Biometric imaging device comprising polarizers
US11995911B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2022 |
| Grant date | May 28, 2024 |
| Priority date | — |
| Expiry date | Feb 3, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V10/147
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical biometric imaging device includes an image sensor having a plurality of photodetector pixels; a lens assembly having at least one lens configured to focus light reflected by a biometric object onto the image sensor; at least one light source arranged adjacent to the lens assembly and which emits light towards a sensing surface of the biometric imaging device. The at least one light source comprises a waveguide which vertical decouples light; a first linear polarizer arranged between the light source and the image sensor; and a ring-shaped second linear polarizer arranged over the light source to polarize light emitted by the light source in a direction away from the image sensor and having an opening which allows light reflected by a biometric object to reach the lens without being filtered by the second linear polarizer. At least one of the polarizers are rotatable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.