Biometric sensor apparatus and methods

• US 7,254,255 B2
• Filed: 04/11/2003
• Issued: 08/07/2007
• Est. Priority Date: 04/12/2002
• Status: Active Grant

• Current Assignee: Stmicroelectronics (Research & Development) Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Limited (STMicroelectronics NV)
• Inventors: Dennis, Carl
• Primary Examiner(s): Bella; Matthew C.
• Assistant Examiner(s): Bayat; Ali
• Application Number:
  US10/412,645
• Publication Number:
  US 20050008197A1
• Time in Patent Office: 1,579 Days
• Field of Search: 382/312, 382/124, 382115-116, 382125-127, 382/274, 356/71
• US Class Current: 382/115
• CPC Class Codes: G06V 40/13 Sensors therefor
• CPC Class Codes: G06V 40/1388 using image processing

Abstract

The optical biometric sensor apparatus and methods for analyzing images of biometric features such as fingerprints are adapted to distinguish between live body members and inanimate objects, and to detect spoofing devices applied to live body members. Live body members are detected by transmitting IR light from a first IR light source through an object to an image sensor. The IR transmission characteristics of a live body member vary with the human heartbeat, and multiple images are analyzed to verify whether the object is a genuine live body member. A visible light source illuminates the object for obtaining a detailed image from the sensor for conventional biometric analysis. Transmitted IR images and reflected visible light images are also processed to detect the presence of spoofing devices applied to live body members. Multiple IR and visible light sources of different wavelengths may be used for this purpose.

Claims

1. A biometric sensor device comprising:

a translucent platen having a first side against which a body member to be analyzed is placed, and a second side;

at least one infrared (IR) light source located adjacent the first side of the translucent platen for transmitting IR light through the body member and the translucent platen to the second side of the translucent platen;

an optical image sensor located adjacent the second side of the translucent platen for detecting IR light transmitted through the body member and the translucent platen; and

data storage and processing means for storing and processing signals output from the optical image sensor;

data storage and data processing means being adapted to store and process a plurality of images obtained from the optical image sensor in response to IR light transmitted from the IR light source through an object placed on the translucent platen to determine whether the object is a live body member, the data processing means being adapted to analyze relative intensities of the plurality of images to determine whether variations in those intensities are consistent with characteristics indicative of a human heartbeat.

2. The device of claim 1, further comprising at least one visible light source located adjacent the second side of the translucent platen and arranged so that visible light from the visible light source is transmitted through the translucent platen and reflected by the body member for detection by the optical image sensor.

3. The device of claim 1, further comprising at least one visible light source located adjacent the second side of the translucent platen and arranged so that visible light from the visible light source is transmitted through the translucent platen and reflected by the body member for detection by the optical image sensor;

and wherein the data storage and processing means is adapted to process at least one image obtained from the optical image sensor in response to IR light transmitted from the IR light source through a live body member placed on the translucent platen and at least one image obtained from the optical image sensor in response to visible light from the visible light source reflected from the live body member placed on the translucent platen so as to determine the presence or absence of a spoofing device associated with the live body member.

4. The device of claim 1, wherein the at least one IR light source comprises a plurality of IR light sources for transmitting IR light through the body member, each of the ER light sources emitting IR light in a different waveband.

5. The device of claim 4, wherein each IR light source emits IR light in a waveband in the range 700 rim to 1100 rim.

6. The device of claim 5, wherein a first IR light source of the plurality of IR light sources emits IR light with a wavelength of 850 nm.

7. The device of claim 6, wherein a second IR light source of the plurality of IR light sources emits IR light with a wavelength of 750 nm.

8. The device of claim 1, further comprising a plurality of visible light sources located adjacent the second side of the platen and arranged so that visible light from the visible light sources is transmitted through the translucent platen and reflected by the body member for detection by the optical image sensor, each of the visible light sources emitting visible light in a different waveband.

