JP2008198083A - Individual identification device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an individual identification device for accurately calculating the position deviation value of the fingertip between in fingerprint registration and fingerprint collation, and for highly precisely executing individual identification. <P>SOLUTION: This individual identification device is provided with: a light source 7 and a light source 8 which emit rays of light whose wavelengths are different to the fingertip 1; an imaging means 9 for imaging the rays of light emitted by the light source 7 and the light source 8, and for outputting image information; a vein data extraction part 14 for extracting the vein data of the fingertip 1 when the rays of light are emitted from the light source 7; a fingerprint data extraction part 15 for extracting the fingerprint data of the fingertip 1 when the rays of light are emitted from the light source 8; and a storage part 16 for storing the vein data and the fingerprint data in fingerprint registration, and is configured to calculate the position deviation value of the fingertip 1 between in fingerprint registration and fingerprint collation based on each vein data in fingerprint collation and fingerprint registration, and to perform position correction of the fingerprint data in fingerprint collation on the basis of the calculated position deviation value, and to compare the fingerprint data whose position has been corrected and the fingerprint data in fingerprint registration for individual authentication. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a personal identification device that identifies a person by collating fingerprints.

  The fingerprint of a human hand is composed of convex portions and concave portions formed on the ventral surface of the fingertip, and each has a different concave / convex pattern. A personal identification device that identifies individuals by collating fingerprints registers fingerprint data based on such a fingertip uneven pattern in advance, and the fingerprint data input during fingerprint collation matches the pre-registered fingerprint data Authenticate yourself depending on whether you want to do it.

  For personal identification devices, various methods for collecting fingerprint data have been proposed. For example, as a conventional technique, a technique has been proposed in which fingerprint data is collected by imaging light emitted from the nail side of a fingertip that is a subject through an abdominal surface of the fingertip and then imaging with an imaging means (patent Reference 1). In such a personal identification device, first, an imaging means images a difference in transmittance generated between the convex portion and the concave portion when light passes through the fingertip. Here, since the transmittance of the concave portion of the fingertip is higher than the transmittance of the convex portion, the convex portion is dark and the concave portion can be obtained as a bright image. Then, fingerprint data is collected based on the brightness of the image.

JP 2003-85538 A

  In general, when an individual is identified by a personal identification device, it is difficult to request the person to be authenticated to place his fingertip at exactly the same position as when registering a fingerprint during fingerprint verification. For this reason, in many cases, a positional deviation occurs in the obtained concavo-convex pattern (transmittance pattern) between fingerprint registration and fingerprint collation. For this reason, in the personal identification device, first, the positional deviation between the concavo-convex pattern obtained at the time of fingerprint collation and the concavo-convex pattern registered in advance is calculated by signal processing, and then both concavo-convex patterns ( The user must be authenticated by comparing fingerprint data obtained based on the concavo-convex pattern.

  Conventionally, the following processing has been performed in calculating the positional deviation amount. That is, after a captured fingerprint image (eg, an image of 320 × 320 pixels) is divided into a plurality of small regions of about 16 × 16 pixels, each small region is binarized (pixels brighter than a predetermined threshold are “ 1 ”, a pixel darker than a predetermined threshold is set to“ 0 ”), and the direction of the ridge within each small region is determined. Here, FIG. 3 shows the direction of the ridge in the small area and the small area. In the following, the direction of the ridge for each small area is referred to as direction angle data.

  When calculating the amount of positional deviation, the angle difference for each small region between the direction angle data at the time of fingerprint matching indicated by a solid line in FIG. 3 and the direction angle data at the time of fingerprint registration indicated by a broken line. Is calculated while shifting each small region up, down, left, and right, and a shift amount that minimizes the sum of the angle differences is obtained. That is, the amount of shift that minimizes the sum of the angle differences corresponds to the amount of positional deviation of the finger placement during fingerprint registration and fingerprint collation.

  However, when the direction angle data is used to calculate the amount of misalignment as in the past, if the uneven pattern obtained at the time of collation has a lot of noise (for example, rough surface or scratches on the ventral side of the fingertip) There has been a problem that an error occurs in the process of calculating the ridges in the small area, and the correct amount of misalignment cannot be calculated.

  The present invention has been made to solve the above-described problems, and its purpose is to accurately calculate the amount of positional deviation of the fingertip that occurs during fingerprint registration and fingerprint collation, and to identify individuals with high accuracy. It is to provide a personal identification device that can be implemented.

