Method and a touch sensing device for implementing the method

• US 9,086,764 B2
• Filed: 06/22/2010
• Issued: 07/21/2015
• Est. Priority Date: 06/23/2009
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Ing, Ros Kiri, Schevin, Olivier, LeBlanc, Alexandre
• Primary Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US13/380,475
• Publication Number:
  US 20140225872A1
• Time in Patent Office: 1,855 Days
• Field of Search: 345173-179, 178 1801- 1804
• US Class Current: 1/1
• CPC Class Codes: G06F 3/043 using propagating acoustic waves

Abstract

The present invention relates to a method for determining an acoustic response attributed to a location of an impact, in particular a touch event, on a surface of an object including at least one transducer comprising the steps of: a) receiving an acoustic signal from at least one transducer, wherein the signal corresponds to a predetermined excitation (E) at at least one location on the surface; b) determining an acoustic response based on the acoustic signal received in step a); and c) determining the acoustic response attributed to at least one location on the surface different to the location of the predetermined excitation based on at least two different acoustic responses determined in step b).

Claims

1. A method for determining an acoustic response attributed to a location of an impact, in particular a touch event, on a surface of an object including at least one transducer comprising the steps of:

a) receiving an acoustic signal from the at least one transducer, wherein the signal corresponds to a predetermined excitation (E) at at least one location on the surface;

b) determining an acoustic response based on the acoustic signal received in step a);

c) determining the acoustic response attributed to at least one location on the surface different to the location of the predetermined excitation based on at least two different acoustic responses determined in step b);

g) determining a first representative function based on the distance between an auxiliary location, which is positioned away from the location of the predetermined excitation and the locations on the surface different to the location of the predetermined excitation, and the location on the surface different to the location of the predetermined excitation;

h) determining a second representative function based on the distance between the auxiliary location and the location of the predetermined excitation;

i) computing a ratio between the first representative function determined in step g) and the second representative function determined in step h);

j) repeating step g) for each location on the surface different to the location of the predetermined excitation and for each auxiliary location; and

k) repeating step h) for each location of the predetermined excitation.

2. The method according to claim 1, wherein the acoustic signals are received from at least two transducers and the acoustic signals correspond to at least one predetermined excitation at at least one location on the surface.

3. The method according to claim 1, wherein the acoustic signals are received from at least one transducer and the acoustic signals correspond to predetermined excitations at at least two locations on the surface.

4. The method according to claim 1, wherein the predetermined excitation is applied at a location that is positioned in a border region of a part of the surface of the object serving as a touch sensitive input area or outside the border region.

5. The method according to claim 1, further comprising a step d) of:

determining acoustic responses at a plurality of locations on the surface different to the at least one location of the predetermined excitation based on the acoustic response determined in step b).

6. The method according to claim 5, further comprising a step e) of:

gathering the acoustic responses determined at a plurality of locations on the surface different to the locations of the predetermined excitations in step d) to form a lookup table.

7. The method according to claim 6, further comprising a step m) of comparing the acoustic response with a previously determined acoustic response corresponding to that location on the surface of the lookup table.

8. The method according to claim 1, further comprising a step f) of:

selecting only acoustic responses, determined during step b) for carrying out step c), that satisfy predetermined criteria including at least one of signal-to-noise ratio or coherence of the measurements.

9. The method according to claim 1, wherein the auxiliary locations are outside the surface and away from each location of a predetermined excitation and away from each location on the surface different to each location of a predetermined excitation.

10. The method according to claim 1, further comprising a step l) of repeating steps a) to c) based on at least one of an on demand basis or a scheduled basis.

11. The method according to claim 1, wherein the predetermined excitations are provided such that the spacing λ

between two neighboring locations of predetermined excitations satisfy the relation λ

≦

1.2 A wherein A is proportional to

12. The method according to claim 11, wherein the predetermined excitations are provided such that the spacing λ

satisfy the relation 0.5 A≦

λ

≦

1.2 A.

13. The method according to claim 11, wherein:

ω

is a maximum frequency of interest; and

the spacing λ

between two neighboring locations of predetermined excitations satisfy the relation 0.5 A λ

≦

1.2 A.

14. The method according to claim 1, wherein the predetermined excitations are provided such that the number of locations of the predetermined excitations per wavelength of the acoustic signal is more than one.

15. The method according to claim 1, wherein the at least one transducer is located on an axes of symmetry of the surface of the object.

16. The method according to claim 15, wherein the surface is shaped to be rectangular, the at least one transducer is located on at least one axes of symmetry of the rectangular surface and the predetermined excitation is provided at locations of every second quadrant of the rectangular surface.

17. The method according to claim 1, wherein the locations of the predetermined excitations are randomly arranged.

18. The method according to claim 1, wherein the locations of the predetermined excitations are formed in at least two rows such that the spacing between the locations in a first row are different with respect to the spacing between the locations in a second.

