SYSTEM AND METHOD FOR DIFFERENTIATING BETWEEN INTENDED AND UNINTENDED USER INPUT ON A TOUCHPAD

• US 20100127995A1
• Filed: 07/24/2009
• Published: 05/27/2010
• Est. Priority Date: 11/26/2008
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: YUN, Tiffany, MORIN, Philippe, KRYZE, David, RIGAZIO, Luca
• Granted Patent: US 8,502,787 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus

Abstract

A method and system for differentiating between intended user input and inadvertent or incidental contact with a touchpad is herein disclosed. When a user engages the touchpad, sensors on the touchpad are activated and generate touch sensor signals. Based on the pattern of engaged sensors, a hand pattern can be determined. From the hand pattern, a hand model may be retrieved. The hand model may indicate passive zones and active zones. Contact in the active zones may be considered intentional, while contact in the passive zones may be considered unintended or incidental. Moreover, a global shift may be calculated, and input from the active zones may be compensated for the global shift. The input from the active zones can then be used to control a graphical user interface.

Claims

1. A method for distinguishing intended user input from unintended user interaction with a touchpad comprising:

receiving a touch sensor signal from the touchpad indicating points of contact between sensors of the touchpad and a user, wherein a point of contact is a location of a sensor on the touchpad that is in contact with the user;

identifying points of contact corresponding to at least one of the user'"'"'s finger and points of contact corresponding to at least one of a user'"'"'s thumb and a user'"'"'s palm based on the touch sensor signal and a model of a hand; and

identifying intended user input from the touch sensor signal wherein the intended user input corresponds to a portion of the touch sensor signal originating from the points of contact corresponding to a user'"'"'s finger.

2. The method of claim 1 further comprising calculating a global shift indicating a shift of a majority of the user'"'"'s hand with respect to the touchpad.

3. The method of claim 2 wherein the intended user input is adjusted according to the global shift.

4. The method of claim 2 further comprising determining an amount of movement of the device based on a signal received from an accelerometer associated with the device, wherein the movement of the device is used in part to calculate the global shift.

5. The method of claim 1 wherein portions of the touch sensor signal corresponding to a user'"'"'s palm are used to determine the global shift.

6. The method of claim 1 wherein the locations of points of contact corresponding to at least one of the user'"'"'s finger and the locations of points of contact corresponding to at least one of a user'"'"'s thumb and a user'"'"'s palm are identified from predetermined areas in the at least one model of the hand.

7. The method of claim 6 further comprising maintaining a hand model database storing a plurality of models of the hand, wherein a user hand pattern is extracted from the touch sensor signal and matched to one of the plurality of models of the hand.

8. The method of claim 7 further comprising determining a hand rotation angle indicating an angle of the user'"'"'s hand with respect to the touchpad, wherein the rotation angle is used in part to match the user hand pattern to the one of the plurality of models of the hand.

9. The method of claim 7 further comprising determining a user hand size based on the touch sensor signal and normalizing the user hand pattern to a predetermined size, wherein the plurality of models of the hand are all of predetermined size.

10. The method of claim 1 further comprising controlling a graphical user interface using the intended touch sensor signals.

11. A method for controlling a user interface using a touchpad comprising:

receiving a touch sensor signal from the touchpad indicating points of contact between sensors of the touchpad and a user, wherein a point of contact is a location of a sensor on the touchpad that is in contact with the user

estimating a user hand pattern indicating an orientation of the user'"'"'s hand with respect to the touchpad based on the touch sensor signals;

retrieving a hand model from a hand model database based on the user hand pattern, wherein the hand model indicates active spatial locations relative to the touchpad where the user'"'"'s hand motions are classified as intended motions and passive spatial locations relative to the touchpad where the user'"'"'s hand motions are classified as inadvertent contact;

calculating a global shift indicating movement of a majority of the user'"'"'s hand relative to the touchpad; and

adjusting touch sensor signals corresponding to the active spatial locations based on the calculated global shift; and

controlling a user interface based on adjusted touch sensor signals.

12. The method of claim 11 further comprising determining locations of contact points between the user'"'"'s hand and the touchpad, wherein the locations of the contact points are used to estimate a user hand pattern.

13. The method of claim 12 further comprising determining a rotation angle of the user'"'"'s hand with respect to the touchpad based on the locations of the contact points, wherein the rotation angle is used to estimate a user hand pattern.