  The personal identification device according to the present invention images the light emitted from the first light source and the second light source, and the light emitted from the first light source and the second light source, respectively. An imaging means for outputting image information, a vein data extraction unit for extracting vein data of fingertips based on image information from the imaging means when light is emitted from the first light source, and a second light source Fingerprint data extraction unit that extracts fingerprint data of the fingertip based on image information from the imaging means when light is emitted from the vein, and vein data extracted by the vein data extraction unit and the fingerprint data extraction unit during fingerprint registration And the fingertip at the time of fingerprint registration and at the time of fingerprint verification based on the vein data extracted by the vein data extraction unit at the time of fingerprint matching and the vein data at the time of fingerprint registration stored in the storage unit of The amount of displacement is calculated, and the fingerprint data extracted by the fingerprint data extraction unit at the time of fingerprint collation is corrected based on the calculated amount of displacement, and then stored in the storage unit and the corrected fingerprint data. Signal processing means for comparing the fingerprint data at the time of fingerprint registration and authenticating the user.

  According to the present invention, it is possible to accurately calculate the amount of positional deviation of the fingertip that occurs at the time of fingerprint registration and fingerprint collation, and to perform individual identification with high accuracy.

  In order to explain the present invention in more detail, it will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
FIG. 1 is a diagram showing the configuration of a personal identification device according to Embodiment 1 of the present invention, and FIG. 2 is a diagram for explaining the operation of the personal identification device according to Embodiment 1 of the present invention. In FIG. 1 and FIG. 2, reference numeral 1 denotes a fingertip as a subject, and naturally has a fingerprint 2. That is, a concave / convex pattern including the convex portions 3 and the concave portions 4 is formed on the ventral side surface of the fingertip 1. Reference numeral 5 denotes a subject holding unit on which the person to be authenticated puts the fingertip 1. The subject holding part 5 has an opening 6 at a predetermined position so that the collation part of the placed fingertip 1 can be held in a non-contact state.

  Reference numerals 7 and 8 are arranged above the subject holding unit 5 and are located on the nail side of the fingertip 1 (the fingertip on which the fingerprint 2 is formed) with respect to the fingertip 1 of the person to be authenticated placed on the upper surface of the subject holding unit 5. 1 is a light source that emits light from the side opposite to the ventral side of 1. Here, the light source 7 (first light source) and the light source 8 (second light source) irradiate light of different wavelengths on the fingertip 1 from above in order to photograph different objects, for example, far from red. Light in the infrared region or light including light in the red to far infrared region is emitted to the fingertip 1. Specifically, the light source 7 is a light source for photographing a vein inside the fingertip 1 placed on the subject holding unit 5 and emits light having a wavelength of, for example, 800 to 900 nm. The light source 8 is a light source for photographing the fingerprint 2 of the fingertip 1 placed on the subject holding unit 5 and emits light having a wavelength of 600 to 800 nm, for example. The light emitted from the light source 7 and the light source 8 to the fingertip 1 placed on the subject holding unit 5 passes through the inside of the fingertip 1 and is emitted from the ventral surface of the fingertip 1, and then imaging means. 9 is imaged and imaged.

  The imaging means 9 is a means for imaging light from the light sources 7 and 8 that have passed through the inside of the fingertip 1, and includes, for example, an imaging lens 10, an imaging element 11, an image output circuit 12, and the like. Then, the imaging means 9 images the transmittance pattern when the light emitted from the light sources 7 and 8 is transmitted through the fingertip 1 by the imaging device 11, and outputs image information obtained based on the transmittance pattern to the image output circuit. 12 to output. Reference numeral 13 denotes a light source lighting control unit, 14 denotes a vein data extraction unit, 15 denotes a fingerprint data extraction unit, 16 denotes a storage unit, 17 denotes a positional deviation amount calculation unit, 18 denotes a positional deviation correction unit, and 19 denotes an authentication unit.

  The light source lighting control unit 13 performs ON / OFF control of the light sources 7 and 8, outputs a lighting signal to the vein data extraction unit 14 when the light source 7 is turned on, and turns on the light source 8. A lighting signal is output to the fingerprint data extraction unit 15. That is, the vein data extraction unit 14 is notified that one light source 7 is turned on, and the fingerprint data extraction unit 15 is notified that the other light source 8 is turned on. The vein data extraction unit 14 is output from the image output circuit 12 when light is emitted from the light source 7 to the fingertip 1, that is, when a lighting signal is input from the light source lighting control unit 13. Based on the obtained image information, vein data of the fingertip 1 placed on the subject holding unit 5 is extracted.

