, thereby diffusing the light reaching the inspection object 1 in the inspection object 1. Using the phenomenon, the luminance of the inspection object 1 can be efficiently increased. Therefore, the vein pattern can be accurately read with a smaller amount of light than a conventional light irradiation structure that uniformly irradiates light on the entire inspection target.

The light emitter 2 is arranged such that the optical axis L thereof is on the same plane P as the axis M of the inspection object 1 and the line of sight N of the imaging means 4. The specific region 3 is formed on the visual axis N.
If it carries out like this, many light will be scattered in the longitudinal direction of the test object 1 in the test object 1, and the dissipation from the width direction will decrease. Furthermore, with this arrangement, it is possible to increase the luminance of only the part to be imaged with the specific region 3 on the line of sight axis N. Therefore, the brightness of the inspection object can be increased more efficiently.

Furthermore, the light emitter 2 is disposed at a position near the tip of the inspection object 1 placed in an inspectable state.
If it carries out like this, as shown in FIG. 4, it will become possible to provide the permeation | transmission part 13 for confirming the mounting part 10 from the outside above the mounting part 10. FIG. In addition, although the transparent resin board is engage | inserted in this permeation | transmission part 13, it is good also as an open state which removed the resin board.

  In this embodiment, two LEDs arranged side by side are used as the light emitter 2, but the number of LEDs is not limited. As long as a sufficient amount of light can be obtained, the number of LEDs may be one as shown in FIG. In FIG. 5, substantially the same parts as those in the specific examples shown in FIGS.

FIG. 6 is a side view showing a schematic configuration of a specific example of the second light irradiation structure according to the present invention. In FIG. 6, parts that are substantially the same as the specific examples shown in FIGS. 1 to 5 are given the same reference numerals, and descriptions thereof are omitted.
In this light irradiation structure, the light emitter 2 having the light irradiation structure shown in FIGS. 1 to 5 is replaced with a laser having higher directivity than the LED. The light 6 emitted from the light emitter 2 is concentrated at a specific point 5 on the inspection target.

  According to this light irradiation structure, by concentrating the light at the specific point 5, the luminance of the inspection object 1 can be increased more efficiently than when a light emitter with low directivity is employed. Therefore, compared with the light irradiation structure shown in FIGS. 1-5 which employ | adopted the light emitter with weak directivity, the number of light emitters can further be reduced and it can reduce the effort required for maintenance, such as adjustment of an optical axis.

Next, the Example of the light illumination structure concerning this invention is described.
In the embodiment described below, only the minimum necessary elements for reading the finger vein pattern shown in FIGS. 1 to 3, 5, and 6 are used, and the device as a finished product as shown in FIG. 4 is used. Is not used. Moreover, although the mounting part 10 was provided in the flat work bench | platform, the surrounding side wall was not provided but it implemented under room lighting. The image pickup means 4 is a mass-produced normal camera, and is installed at a position where the lens surface is 45 mm below the mounting portion 10.

  In the first embodiment, L-53SF7C (product name: Kingbright) was adopted as the LED, and two LEDs were installed side by side in the direction of the visual axis N of the imaging means 4 as shown in FIGS. The main characteristics of L-53SF7C are a wavelength of 850 nm, an output of 100 mW / sr, a current of 50 mA, and a directivity of 30 degrees.

  The inspection targets were the left and right index and middle fingers. Then, six images with an average luminance of about 70 to 150 were taken and compared with each other to obtain a matching score.

  The distance D from the fingertip of the LED was 10 mm, and the angle R of the optical axis L of the LED with respect to the installation part 10 was set to 2 degrees and 12 degrees, and each was carried out. The height H with respect to the mounting part 10 became a little different with the change of the installation angle of LED, and the former was 25 mm and the latter was 30 mm.

Table 1 shows the results of the first example.
An example of the obtained image data is shown in FIGS.
7 is an image before processing, FIG. 8 is an image after gradation difference emphasis processing, and FIG. 9 is an accumulation of binarized images.

  According to the first embodiment, even if there are only two LEDs, it is possible to obtain necessary and sufficient coincidence points for authentication using vein patterns by concentrating light emitted from the LEDs on a specific region to be examined. It could be confirmed.

  In the second embodiment, L760-02AU, L830-02AU, and L850-02UP (all of which are product names: ALPHA-ONE) are adopted as LEDs, and light having wavelengths of 760 nm, 830 nm, and 850 nm are used. Illuminated using one LED as shown in FIG. As common characteristics of these LEDs, the output is 100 mW / sr, the current is 50 mA, and the directivity is 10 degrees. On the other hand, each output wavelength is indicated by a number following L. In this example, all three types of wavelengths were verified.