14. The method of claim 11 further comprising estimating a user hand size based on the locations of the contact points.

15. The method of claim 14 wherein the hand pattern is normalized to a predetermined size based on the hand size and the predetermined size, wherein the normalized hand pattern is used to retrieve the hand model from the hand model database.

16. The method of claim 11 wherein the active zone is associated with points of contact between at least one of the user'"'"'s fingers and the touchpad and wherein the passive zone is associated with points of contact between at least one of the user'"'"'s palm and the user'"'"'s thumb.

17. The method of claim 11 wherein the touchpad is an array of capacitive sensors.

18. The method of claim 17 further comprising calculating a center of mass of the hand pattern based on points of contact between the user'"'"'s hand and the touchpad and the capacitance at the points of contact.

19. The method of claim 18 further comprising calculating an amount of movement of the center of mass of the hand pattern with respect to the touchpad.

20. The method of claim 11 wherein the global shift is further based on accelerometer data received from an accelerometer associated with the device.

21. The method of claim 11 wherein the touchpad is a back touchpad located on a rear surface of the device, wherein a display of the device is on the front surface of the device.

22. The method of claim 11 wherein the touchpad controls the graphical user interface of an interactive tabletop having a display on an upward facing surface of the tabletop.

23. The method of claim 22 wherein the graphical user interface displays an input interface at a location corresponding to the passive spatial locations of the touchpad, wherein the user enters input via the user interface at locations corresponding to the active spatial locations of the touchpad.

24. A method for controlling a user interface using a touchpad comprising:

receiving touch sensor signals from a touchpad, wherein a touch sensor signal includes a plurality of contact points between a user'"'"'s hand and the touchpad;

estimating a user hand pattern that indicates an orientation of the user'"'"'s hand with respect to the touchpad based on the touch sensor signals;

retrieving a hand model from a hand model database based on the user hand pattern, wherein the hand model indicates active spatial locations relative to the touchpad where the user'"'"'s hand motions are classified as intended motions and passive spatial locations relative to the touchpad where the user'"'"'s hand motions are classified as inadvertent; and

controlling a graphical user interface based on touch sensor signals received from sensors in the active spatial locations of the touchpad.

25. The method of claim 24 further comprising:

calculating a global shift based on the touch sensor signals, wherein the global shift indicates movement of a majority of the user'"'"'s hand relative to the touchpad; and

adjusting touch sensor signals corresponding to the active spatial locations based on the calculated global shift.

26. The method of claim 25 wherein the touchpad is an array of capacitive sensors.

27. The method of claim 26 further comprising calculating a center of mass of the hand pattern based on points of contact between the user'"'"'s hand and the touchpad and the capacitance at the points of contact.

28. The method of claim 27 further comprising calculating an amount of movement of the center of mass of the hand pattern with respect to the touchpad.

29. The method of claim 25 wherein the global shift is further based on accelerometer data received from an accelerometer associated with the device.

30. The method of claim 24 further comprising determining locations of contact points between the user'"'"'s hand and the touchpad, wherein the locations of the contact points are used to estimate a user hand pattern.

31. The method of claim 30 further comprising determining a rotation angle of the user'"'"'s hand with respect to the touchpad based on the locations of the contact points, wherein the rotation angle is used to estimate a user hand pattern.

32. The method of claim 24 further comprising estimating a user hand size based on the locations of the contact points.

33. The method of claim 32 wherein the hand pattern is normalized to a predetermined size based on the hand size and the predetermined size, wherein the normalized hand pattern is used to retrieve the hand model from the hand model database.

34. A device having a graphical user interface comprising:

a front surface and a rear surface;

a display unit on the front surface of the device;

a touchpad on the rear surface of the device having sensors dispersed along an outer surface of the touchpad, wherein the sensors are sensitive to a user'"'"'s touch, and wherein the touchpad generates a touch sensor signal indicating locations of points of contact between the user'"'"'s hand and the touchpad;

a signal processing module that receives the touch sensor signal and determines a user hand pattern based on the touch sensor signal and a model of a hand, wherein a hand pattern includes points of contact of the user'"'"'s fingers and points of contact of at least one of the user'"'"'s palm and the user'"'"'s thumb; and

the signal processing module identifies intended user input from the touch sensor signal, wherein the intended user input corresponds to a portion of the touch sensor signal originating from the points of contact corresponding to a user'"'"'s finger.