Method for initializing an electro-optical material and system for capturing a fingerprint image

Abstract

A fingerprint image capture system comprises an electro-optical material which captures a static fingerprint image and an apparatus for converting the static fingerprint image into an electronic signal. The image capture system includes an electrode for contacting a finger, and a bias supply for creating an electric field where epidermal ridges contact the electro-optical material. A transistor array senses charge or optical density variations in the electro-optical material to create an electronic representation of the fingerprint image. An initialization electrode places the electro-optical material into a uniform condition prior to acquisition of the fingerprint image. A physical artifact of the fingerprint image can be archived by removing the electro-optical material from the system following the fingerprint image acquisition.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional application of, and claims benefit to, U.S. patent application Ser. No. 15 / 821942, filed Nov. 24, 2017, entitled “METHOD AND APPARATUS FOR CAPTURE OF A FINGERPRINT USING AN ELECTRO-OPTICAL MATERIAL,” which is incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The present invention is related to the capture and retention of a fingerprint image. More specifically, the present invention provides an improved method and apparatus for capturing a fingerprint while achieving other useful objectives such as simplification of power supply electronics and non-volatile storage with a physical artifact for archival.BACKGROUND ART[0003]Fingerprint capture devices are finding increased use in law enforcement, security, financial, and other applications. The underlying motivation for fingerprint acquisition is the widely accepted belief that fingerprints are unique to an individual, and therefore compr...

AI Technical Summary

Benefits of technology

The present invention provides an improved fingerprint acquisition device and system using an opto-electronic material, such as pigmented electrophoretic material. The device creates a fingerprint image by placing the finger into contact with the material, resulting in an image that looks like a traditional ink on paper fingerprint. The fingerprint image can be archived or incorporated into an electronic storage medium. The invention addresses the need for better fingerprint acquisition technology, providing a more accurate and reliable method and apparatus for acquiring fingerprint images.

Problems solved by technology

The prior art fingerprint acquisition system of FIG. 1 has several undesirable characteristics: First, the visible fingerprint image is present only for the duration that the finger is in contact with the light emitting film and the ac power is applied.

Because the fingerprint image is constrained to only the portion of the finger contacting the device, it is not possible to obtain an extended contact image by rolling the finger from one side to another.

The power supply needed to generate these operating conditions typically adds complexity, cost, and lowers efficiency as compared with a typical low voltage direct current (dc) power supply.

Because the visible fingerprint image depends on light emission from a phosphor, the image may be rendered difficult or impossible to see under conditions of high external illumination, for example outside in bright sunlight.

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