Personal identification device and method

#The present invention relates to a device and a method for identifying a person by utilizing a vein pattern obtained by imaging light transmitted through his or her finger.

#Personal identification techniques include methods based on fingerprints, irises, voice, veins on the back of a hand and so forth. A number of companies are already manufacturing and marketing fingerprint-based personal identification devices. These products identify a person by reading his or her fingerprint by having the fingerprint come into contact with a fingerprint sensor, recognizing end points and branching points of the fingerprint, and collating them with characteristic points of registered fingerprints.

#JP-A-295674/1998 discloses a personal identification device based on veins on the back of a hand. According to this, the back of a hand is faced toward an image pick-up camera, and the reflection of the light emitted from the camera is used to pick up a blood vessel pattern to identify the person on that basis. The device is designed to prevent the location of the hand to be imaged from fluctuating from one round of identification to another by having the hand grasp a fixed rod-shaped guide.

#FIG. 1 illustrates an example of system configuration for implementing the present invention;

#FIG. 2 illustrates an example of configuration of an input interface for acquiring a finger vein image;

#FIG. 3 illustrates another example of configuration of an input interface for acquiring a finger vein image;

#One embodiment of the present invention will be described in detail below. FIG. 1 is a schematic block diagram of a system configuration for implementing the invention. Within a vein pattern input interface 1, which corresponds to the part into which fingers are to be inserted, there are a light source 2, an optical filter 3 and a CCD camera 4. Insertion of fingers between the light source 2 and the optical filter 3 results in acquisition of a vein pattern. Light transmitted through fingers is picked up by the CCD camera 4 via the optical filter 3. Image signals picked up by the CCD camera 4 are taken into a personal computer (PC) 6 by using an image capture board 5. Within the PC 6, the image signals that have been taken in are stored into a memory 8 via an interface 7. A registered image kept in an outer storage 10 is also stored into the memory 8. Then, in accordance with a program stored in the memory 8, a CPU 9 determines whether or not the taken-in image is identical with the registered image. Incidentally, this program may as well be supplied to the identification device using an outer storage medium. As the storage medium, for example, a floppy disk, hard disk, optical disk, photomagnetic disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card or ROM can be used.

#FIG. 2 shows an example of structure of the finger vein pattern input interface 1 for acquiring a finger vein pattern image by a non-contact method. The interface has a finger inlet 22, which is a groove-shaped gap. By passing fingers 20 through that part, a vein pattern is acquired. In doing so, there is no need to bring the fingers into contact with the identification device itself. Also, by passing a plurality of fingers through the groove, a vein pattern of a plurality of fingers can be picked up. Furthermore, by swinging down the fingers in an arc track centering on a shoulder, elbow or wrist, it is also possible to pick up a finger image by be consecutively passing the plurality of fingers 20 through the finger inlet 22. Where such a non-contact image pick-up method is adopted, the picked-up finger image rotates relative to the plane of the picked-up image. Therefore, the picked-up finger image inevitably requires rotational correction.

#To add, while the groove may have any direction relative to the ground, especially where the groove is provided in a direction vertical to the ground, there is a convenience of use that a patterned image can be acquired by a natural action of the user in which his or her hand is swung following gravity.