Browse Prior Art Database

Direct Optical Input System for Fingerprint Verification

IP.com Disclosure Number: IPCOM000081127D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Follette, DT: AUTHOR [+3]

Abstract

Present direct entry systems for fingerprint verification and identification produce a distorted image of the print. In the present system, the image is geometrically similar to the object by making the object and image planes parallel to each other; and the system is in focus over the entire image area, by virtue of the fact that the plane normal to the lens axis and passing through the center of the lens intersects the intersection of the object in image planes.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Direct Optical Input System for Fingerprint Verification

Present direct entry systems for fingerprint verification and identification produce a distorted image of the print. In the present system, the image is geometrically similar to the object by making the object and image planes parallel to each other; and the system is in focus over the entire image area, by virtue of the fact that the plane normal to the lens axis and passing through the center of the lens intersects the intersection of the object in image planes.

Referring to the figure, the light reflected from the finger through the prism is transmitted to a wide-angle lens having a field of around 100 Degrees. The preferred lens is of the superangulon type with a 66 mm., f/8 lens. The lens axis is tilted at 4 degrees 40' to the axis of the surface of the prism and only 9 Degrees of the full field of the lens is taken up by the image of the finger. A vidicon having the same axis as the prism receives the projected image through the lens. The vidicon digitizes the information on the finger for use by the remainder of the fingerprint system.

Other optical components for folding the optical path, magnification, rectification and image reduction can be easily assimilated into the system.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]