Patent EP0098607A2 successfully refreshed from Google Patents.
EP0098607A2
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EP
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Fingerprint image refinement
Assignee: Fingermatrix Inc
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Filing: 1983-07-07
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Granted: —
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Expires: 2003-07-07
Abstract
Abstract @ In an optical fingerprint image processing apparatus a light beam is scanned across a finger placed against a transparent platen in order to provide a reflected modulated light beam carrying fingerprint information. The modulated light beam is imaged and the image is intercepted by an array of photo receptors that detect the image and convert the optical signal into electrical signals. The improvement is in placing a diffuser element, which may be a ground glass wafer, in the interrogating light beam. The diffusion of the light beam acts as an effective filter to eliminate the higher spatial frequency components of the optical image and thus provide a fingerprint image having improved continuity.
Inventors
- 👤 Michael Schiller
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 10:52
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/10; A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172; G06V40/00; G06V40/10; G06V40/12; G06V40/13; G06V40/1324
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
81 words
In an optical fingerprint image processing apparatus in which a light beam is scanned across a finger object on a platen to provide a modulated reflected light beam, an imaging lens in the reflected light beam and a photo-responsive sensor downstream from the imaging lens to receive and detect the image of the finger being interrogated, the improvement comprising: a diffuser element positioned within the interrogating light beam to provide a diffused interrogating light beam to the finger object being scanned.
Claim 2
Dependent Claim
81 words
In an optical fingerprint image processing apparatus in which a light beam is scanned across a finger object on a platen to provide a modulated reflected light beam, an imaging lens in the reflected light beam and a photo-responsive sensor downstream from the imaging lens to receive and detect the image of the finger being interrogated, the improvement comprising: a diffuser element positioned within the interrogating light beam to provide a diffused interrogating light beam to the finger object being scanned.
Claim 3
Dependent Claim
52 words
The improvement of claim 1 wherein said platen has a transparent substrate and a degormable, resilient layer on the finger receiving surface thereof, said layer being responsive to an applied finger to provide the fingerprint object, said deformable layer including a reflective layer to provide the fingerprint object as a reflective object.
Claim 4
Dependent Claim
22 words
The improvement of claim 1 wherein said platen has a transparent substrate and an anti-reflective coating on the finger receiving surface thereof.
Claim 5
Dependent Claim
22 words
The improvement of claim 1, wherein said diffuser element has a diffusing surface with a grain size approximately ten micrometers in diameter.
Claim 6
Dependent Claim
22 words
The improvement of claim 2, wherein said diffuser element has a diffusing surface with a grain size approximately ten micrometers in diameter.
Claim 7
Dependent Claim
22 words
The improvement of claim 3, wherein said diffuser element has a diffusing surface with a grain size approximately ten micrometers in diameter.
Claim 8
Dependent Claim
86 words
In the method of optically processing a fingerprint image in which a fingerprint object is optically scanned by an interrogating light beam to provide a reflected light beam modulated with the fingerprint information and wherein the modulated light beam is imaged by an imaging lens and an array of photodetectors is positioned downstream from the lens to receive and detect the image formed, the improvement comprising the step of: diffusing the interrogating light beam sufficiently to eliminate the higher spatial frequency components of the reflected image.
Claim 9
Dependent Claim
86 words
In the method of optically processing a fingerprint image in which a fingerprint object is optically scanned by an interrogating light beam to provide a reflected light beam modulated with the fingerprint information and wherein the modulated light beam is imaged by an imaging lens and an array of photodetectors is positioned downstream from the lens to receive and detect the image formed, the improvement comprising the step of: diffusing the interrogating light beam sufficiently to eliminate the higher spatial frequency components of the reflected image.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein said step of diffusing is insufficient to substantially degrade the interrogating light beam.
Claim 11
Dependent Claim
41 words
The method of claim 7 wherein the fingerprint object is formed from a finger placed against a platen and wherein the interrogating light beam is modulated by differential scattering of the light reflected respectively from beneath the valley and ridge zones.
Claim 12
Dependent Claim
28 words
The method of claim 7 wherein the fingerprint object is formed from a finger placed against a platen having an anti-reflective coating on the finger receiving surface thereof.
References Cited (Backward Citations)
No citation records indexed.
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