| 摘要 |
PROBLEM TO BE SOLVED: To provide a reader equipped with a back light whose power consumption can be reduced. SOLUTION: The emitting angle of maximum luminance in the distributed light of a back light 50 arranged on the rear side of a photosensor part for optically reading a fingerprint by transmitting light made incident from the rear side, reflecting the light on the tip of a finger touching the front side and receiving this reflected light by a double gate transistor 10a is made oblique to the direction perpendicular to the front of the back light 50. |
