Method and apparatus for two-dimensional finger motion tracking and control

• US 8,358,815 B2
• Filed: 12/14/2007
• Issued: 01/22/2013
• Est. Priority Date: 04/16/2004
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Validity Sensors Incorporated (Synaptics Incorporated)
• Inventors: Benkley, Fred George, Geoffroy, David Joseph, Satyan, Pallavi
• Primary Examiner(s): DRENNAN, BARRY T
• Application Number:
  US11/957,332
• Publication Number:
  US 20080240523A1
• Time in Patent Office: 1,866 Days
• Field of Search: None
• US Class Current: 382/124
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• 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

Enhanced accuracy finger position and motion sensors devices, algorithms, and methods are disclosed that can be used in a variety of different applications. The sensors can be used in conjunction with partial fingerprint imagers to produce improved fingerprint scanners. The finger motion sensors may also be used (either with or without a partial fingerprint imager) to control electronic devices. When several of these finger motion and position sensors are aligned in different directions, finger motion over a two dimensional surface may be detected. This creates a finger controlled “mouse” computer input device. Motion of a finger along the surface of such sensors may allow a user to control the movement of an indicator on a display screen, and control a microprocessor device. Such techniques are particularly useful for small space constrained devices, such as cell phones, smart cards, music players, portable computers, personal digital accessories, and the like.

Claims

1. A finger motion tracking apparatus used to provide user input to a computing_device, comprising:

at least two linear sensor arrays each configured to sense overlapping line segments of features of a fingerprint of a finger moving along a one of at least two axes of motion of the finger, each linear sensor array including a plurality of linear sensor array sensing elements configured to capture segments of fingerprint image data, at least one of the at least two axes of motion being in a direction other than a direction of a swipe of the finger surface over the sensor surface, the overlapping line segments of the features of the fingerprint image each being sensed at different times;

a memory configured to receive and store image data from each linear sensor array; and

a computing device configured to generate finger motion data by comparing overlapping line segments of the fingerprint image that match each other, sensed by one of the at least two linear sensor arrays at different times, thereby determining a velocity of finger motion along each of the at least two axes of motion of the finger;

wherein the at least two linear sensor arrays are each present on the same unitized electrical component.

2. The apparatus of claim 1, wherein the apparatus is configured to use data collected from at least one of the at least two finger position sensor arrays to control the creation of a complete fingerprint image from partial fingerprint images collected using at least one partial fingerprint sensor.

3. The apparatus of claim 2, wherein the at least one finger position sensor array and the at least one partial fingerprint imager are driven by the same integrated circuit chip.

4. The apparatus of claim 2, wherein at least one of the at least one finger position sensor array or the at least one of the partial fingerprint imager are deep finger penetrating radio frequency (RF) based sensors.

5. The apparatus of claim 2, wherein there are a plurality of the at least one partial fingerprint imagers, and in which the orientation of at least some of the partial fingerprint imagers are different from the others, whereby when a finger is swiped at an arbitrary two dimensional angle an adequate fingerprint image is obtained.

6. The apparatus of claim 2, wherein both the at least one finger position sensor array and the at least one partial fingerprint imager are located on the same flexible support, and an integrated circuit that drives at least some of the finger position sensor arrays and at least some of the partial fingerprint imagers is located on the same flexible support.

7. The apparatus of claim 2, in which outputs from the apparatus include at least two spatial dimensions of finger position or finger motion data, and the partial fingerprint images from at least one partial fingerprint imager.

8. The apparatus of claim 7, wherein at least one of the finger position sensor arrays is a linear array of electrically conducting plates, and in which at least one of the partial finger print imagers produces a one dimensional partial image of a fingerprint.

9. The apparatus of claim 1, wherein there are a plurality of the at least one finger position sensor arrays, and in which the orientation of at least some of the finger position sensor arrays are different from the others, whereby two dimensional finger motion or location information is obtained.

10. The apparatus of claim 1, in which outputs from the apparatus include at least two spatial dimensions of finger position or finger motion data.

11. A finger motion tracking apparatus used to provide a user input to_a computing device comprising:

at least two linear sensor arrays configured to sense overlapping line segments of features of a fingerprint of a finger moving along one of at least two axes of motion of the finger, each linear sensor array including a plurality of linear sensor array sensing elements configured to capture segments of fingerprint image data, at least one of the at least two axes of motion being in a direction other than a direction of a swipe of the finger surface over the sensor surface, the overlapping line segments of the features of the fingerprint image each being sensed at different times;

a memory configured to receive and store image data from each linear sensor array; and

a computing device configured to generate finger motion data by comparing overlapping line segments of the fingerprint image that match each other, sensed by one of the at least two linear sensor arrays at different times, thereby determining a velocity of finger motion along each of the at least two axes of motion of the finger.

12. An apparatus according to claim 11, wherein the linear sensor array is configured to sense at least two overlapping line segments of fingerprint data, including a first overlapping line segment and a subsequently sensed second overlapping line segment;

and wherein the computing device is configured to generate motion data based on an amount of shift between the first overlapping line segment and the subsequently sensed second overlapping line segment and navigation data based on the amount of shift in each of the at least two axes.