19. A non-transitory computer readable medium including computer executable instructions stored thereon that when executed by a processor configure the processor to:

a) receive an acoustic signal from at least one transducer, wherein the signal corresponds to a predetermined excitation (E) at at least one location on a surface of an object including the at least one transducer;

b) determine an acoustic response based on the acoustic signal received in step a); and

c) determine the acoustic response attributed to at least one location on the surface different to the location of the predetermined excitation based on at least two different acoustic responses determined in step b);

g) determine a first representative function based on the distance between an auxiliary location, which is positioned away from the location of the predetermined excitation and the locations on the surface different to the location of the predetermined excitation, and the location on the surface different to the location of the predetermined excitation;

h) determine a second representative function based on the distance between the auxiliary location and the location of the predetermined excitation;

i) compute a ratio between the first representative function determined in step g) and the second representative function determined in step h);

j) repeat step g) for each location on the surface different to the location of the predetermined excitation and for each auxiliary location; and

k) repeat step h) for each location of the predetermined excitation.

20. A touch sensing device comprising:

an interaction surface;

at least one transducer; and

a controller configured to;

a) receive an acoustic signal from at least one transducer, wherein the signal corresponds to a predetermined excitation (E) at at least one location on the interaction surface;

b) determine an acoustic response based on the received acoustic signal;

c) determine the acoustic response attributed to at least one location on the interaction surface different to the location of the predetermined excitation based on at least two different acoustic responses determined based on the received acoustic signal;

g) determine a first representative function based on the distance between an auxiliary location, which is positioned away from the location of the predetermined excitation and the locations on the surface different to the location of the predetermined excitation, and the location on the surface different to the location of the predetermined excitation;

h) determine a second representative function based on the distance between the auxiliary location and the location of the predetermined excitation;

i) compute a ratio between the first representative function determined in step g) and the second representative function determined in step h);

j) repeat step g) for each location on the surface different to the location of the predetermined excitation and for each auxiliary location; and

k) repeat step h) for each location of the predetermined excitation.

21. The device according to claim 20, wherein the controller is configured to receive acoustic signals from at least two transducers and the acoustic signals correspond to the predetermined excitation at the at least one location on the surface or wherein the controller is configured to receive acoustic signals from the at least one transducer and the acoustic signals correspond to predetermined excitations at at least two locations on the surface.

22. The device according to claim 20, wherein the controller is configured to determine acoustic responses at a plurality of locations on the surface different to the at least one location of the predetermined excitation based on the received acoustic response.

23. The device according to claim 20, wherein the controller is configured to gather the acoustic responses determined at a plurality of locations on the surface different to the locations of the predetermined excitations to form a lookup table corresponding to the locations on the surface.

24. The device according to claim 20, further comprising:

a re-calibration unit for re-determining an acoustic response based on at least one of an on demand basis or a scheduled basis.

25. The device according to claim 24, wherein the re-calibration unit is configured to compare the acoustic response of the lookup table corresponding to the location on the surface to the re-determined acoustic response.

26. The device according to claim 24, wherein the re-calibration unit further comprises at least one actuator at the location of the predetermined excitation such that the predetermined excitation is applied at one location of a predetermined excitation by the at least one actuator.

27. The device according to claim 26, wherein the at least one actuator is positioned at the border of a region of interest of the surface of the object.

28. A touch sensitive device calibrating system, comprising:

a touch sensitive device including;

an interaction surface;

at least one transducer; and

a controller configured to;

a) receive an acoustic signal from at least one transducer, wherein the signal corresponds to a predetermined excitation (E) at at least one location on the interaction surface;

b) determine an acoustic response based on the received acoustic signal;

c) determine the acoustic response attributed to at least one location on the interaction surface different to the location of the predetermined excitation based on at least two different acoustic responses determined based on the received acoustic signal;

g) determine a first representative function based on the distance between an auxiliary location, which is positioned away from the location of the predetermined excitation and the locations on the surface different to the location of the predetermined excitation, and the location on the surface different to the location of the predetermined excitation;

h) determine a second representative function based on the distance between the auxiliary location and the location of the predetermined excitation;

i) compute a ratio between the first representative function determined in step g) and the second representative function determined in step h);

j) repeat step g) for each location on the surface different to the location of the predetermined excitation and for each auxiliary location; and

k) repeat step h) for each location of the predetermined excitation;

an input/output unit configured to communicate with one or more of the at least one transducer and the controller;

an excitation means for providing the predetermined excitation at the at least one location on the surface, wherein the predetermined excitation is provided by a mechanical contact between the excitation means and the surface; and

a positioning means configured to locate the excitation means at the at least one location on the surface such that the excitation means provides an excitation at the at least one location on the surface.

29. The device according to claim 28, wherein the input/output unit is configured to receive the acoustic signal from the at least one transducer.