TOUCH INTERFACE DEVICE HAVING AN ELECTROSTATIC MULTITOUCH SURFACE AND METHOD FOR CONTROLLING THE DEVICE

• US 20120287068A1
• Filed: 05/10/2012
• Published: 11/15/2012
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: Northwestern University
• Original Assignee: Northwestern University
• Inventors: Colgate, J. Edward, Peshkin, Michael A.
• Granted Patent: US 9,733,746 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 2203/04113 Peripheral electrode pattern in resistive digitisers, i.e. electrodes at the periphery of the resistive sheet are shaped in patterns enhancing linearity of induced field
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A touch interface device includes a touch surface, a first electrode, and a second electrode. The first electrode is coupled with the touch surface. The first electrode also configured to receive a first haptic actuation electric potential. The second electrode is coupled with the touch surface. The second electrode also is configured to receive a different, second haptic actuation electric potential having an opposite polarity than the first haptic actuation potential. The first and second electrodes generate an electrostatic force that is imparted on one or more appendages of an operator that touches the touch surface above both the first electrode and the second electrode in order to generate a haptic effect.

Claims

1. A touch interface device comprising:

a touch surface;

a first electrode coupled with the touch surface, the first electrode also configured to receive a first haptic actuation electric potential; and

a second electrode coupled with the touch surface and configured to receive a different, second haptic actuation electric potential having an opposite polarity than the first haptic actuation potential, wherein the first and second electrodes generate an electrostatic force that is imparted on one or more appendages of an operator that touches the touch surface above both the first electrode and the second electrode in order to generate a haptic effect.

2. The device of claim 1, further comprising a control unit configured to modulate the polarities of the first haptic actuation electric potential and the second haptic actuation electric potential at a frequency of at least 500 hertz.

3. The device of claim 1, wherein the first electrode lies across the second electrode without being conductively coupled with the second electrode at a first intersection, and the first and second electrodes are configured to generate the electrostatic force on the one or more appendages that engage the touch surface above the first intersection of the first and second electrodes.

4. The device of claim 3, wherein the electrostatic force that is generated by the first and second electrodes at the first intersection is greater than other electrostatic forces generated by the first electrode or the second electrode in one or more locations separated from the first intersection.

5. The device of claim 3, further comprising a third electrode and a fourth electrode coupled with the touch surface and configured to receive third and fourth haptic actuation electric potentials having opposite polarities, respectively, wherein the third electrode extends across the fourth electrode at a second intersection without the third electrode being conductively coupled with the fourth electrode.

6. The device of claim 5, wherein the first and second electrodes are configured to generate the electrostatic force on a first appendage of the operator when the first appendage engages the touch surface above the first intersection of the first and second electrodes, and wherein the third and fourth electrodes are configured to generate another, different electrostatic force on a different, second appendage of the operator when the second appendage concurrently engages the touch surface above the second intersection of the third and fourth electrodes.

7. The device of claim 1, wherein at least one of the first electrode or the second electrode is configured to also receive a sensing electric current in order to sense touch of the touch surface by the one or more appendages of the operator.

8. The device of claim 7, wherein the at least one of the first electrode or the second electrode is configured to concurrently receive (a) the sensing electric current and (b) the first haptic actuation electric potential or the second haptic actuation electric potential, respectively, to generate the electrostatic force and concurrently sense the touch of the touch surface by the one or more appendages.

9. The device of claim 8, wherein the at least one of the first electrode or the second electrode is configured to receive the first haptic actuation electric potential or the second haptic actuation electric potential, respectively at a first frequency and the sensing electric current at a different, second frequency to concurrently generate the electrostatic force and sense the touch of the touch surface by the one or more appendages.

10. The device of claim 7, wherein the at least one of the first electrode or the second electrode is configured to receive (a) the sensing electric current and (b) the first haptic actuation electric potential or the second haptic actuation electric potential, respectively, during different time periods.

11. The device of claim 7, wherein the at least one of the first electrode or the second electrode is elongated between opposite ends along a first direction, and further comprising a control unit configured to determine where the touch of the touch surface by the one or more appendages of the operator occurs along the first direction of the at least one of the first electrode or the second electrode by monitoring electric charge that is discharged from one or more of the opposite ends of the at least one of the first electrode or the second electrode.

12. The device of claim 11, wherein the control unit is configured to monitor the electric charge discharged from each of the opposite ends of the at least one of the first electrode or the second electrode and to compare the electric charges to determine where the touch of the touch surface by the one or more appendages occurs along the first direction of the at least one of the first electrode or the second electrode.

13. The device of claim 11, wherein the control unit is configured to monitor the electric charges discharged from at least one of the ends of both the first electrode and the second electrode and to compare the electric charges to determine where the touch of the touch surface by the one or more appendages occurs along a different, second direction.

14. The device of claim 1, wherein the first and second electrodes are configured to impart the electrostatic force on the one or more appendages when the touch surface is moving in one or more directions relative to the one or more appendages.

15. The device of claim 14, wherein a combination of the electrostatic force and movement of the touch surface generates the haptic effect.

16. The device of claim 1, wherein the first electrode and the second electrode are elongated conductive bodies oriented along parallel directions.

17. The device of claim 1, wherein the first electrode and the second electrode are sufficiently small such that a finger of the operator that engages the touch surface above the first electrode also is disposed above at least a portion of both the second electrode.

18. A touch interface device comprising:

a touch surface; and

elongated electrodes coupled with the touch surface, the electrodes including a first electrode oriented along a first direction and a second electrode oriented along a different, second direction, the first electrode extending over the second electrode at a first intersection, wherein the first and second electrodes are configured to receive haptic actuation electric potentials of opposite polarities to generate an electrostatic force that is imparted on the one or more appendages of the operator that touch the touch surface above the first intersection.

