The present invention relates to a finger vein authentication input apparatus to be used for a personal certification or authentication, with reproduction of pattern information of a finger vein, and it relates to, in particular, a technology for improving an accuracy of positioning a finger thereon.
In recent years, from a viewpoint of safety management for properties and/or information, an expectation is increased for the personal authentication, and in particular, an attention is paid upon the authentication apparatus of using the finger vein, because of no change is caused therein for a lifetime of a human being, from viewpoints of difficulty of forgery, usability, and a sense of security.
The authentication technology for an authentication apparatus of utilizing the finger vein is discloses, for example, in Japanese Patent Laying-Open No. 2004-49705 (2004). In this Japanese Patent Laying-Open No. 2004-49705 (2004) is described a personal authentication apparatus, having a light source portion for irradiating a penetrating light upon an upper surface of a finger, an interference filter portion, an image pickup portion for picking up an image of the light penetrating through said interference filter portion, and an image process portion for processing a vein pattern or print that is outputted from that image pickup portion. In particular, there is disclosed a technology for providing the following: a finger bump portion 4, so as to bump a tip of finger thereon, at the deepest portion (or a bottom) of a finger insertion portion, for the purpose of shifting thereof, in particular, in the major axis of the finger, a triangle mark 1 indicative of a center of the finger inserted into a inlet portion of the finger insertion portion of a case, for the purpose of preventing the finger from shifting in the minor axis of the finger and also from rotating around the axis of the major axis of the finger, an upper finger base bump portion 4, to be bumped with a finger base portion in the finger insertion portion, for the purpose of presenting the finger 7 from shifting from the image pickup portion, and a projection portion 5 in front of the finger bump portion 4.
In particular, in the finger vein authentication input apparatus, it is important to improve accuracy on the authentication, and for that purpose, it is a key to achieve an increase of the accuracy of positioning the finger therein. However, with the finger vein authentication input apparatus disclosed in the patent document mentioned above, although it has such the finger positioning parts therein, but there is still remained a problem for achieving the positioning with much higher accuracy.
According to the present invention, for accomplishing the increase of the authentication accuracy thereof, an object thereof is to provide a technology for lowering fluctuation or dispersion in positioning of a finger.
For accomplishing the object mentioned above, according to the present invention, there is provided a finger vein authentication input apparatus, for picking up an image of a vein authentication pattern of a finger with irradiating near infrared lights thereon, comprising: a finger positioning stand for positioning said finger thereon; a light source portion for irradiating the near infrared lights upon said finger; and an image pickup camera portion, being inputted with the near infrared lights penetrating through said finger, for converting into an image signal of the vein authentication pattern, wherein said finger positioning stand is provided at a position corresponding to a tip of said finger when picking up the image thereof, and has a fingertip projection portion protruding into a horizontal direction so as to be in contact with the tip of said finger, horizontally.
Further, according to the present invention, the finger vein authentication input apparatus, as described in the above, wherein said finger positioning portion further comprises a finger pulp projection portion, being provided at a position corresponding to the tip of said finger when picking up the image thereof, protruding into a vertical direction so as to contact with a pulp portion of said finger, vertically, and also a base guide portion, being provided at a position corresponding to a base side than a second joint of said finger when picking up the image thereof, and having a configuration being curved along a cross-section configuration of said finger.
According to the present invention, since it is possible to lower the fluctuation in positioning of a finger within the finger vein authentication input apparatus, thereby achieving an improvement on the accuracy of finger vein authentication.
Those and other objects, features and advantages of the present invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings wherein:
Hereinafter, embodiments according to the present invention will be fully explained by referring to the attached drawings.
Next, explanation will be made on a method for picking up a vein pattern of the finger 7. In
Because hemoglobin in the blood absorbs the near infrared lights, the near infrared lights cannot penetrate through the vein. With using this characteristic, a near infrared light image of vein is taken within the image pickup portion 2, and it is converted into a picture signal. Upon basis of the picture signal obtained, the vein is patterned, and then it is matched with the pattern, which is registered in advance, i.e., conducting the authentication.
