Latent fingerprint detectors and fingerprint scanners therefrom

摘要

This document relates to systems and method for latent fingerprint detection using specular reflection (glare). An exemplary system may include a light source alignment portion configured to align a light source at an illumination angle relative to a sample surface such that the light source illuminates a sample surface so that the surface produces specular reflection. The system may also include a specular reflection discriminator that directs the produced specular reflection to an optical detector aligned relative to said sample surface at an alignment angle that is substantially equal to an angle of reflection of the produced specular reflection. Preferably, the directed specular reflection does not saturate the optical detector; and the optical detector captures the specular reflection from the sample surface and generates image data using essentially only the specular reflection.

主权项

1. A surface contaminant detection system, comprising:
a first light source that illuminates a sample surface such that the sample surface produces specular reflection; and an optical detector arranged at a critical alignment angle relative to the first light source such that the optical detector captures the specular reflection from the sample surface and generates image data using essentially only the specular reflection to generate image data of the sample surface; wherein said first light source and said optical detector comprise substantially equal and opposite numerical apertures to create geometric filtering to discriminate against diffuse reflection.