Apparatus for identifying fingerprints
US5822445A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Jul 8, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1324
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fingerprint identifying device includes a transparent prism having a fingerprint receiving face, a fingerprint viewing face at an acute angle to the fingerprint receiving face, two opposed parallel faces perpendicular to the fingerprint receiving face and a further light-absorbing face generally opposite to the fingerprint viewing face. A light source in the form of a bank of LEDs is provided for transmitting light into the prism. A light diffuser is provided for light transmitted from the light source such that in operation diffused light is transmitted into the prism through both of the parallel faces and against the fingerprint receiving face to provide substantially uniform illumination of a finger contacting the fingerprint receiving face, a fingerprint image being visible through the fingerprint viewing face. Preferably, the bank of LEDs is disposed at the two opposed parallel faces adjacent to the fingerprint receiving face. It is also preferred if the light source extends above the plane of the fingerprint receiving face to illuminate the edges of a finger from outside of the prism.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.