  The fingerprint data extraction unit 15 outputs an image output from the image output circuit 12 when light is emitted from the light source 8 to the fingertip 1, that is, when a lighting signal is input from the light source lighting control unit 13. Based on the information, the fingerprint data of the fingertip 1 placed on the subject holding unit 5 is extracted. The storage unit 16 stores various information for authenticating the user. For example, the vein data extracted by the vein data extraction unit 14 at the time of fingerprint registration or the fingerprint data extraction at the time of fingerprint registration. The fingerprint data extracted by the unit 15, the vein data and the password for associating the fingerprint data are stored.

  The misregistration amount calculation unit 17 uses the vein data extracted by the vein data extraction unit 14 at the time of fingerprint collation and the vein data at the time of fingerprint registration stored in the storage unit 16 in advance and at the time of fingerprint registration. The amount of displacement of the fingertip 1 from the time of collation is calculated. The misregistration correction unit 18 is based on the misregistration amount of the fingertip 1 between the fingerprint registration and the fingerprint collation calculated by the misregistration amount calculation unit 17, and the fingerprint extracted by the fingerprint data extraction unit 15 during the fingerprint collation. The position of the data is corrected so that the positional deviation from the fingerprint data at the time of fingerprint registration stored in advance in the storage unit 16 is minimized. The authentication unit 19 compares the fingerprint data at the time of fingerprint collation corrected by the positional deviation correction unit 18 with the fingerprint data at the time of fingerprint registration stored in advance in the storage unit 16 to perform personal authentication. In the first embodiment, the signal processing means includes the positional deviation amount calculation unit 17, the positional deviation correction unit 18, and the authentication unit 19.

Next, the operation of the personal identification device having the above configuration will be described.
A person who requires personal authentication by the personal identification device registers his / her vein data and fingerprint data in the personal identification device (storage unit 16) in advance. When performing personal authentication, first, the person to be authenticated performs a predetermined operation for starting the personal authentication, and places the fingertip 1 at a predetermined position of the subject holding unit 5. Then, the light source 7 is turned on by the operation of the light source lighting control unit 13, and the fingertip 1 placed on the subject holding unit 5 is irradiated with light from the nail side. At this time, the light source 8 is turned off.

  The light emitted from the light source 7 enters the fingertip 1 from the nail side of the fingertip 1, passes through the inside of the fingertip 1, and then is emitted from the ventral surface of the fingertip 1. The light emitted from the ventral surface of the fingertip 1 is input to the imaging means 9 disposed below the fingertip 1 and is imaged and imaged by the imaging means 9. Then, predetermined processing is performed in the imaging means 9 and image information is output from the image output circuit 12. At this time, the image information output from the image output circuit 12 includes vein information in the fingertip 1.

  The light source lighting control unit 13 outputs a lighting signal to the vein data extraction unit 14 together with the above operation of lighting the light source 7. The vein data extraction unit 14 extracts the vein data of the fingertip 1 based on the image information output from the image output circuit 12 when the lighting signal is input from the light source lighting control unit 13.

  Note that the vein data extracted by the vein data extraction unit 14 includes, for example, information on the branch position of the vein shown in FIG. Here, in FIG. 2, a solid line indicates a vein image at the time of fingerprint registration, and a broken line indicates a vein image at the time of fingerprint collation. That is, the vein data extraction unit 14 extracts vein branch positions A ′ and B ′ indicated by broken lines in FIG. 2 as vein data and outputs the vein data to the positional deviation amount calculation unit 17.

  Here, the processing in the vein data extraction unit 14 is performed by the following method, for example. First, the image information input from the image output circuit 12 is subjected to Fourier transform and converted to frequency components. Next, only the predetermined frequency component corresponding to the width of the vein is left from the result of the Fourier transform, and the other frequency components are set to 0, and then the inverse Fourier transform is performed. Through the above processing, only vein information can be extracted from the input image information (bandpass filter). Then, after binarizing the extracted vein information, it is converted into a line drawing by thinning processing, and branch positions A ′ and B ′ are extracted from the obtained line drawing.

  Then, the positional deviation amount calculation unit 17 calculates and calculates the positional deviation amount between the vein data extracted by the vein data extraction unit 14 and the vein data at the time of fingerprint registration stored in the storage unit 16 in advance. The positional deviation amount is output to the positional deviation correction unit 18. Here, FIG. 2 shows a case where a predetermined positional deviation occurs between fingerprint registration and fingerprint collation.

  The light source lighting control unit 13 turns off the light source 7 and turns on the light source 8 after detecting that the image information from the image output circuit 12 is input to the vein data extraction unit 14. The light emitted from the light source 8 passes through the fingertip 1 and is imaged and imaged by the imaging means 9 in the same manner as the light emitted from the light source 7. Then, image information is output from the image output circuit 12. At this time, the image information output from the image output circuit 12 includes information on the fingerprint 2 of the fingertip 1.

