Apparatus for identifying an individual based on a fingerprint image
First Claim
1. An individual identification apparatus for measuring correlation between a body portion of a specific individual and a body portion of an arbitrary individual to thereby determine whether the arbitrary individual is or is not the specific individual, the individual identification apparatus comprising:
- first positioning means for positioning, at a predetermined first position, a portion of a body of an arbitrary individual to be identified with a specific individual;
first reading means for irradiating light onto the portion of the body of the arbitrary individual which is positioned at the first position to obtain a single optical image of the portion of the body of the arbitrary individual;
specific individual image producing means for producing a single optical image of a portion of a body of the specific individual based on information contained in an image of the portion of the body of the specific individual;
light producing means for producing coherent first and second read-lights, the second read-light being a linearly-polarized coherent beam having a polarization plane parallel to a first plane;
first spatial light modulating means for receiving an optical joint image made up of the single optical image of the portion of the body of the arbitrary individual and the single image of the portion of the body of the specific individual, the optical joint image having the single image of the portion of the body of the specific individual and the single image of the portion of the body of the arbitrary individual at different positions, said first spatial light modulating means receiving the first read-light and modulating the first read-light in accordance with the joint image to output the modulated first read-light;
a lens for Fourier transforming the modulated first read-light outputted from said first spatial light modulating means to thereby produce an optical Joint Fourier Transform image;
second spatial light modulating means for receiving the optical Joint Fourier Transform image and for receiving the second read-light and modulating the second read-light in accordance with the Joint Fourier Transform image to output a modulated second read-light, said second spatial light modulating means including a second optically-addressable spatial light modulator which has a single cell structure having a single optically-addressing part and a single modulating part, the optically-addressing part receiving the optical Joint Fourier Transform image and changing optical characteristic of the modulating part in accordance with the optical Joint Fourier Transform image, the modulating part receiving the second read-light and modulating the second read-light in accordance with the changed optical characteristic to output the modulated second read-light;
wherein the modulating part of said second optically-addressable spatial light modulator receives the second read-light and modulates phase of the second read-light in accordance with the changed optical characteristic,wherein the optically-addressing part of said second optically-addressable spatial light modulator includes a photosensing layer made of photoelectric material, said photosensing layer receiving the optical Joint Fourier Transform image and changing impedance of the photoelectric material dependently on the optical Joint Fourier Transform image,wherein the modulating part of said second optically-addressable spatial light modulator includes a liquid crystal layer formed of liquid crystal molecules of nematic phase and a pair of alignment layers provided to sandwich said liquid crystal layer therebetween for arranging the liquid crystal molecules in said liquid crystal layer in a homogenous arrangement so that the liquid crystal molecules are arranged to extend along a plane parallel to the first plane,wherein said second optically-addressable spatial light modulator further includes electric voltage applying means for applying an electric voltage through said photosensing layer and said liquid crystal layer to thereby produce an electric field in said liquid crystal layer, andwherein said photosensing layer changes the electric field produced in said liquid crystal layer in accordance with the changed impedance of the photoelectric material and causes the liquid crystal molecules to rotate along the plane parallel to the first plane due to dielectric anisotropy of the nematic liquid crystal molecules so as to electrically control the birefringence of the liquid crystal molecules to modulate the phase of the linearly-polarized second read-light in accordance with the electrically controlled birefringence,a lens for Fourier transforming the second read-light modulated by and outputted from said second spatial light modulating means to thereby produce an optical output correlation image;
intensity detecting means for detecting intensity of the optical output correlation image; and
calculating means for comparing a value of the detected intensity with a predetermined threshold value so as to judge correlation of the image of the portion of the body of the specific individual and the image of the portion of the body of the arbitrary individual to thereby determine whether or not the arbitrary individual and the specific individual are the same individual.
2 Assignments
0 Petitions
Accused Products
Abstract
In an individual identification apparatus, a hologram 11 recorded on a card is irradiated with laser light to read out a fingerprint image of a specific person. A finger of an arbitrary person to be identified with the specific person is irradiated with laser light to obtain a fingerprint image. Thus obtained fingerprint images are jointly written in a first SLM. Then, the joint image is read out and Fourier transformed to obtain a Joint Fourier Transform image, which is then written in a second SLM. The Joint Fourier Transform image is then read out and Fourier transformed to obtain a pair of output correlation peaks. A photodetector detects the intensity of the output correlation peaks and outputs a signal indicative of the intensity. A threshold processor compares the value of the signal with a predetermined threshold value to positively or negatively identify the arbitrary person with the specific person.
