Systems and methods for removing electrical noise from a touchpad signal

• US 8,319,746 B1
• Filed: 07/22/2011
• Issued: 11/27/2012
• Est. Priority Date: 07/22/2011
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Ho, Harvey, Wong, Adrian
• Primary Examiner(s): Eisen, Alexander
• Assistant Examiner(s): MARINELLI, PATRICK
• Application Number:
  US13/188,968
• Time in Patent Office: 494 Days
• Field of Search: 345156-184, 345 11- 9, 178 1801- 2004
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0433 in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

Systems and methods for removing electrical noise from an input signal from a touchpad device are provided. The touchpad device and one or more sensors may be coupled to a frame. Mechanical vibrations resulting from contact with a surface of the touchpad device during a motion input to the touchpad device may propagate via the frame to the one or more sensors. Information from the input signal and mechanical vibration signals received by one or more sensors may be processed to remove the electric noise from the input signal. In one example, information associated with relative motion of the input may be determined based on varying intensities of mechanical vibration signals received from the one or more sensors. Information of the input signal and the information associated with the relative motion may be correlated to determine position and/or movement information associated with the motion input.

Claims

1. A method comprising:

receiving an input signal from a touchpad device indicating a motion that is input to a surface of the touchpad device, wherein the touchpad device is a capacitive touchpad device that is coupled to a frame, and wherein the input signal includes information indicative of the motion input to the surface of the touchpad device being a sliding motion across the surface of the touchpad device;

receiving from one or more sensors coupled to the frame one or more vibration signals resulting from a contact with the surface of the touchpad device during the motion, wherein one or more auditory or mechanical vibrations propagate from the contact with the surface to the one or more sensors via the frame;

determining information associated with relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the one or more vibration signals, wherein relative motion indicates movement with respect to a known position of the one or more sensors; and

processing information of the input signal and the information associated with the relative motion to compensate for electrical noise in the input signal by;

estimating state information associated with the motion that is input to the surface of the touchpad device based on a correlation of the information of the input signal and the information associated with the relative motion;

determining one of position and movement information associated with the motion that is input to the surface of the touchpad device based on the state information; and

providing a modified input signal as a substitute for the input signal, wherein a portion of the information of the input signal is modified based on the one of position and movement information.

2. The method of claim 1, further comprising:

the one or more sensors receiving the one or more auditory or mechanical vibrations; and

the one or more sensors outputting the one or more vibration signals being indicative of the contact with the surface of the touchpad device during the motion.

3. The method of claim 1, wherein determining information associated with relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the one more vibration signals comprises accessing a database to associate the varying intensities of the one or more vibration signals with a known motion.

4. The method of claim 1, wherein the touchpad device is operated in a noisy electrical environment, wherein an electrical circuit of the touchpad is disturbed by electromagnetic interference resulting in electrical noise within the input signal.

5. The method of claim 1, wherein the one or more sensors comprise a microphone coupled to a known position on the frame, and the method further comprising determining relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the vibration signal from the microphone.

6. The method of claim 5, wherein the one or more sensors comprise a second microphone coupled to a second known position, and the method further comprising determining two-dimensional position and movement of the motion that is input to the surface of the touchpad device based on outputs from the microphone and the second microphone.

7. The method of claim 1, wherein the one or more sensors comprise an accelerometer coupled to a known position on the frame, and the method further comprising determining relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the vibration signal from the accelerometer.

8. The method of claim 1, wherein the contact with the surface comprises a gesture on the surface.

9. The method of claim 1, further comprising accessing a database to determine whether the state information is associated with a known gesture.

10. The method of claim 1, further comprising:

determining a position of the touchpad device and the one or more sensors relative to the frame;

generating a plurality of input signals and vibration signals by inputting a plurality of motions to the surface of the touchpad;

matching the information of the input signal and one or more vibration signals to one of the generated input signals and vibration signals to determine one of position and movement information associated with the motion that is input to the surface of the touchpad device.