  The light source lighting control unit 13 outputs a lighting signal to the fingerprint data extraction unit 15 together with the above operation of lighting the light source 8. The fingerprint data extraction unit 15 receives the lighting signal from the light source lighting control unit 13, extracts the fingerprint data of the fingertip 1 based on the image information output from the image output circuit 12, and the positional deviation correction unit 18. Output fingerprint data for Then, the position deviation correction unit 18 corrects the position of the fingerprint data at the time of fingerprint collation input from the fingerprint data extraction unit 15 based on the position deviation amount calculated by the position deviation amount calculation unit 17, and then performs position correction. The authentication unit 19 compares the fingerprint data that has been stored with the fingerprint data that has been stored in advance in the storage unit 16, and authenticates the person.

  According to the first embodiment of the present invention, it is possible to accurately calculate the amount of positional deviation of the fingertip 1 that occurs at the time of fingerprint registration and fingerprint collation, and to perform individual identification with high accuracy. That is, in the personal identification device, the positional deviation amount of the fingertip 1 is calculated based on the vein data at the time of fingerprint registration and the vein data at the time of fingerprint collation. Since veins are much thicker than the ridges of fingerprint 2, they are less susceptible to fingertip 1 roughness and scratches, and the amount of displacement is calculated using directional angle data as in the past. Compared with the case where it does, accurate and stable calculation of the amount of position shift is attained. Therefore, individual identification can be performed with high accuracy.

It is a figure which shows the structure of the personal identification device in Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the personal identification device in Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the conventional personal identification device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fingertip 2 Fingerprint 3 Convex part 4 Concave part 5 Subject holding part 6 Opening part 7, 8 Light source 9 Imaging means 10 Imaging lens 11 Imaging element 12 Image output circuit 13 Light source lighting control part 14 Vein data extraction part 15 Fingerprint data extraction part 16 storage unit 17 misregistration amount calculation unit 18 misregistration correction unit 19 authentication unit

Claims (4)

A first light source and a second light source that respectively emit light of different wavelengths to the fingertip;
Imaging means for imaging light emitted from the first light source and the second light source and outputting image information;
A vein data extraction unit that extracts vein data of the fingertip based on image information from the imaging unit when light is emitted from the first light source;
A fingerprint data extraction unit that extracts fingerprint data of the fingertip based on image information from the imaging means when light is emitted from the second light source;
A storage unit for storing vein data and fingerprint data extracted by the vein data extraction unit and the fingerprint data extraction unit at the time of fingerprint registration;
Based on the vein data extracted by the vein data extraction unit at the time of fingerprint verification and the vein data at the time of fingerprint registration stored in the storage unit, the amount of positional deviation of the fingertip between the fingerprint registration and the fingerprint verification is calculated. The fingerprint data extracted by the fingerprint data extraction unit at the time of fingerprint collation is corrected based on the calculated positional deviation amount, and then the fingerprint data subjected to position correction and the fingerprint registration stored in the storage unit Signal processing means for comparing the fingerprint data and authenticating the person,
A personal identification device comprising: The signal processing means
Based on the vein data extracted by the vein data extraction unit at the time of fingerprint verification and the vein data at the time of fingerprint registration stored in the storage unit, the amount of positional deviation of the fingertip at the time of fingerprint registration and at the time of fingerprint verification is calculated. A positional deviation amount calculation unit to be calculated;
Based on the positional deviation amount calculated by the positional deviation amount calculation unit, a positional deviation correction unit that corrects the position of the fingerprint data extracted by the fingerprint data extraction unit during fingerprint matching;
An authentication unit that performs identity authentication by comparing the fingerprint data that has been position-corrected by the positional deviation correction unit and the fingerprint data that was stored in the storage unit at the time of fingerprint registration;
The personal identification device according to claim 1, further comprising: The lighting and extinguishing control of the first light source and the second light source is performed, and when the first light source is turned on, a lighting signal is output to the vein data extraction unit to turn on the second light source. A light source lighting control unit that outputs a lighting signal to the fingerprint data extraction unit when
The personal identification device according to claim 1, further comprising: The first light source and the second light source irradiate light on the fingertip from the nail side of the fingertip,
The imaging means images the light emitted from the first light source and the second light source on the ventral side of the fingertip, and the light emitted from the first light source and the second light source is the fingertip. 4. The personal identification device according to claim 1, wherein the image information is obtained based on a transmittance when the light is transmitted.

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