| 摘要 |
PURPOSE:To reduce noise caused by contamination, and to improve S/N of a fingerprint collection data by providing a finger holder which has the pressure surface for making an acute angle against the finger content surface and biased in the reverse direction against the inserting direction of a finger. CONSTITUTION:The titled device is provided with a finger holder 6 having the pressure surface 6a for making an acute angle against the finger contact surface 2a of a right angle triangular prism 2, and an elastic member 7 which has been attached so that the finger holder 6 is pushed back in the direction opposite to the inserting direction of finger. In this state, when a fingertip is put against the pressure surface 6a of the finger holder 6 and said surface is pushed in the direction as indicated with an arrow 9A, he finger 1 receives reaction force of the finger holder 6, and by a component vertical to the pressure surface 6a in the reaction force, the finger is pressed against the finger contact surface 2a. As a result, a finger print collecting part moves, while being pressed against the finger contact surface, contamination on the finger contact surface is pushed away upward, and in a fingerprint collecting area, contamination is eliminated. In such a way, a fingerprint information scarcely has the noise caused by contamination. |