9. The device of claim 1, wherein the optical image sensor comprises a CMOS image sensor.

10. A biometric sensor device comprising:

a platen having a sensing portion to receive a body member;

at least one infrared (IR) light source located adjacent the sensing portion for transmitting IR light through the body member;

an optical image sensor located opposite the sensing portion for detecting IR light transmitted through the body member; and

a memory and processor cooperating therewith for storing and processing signals output from said optical image sensor;

said memory and processor cooperating for storing and processing a plurality of images obtained from said optical image sensor in response to IR light transmitted from said IR light source through an object placed on said platen to determine whether the object is a live body member, said memory and processor cooperating for analyzing relative intensities of the plurality of images to determine whether variations in those intensities are consistent with characteristics indicative of a human heartbeat.

11. The device of claim 10, further comprising at least one visible light source located opposite the sensing portion to transmit visible light through said platen and reflected by the body member for detection by said optical image sensor.

12. The device of claim 10, further comprising at least one visible light source located opposite the sensing portion to transmit visible light through said platen and reflected by the body member for detection by said optical image sensor;

and wherein said memory and processor cooperate for processing at least one image obtained from said optical image sensor in response to IR light transmitted from said IR light source through a live body member placed on said platen and at least one image obtained from said optical image sensor in response to visible light from the visible light source reflected from the live body member placed on said platen to determine the presence or absence of a spoofing device associated with the live body member.

13. The device of claim 10, wherein said optical image sensor comprises a CMOS image sensor.

14. A method for determining whether an object presented to a biometric sensor device is a live body member, the method comprising:

transmitting IR light from an IR light source through the object;

detecting IR light transmitted through the object using an optical image sensor;

obtaining a plurality of images from the optical image sensor in response to IR transmitted from the IR light source through the object; and

processing the images to determine whether the object has characteristics of a live body member by analyzing relative intensities of the plurality of images to determine whether variations in those intensities are consistent with characteristics indicative of a human heartbeat.

15. A method of determining whether a live body member presented to a biometric sensor device has a spoofing device associated therewith, the method comprising:

transmitting IR light from at least one IR light source through the body member;

detecting IR light transmitted through the body member using an optical image sensor;

obtaining at least one image from the optical image sensor in response to IR light transmitted from the IR light source through the body member;

reflecting visible light from at least one visible light source from the body member;

detecting visible light reflected from the body member using the optical image sensor;

obtaining at least one image from the optical image sensor in response to visible light from the visible light source reflected from the body member; and

processing the images determine the presence or absence of a spoofing device associated with the body member by analyzing relative intensities of the images to determine whether variations in those intensities are consistent with characteristics indicative of a human heartbeat.

16. A method of operating a biometric sensor device comprising:

placing a body member on a sensing portion of a platen;

transmitting IR light through the body member with at least one infrared (IR) light source located adjacent the sensing portion;

detecting IR light transmitted through the body member with an optical image sensor located opposite the sensing portion; and

storing and processing signals output from the optical image sensor by

processing a plurality of images obtained from the optical image sensor in response to IR light transmitted from the IR light source through an object placed on the platen to determine whether the object is a live body member, and

analyzing relative intensities of the plurality of images to determine whether variations in those intensities are consistent with characteristics indicative of a human heartbeat.

17. The method of claim 16, further comprising transmitting visible light through the platen and reflected by the body member with at least one visible light source located opposite the sensing portion for detection by the optical image sensor.

18. The method of claim 16, further comprising transmitting visible light through the platen and reflected by the body member with at least one visible light source located opposite the sensing portion for detection by the optical image sensor;

and wherein storing and processing comprises processing at least one image obtained from the optical image sensor in response to IR light transmitted from the IR light source through a live body member placed on the platen and at least one image obtained from the optical image sensor in response to visible light from the visible light source reflected from the live body member placed on the platen to determine the presence or absence of a spoofing device associated with the live body member.