US4569080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fingerprint image refinement
Assignee: FINGEERMATRIX INC NY CORP
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Filing: 1983-06-23
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Granted: 1986-02-04
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Expires: 2003-06-23
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
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:55
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172; G; G06; G06V; G06V40/00; G06V40/10; G06V40/12; G06V40/13
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
In an optical fingerprint image processing apparatus wherein a fingerprint object on a platen 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 photo detectors is positioned downstream from the lens to receive and detect the image formed, the improvement comprising: a diffuser element positioned within the interrogating light beam to partially diffuse said beam and to provide an interrogating light beam at the fingerprint object which is sufficiently diffused to eliminate the higher spatial frequency components of the reflected image; whereby over-modulation components of the reflected image are avoided.
Claim 2
Dependent Claim
116 words
In an optical fingerprint image processing apparatus wherein a fingerprint object on a platen 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 photo detectors is positioned downstream from the lens to receive and detect the image formed, the improvement comprising: a diffuser element positioned within the interrogating light beam to partially diffuse said beam and to provide an interrogating light beam at the fingerprint object which is sufficiently diffused to eliminate the higher spatial frequency components of the reflected image; whereby over-modulation components of the reflected image are avoided.
Claim 3
Dependent Claim
52 words
The improvement of claim 1, wherein said platen has a transparent substrate and a deformable 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 2, wherein said diffuser element has a diffusing surface with a grain size approximately ten micrometers in diameter.
Claim 5
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 6
Dependent Claim
22 words
The improvement of claim 4, 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 1, wherein said diffuser element has a diffusing surface with a grain size approximately ten micrometers in diameter.
Claim 8
Dependent Claim
106 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: partially diffusing the interrogating light beam, the partial diffusion being sufficient to eliminate the higher spatial frequency components of the fingerprint image carried by the reflected light beam, whereby over-modulation components of the reflected image are avoided.
Claim 9
Dependent Claim
106 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: partially diffusing the interrogating light beam, the partial diffusion being sufficient to eliminate the higher spatial frequency components of the fingerprint image carried by the reflected light beam, whereby over-modulation components of the reflected image are avoided.
Claim 10
Dependent Claim
19 words
The method fo 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)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |