IMAGE READER, ITS METHOD AND DEVICE APPLYING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an image reader capable of reading both of fingerprints and a reading object such as characters with gradation by using a linear photoelectric conversion element with high accuracy. SOLUTION: A finger 1 is placed on an input surface 2 of an input member 3. A light source 4 for illumination exists on the opposite side of the reading object and the input surface 2 and the entire image is composited from partial images by moving the finger. In this case, a refraction angle 7 in the input member of diffused light to be received by the photoelectric conversion element is equal to or larger than the critical angle 8 between the input surface and the air, and on the other hand, an incident angle 6 of light from the light source 4 is smaller than the critical angle 8.