| 摘要 |
PURPOSE:To detect a fingerprint image having no distortion by a wide range of a fingertip, by forming concentrically an input surface of uneven information of a light leading body, and the outside peripheral surface of the light leading body. CONSTITUTION:An uneven surface information input surface 20 of a light leading body 15 and its outside peripheral surface 21 are formed concentrically centering around a shaft center 16. When a fingertip 10 is placed on this input surface 20, a cylindrical lens 22 rotates and a light beam is irradiated, and a light beam exceeding a critical angle, among the light beams which have been scattered by a projecting part 6 of a fingerprint is made incident on a hologram 3. Subsequently, the light beam which has been diffracted by the hologram 3 is detected in a shape of a line by a line sensor 23. In that case, since the input surface 2 and the outside peripheral surface 21 form a concentric circle, the wall thickness becomes equal, and an optical path length to the hologram 3 becomes constant, therefore, an image having no distortion is obtained. Also, since the input surface is a concave curved surface, information can be inputted by a wide range of the fingertip.
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