Method of recognizing a fingerprint
First Claim
1. Method of recognizing fingerprints and similar skin surface structures in which the structure of a finger surface placed on a smooth surface is scanned and compared with a characteristic structure stored on a record carrier, characterized in that the structure of the finger surface is scanned with soundwaves generated by an ultrasound source, the soundwaves being directed through a liquid and/or solid body at least from the ultrasound source to the smooth surface and being directed through the smooth surface to the finger surface, the soundwave structure obtained being transformed to suitable evaluation characteristics and being compared with the stored characteristic structure.
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Accused Products
Abstract
A method of detecting fingerprints by sensing scanning with ultrasonic waves. For comparison, an acoustic hologram of the characteristics of the respective finger is disposed in an identification card. The hologram is compared in a recognition device with an ultrasonic interference pattern which is obtained by reflection of ultrasonic waves at an interface formed between the surface of the finger and a planar application or support surface.
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Citations
20 Claims
- 1. Method of recognizing fingerprints and similar skin surface structures in which the structure of a finger surface placed on a smooth surface is scanned and compared with a characteristic structure stored on a record carrier, characterized in that the structure of the finger surface is scanned with soundwaves generated by an ultrasound source, the soundwaves being directed through a liquid and/or solid body at least from the ultrasound source to the smooth surface and being directed through the smooth surface to the finger surface, the soundwave structure obtained being transformed to suitable evaluation characteristics and being compared with the stored characteristic structure.
- 14. A system of recognizing fingerprints and similar skin surface structures, said system comprising an application plate (1) made of a material transparent to ultrasonic waves and having a smooth surface (2) for supporting a finger (3), a record carrier (11, 13) having a acoustic hologram containing the characteristics of a fingerprint, an ultrasonic generator (10) for producing ultrasonic energy, a raster receiver (12) for converting ultrasonic energy to electrical signals, the soundwaves emitted by said ultrasonic generator being directed through a liquid and/or solid body at least from said ultrasonic generator to said smooth surface with at least some of the soundwaves passing through said smooth surface, the soundwaves emitted by said generator impinging successively or simultaneously on the finger surface and the acoustic hologram, the soundwaves reflected thereby being supplied to said raster receiver, and an electronic evaluating unit for evaluating said signals from said raster receiver.
Specification