11. A non-transitory computer readable medium having stored therein instructions executable by a computing device to cause the computing device to perform functions comprising:

receiving an input signal from a touchpad device indicating a motion that is input to a surface of the touchpad device, wherein the touchpad device is a capacitive touchpad device that is coupled to a frame, and wherein the input signal includes information indicative of the motion input to the surface of the touchpad device being a sliding motion across the surface of the touchpad device;

receiving from one or more sensors coupled to the frame one or more vibration signals resulting from a contact with the surface of the touchpad device during the motion, wherein one or more auditory or mechanical vibrations propagate from the contact with the surface to the one or more sensors via the frame;

determining information associated with relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the one or more vibration signals, wherein relative motion indicates movement with respect to a known position of the one or more sensors; and

processing information of the input signal and the information associated with the relative motion to compensate for electrical noise in the input signal by;

estimating state information associated with the motion that is input to the surface of the touchpad device based on a correlation of the information of the input signal and the information associated with the relative motion;

determining one of position and movement information associated with the motion that is input to the surface of the touchpad device based on the state information; and

providing a modified input signal as a substitute for the input signal, wherein a portion of the information of the input signal is modified based on the one of position and movement information.

12. The computer readable medium of claim 11, further comprising instructions executable for:

the one or more sensors receiving the one or more auditory or mechanical vibrations; and

the one or more sensors outputting the one or more vibration signals being indicative of the contact with the surface of the touchpad device during the motion.

13. A system comprising:

a memory;

a processor coupled to the memory; and

instructions stored in the memory and executable by the processor to perform functions comprising;

receiving an input signal from a touchpad device indicating a motion that is input to a surface of the touchpad device, wherein the touchpad device is a capacitive touchpad device that is coupled to a frame, and wherein the input signal includes information indicative of the motion input to the surface of the touchpad device being a sliding motion across the surface of the touchpad device;

receiving from one or more sensors coupled to the frame one or more vibration signals resulting from a contact with the surface of the touchpad device during the motion, wherein one or more auditory or mechanical vibrations propagate from the contact with the surface to the one or more sensors via the frame;

determining information associated with relative motion of the motion that is input to the surface of the touchpad device based on varying intensities of the one or more vibration signals, wherein relative motion indicates movement with respect to a known position of the one or more sensors; and

processing information of the input signal and the information associated with the relative motion to compensate for electrical noise in the input signal by;

estimating state information associated with the motion input to the surface of the touchpad device based on a correlation of the information of the input signal and the information associated with the relative motion;

determining one of position and movement information associated with the motion that is input to the surface of the touchpad device based on the state information; and

providing a modified input signal as a substitute for the input signal, wherein a portion of the information of the input signal is modified based on the one of position and movement information.

14. The system of claim 13, further comprising instructions for providing the modified input signal to a computing device coupled to the frame.

15. The system of claim 14, wherein the computing device includes a wearable computing device.

16. The system of claim 15, wherein the computing device includes a head-mounted display device and the frame includes a frame of a pair of glasses.

17. The system of claim 13, wherein providing a modified input signal comprises:

matching the information of the input signal with the information associated with relative motion in time based on varying intensities of the one or more vibration signals received at substantially the same time as the motion that is input to the surface of the touchpad device;

modifying a portion of the information of the input signal associated with an instance in time where the variation of the portion of the information of the input signal with respect to the matching information associated with relative motion is above a tolerance using the matching information associated with relative motion so as to provide a modified input signal; and

determining state information associated with the motion that is input to the surface of the touchpad device based on the modified input signal.

18. The system of claim 13, wherein estimating state information associated with the motion that is input to the surface of the touchpad device based on a correlation of the information of the input signal and the information associated with the relative motion comprises:

determining a first uncertainty value of the information of the input signal;

determining a second uncertainty value of the information associated with the relative motion;

processing information of the input signal and information associated with the relative motion using a weighted average, wherein a weight of the information of the input signal is the first uncertainty value and a weight of the information associated with the relative motion is a second uncertainty value; and

determining state information associated with the motion that is input to the surface of the touchpad device based on the weighted average.

19. The system of claim 18, wherein the first uncertainty value and second uncertainty value are covariance values associated with one or more relationships between information of the input signal and information associated with the relative motion.

20. The system of claim 13, wherein the one or more sensors are separate and distinct from the touchpad device used to generate the input signal.