Browse Prior Art Database

Fingerprint Comparator

IP.com Disclosure Number: IPCOM000084545D
Original Publication Date: 1975-Nov-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 50K

Publishing Venue

IBM

Related People

Riskin, SI: AUTHOR

Abstract

An arrangement is described to compare a live fingerprint against a reference print, in order to confirm a match or reject if no match is obtained. Such an arrangement may be used at locations where it is necessary to permit or prevent access to a secured facility.

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Fingerprint Comparator

An arrangement is described to compare a live fingerprint against a reference print, in order to confirm a match or reject if no match is obtained. Such an arrangement may be used at locations where it is necessary to permit or prevent access to a secured facility.

In order to determine whether a match is present or not, the negative, for example, of a selected authorized reference print is compared to the positive of the live print. The prints are moved with respect to one another in an effort to align the prints. If full opacity is obtained when the prints are aligned, a match is present.

As shown in the figure, master reference print 1 is positioned beneath illumination source 3. Typically, the master reference print is a negative print or image corresponding to the print against which the live print is to be compared. A file of authorized reference prints against which comparison is to be made may be stored locally.

Alternatively, rather than have a file of reference prints stored locally at each point where access is to be made to the facility, a badge storing the authorized print against which comparison is to be made may be carried by the owner of the print. Thus, anyone who is permitted access to the facility would utilize the badge with an authorized reference print at the point of local access, and the comparator device shown would act to compare the fingerprint of the badge carrier with the reference print stored on the badge.

As shown in the figure, the live fingerprint or image is represented by 5. As is evident, where the master reference print 1 is a negative image, the live fingerprint 5 is a positive image. However, it is clear that these may be reversed, such that reference print 1 is a positive image and live print 5 is a negative image. Where reference print 1 is retrieved from a local file, any of a variety of devices such as a filmstrip, carousel, and the like may be utilized to store the various authorized prints to be used as references.

Where a file system is used, selection of the appropriate frame may be made by a user-initiated signal or by a coded badge, either of which would specify the frame number against which comparison is to be made. In this regard, it is clear that the frame may include additional machine readable information for local or remote use. For example, the frame could readily include information such as a coded user identification for sign-on, and any of a variety of parameters which may be utilized to assist in the compare and sensing process.

In addition to specifying the frame number of the print against which a comparison is to be made, the user places the appropriate finger upon an optical surface, such as a prism. For this purpose, a concave surface may be desirable to maximize contact. With the appropriate finger on the optical surface, a high- contrast positive photographic transparency is taken of the live print. In this regard, pressure on the prism ma...