Finger identification apparatus and method
First Claim
1. Fingerpress processing apparatus comprising:
- scanning means to scan an interrogating beam of spatially coherent light having a predetermined cross sectional shape across a fingerpress to provide a reflected light beam modulated with minutia identification information,a holographic correlator coupled to said reflected light beam,said correlator including a hologram of a predetermined character plate having a plurality of standardized finger identification minutia, said minutia including a first set of bifurcation minutia and a second set of line ending minutia, each of the bifurcation minutia in the first set being identical to one another in shape and having an angular orientation unique relative to all other bifurcation minutia, each of said line ending minutia being identical to one another in shape and having an angular orientation unique relative to all other line ending minutia, each of said standardized minutia having a predetermined spatial position on said character plate, andprojection means to project the Fourier transform of said reflected light beam onto said hologram to provide a plurality of correlation light beams indicative of the minutia being scanned on said fingerpress.
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Accused Products
Abstract
A slit beam of coherent light is scanned across a flat finger print or fingerpress to provide a modulated reflected light beam. A Fourier transform of the modulated light beam is projected onto a hologram of a standard character plate. The character plate, from which the hologram is made, contains standardized minutia; specifically, line bifurcations and line endings, that are typical of a finger surface image. Correspondence between one of the minutia being scanned and one of the minutia in the character plate results in correlation of the Fourier transform of the minutia being scanned with the hologram of the corresponding minutia on the character plate to produce a correlation beam. An array of photocells is placed optically downstream from the hologram. Excitation of one of the photocells by one of the correlation light beams serves to identify the minutia being scanned by type of minutia, position of minutia and angular orientation thereof.
42 Citations
16 Claims
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1. Fingerpress processing apparatus comprising:
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scanning means to scan an interrogating beam of spatially coherent light having a predetermined cross sectional shape across a fingerpress to provide a reflected light beam modulated with minutia identification information, a holographic correlator coupled to said reflected light beam, said correlator including a hologram of a predetermined character plate having a plurality of standardized finger identification minutia, said minutia including a first set of bifurcation minutia and a second set of line ending minutia, each of the bifurcation minutia in the first set being identical to one another in shape and having an angular orientation unique relative to all other bifurcation minutia, each of said line ending minutia being identical to one another in shape and having an angular orientation unique relative to all other line ending minutia, each of said standardized minutia having a predetermined spatial position on said character plate, and projection means to project the Fourier transform of said reflected light beam onto said hologram to provide a plurality of correlation light beams indicative of the minutia being scanned on said fingerpress. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. Fingerpress processing apparatus comprising:
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a source of spatially coherent light providing an interrogating beam having a predetermined cross sectional shape, scanning means to scan said interrogating beam across a fingerpress to provide a reflected light beam modulated with identification information, and an off-axis holographic correlator coupled to said reflected light beam, said correlator including a hologram of a predetermined character plate having a plurality of standardized finger identification minutia, said minutia including a first set of bifurcation minutia and a second set of line ending minutia, each of the bifurcation minutia in the first set being identical to one another in shape and having an angular orientation unique relative to all other bifurcation minutia, each of said line ending minutia being identical to one another in shape and having an angular orientation unique relative to all other line ending minutia, each of said standardized minutia having a predetermined spatial position on said character plate, said correlator including an identification plate having a two dimensional array of photo-receptors, each of said receptors having a first state and a second state, the correlation of a minutia being scanned on said fingerpress with a corresponding minutia of said predetermined character plate providing a light signal sufficient in intensity to change the state of at least one of said photoreceptors, whereby each minutia in the fingerpress being scanned is identified as to kind, location and orientation. - View Dependent Claims (10, 11, 12)
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13. The method of identifying a fingerpress comprising the steps of:
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scanning said fingerpress with an interrogating beam of spatially coherent light having a predetermined cross-sectional shape to provide a reflected light beam modulated with identification information, and correlating the minutia images carried by said reflected light beam against a plurality of predetermined standardized finger identification minutia from a character plate having a plurality of standardized finger identification minutia, said minutia including a first set of bifurcation minutia and a second set of line ending minutia, each of the bifurcation minutia in the first set being identical to one another in shape and having an angular orientation unique relative to all other bifurcation minutia, each of said line ending minutia being identical to one another in shape and having an angular orientation unique relative to all other line ending minutia, each of said standardized minutia having a predetermined spatial position on said character plate, said step of correlating including projecting the Fourier transform of said reflected light beam on a hologram of said character plate to provide correlation light beams representative of each correlation obtained. - View Dependent Claims (14, 15, 16)
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Specification