19. The device of claim 18, further comprising a control unit configured to modulate the polarities of the haptic actuation electric potentials.

20. The device of claim 18, wherein the elongated electrodes include a third electrode and a fourth electrode with the third electrode extending across the fourth electrode at a second intersection, and wherein the first and second electrodes are configured to generate a first electrostatic force on a first appendage of the operator that engages the touch surface above the first intersection, and wherein the third and fourth electrodes are configured to generate different, second electrostatic force on a different, second appendage of the operator that concurrently engages the touch surface above the second intersection.

21. The device of claim 19, wherein at least one of the electrodes is configured to also receive a sensing electric current in order to sense touch of the touch surface by the one or more appendages.

22. The device of claim 21, wherein the at least one of the electrodes is configured to concurrently receive the haptic actuation electric potential and the sensing electric current to both generate the electrostatic force and sense the touch of the touch surface by the one or more appendages.

23. The device of claim 22, wherein the at least one of the electrodes is configured to receive the haptic actuation electric potential at a first frequency and the sensing electric current at a different, second frequency to simultaneously generate the electrostatic force and sense the touch of the touch surface by the one or more appendages.

24. The device of claim 21, wherein the at least one of the electrodes is configured to receive the haptic actuation electric potential and the sensing electric current during different time periods.

25. The device of claim 18, wherein the electrodes are elongated between opposite ends, and further comprising a control unit configured to determine where touch of the touch surface occurs along at least one of the electrodes by the one or more appendages by monitoring electric charge that is discharged from one or more of the ends of the at least one of the electrodes.

26. The device of claim 25, wherein the control unit is configured to monitor the electric charge discharged from each of the opposite ends of the at least one of the electrodes and to compare the electric charges to determine where the touch of the touch surface by the one or more appendages occurs along the at least one of the electrodes.

27. The device of claim 18, wherein at least a subset of the electrodes are oriented parallel to each other, and further comprising a control unit configured to determine where touch of the touch surface by the one or more appendages occurs laterally across the subset of the electrodes that are parallel to each other by comparing the electric charges that are discharged from two or more of the electrodes in the subset.

28. A method comprising:

applying a first haptic actuation electric potential having a first polarity to a first electrode coupled with a touch surface of a touch interface device; and

applying a second haptic actuation electric potential having a second polarity to a second electrode that is coupled with the touch surface, the second polarity of the second haptic actuation potential being opposite of the first polarity of the first haptic actuation potential, wherein the first and second haptic actuation potentials generate an electrostatic force that is imparted on one or more appendages of an operator that touch the touch surface above the first and second electrodes.

29. The method of claim 28, further comprising modulating the first and second polarities of the first and second haptic actuation electric potentials.

30. The method of claim 28, wherein the first electrode lies across the second electrode without being conductively coupled with the second electrode at a first intersection, and the first and second haptic actuation potentials generate the electrostatic force on the one or more appendages that engage the touch surface above the first intersection of the first and second electrodes.

31. The method of claim 30, wherein the electrostatic force that is generated by the first and second haptic actuation potentials at the first intersection is greater than other electrostatic forces generated by the first electrode or the second electrode in one or more locations separated from the first intersection.

32. The method of claim 28, further comprising:

applying a third haptic actuation potential to a third electrode that is coupled to the touch surface; and

applying a fourth haptic actuation potential to a fourth electrode that is coupled to the touch surface, the third and fourth haptic actuation potentials having opposite polarities, wherein the first electrode extends across the second electrode at a first intersection beneath the touch surface without being conductively coupled with the second electrode and the third electrode extends across the fourth electrode at a second intersection beneath the touch surface without the third electrode being conductively coupled with the fourth electrode.

33. The method of claim 32, wherein the first and second haptic actuation potentials that are applied to the first and second electrodes generate a first electrostatic force on a first appendage of the operator that touches the touch surface above the first intersection, and wherein the third and fourth haptic actuation potentials that are applied to the third and fourth electrodes generate a different, second electrostatic force on a different, second appendage of the operator when the second appendage concurrently engages the touch surface above the second intersection.

34. The method of claim 28, further comprising applying a sensing electric current to the first electrode in order to sense touch of the touch surface by the one or more appendages.

35. The method of claim 34, wherein applying the first haptic actuation electric potential occurs at a first frequency and applying the sensing electric current to the first electrode occurs at a different, second frequency to concurrently generate the electrostatic force and sense the touch of the touch surface by the one or more appendages using the first electrode.

36. The method of claim 33, wherein applying the first haptic actuation electric potential and applying the sensing electric current occur during different time periods.

37. The method of claim 33, wherein the at least one of the first electrode or the second electrode is elongated between opposite ends along a first direction, and further comprising determining where the touch of the touch surface by the one or more appendages of the operator occurs along the at least one of the first electrode or the second electrode by monitoring electric charge that is discharged from one or more of the opposite ends of the at least one of the first electrode or the second electrode.

38. The method of claim 37, further comprising monitoring the electric charge discharged from each of the opposite ends of the at least one of the first electrode or the second electrode and comparing the electric charges to determine where the touch of the touch surface by the one or more appendages occurs along the at least one of the first electrode or the second electrode.

39. The method of claim 37, further comprising monitoring the electric charges discharged from at least one of the ends of both the first electrode and the second electrode and comparing the electric charges to determine where the touch of the touch surface by the one or more appendages occurs along a different, second direction.