Patent ID: 6122394
Filing Date: 2000-09-19
Classification: G02B,G06K

Abstract:
A compact, simplified, image-building scanner for generating a time-varying electrical signal that represents a fingerprint of a human subject, the scanner comprising:a solid block formed from a material that is transparent to electro-magnetic radiation of a pre-established wavelength, said block including a scanned surface that the human subject touches with a finger for which a representation of the fingerprint is to be generated, said block also including a radiation inlet-face for admitting into said block a beam of electro-magnetic radiation having the pre-established wavelength, and said block further including a radiation outlet-face through which exits from said block at least a portion of electro-magnetic radiation admitted into said block through the radiation inlet-face, the radiation inlet-face and the radiation outlet-face of said block being distinct from the scanned surface thereof, said block being shaped so that the beam of electro-magnetic radiation entering through the radiation inlet-face impinges upon the scanned surface of said block before exiting from said block through the radiation outlet-face;a radiation source for emitting a beam of electro-magnetic radiation having the pre-established wavelength;a first micromachined scanner having a mirror for deflecting the beam emitted from said radiation source, the beam of electro-magnetic radiation emitted by said radiation source impinging upon the mirror of said first micromachined scanner and being deflected thereby to form a two dimensional (""2D"") raster of the beam, the 2D raster formed by the deflected beam emitted from said first micromachined scanner being directed into said block through the radiation inlet-face thereof, whereby the 2D raster of the beam impinges upon the scanned surface of said block; anda radiation detector which receives electro-magnetic radiation admitted into said block through the radiation inlet-face thereof, impinges upon the scanned surface of said block, and exits from said block through the radiation outlet-face thereof, said radiation detector being responsive to the received electro-magnetic radiation for producing the time-varying electrical signal that represents the fingerprint of the human subject's finger then touching the scanned surface of said block.