Imaging system and apparatus for combining finger recognition and finger navigation

• US 20040208348A1
• Filed: 04/18/2003
• Published: 10/21/2004
• Est. Priority Date: 04/18/2003
• Status: Active Grant

• Current Assignee: Qwerx Incorporated
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Ang, Jin Kiong, Machida, Akihiro, Blalock, Travis N., Smith, George E., Baharav, Izhak
• Granted Patent: US 7,274,808 B2
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement

Abstract

An imaging system for imaging a fingerprint operates in at least two different modes to provide both finger recognition and finger navigation applications. A light source illuminates a swipe interface having an elongated sensing area upon which a user swipes a finger. Light reflected from the finger is captured by an optical image sensor as image data representing a sequence of images resulting from motion of the digit over the sensing area of the swipe interface. The captured image data is output by the optical image sensor for processing of the data in one of the at least two different modes.

Claims

1. An apparatus for imaging a fingerprint in one of at least two different modes of operation, one of the modes being a finger navigation mode and another of the modes being a finger recognition mode, said apparatus comprising:

a swipe interface having an elongated sensing area on a surface thereof against which a portion of the tip of a human finger may be placed, said elongated sensing area being smaller than the tip of the human finger in at least one dimension;

a light source for emitting light to illuminate the portion of the tip of the human finger placed against the surface of said swipe interface; and

an optical image sensor for capturing light reflected from the portion of the tip of the human finger as an image thereof, producing image data representing a sequence of images resulting from motion of the human finger across said swipe interface and outputting said image data for processing in a selected one of the at least two different modes of operation.

2. The apparatus of claim 1, further comprising:

image transfer optics for transferring the image to said optical image sensor, said image transfer optics having a magnification less than unity.

3. The apparatus of claim 2, wherein said image transfer optics comprise folded optics.

4. The apparatus of claim 2, further comprising:

illumination optics for directing the light towards the surface of said swipe interface at a desired angle of incidence.

5. The apparatus of claim 2, wherein said illumination optics directs the light towards the surface of said swipe interface at the desired angle of incidence to illuminate the human finger using a total internal reflection mechanism.

6. The apparatus of claim 1, wherein said optical image sensor comprises an array of photo detectors, each of the photo detectors for capturing a respective pixel of the image, and wherein the human digit has micro texture features thereon, each of the pixels of the image having a size less than or equal to one of the micro texture features, whereby each of the micro texture features is captured by at least one of the photo detectors.

7. The apparatus of claim 1, wherein said swipe interface is between 7 and 9 mm in a first and between 1 and 2 mm in a second direction orthogonal to the first direction.

8. The apparatus of claim 7, wherein said swipe interface is between 0.5 and 1 mm in a third direction orthogonal to the first and second directions.

9. The apparatus of claim 1, wherein said light source has an on condition and an off condition and is capable of operating in a sequential manner between the on condition and the off condition to provide notification of a received message.

10. The apparatus of claim 1, further comprising:

a housing enclosing said light source and said sensor, said housing having an external surface, said swipe interface protruding through and above the external surface of said housing.

11. The apparatus of claim 10, wherein the external surface of said housing has a groove therein for directing the human digit across said swipe interface in a non-rotational motion.

12. An imaging system for operating in at least two different modes, said imaging system comprising:

a processor connected to receive image data representing a sequence of images resulting from motion of a portion of a tip of a human finger across an elongated sensing area, said processor further for processing said image data in a selected one of said at least two different modes, said at least two different modes including at least a finger navigation mode and a finger recognition mode; and

a mode switch connected to said processor to select said selected mode.

13. The imaging system of claim 12, wherein said processor further correlates said image data representing said sequence of images to determine navigation information indicating the magnitude and direction of movement of the human finger between successive ones of the sequence of images.

14. The imaging system of claim 13, wherein said processor correlates said image data representing said sequence of images using micro texture features present on the tip of the human finger.

15. The imaging system of claim 13, wherein said processor further outputs said navigation information to control the position of a cursor on a display of an electronic device using said navigation information when said selected mode is the finger navigation mode.

16. The imaging system of claim 13, wherein said processor further stitches said image data representing said sequence of images together to form one continuous image of a fingerprint of the human finger when said selected mode is the finger recognition mode, said fingerprint having a sufficient number of micro texture features for fingerprint matching.

17. The imaging system of claim 16, wherein said processor further outputs fingerprint information necessary for extracting minutiae of the captured fingerprint and comparing said image data representing the minutiae to previously stored image data representing template fingerprint minutiae to match the captured fingerprint with the template fingerprint.

18. The imaging system of claim 16, wherein said processor further determines one or more finger strokes associated with the motion of the human finger across the sensing area using said navigation information when said selected mode is a stylus mode, said processor further for determining a character associated with the one or more finger strokes.

19. The imaging system of claim 12, further comprising:

a switch connected to said processor for sequentially illuminate said sensing area to produce a blinking light indicative of a message waiting status.

20. A method for operating an imaging system in at least two different modes, said method comprising:

receiving image data representing a sequence of images resulting from motion of a portion of a tip of a human finger across a swipe interface having an elongated sensing area on a surface thereof, said elongated sensing area being smaller than the tip of the human finger in at least one dimension;

selecting one of said at least two different modes for processing said image data, said at least two different modes including at least a finger navigation mode and a finger recognition mode;

correlating said image data representing said sequence of images to determine navigation information indicating the magnitude and direction of movement of the human finger between successive ones of the sequence of images; and

processing said image data in said selected mode using said navigation information.

21. The method of claim 20, wherein said correlating further comprises:

correlating said image data representing said sequence of images using micro texture features present on the tip of the human finger.

22. The method of claim 20, wherein said processing further comprises:

outputting said navigation information to control the position of a screen pointer on a display of an electronic device using said navigation information when said selected mode is the finger navigation mode.

23. The method of claim 20, wherein said processing further comprises:

stitching said image data representing said sequence of images together to form one continuous image of a fingerprint of the human finger when said selected mode is the finger recognition mode, said fingerprint having a sufficient number of micro texture features for fingerprint matching.

24. The method of claim 23, wherein said processing further comprises:

outputting finger information necessary for extracting minutiae from the captured fingerprint and comparing said image data representing the minutiae to previously stored image data representing template fingerprint minutiae to match the captured fingerprint with the template fingerprint.

25. The method of claim 20, wherein said processing further comprises:

determining one or more finger strokes associated with the motion of the human finger across the sensing area using said navigation information when said selected mode is a stylus mode; and

determining a character associated with the one or more finger strokes.

26. The method of claim 20, further comprising:

sequentially illuminating said sensing area to produce a blinking light indicative of a message waiting status.