OPTICAL SYTEM FOR FINGERPRINT RECOGNIZING DEVICE

摘要

An optical system for a fingerprint recognizing device is provided to realize correct fingerprint recognition by preventing image formation of the fingerprint image by an image sensor distortion. A prism(130) includes a touch side(130b) tilted to touch with a finger, the first incident side(130a) receiving light advanced to the touch side, and the first output side(130c) outputting the light reflected from the finger and tilted as much as the first summit angle to the touch side. A middle optical system(150) includes a lens to make the fingerprint image imaged to the image sensor between the first output side and an image sensor. The first output side is tilted as much as the first tilt angle to a vertical axis orthogonally crossing a virtual central axis extended from an optical axis of the lens along an optical path. The middle optical system includes a correction prism(160) for correcting anamorphic distortion of the fingerprint image caused from the first vertical angle.