Fingerprint imaging device with fake finger detection

摘要

A fingerprint imaging device includes an optical plate having a finger receiving surface for creating an image of a fingerprint pattern. The fingerprint pattern is illuminated with light from an illuminating tool to create imaging light rays. The imaging light rays from the fingerprint pattern are received by an imaging lens that projects an image of the fingerprint pattern to an image sensor. Another light source is provided to project a light beam onto finger receiving surface. This light source is used to determine whether an object on the finger receiving surface is real or fake.