| 摘要 |
A device for sensing and digitizing a fingerprint from a subject finger comprising a prism, a pixilated LED array affixed to the bottom surface of the prism and providing for the internal illumination, with a plurality of sub-beams, of the contact surface where the finger of the subject is pressed on the top surface of the prism, and a photoelectric sensor to detect the sub-beam radiation reflected from the fingerprint valley points. A sensor lens may also used for focusing the sub-beam radiation on the sensor. A lens wafer may be affixed between the prism and the LED array for focusing the radiation from each LED on its corresponding illumination point on the contact surface. The fingerprint ridge contact points do not reflect incident sub-beam radiation. A computer can provide for sequential emission of the sub-beams so that a single cell photoelectric sensor can be used to detect the reflected sub-beams or a multiple cell photoelectric sensor can be used, with each cell corresponding to a particular sub-beam. Reflected sub-beam radiation corresponds to a fingerprint valley point. Non-reflected sub-beam radiation corresponds to a fingerprint ridge point. The fingerprint is converted to a set of binary codes that can be used for imaging or identification purposes.
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