Finger identification
US4053228A · kind A · utility
Inventor
Key dates
| Filing date | Dec 12, 1975 |
| Grant date | Oct 11, 1977 |
| Priority date | — |
| Expiry date | Dec 12, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C9/37
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fingerpress is formed by pressing a finger against the back surface of a transparent glass plate and holding it in a predetermined position thereon. This fingerpress is interrogated by a light beam directed through the front surface of the glass plate. The interrogating beam is partially reflected at the back surface to provide a signal beam carrying fingerpress information. The signal beam is created by virtue of the optical discontinuity between the glass plate and the fingerpress. There is one discontinuity between the glass plate and the air underlying the valleys of the fingerpress and another discontinuity between the glass plate and the finger oil at the crests of the fingerpress. The two discontinuities cause differing amounts of light to be reflected and the signal beam is thus created. The signal beam is correlated against a hologram of the same fingerpress to provide identification. The hologram is created either from a film image of the fingerpress or from the fingerpress in real time. The finger is held in predetermined registration position both in making the hologram, or film on which the hologram is made, and when being interrogated for identification so that corr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.