Patent ID: 7366331

Claim:
A fingerprint input device comprising: at least one light source injecting light into a cortex of a measurement target finger, said light scattering inside said measurement target finger; a two-dimensional image sensor for picking up a fingerprint image from a fingerprint measured portion of the measurement target finger, said fingerprint measured portion having a fingerprint ridgeline portion and a fingerprint valley portion, said fingerprint image being formed upon a surface of said two-dimensional image sensor by an incident light from said inside of said measurement target finger that is incident upon the surface of said two-dimensional image sensor; and a transparent solid film mounted on an image pickup surface of said two-dimensional image sensor, said fingerprint measured portion being mounted on said transparent solid film when said two-dimensional image sensor picks up said fingerprint image, wherein said fingerprint input device picks up an image of said fingerprint ridgeline portion in said fingerprint measured portion as a light portion, and picks up an image of said fingerprint valley portion in said fingerprint measured portion as a dark portion, based on a difference of light direction in said fingerprint valley portions due to differences of refractive indices at an air interface in said valley portion.