Mirror system and method for acquiring biometric data
View Patent ↗A system and method for obtaining biometric imagery such as iris imagery from large capture volumes is disclosed wherein a substantially rotationally symmetric mirror such as a cone or sphere is rotated at a constant velocity about a central axis.
1. A method for acquiring biometric imagery in a large capture volume, the method comprising:
rotating a first rotationally symmetric mirror about a first axis;
rotating a second rotationally symmetric mirror about a second axis, the second axis substantially perpendicular to the first axis, the first rotationally symmetric mirror reflecting biometric imagery that is reflected off the second rotationally symmetric mirror; and
acquiring, by a sensor, biometric imagery reflected off the first rotationally symmetric mirror as the first rotationally symmetric mirror is rotated about the first axis.
2. The method of claim 1 , wherein rotating the first rotationally symmetric mirror comprises rotating the first rotationally symmetric mirror at a substantially constant rotational velocity around the first axis.
3. The method of claim 1 , wherein acquiring biometric imagery comprises acquiring biometric imagery in synchronization with the rotation of the first rotationally symmetric mirror.
4. The method of claim 1 , wherein acquiring biometric imagery comprises acquiring biometric imagery in synchronization with stroboscopic illumination on a corresponding subject.
5. The method of claim 1 , wherein acquiring biometric imagery comprises acquiring portions of a scene that are offset with respect to each other.
6. The method of claim 1 , further comprising illuminating a corresponding subject with stroboscopic illumination.
7. The method of claim 1 , further comprising maintaining the sensor in a fixed position.
8. A system for acquiring biometric imagery in a large capture volume, the system comprising:
a first rotationally symmetric mirror;
motor means to rotate the first rotationally symmetric mirror about a first axis;
a second rotationally symmetric mirror rotating about a second axis, the second axis substantially perpendicular to the first axis, the first rotationally symmetric mirror reflecting biometric imagery that is reflected off the second rotationally symmetric mirror; and
a sensor to acquire biometric imagery reflected off of the first rotationally symmetric mirror as the first rotationally symmetric mirror is rotated about the first axis.
9. The system of claim 8 , wherein the first rotationally symmetric mirror rotates at a substantially constant rotational velocity around the first axis.
10. The system of claim 8 , wherein the sensor acquires biometric imagery in synchronization with the rotation of the first rotationally symmetric mirror.
11. The system of claim 8 wherein the sensor acquires biometric imagery in synchronization with stroboscopic illumination on a corresponding subject.
12. The system of claim 8 , wherein the sensor acquires portions of a scene that are offset with respect to each other.
13. The system of claim 8 , further comprising stroboscopic illumination for illuminating a corresponding subject.
14. The system of claim 8 , wherein the sensor is maintained in a fixed position.
15. A method for acquiring biometric imagery in a large capture volume, comprising:
mounting a first non-flat reflective surface on a first rotating axis such that at least a portion of the first surface is not perpendicular to the first axis;
mounting a second non-flat reflective surface on a second rotating axis, the second axis substantially perpendicular to the first axis, the first non-flat reflective surface reflecting biometric imagery that is reflected off the second non-flat reflective surface;
configuring a sensor to view a scene reflected off the first non-flat surface,
the sensor comprising at least one lens for removing distortion due to the first non-flat reflective surface; and
acquiring imagery of the scene when the first non-flat reflective surface is rotating about the first rotating axis.
16. A method for acquiring biometric imagery in a large capture volume, comprising:
mounting a first non-flat reflective surface on a first rotating axis such that at least a portion of the first surface is not perpendicular to the first axis;
configuring a sensor to view a scene reflected off the first non-flat surface, the sensor using a second reflective surface to remove distortion due to the first non-flat reflective surface, the second reflective surface being configured to rotate about a second rotating axis, the second axis substantially perpendicular to the first axis, the first non-flat reflective surface reflecting biometric imagery that is reflected off the second non-flat reflective surface; and
acquiring imagery of the scene when the first non-flat reflective surface is rotating about the first rotating axis.
17. A method for acquiring biometric imagery in a large capture volume, comprising:
mounting a first non-flat reflective surface on a first rotating axis such that at least a portion of the first surface is not perpendicular to the first axis;
mounting a second non-flat reflective surface on a second rotating axis, the second axis substantially perpendicular to the first axis, the first non-flat reflective surface reflecting biometric imagery that is reflected off the second non-flat reflective surface;
configuring a sensor to view a scene reflected off the first non-flat surface, the sensor digitally removing distortion due to reflection off the first non-flat reflective surface; and
acquiring imagery of the scene when the first non-flat reflective surface is rotating about the first rotating axis.