Showing papers on "Fingerprint recognition published in 1974"

Fingerprint recognition apparatus using non-coherent optical processing

Abstract: Apparatus for fingerprint recognition is disclosed utilizing relatively simple and inexpensive non-coherent optical processing techniques wherein the fingerprint ridge line orientations in a plurality of finite sampling areas of the fingerprint image are inspected with the aid of a rotating onedirectional lightsmearing element inserted in the reimaging light path. The apparatus employs light that is transmitted or scattered by the rotating element and uses the consequent time variation of the light level at an image plane to determine ridge orientation. At the image plane of the processor, there is located a plurality of photodetectors, each individual detector of the array corresponding to a particular sampling area of the fingerprint. The time delay between a reference orientation of the light smearing element and the occurrence of a light peak at each detector may be noted and a proportional analog or digital representation may be generated for immediate or subsequent comparison with corresponding signals representative of the fingerprints being presented for identification.