Prism fingerprint sensor that uses a holographic optical element.

@article{Bahuguna1996PrismFS,
  title={Prism fingerprint sensor that uses a holographic optical element.},
  author={Rakesh Bahuguna and T Corboline},
  journal={Applied optics},
  year={1996},
  volume={35 26},
  pages={5242-5}
}
A prism fingerprint sensor is described that uses a holographic grating glued to a right-angled prism. A light source normally illuminates the hypotenuse side of the prism with the finger pressed against the grating. The ridges and valleys of the finger are sensed on the basis of the principle of total internal reflection. The grating is used essentially to… CONTINUE READING