Apparatus and method for electronically acquiring fingerprint images
First Claim
1. An optical system for acquiring a fingerprint image, comprising:
- a housing defining an imaging aperture;
an incoherent light source directing light toward said imaging aperture at a non-normal angle;
an array of light sensors to receive sensed working image signals indicative of a fingerprint image; and
a platen affixed to said housing over said imaging aperture, said platen including a light receiving side and a fingerprint receiving side, said fingerprint receiving side receiving a fingerprint that produces fingerprint flesh regions and fingerprint valley regions on said fingerprint receiving side, said light receiving side including a plurality of adjacent optical structures that reduce the reflection of non-working image light signals from said light receiving side and pass working image light signals, said working image light signals being reflected at said fingerprint valley regions to produce a light portion of said sensed working image signals and passing through said fingerprint flesh regions to produce a dark portion of said sensed working image signals.
25 Assignments
0 Petitions
Accused Products
Abstract
A thin, inexpensive, removable platen for a direct fingerprint reader without a permanently attached platen. A removable platen is formed as a transparent area on a credit card, passport or identification card or as a separate card. The portable platen on the card is inserted over an imaging area of the direct fingerprint reader. Light from the direct fingerprint reader passes through an optical surface formed on the underside of the portable platen, is reflected off the fingerprint and passes back through the optical surface to the imaging apparatus where the image is digitized and analyzed. The optical surface is formed such that the incident light is not refracted away from the fingerprint and the reflected light from the fingerprint is not refracted away from the imaging apparatus.
84 Citations
25 Claims
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1. An optical system for acquiring a fingerprint image, comprising:
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a housing defining an imaging aperture; an incoherent light source directing light toward said imaging aperture at a non-normal angle; an array of light sensors to receive sensed working image signals indicative of a fingerprint image; and a platen affixed to said housing over said imaging aperture, said platen including a light receiving side and a fingerprint receiving side, said fingerprint receiving side receiving a fingerprint that produces fingerprint flesh regions and fingerprint valley regions on said fingerprint receiving side, said light receiving side including a plurality of adjacent optical structures that reduce the reflection of non-working image light signals from said light receiving side and pass working image light signals, said working image light signals being reflected at said fingerprint valley regions to produce a light portion of said sensed working image signals and passing through said fingerprint flesh regions to produce a dark portion of said sensed working image signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An optical system for acquiring a fingerprint image, comprising:
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a housing defining an imaging aperture; an incoherent light source directing light toward said imaging aperture at a normal angle; an array of light sensors to receive sensed working image signals indicative of a fingerprint image; and a platen affixed to said housing over said imaging aperture, said platen including a light receiving side and a fingerprint receiving side, said fingerprint receiving side receiving a fingerprint that produces fingerprint flesh regions and fingerprint valley regions on said fingerprint receiving side, said light receiving side including a plurality of adjacent optical structures that reduce the reflection of non-working image light signals from said light receiving side and pass working image light signals, said working image light signals passing through said fingerprint valley regions to produce a dark portion of said sensed working image signals and reflecting from said fingerprint flesh regions to produce a light portion of said sensed working image signals. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for acquiring a fingerprint image, comprising the steps of:
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directing light from an incoherent light source toward an imaging aperture; directing said light through a platen affixed to a housing over said imaging aperture, said platen including a light receiving side and a fingerprint receiving side, said fingerprint receiving side receiving a fingerprint that produces fingerprint flesh regions and fingerprint valley regions on said fingerprint receiving side, said light receiving side including a plurality of adjacent optical structures that reduce the reflection of non-working image light signals from said light receiving side and pass working image light signals; and sensing said working image signals indicative of a fingerprint image by an array of light sensors.
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18. A platen for use in a fingerprint imaging system, comprising:
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a light receiving side including a plurality of adjacent optical structures that reduce the reflection of non-working image light signals from said light receiving side; and a fingerprint receiving side which receives a fingerprint that produces fingerprint flesh regions and fingerprint valley regions on said fingerprint receiving side when light is applied to said platen from said light receiving side. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification