Method and apparatus for measuring structures in a fingerprint
US7333639B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 2006 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | Sep 18, 2026 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/1172
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A plurality of images of portions of a fingerprint surface is generated by measuring structural features the portions of the surface with a sensor array as the surface is moved relative to the array. A two-dimensional image of the fingerprint surface is constructed from a portion of the plurality of images. In one embodiment, a varying voltage is applied to a finger positioned over an exciting electrode and a capacitive sensor array, and the capacitance or impedance through the finger is measured between the electrode and the array to detect variations in capacitance or impedance caused by variations in the structural features of the fingerprint surface. In one embodiment, the speed of the fingerprint surface relative to the sensor array is determined by sensing features of the fingerprint surface at two spaced-apart sensing elements and determining the speed from the distance between the sensing elements and the time lapse between passage of identical features of the fingerprint surface from one of the sensing elements to the other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.