METHODS AND DEVICES FOR DETERMINING USER INPUT LOCATION USING ACOUSTIC SENSING ELEMENTS

• US 20120032928A1
• Filed: 08/04/2011
• Published: 02/09/2012
• Est. Priority Date: 08/06/2010
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Alberth, William, Schellinger, Michael
• Granted Patent: US 8,907,930 B2
• Time in Patent Office: Days
• US Class Current: 345/177
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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

Abstract

Methods and devices are provided for determining location of an input on a surface of a device using an acoustic sensing element. An exemplary method begins by determining an anticipated acoustic response resulting from an output generated by a component of the device at the acoustic sensing element. The method continues by subtracting the anticipated acoustic response from a measured acoustic response at the acoustic sensing element to obtain a nominal acoustic response, and determining the location of the input based on the nominal acoustic response.

Claims

1. A method for determining location of an input on a surface of a device using an acoustic sensing element, the method comprising:

determining an anticipated acoustic response at the acoustic sensing element, the anticipated acoustic response resulting from an output generated by a component of the device;

subtracting the anticipated acoustic response from a measured acoustic response at the acoustic sensing element to obtain a nominal acoustic response; and

determining the location of the input based on the nominal acoustic response.

2. The method of claim 1, wherein determining the anticipated acoustic response comprises applying a transfer function for acoustic response attributable to the component of the device at a location of the acoustic sensing element to the output generated by the component of the device.

3. The method of claim 2, further comprising:

identifying a recalibration condition; and

determining an updated transfer function for acoustic response attributable to the component of the device at the location of the acoustic sensing element in response to identifying the recalibration condition.

4. The method of claim 3, wherein identifying the recalibration condition comprises identifying a difference between the location of the input based on the nominal acoustic response and a verified location for the input is greater than a threshold value.

5. The method of claim 4, further comprising determining the verified location using a touch panel having the input provided thereon.

6. The method of claim 2, further comprising:

generating a known output by the component of the device;

obtaining acoustic response attributable to the known output at the location of the acoustic sensing element; and

determining the transfer function for acoustic response attributable to the component of the device at the location of the acoustic sensing element based on a relationship between the acoustic response attributable to the known output at the location of the acoustic sensing element and the known output.

7. The method of claim 6, the component of the device comprising an audio output device, wherein generating the known output comprises generating a known auditory signal by the audio output device.

8. The method of claim 7, wherein generating the known auditory signal comprises generating a white noise signal by the audio output device.

9. The method of claim 6, the component of the device comprising a haptic output device, wherein generating the known output comprises generating a known haptic output by the haptic output device.

10. The method of claim 9, wherein generating the known haptic output comprises vibrating the device with a predetermined frequency.

11. A device comprising:

an acoustic sensing element configured to obtain a measured acoustic response in response to an input on a surface of the device;

a component configured to generate an output; and

a control module coupled to the acoustic sensing element and the component, wherein the control module is configured to;

determine an anticipated acoustic response resulting from the output at the acoustic sensing element;

subtract the anticipated acoustic response from the measured acoustic response to obtain a nominal acoustic response; and

determine the location of the input on the surface based on the nominal acoustic response.

12. The device of claim 11, wherein the control module is configured to:

cause the component to generate a known output;

obtain acoustic response attributable to the known output from the acoustic sensing element;

determine a transfer function for acoustic response attributable to the component of the device at the acoustic sensing element based on a relationship between the acoustic response attributable to the known output and the known output; and

determine the anticipated acoustic response by applying the transfer function to the output generated by the component of the device.

13. The device of claim 12, wherein the control module is configured to:

identify a recalibration condition; and

determine an updated transfer function for acoustic response attributable to the component of the device at the acoustic sensing element in response to identifying the recalibration condition.

14. The device of claim 13, further comprising a touch panel coupled to the control module, the input being provided on the touch panel, wherein the control module is configured to:

obtain a verified location for the input from the touch panel; and

identify the recalibration condition when a difference between the verified location and the location of the input determined based on the nominal acoustic response is greater than a threshold value.

15. The device of claim 12, wherein:

the component of the device comprises an audio output device coupled to the control module; and

the known output comprises a bandlimited white noise signal.

16. The device of claim 12, wherein:

the component of the device comprises a haptic output device; and

the known output comprises a predetermined vibration frequency.

17. A method for determining location of an input on a surface of a device using an acoustic sensing element, the method comprising:

calculating an anticipated acoustic response at the acoustic sensing element based on an output generated by a component of the device using a transfer function for acoustic response resulting from the component at the acoustic sensing element;

determining a nominal acoustic response at the acoustic sensing element based on the anticipated acoustic response and a measured acoustic response at the acoustic sensing element; and

determining the location of the input on the surface of the device based on the nominal acoustic response and an acoustic signature for the device.

18. The method of claim 17, wherein determining the nominal acoustic response comprises subtracting the anticipated acoustic response from the measured acoustic response.

19. The method of claim 18, wherein calculating the anticipated acoustic response comprises applying the transfer function for acoustic response resulting from the component at a location of the acoustic sensing element to the output generated by the component of the device.

20. The method of claim 17, further comprising:

determining whether a difference between the location of the input and a verified location for the input is greater than a threshold value; and

determining an updated transfer function for acoustic response resulting from the component at the acoustic sensing element in response to determining the difference between the location of the input and the verified location is greater than the threshold value.