Compact, simple, 2D raster, image-building fingerprint scanner
US6122394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1997 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | May 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1329
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A beam (38) of electromagnetic radiation deflected by a moving mirror plate (56) of a micromachined scanner (54) produces a two dimensional ("2D") raster (132) on a scanned surface (28) of a block (34). The block (34) is transparent to electro-magnetic radiation of pre-established wavelengths. A radiation inlet-face (36) of the block (34) admits the beam (38) that then impinges on the scanned surface (28) to exit the block (34) through a radiation outlet-face (42). After exiting the block (34), the beam (38) impinges upon a radiation detector (142). Total internal reflection ("TIR") of the beam (38) from the scanned surface (28) at fingerprint valleys and frustration of TIR at fingerprint ridges causes the radiation detector (142) to produce a time-varying electrical signal that represents the fingerprint. The scanned surface (28) may be formed by a patch (302) of resilient material, that may be tinted to be transparent only at the pre-established wavelength of the electro-magnetic radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.