Frishauf, Holtz, Goodman, Langer & Chick, P.C.
Apparatus for reading fingerprint
 A light beam emitted by a surface illuminant reaches the surface of a transparent base layer of a recess/projection detection optical element. A light beam emitted almost vertically is emitted to an air layer. A light beam incident on the transparent base layer at an angle larger than a total reflection angle returns to a two-dimensional photosensor at a portion contacting the air layer, but scatters in a transparent particle at a portion contacting the transparent particle. When a finger is brought into contact with a scattering reflection layer, the scattering reflection state does not change in an area corresponding to a valley of a fingertip. As indicated by an arrow, an amount of reflected light beam is large. In an area corresponding to a ridge of the fingertip, the light beam scattered by the transparent particle is absorbed. The amount of reflected light beam is small, as indicated by an arrow. An image having bright and dark portions optically emphasized in correspondence with the valley and ridge of the fingertip of the finger can be obtained. 
Casio Computer Co., Ltd.
G
G06V
inventional
Tetsuo Minoru Makoto Hiromitsu
Muto Fujiwara Sasaki Ishii