Method and device for recognition of natural skin during contact-free biometric identification of a person

摘要

A contact-free biometric identification apparatus includes a housing, a first light-emitting diode (LED) positioned in the housing having a first predetermined wavelength to illuminate a portion of skin, a second LED positioned in the housing having a second predetermined wavelength to illuminate the portion of skin, an irradiation location outside of the housing and defined by illumination from the first and second LED on the portion of skin, a detector at a predetermined position in the housing for detecting a fraction of the first and second LED light scattered from the irradiation. location and a processing unit that employs a scatter function to determine the presence of live skin based on a correspondence of the detected light to stored data of optical properties of skin.