Small reliable image input apparatus incorporated in finger-print collation system of personal identification
US6011860A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1998 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Feb 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C9/37
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An image input device has a optical guide plate exposed to a window of a photo-shield case, a pair of light emitting diodes attached to side surfaces of the optical guide plate for radiating light into it, an area image sensor provided under the optical guide plate, a gradient index lens unit provided between the optical guide plate and the area image sensor and a filter connected to the area image sensor for eliminating a low frequency component from an image carrying signal; when a person presses a finger on the optical guide plate, the fingerprint scatters the light toward the gradient index lens unit, and the area image sensor produces the image carrying signal from the incident light; the reflection on valley lines is gradually varied along the width of the finger, and the elimination of the low frequency component makes the contrast of the image clear.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.