As was mentioned above, since the authentication is made by the pattern matching in the finger vein authentication, it is important to lessen repetitive error of a vein pattern to be pickup, for the purpose of obtain an improvement of a rate of authentication. With the structures of the fingertip positioning stand 81 and the finger-base positioning stand 82, according to the present invention, it is possible to bring the setting position of the finger 7 to be constant, and therefore it is possible to reduce the repetitive error of the vein pattern, i.e., being effective for an increase of the authentication rate. Hereinafter, explanation will be made in details of the structures of the fingertip positioning stand 81 and the finger-base positioning stand 82.
As is shown in
For obtaining such the structures as was mentioned above, the inventors made evaluations on a sense of contacting, for each contacting portion of the finger 7 with the finger positioning stand. In more details thereof, the contacting sense evaluation is conducted while pushing a rod of circular cross-section of +1.5 mm, on each portion at the tip of the finger 7 at weight of 50 g. As a result thereof, it is apparent that the contacting sensitivity is the strongest at the position just below the fingernail 71, among those contacting sensitivities made along a central line 10 extending into the longitudinal direction of the finger 7, and that it is gradually weaken, directing from the fingernail 7 to the pulp of finger.
From such the results of contacting senses, it can be seen that the positioning error of the finger can be made small, by applying the structures of bumping the projection portion at the tip portion of the finger 7, below the fingernail 71, at around the right angles (90 degree), as was mentioned above. For the purpose of increasing this effect, as is shown in
Also, for determining an optimal length “L” on the cross-section of the fingertip projection portion 5 shown in
Or, as is shown in
From the estimation results mentioned above, upon the sensitivity of the contacting sense at each of the contacting points on the finger 7 between the finger positioning stand, because the sensitivity of the contacting sense on the pulp portion of the finger 7 is low comparing to that below the fingernail 71, therefore for compensating that, the length in the longitudinal direction of the finger is made longer than that in the width direction of the finger. In the similar manner to that mentioned above, for determining the finger pulp projection portion 4, it is also necessary to take the safety and the sense of incompatibility when contacting or the like, into the consideration thereof, other than the characteristics of sensitivity of the contacting sense, and from the result of the total estimation made by us, it is apparent that the above mentioned can be satisfied by setting the finger pulp projection portion 4 within a range of ratio from 2.0 to 8.0, of the length of in the longitudinal direction of the finger to that in the width direction of the finger.
Further, as is shown in
Next, explanation will be made on the situation of increasing the positioning accuracy of the finger, with provision of the fingertip projection portion 5, the finger pulp projection portion 4, and the finger contact portion 91, by referring to FIGS. 3 to 6.
As is shown in
Also, as shown in
Or, as is also shown in
According to the present invention, because of the structures of the finger positioning stand, having the fingertip positioning stand and the finger base positioning stance, wherein the fingertip projection portion and the finger pulp projection portion are provided on the fingertip positioning portion, while providing the guide portion along the finger configuration on the finger base positioning stand, it is possible to obtain a large merit or advantages, i.e., maintaining high accuracy of positioning of the finger, with an aid of the fingertip projection portion that is provided on the fingertip positioning portion, against the position shift when positioning the finger in the longitudinal direction thereof, while maintaining high accuracy of positioning of the finger, with an aid of the finger pulp projection portion that is provided on the fingertip positioning portion, against the position shift of the fingertip portion in the width direction of thereof, or with an aid of the finger base guide portion that is provided on the finger base positioning stand, against the position shift in the width direction of the finger at the finger base portion thereof.
While we have shown and described several embodiments in accordance with our invention, it should be understood that disclosed embodiments are susceptible of changes and modifications without departing from the scope of the invention. Therefore, we do not intend to be bound by the details shown and described herein but intend to cover all such changes and modifications that fall within the ambit of the appended claims.
Number | Date | Country | Kind |
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2006-258236 | Sep 2006 | JP | national |