77 Citations
21 Claims
-
1. An individual identification apparatus for measuring correlation between a body portion of a specific individual and a body portion of an arbitrary individual to thereby determine whether the arbitrary individual is or is not the specific individual, the individual identification apparatus comprising:
-
first positioning means for positioning, at a predetermined first position, a portion of a body of an arbitrary individual to be identified with a specific individual; first reading means for irradiating light onto the portion of the body of the arbitrary individual which is positioned at the first position to obtain a single optical image of the portion of the body of the arbitrary individual; specific individual image producing means for producing a single optical image of a portion of a body of the specific individual based on information contained in an image of the portion of the body of the specific individual; light producing means for producing coherent first and second read-lights, the second read-light being a linearly-polarized coherent beam having a polarization plane parallel to a first plane; first spatial light modulating means for receiving an optical joint image made up of the single optical image of the portion of the body of the arbitrary individual and the single image of the portion of the body of the specific individual, the optical joint image having the single image of the portion of the body of the specific individual and the single image of the portion of the body of the arbitrary individual at different positions, said first spatial light modulating means receiving the first read-light and modulating the first read-light in accordance with the joint image to output the modulated first read-light; a lens for Fourier transforming the modulated first read-light outputted from said first spatial light modulating means to thereby produce an optical Joint Fourier Transform image; second spatial light modulating means for receiving the optical Joint Fourier Transform image and for receiving the second read-light and modulating the second read-light in accordance with the Joint Fourier Transform image to output a modulated second read-light, said second spatial light modulating means including a second optically-addressable spatial light modulator which has a single cell structure having a single optically-addressing part and a single modulating part, the optically-addressing part receiving the optical Joint Fourier Transform image and changing optical characteristic of the modulating part in accordance with the optical Joint Fourier Transform image, the modulating part receiving the second read-light and modulating the second read-light in accordance with the changed optical characteristic to output the modulated second read-light; wherein the modulating part of said second optically-addressable spatial light modulator receives the second read-light and modulates phase of the second read-light in accordance with the changed optical characteristic, wherein the optically-addressing part of said second optically-addressable spatial light modulator includes a photosensing layer made of photoelectric material, said photosensing layer receiving the optical Joint Fourier Transform image and changing impedance of the photoelectric material dependently on the optical Joint Fourier Transform image, wherein the modulating part of said second optically-addressable spatial light modulator includes a liquid crystal layer formed of liquid crystal molecules of nematic phase and a pair of alignment layers provided to sandwich said liquid crystal layer therebetween for arranging the liquid crystal molecules in said liquid crystal layer in a homogenous arrangement so that the liquid crystal molecules are arranged to extend along a plane parallel to the first plane, wherein said second optically-addressable spatial light modulator further includes electric voltage applying means for applying an electric voltage through said photosensing layer and said liquid crystal layer to thereby produce an electric field in said liquid crystal layer, and wherein said photosensing layer changes the electric field produced in said liquid crystal layer in accordance with the changed impedance of the photoelectric material and causes the liquid crystal molecules to rotate along the plane parallel to the first plane due to dielectric anisotropy of the nematic liquid crystal molecules so as to electrically control the birefringence of the liquid crystal molecules to modulate the phase of the linearly-polarized second read-light in accordance with the electrically controlled birefringence, a lens for Fourier transforming the second read-light modulated by and outputted from said second spatial light modulating means to thereby produce an optical output correlation image; intensity detecting means for detecting intensity of the optical output correlation image; and calculating means for comparing a value of the detected intensity with a predetermined threshold value so as to judge correlation of the image of the portion of the body of the specific individual and the image of the portion of the body of the arbitrary individual to thereby determine whether or not the arbitrary individual and the specific individual are the same individual. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A fingerprint identification apparatus for measuring correlation of an image of a fingerprint of a specific individual and an image of a fingerprint of an arbitrary individual to thereby determine whether or not the arbitrary individual is identified with the specific individual, the fingerprint identification apparatus comprising:
-
light producing means for producing coherent first and second read-lights, the second read-light being a linearly-polarized coherent beam having a polarization plane parallel to a first plane; first spatial light modulating means for receiving information contained in a joint image having a single image of a fingerprint of a specific individual and a single image of a fingerprint of an arbitrary individual to be identified with the specific individual and for receiving the first read-light to spatially modulate the first read-light in accordance with the joint image; a first Fourier transform lens for receiving the first read-light modulated by and outputted from said first spatial light modulating means and spatially Fourier transforming the first read-light to thereby allow the first read-light to form a Joint Fourier Transform image for the image of the fingerprint of the specific individual and the image of the fingerprint of the arbitrary individual; second spatial light modulating means for receiving the Joint Fourier Transform image and for receiving the second read-light to spatially modulate the second read-light in accordance with the Joint Fourier Transform image; a second Fourier transform lens for receiving the second read-light modulated by and outputted from said second spatial light modulating means and spatially Fourier transforming the second read-light to thereby allow the second read-light to form a pair of correlation peaks representative of correlation of the image of the fingerprint of the specific individual and the image of the fingerprint of the arbitrary individual; correlation detecting means for detecting intensity of one of the pair of correlation peaks; and calculating means for comparing a value of the detected intensity with a predetermined threshold value so as to judge correlation of the image of the fingerprint of the specific individual and the image of the fingerprint of the arbitrary individual to thereby determine whether or not the arbitrary individual is identified with the specific individual, wherein said second spatial light modulating means includes an optically-addressable SLM which has a single cell structure having a single optically-addressing part for receiving an optical image and a single modulation part having an optical characteristic, the optically-addressing part changing the optical characteristic of the modulation part dependently on the received optical image, the modulation part receiving and modulating the second read-light in accordance with the changed optical characteristic, wherein the optically-addressing part of said optically-addressable spatial light modulator includes a photosensing layer made of photoelectric material, said photosensing layer receiving the optical Joint Fourier Transform image and changing impedance of the photoelectric material dependently on the optical Join Fourier Transform image, wherein the modulating part of said optically-addressable spatial light modulator includes a liquid crystal layer formed of liquid crystal molecules of nematic phase and a pair of alignment layers provided to sandwich said liquid crystal layer therebetween for arranging the liquid crystal molecules in said liquid crystal layer in a homogeneous arrangement so that the liquid crystal molecules are arranged to extend along a plane parallel to the first plane, wherein said optically-addressable spatial light modulator further includes electric voltage applying means for applying an electric voltage through said photosensing layer and said liquid crystal layer to thereby produce an electric field in said liquid crystal layer, and wherein said photosensing layer changes the electric field produced in said liquid crystal layer in accordance with the changed impedance of the photoelectric material and causes the liquid crystal molecules to rotate along the plane parallel to the first plane due to dielectric anisotropy of the nematic liquid crystal molecules so as to electrically control the birefringence of the liquid crystal molecules to modulate the phase of the linearly-polarized second read-light in accordance with the electrically controlled birefringence. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
Specification