MINIATURIZED OPTICAL BIOMETRIC SENSING

• US 20150254495A1
• Filed: 05/21/2015
• Published: 09/10/2015
• Est. Priority Date: 10/11/2013
• Status: Active Grant

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Lumidigm Incorporated (Assa Abloy AB)
• Inventors: Rowe, Robert K., Martin, Ryan Eric
• Granted Patent: US 9,886,617 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61B 5/6898 Portable consumer electronic devices, e.g. music players, telephones, tablet computers
• CPC Class Codes: G06V 40/1312 direct reading, e.g. contactless acquisition
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/1341 Sensing with light passing through the finger

Abstract

Systems and methods are described for providing reliable biometric access control using an optical biometric sensor in a miniaturized form factor. Some implementations include multiple light sources that can illuminate skin or other tissue at multiple locations during a single measurement session. An imaging array can be arranged to form images of the light exiting the tissue only after undergoing diffuse reflectance in the tissue. Some implementations use the images to perform biometric functions. For example, the images can be used to identify an individual, verify identity of an individual, estimate demographic characteristics of an individual, etc. Such biometric functions can further be used to determine and affect access to secured assets.

Claims

1. A biometric access system comprising:

a biometric sensor comprising;

an interface subsystem comprising an interface surface disposed to contact purported tissue of a subject;

an illumination subsystem disposed to pass source illumination into the purported tissue of a subject via a set of first surface regions of the purported tissue; and

a detector subsystem disposed to acquire a plurality of images corresponding to a plurality of optical imaging conditions, the plurality of images being based on response illumination exiting a set of second surface regions of the purported tissue, the set of second surface regions being different from the set of first surface regions, the response illumination produced by interactions between the source illumination and subsurface characteristics of the purported tissue.

2. The biometric access system of claim 1, wherein the interface subsystem further comprises:

a shield disposed to substantially block the source illumination from reaching the detector subsystem without first entering the purported tissue.

3. The biometric access system of claim 1, wherein the interface subsystem further comprises:

a set of optical guides disposed to guide the source illumination from the illumination subsystem to the set of first surface regions, thereby substantially blocking the source illumination from reaching the detector subsystem without first entering the purported tissue.

4. The biometric access system of claim 3, wherein the set of optical guides are instantiated in a fiber-optic faceplate, and the interface surface is integrated with the fiber-optic faceplate.

5. The biometric access system of claim 1, wherein the detector subsystem is further disposed to detect presence of the purported skin site with respect to the interface surface prior to acquiring the plurality of images.

6. The biometric access system of claim 1, wherein a wavelength of the source illumination is different between each of the plurality of optical imaging conditions.

7. The biometric access system of claim 1, wherein the detector subsystem is disposed to acquire the plurality of images corresponding to the plurality of optical imaging conditions, such that each image is acquired under a different combination of illumination wavelengths and exposure times.

8. The biometric access system of claim 1, wherein:

the set of first surface regions comprises a plurality of first surface regions;

the illumination subsystem comprises a plurality of illumination sources; and

each illumination source is disposed to pass a respective portion of the source illumination into the purported tissue via a respective one of the first surface regions.

9. The biometric access system of claim 8, wherein the each illumination source is disposed to provide a different wavelength of illumination.

10. The biometric access system of claim 1, wherein the detector system further comprises a set of optics, and each of the plurality of optical imaging conditions is affected by the response illumination and the set of optics.

11. The biometric access system of claim 1, wherein the detector subsystem comprises an imaging array disposed to generate the plurality of images, the imaging array having an array of pixels that provides information that is spatially correlated to imaged regions of the purported tissue.

12. The biometric access system of claim 11, further comprising:

a processor disposed to differentiate between the purported tissue being genuine tissue and a spoof according to a spatiospectral analysis of the plurality of images.

13. The biometric access system of claim 1, further comprising:

a processor disposed to biometrically authorize the subject by processing the plurality of images.

14. The biometric access system of claim 13, wherein the processor is disposed to biometrically authorize the subject by:

computing a first plurality of keypoints in the plurality of images; and

comparing the first plurality of keypoints with a second plurality keypoints associated with previously stored biometric information.

15. The biometric access system of claim 14, wherein:

the plurality of images comprises multispectral information; and

each of the first plurality of keypoints is computed as a corner in a spatial gradient of at least one of the plurality of images.

16. The biometric access system of claim 13, wherein the processor is disposed to biometrically authorize the subject by identifying the subject or verifying the identity of the subject.

17. The biometric access system of claim 13, wherein the processor is disposed to biometrically authorize the subject according to a biometric template corresponding to the subject and generated during prior biometric enrollment of the subject.

18. The biometric access system of claim 13, wherein the biometric sensor is a miniaturized biometric sensor, and the prior biometric enrollment of the subject was performed on non-miniaturized biometric sensor.

19. The biometric access system of claim 13, further comprising:

a physical interface of a portable communications device, the physical interface having the biometric sensor integrated therewith, and the physical interface disposed to permit access by the subject to the portable communications device when the subject is biometrically authorized by the biometric sensor.

20. The biometric access system of claim 13, further comprising:

a mechanical locking assembly moveable between locked and unlocked positions to enable and disable opening of a restricted access area; and

a handle for opening the restricted access area when unlocked,

wherein the biometric sensor is physically integrated with the handle and in communication with the mechanical locking assembly, so that the mechanical locking assembly is moveable to its unlocked position according to whether the subject is biometrically authorized by the biometric sensor.