13. An apparatus according to claim 12, wherein the user input moves a cursor on a graphical user interface.

14. An apparatus according to claim 11, wherein the motion data includes velocity data and directional data.

15. The apparatus according to claim 11, wherein the linear sensor array is configured to sense a first set of features of a fingerprint along a first axis of finger motion and to generate a first set of image data captured by a plurality of sensors in the linear sensor array and to subsequently sense a second set of features of the fingerprint along the first axis of finger motion and to generate a second set of image data captured by the plurality of sensors in the linear sensor array, and wherein the computing device is configured to compare the first set and the second set of image data to determine the distance traveled by the finger over a time interval, and wherein the distance and time interval are used to calculate navigational data for navigating the cursor on the graphical user interface.

16. The apparatus according to claim 11, further comprising the second of the at least two linear sensor arrays configured to sense features of the fingerprint along the second of the at least two axes and to generate directional image data captured by a plurality of sensors, wherein the computing device is configured to produce navigation data using the motion data along the second of the at least two axes of motion.

17. The apparatus according to claim 11, further comprising at least a second linear sensor array aligned along a second axis of the at least two axes of motion and configured to sense features of a fingerprint and to generate directional image data captured by a plurality of sensors for use in providing user input for the navigation of an object responsive to the motion of a finger across the sensor surface.

18. The apparatus according to claim 11, wherein the computing device is configured to use at least one of the motion data and the navigation data to assemble fingerprint image portions.

19. A method of tracking motion of a fingerprint with respect to a sensor surface for use in a user input to computing device comprising:

sensing at least two overlapping line segments of a fingerprint image, each located along one of at least two axes of motion of the finger surface with respect to the sensor surface, at least one of the at least two axes of motion being in a direction other than a direction of a swipe of the finger surface over the sensor surface, the overlapping line segments of the fingerprint image each being sensed at different times;

storing digital data corresponding to the at least two overlapping line segments sensed by the sensing elements; and

processing the digital data to generate fingerprint motion data by comparing overlapping line segments of the fingerprint image that match each other, sensed by one of the at least two linear sensor array at different times, thereby determining a velocity of finger motion along each of the at least two axes of motion of the finger, and navigation data based on the amount of shift in each of the at least two axes.

20. A method according to claim 19, further comprising:

comparing digital data of a first overlapping line segment with subsequently sensed digital data of a second overlapping line segment;

determining the amount of shift between the first overlapping line segment and the subsequently sensed second overlapping line segment to determine the distance traveled by the finger across the sensor surface in the direction of the one of the at least two axes; and

generating navigation data from the amount of shift.

21. A method according to claim 20, further comprising:

estimating an estimated distance traveled by the finger surface with respect to the sensor surface in the direction of the one of the at least two axes by multiplying the amount of pixel shift detected times the pitch of the sensor pixels in the line segment of the sensor; and

computing the velocity of the finger surface with respect to the sensor surface by dividing the estimated distance by a time between the sensing of the first overlapping line segment and the second overlapping line segment in the direction of the one of the at least two axes.

22. A method according to claim 20, further comprising:

estimating a distance traveled by the finger surface with respect to the sensor surface by multiplying the pixel shift detected between the first overlapping line segment and the second overlapping line segment in the direction of the one of the at least two axes times the pitch of the pixels in the direction of the one of the at least two axes; and

computing the velocity of the finger surface with respect to the sensor surface by dividing the estimated distance by the time between the sensing of the first overlapping line segment and the sensing of the second overlapping line segment.

23. A tangible machine readable medium storing instructions that, when executed by a computing device, cause the computing device to perform a method, the method comprising:

tracking motion of a fingerprint with respect to a sensor for use in a user input to a computing device comprising;

sensing at least two overlapping line segments of a fingerprint image, each located along one of at least two axes of motion of the finger surface with respect to a sensor surface, at least one of the at least two axes of motion being in a direction other than a direction of a swipe of the finger surface over the sensor surface, the overlapping line segments of the fingerprint image being sensed at different times;

storing digital data corresponding to the at least two overlapping line segments sensed by the sensing elements; and

processing the digital data to generate fingerprint motion data by comparing overlapping line segments of the fingerprint image, that match each other, taken by one of the linear sensor arrays at different times, thereby determining a velocity of finger motion along each of the at least two axes of motion of the finger, and navigation data based on the amount of shift in each of the at least two axes.

24. The machine readable medium of claim 23, the method further comprising:

comparing digital data of a first overlapping line segment with subsequently sensed digital data of a second overlapping line segment;

determining the amount of shift between the first overlapping line segment and the subsequently sensed second overlapping line segment to determine the distance traveled by the finger across the sensor surface in the direction of one of the at least two axes; and

generating navigation data from the amount of shift.

25. A machine readable medium of claim 24, the method further comprising:

estimating an estimated distance traveled by the finger surface with respect to the sensor surface in the direction of one of the at least two axes by multiplying the amount of pixel shift detected times the pitch of the sensor pixels in the line segment of the sensor; and

computing the velocity of the finger surface with respect to the sensor surface by dividing the estimated distance by a time between the sensing of the first overlapping line segment and the sensing of the second overlapping line segment in the direction of one of the at least two axes.

26. A machine readable medium of claim 24, the method further comprising:

estimating a distance traveled by the finger surface with respect to the sensor surface by multiplying the pixel shift detected between the first overlapping line segment and the second overlapping line segment in the direction of the one of the at least two axes times the pitch of the pixels in the direction of the one of the at least two axes; and

computing the velocity of the finger surface with respect to the sensor surface by dividing the estimated distance by the time between the sensing of the first overlapping line segment and the sensing of the second overlapping line segment.