The LED was disposed at a position where the distance from the fingertip is 0 mm, that is, immediately above the fingertip. In addition, the angle R of the LED optical axis L with respect to the installation part 10 is 30 degrees and 60 degrees, and the power supply voltage is changed in three stages for each, and three images with different brightness are taken for each stage (a total of nine images). In the same manner as in the first example, the matching score was obtained. The height H with respect to the mounting part 10 became a little different with the change of the installation angle of LED, and the former was 38 mm and the latter was 76 mm. For comparison, the LED is arranged at a position 30 mm and 60 mm away from the inspection target 1 on the line of sight N of the imaging means 4 and the angle R of the optical axis L with respect to the installation part 10 is 90 degrees. Similarly, the matching score was obtained.
In addition, although the 2nd Example verified about five test objects other than the test object which obtained the result shown below, since the tendency which the result showed was the same, description of those results is Omitted.

Tables 2 to 4 show the results of the second example. Table 2 shows the results when the wavelength is 760 nm, Table 3 shows the results when the wavelength is 830 nm, and Table 4 shows the results when the wavelength is 850 nm.

  According to the second embodiment, even if only one LED having extremely high directivity is used, it is necessary and sufficient for authentication using a vein pattern by concentrating the light emitted from the LED on the specific area 3 of the inspection object 1. It was confirmed that a coincidence point was obtained.

Further, from the results of the first and second embodiments, as long as the light is concentrated on the specific region to be inspected, the angle R of the LED optical axis L with respect to the installation portion 10 may hardly affect the authentication result. It could be confirmed.
Furthermore, with regard to the wavelength, the result was generally good at any wavelength, but it was found that the average result was particularly good at 850 nm. On the other hand, it was confirmed that the power consumption at 830 nm was the smallest and the power consumption at 760 nm was the largest. This is considered to be due to the characteristics of the light absorptance according to the wavelength and the characteristics of the LED according to the wavelength.
Furthermore, when the inspection object is difficult to transmit light (for example, a male finger with a thick epidermis), it is necessary to increase the output of the LED in order to increase the amount of light. It was confirmed that halation occurred (the area that was exposed to light was strongly whitened). In such a case, it was confirmed that it was necessary to cope with the problem by using two LEDs and lowering the output of each LED. The low score when the angle of the optical axis L is 90 degrees and the LED height is 30 mm at a wavelength of 830 nm is considered to be caused by halation.

  The third embodiment is the same as the first and second embodiments in other configurations except that a titanium-sapphire laser is employed as the light emitter. In addition, this 3rd Example is an Example of the 2nd light irradiation structure concerning this invention.

  In this third embodiment, the laser was installed such that the angle R of the optical axis L with respect to the installation part 10 was about 40 degrees, and the wavelength of the output light was 830 nm. FIG. 11 is an image obtained in this example. FIG. 10 is for comparison, and is an image obtained under substantially the same conditions (850 nm, angle 30 degrees) in the second embodiment. Then, comparing FIG. 10 with FIG. 11, it can be seen that in FIG. 11, blood vessels are more clearly reflected.

  According to this embodiment, when the light is concentrated on a specific point using a laser, the vein pattern is more concentrated than when the light is concentrated on a specific area as in the first and second embodiments. It was confirmed that a clearer image was obtained and sufficient data for authentication could be obtained. Since the wavelength distribution of the laser light is focused near the peak wavelength than the LED light, it can be said that the laser is suitable as a light source for obtaining a clearer image.

It is a side view which shows schematic structure of the specific example of the 1st light irradiation structure concerning this invention. It is the same front view. It is the same top view. It is a perspective view of an authentication device provided with the structure. It is a side view which shows schematic structure of the other specific example of the 1st light irradiation structure concerning this invention. It is a side view which shows schematic structure of the specific example of the 2nd light irradiation structure concerning this invention. It is the image before a process obtained in the 1st Example. It is the image after the same gradation difference emphasis process. This is the accumulation of binarized images. It is the image obtained in the 2nd Example. It is the image obtained in the 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection object 2 Light-emitting body 3 Specific area | region 4 Imaging means 5 Specific point 6 Light L Optical axis M Axis line N Visual axis P Plane

Claims (5)

  In the authentication device using the vein pattern, the inspection object (1) is irradiated with light necessary for imaging the vein pattern, and the light (6) emitted from the directional light emitter (2) is the inspection object ( 1) Light irradiation structure characterized by concentrating on the specific area (3) above.   The luminous body (2) is arranged such that its optical axis (L) is on the same plane (P) as the axis (M) of the inspection object (1) and the visual axis (N) of the imaging means (4). The light irradiation structure according to claim 1, wherein the specific region (3) is formed on the line-of-sight axis (N).   In the authentication device using the vein pattern, the inspection object (1) is irradiated with light necessary for imaging the vein pattern, and the light (6) emitted from the directional light emitter (2) is the inspection object ( 1) Light irradiation structure characterized by concentrating on the specific point (5) above.   The luminous body (2) is arranged such that its optical axis (L) is on the same plane (P) as the axis (M) of the inspection object (1) and the visual axis (N) of the imaging means (4). The light irradiation structure according to claim 3, wherein the specific point is formed on the visual axis (N). The light according to any one of claims 1 to 5, wherein the light emitter (2) is arranged at a position near the tip of the inspection object (1) placed in an inspectable state. Irradiation structure.