Fingerprint sensor and method
First Claim
1. Apparatus for sensing fingerprints comprising:
- a) fingerprint differentiation means for internally reflecting illuminating radiation from points of illumination on a contact surface of the fingerprint differentiation means corresponding to fingerprint valleys in one or more fingers of the subject pressed in a contact zone on the contact surface, and for transmitting illuminating radiation through the contact surface at points of illumination corresponding to fingerprint ridges in the fingers of the subject;
b) illuminating means affixed to the fingerprint differentiation means for internally illuminating the contact surface with a plurality of sub-beams of illuminating radiation emitted by an LED array, the angle of incidence of the sub-beams to the contact surface being selected to provide for reflection of the sub-beams from points of illumination corresponding to fingerprint valley points and transmission of sub-beams through the contact surface at fingerprint ridge points which contact the contact surface;
c) sensing means affixed to the fingerprint differentiation means for sensing sub-beams reflected from the contact surface and generating an electric signal for each sub-beam received.
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Accused Products
Abstract
A device for sensing and digitizing a fingerprint from a subject finger comprising a prism, a pixilated LED array affixed to the bottom surface of the prism and providing for the internal illumination, with a plurality of sub-beams, of the contact surface where the finger of the subject is pressed on the top surface of the prism, and a photoelectric sensor to detect the sub-beam radiation reflected from the fingerprint valley points. A sensor lens may also used for focusing the sub-beam radiation on the sensor. A lens wafer may be affixed between the prism and the LED array for focusing the radiation from each LED on its corresponding illumination point on the contact surface. The fingerprint ridge contact points do not reflect incident sub-beam radiation. A computer can provide for sequential emission of the sub-beams so that a single cell photoelectric sensor can be used to detect the reflected sub-beams or a multiple cell photoelectric sensor can be used, with each cell corresponding to a particular sub-beam. Reflected sub-beam radiation corresponds to a fingerprint valley point. Non-reflected sub-beam radiation corresponds to a fingerprint ridge point. The fingerprint is converted to a set of binary codes that can be used for imaging or identification purposes.
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Citations
64 Claims
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1. Apparatus for sensing fingerprints comprising:
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a) fingerprint differentiation means for internally reflecting illuminating radiation from points of illumination on a contact surface of the fingerprint differentiation means corresponding to fingerprint valleys in one or more fingers of the subject pressed in a contact zone on the contact surface, and for transmitting illuminating radiation through the contact surface at points of illumination corresponding to fingerprint ridges in the fingers of the subject;
b) illuminating means affixed to the fingerprint differentiation means for internally illuminating the contact surface with a plurality of sub-beams of illuminating radiation emitted by an LED array, the angle of incidence of the sub-beams to the contact surface being selected to provide for reflection of the sub-beams from points of illumination corresponding to fingerprint valley points and transmission of sub-beams through the contact surface at fingerprint ridge points which contact the contact surface;
c) sensing means affixed to the fingerprint differentiation means for sensing sub-beams reflected from the contact surface and generating an electric signal for each sub-beam received. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. Apparatus for sensing fingerprints comprising:
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a) prism having a prism top surface on which one or more fingers of a subject can be pressed for fingerprint sensing, a prism bottom surface and a prism end surface;
b) illuminating means affixed to the prism bottom surface for internally illuminating points of illumination on the prism top surface with a plurality of sub-beams of illuminating radiation emitted by an LED array, the angle of incidence of the sub-beams to the prism top surface being selected to provide for reflection to the prism end surface from points of illumination corresponding to fingerprint valley points of the fingers of the subject pressed on the prism top surface and for transmission of sub-beams through the prism top surface at fingerprint ridge points which are in contact with the prism top surface;
c) sensing means affixed to the prism end surface for sensing illuminating radiation of sub-beams reflected from the prism top surface and generating an electric signal for each sub-beam received. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. Apparatus for sensing fingerprints comprising:
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a) prism having a prism top surface on which one or more fingers of a subject can be pressed for fingerprint sensing, a prism bottom surface and a prism end surface;
b) LED array affixed to the prism bottom surface; and
c) photoelectric sensor affixed to the prism end surface. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. Method for sensing fingerprints comprising:
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a) step of pressing one or more fingers of a subject on a transparent contact surface, b) step of internally illuminating the contact surface at points of illumination with a plurality of sub-beams of illuminating radiation from an LED array, the angle of incidence of the sub-beams to the contact surface being selected to provide for reflection of the sub-beams from points of illumination corresponding to fingerprint valley points and transmission of sub-beams through the contact surface at fingerprint ridge points;
c) step of sensing sub-beams reflected from the contact surface and generating an electric signal for each sub-beam received. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64)
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Specification