Secure biometric device

1. A device for capturing biometric characteristics, the device comprising an optical sensor having a field of view covering a detection zone for detecting optical characteristics, and an electronic control unit that is connected to the optical sensor in order to control it, wherein the electronic control unit is placed at least in part in the field of view of the optical sensor and includes a memory containing at least one signature resulting from at least one reference optical characteristic of the electronic control unit as seen by the optical sensor, and a comparator module for comparing the signature with at least one corresponding signature that results from at least one optical characteristic of the electronic control unit as supplied by the optical sensor.

2. The device according to claim 1 , wherein the comparator module is also arranged to compare biometric characteristics extracted from images provided by the optical sensor with stored biometric characteristics.

3. The device according to claim 1 , including a mirror placed between the optical sensor, the electronic control unit, and the detection zone, and arranged to enable the electronic control unit and the detection zone to be viewed, one in reflection and the other in transmission.

4. The device according to claim 3 , wherein the mirror is a semi-reflecting mirror.

5. The device according to claim 1 , including a reflecting member surrounding at least part of the electronic control unit.

6. The device according to claim 5 , wherein the reflecting member comprises a plurality of reflecting facets forming angles between one another so as to provide the optical sensor with different angles of view of the electronic control unit.

7. The device according to claim 1 , including a lens disposed between the electronic control unit and the optical sensor to focus an image of the electronic control unit on the optical sensor.

8. The device according to claim 1 , wherein the electronic control unit is covered in a protective layer having optical characteristics that are detectable by the optical sensor.

9. The device according to claim 8 , wherein the protective layer is made of a non-opaque material incorporating optically detectable elements.

10. The device according to claim 9 , wherein the optically active elements comprise reflecting flakes.

11. The device according to claim 10 , including at least one lighting element for lighting the electronic control unit, the element being embedded in the protective layer.

12. The device according to claim 8 , wherein the protective layer is made of a viscous material.

13. The device according to claim 1 , wherein the comparator module is arranged to perform a comparison each time the device is started.

14. The device according to claim 1 , wherein the comparator module is arranged to perform a comparison periodically.

15. The device according to claim 1 , including a plurality of lighting elements for lighting the electronic control unit and controlled by the comparator module to take on different configurations, each corresponding to at least one stored signature.

16. The device according to claim 1 , wherein the memory contains a plurality of signatures resulting from a plurality of reference optical characteristics, and the comparator module is arranged to select a stored signature, to isolate the corresponding optical characteristics from amongst those detected by the optical sensor, and to compare at least one signature resulting from the optical characteristics detected by the optical sensor with the selected stored signature.

17. The device according to claim 1 , wherein the electronic control unit is arranged to prevent the device from operating when the comparison gives a negative result.