FORCE SENSING TOUCH SCREEN

• US 20120105358A1
• Filed: 11/03/2010
• Published: 05/03/2012
• Est. Priority Date: 11/03/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Momeyer, Brian, Beckwith, Kevin M., Oliveira, Louis Dominic, Heimbigner, Wade L., Forutanpour, Babak, Nelson, Hui-Ya L., Schevciw, Andrea Gustavo P.
• Granted Patent: US 9,262,002 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 3/0485 Scrolling or panning
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

A computing device includes a touch screen display with a plurality of force sensors, each of which provides a signal in response to contact with the touch screen display. Using force signals from the plurality of force sensors, a characteristic of the contact is determined, such as the magnitude of the force, the centroid of force and the shear force. The characteristic of the contact is used to select a command which is processed to control the computing device. For example, the command may be related to manipulating data displayed on the touch screen display, e.g., by adjusting the scroll speed or the quantity of data selected in response to the magnitude of force, or related to an operation of an application on the computing device, such as selecting different focal ranges, producing an alarm, or adjusting the volume of a speaker in response to the magnitude of force.

Claims

1. A method, comprising:

receiving signals from a plurality of force sensors coupled between a touch screen display and a housing of a computing device, the signals received in response to contact with the touch screen display;

determining a characteristic of the contact with the touch screen display using the signals from the plurality of force sensors, the characteristic of the contact comprising at least one of a magnitude of force applied normal to a plane defined by the touch screen display, a centroid of force of the contact, and a shear force parallel to the plane defined by the touch screen display;

using the characteristic of the contact to select a command; and

processing the command to control the computing device.

2. The method of claim 1, wherein the plurality of force sensors are resistive force sensors and are arranged around a perimeter of a bottom surface of the touch screen display.

3. The method of claim 1, wherein the magnitude of force comprises at least one of the magnitude of force over the touch screen display and the magnitude of force over an area of contact with the touch screen display.

4. The method of claim 3, wherein determining the magnitude of force over the area of contact with the touch screen display comprises determining the area of contact based on signals from a touch sensor on the touch screen display.

5. The method of claim 1, wherein determining the centroid of force of the contact comprises a vector sum of force vectors determined for each force sensor as a product of a force detected by a distance to a center of the touch screen display.

6. The method of claim 1, wherein determining the shear force comprises:

determining the centroid of force of the contact using the signals received from the plurality of force sensors;

determining a centroid of an area of contact based on signals from a touch sensor on the touch screen display; and

using a difference between the centroid of the area of contact and the centroid of force to determine the shear force.

7. The method of claim 1, wherein determining the shear force comprises using signals received from a subset of the plurality of force sensors, the subset of the plurality of force sensors being arranged on sides of the touch screen display between the touch screen display and the housing.

8. The method of claim 1, further comprising:

detecting motion of the computing device and adjusting a force threshold in response to the motion, wherein the force threshold is increased with greater motion of the computing device; and

comparing the magnitude of force to the force threshold;

wherein a command is selected when the magnitude of force is greater than the force threshold.

9. The method of claim 1, wherein the command comprises manipulating data displayed on the touch screen display.

10. The method of claim 9, wherein manipulating data displayed on the touch screen display comprises controlling a speed of scrolling data displayed on the touch screen display in response to the magnitude of force.

11. The method of claim 9, wherein manipulating data displayed on the touch screen display comprises controlling a quantity of data on the touch screen display that is selected in response to the magnitude of force.

12. The method of claim 1, wherein the command comprises controlling an operation of an application on the computing device.

13. The method of claim 12, the method further comprising determining a rate of change in the magnitude of force, wherein controlling the operation of an application comprises at least partially reversing a selected action in response to the rate of change of the magnitude of force being greater than a threshold.

14. The method of claim 12, wherein controlling the operation of an application comprises selecting between a foreground object and a background object displayed on the touch screen display in response to the magnitude of force applied to the touch screen display.

15. The method of claim 12, wherein controlling the operation of an application comprises selecting a focal range for a camera on the computing device in response to the magnitude of force applied to the touch screen display.

16. The method of claim 12, further comprising determining an area of contact based on signals from a touch sensor on the touch screen display, wherein controlling the operation of an application comprises producing an alarm indicating potential damage to the touch screen display in response to the magnitude of force over the area of contact being greater than a threshold.

17. The method of claim 12, wherein controlling the operation of an application comprises locking the computing device in response to the magnitude of force being greater than a threshold and a location of contact on the touch screen display.

18. The method of claim 12, wherein controlling the operation of an application comprises disabling a touch sensor in the touch screen display in response to the magnitude of force being greater than a threshold and a location of contact on the touch screen display.

19. The method of claim 18, wherein the touch sensor is at least one of a capacitive touch sensor and a resistive touch sensor.

20. The method of claim 12, wherein controlling the operation of an application comprises using the magnitude of force and the centroid of force to control the computing device while a touch sensor in the touch screen display is disabled.

21. The method of claim 12, wherein controlling the operation of an application comprises variably adjusting at least one of a speaker volume, audio frequency equalization, active noise cancellation, dynamic range compression, limiting, and gain control in response to the magnitude of force applied to the touch screen display.

22. The method of claim 1, wherein the plurality of force sensors detect finger movement through a protective element.

23. The method of claim 22, wherein the protective element is a pocket of a garment or a holder.

24. A computing device, comprising:

a housing;

a touch screen display comprising a display and a plurality of force sensors coupled between the housing and the display;

a processor connected to the plurality of force sensors;

memory connected to the processor; and

software held in the memory and run in the processor to cause the processor to determine a characteristic of a contact with the touch screen display using a signals received from the plurality of force sensors, the characteristic of the contact comprising at least one of a magnitude of force applied normal to a plane defined by the touch screen display, a centroid of force of the contact, and a shear force parallel to the plane defined by the touch screen display, to use the characteristic of the contact to select a command, and to process the command to control the computing device.

25. The computing device of claim 24, wherein the plurality of force sensors are resistive force sensors and are arranged around a perimeter of a bottom surface of the touch screen display.

26. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to determine the magnitude of force over the touch screen display.

27. The computing device of claim 24, wherein the touch screen display further comprises a touch sensor coupled to the display, the touch sensor being connected to the processor, wherein the software held in the memory and run in the processor causes the processor to determine an area of contact based on signals received from the touch sensor, and to determine the magnitude of force over the area of contact.

28. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to determine the centroid of force of the contact as a vector sum of force vectors determined for each force sensor as the product of a force detected by a distance to a center of the touch screen display.

29. The computing device of claim 24, wherein the touch screen display further comprises a touch sensor coupled to the display, the touch sensor being connected to the processor, wherein the software held in the memory and run in the processor causes the processor to determine a centroid of an area of contact based on signals received from the touch sensor, and to determine the shear force as a difference between the centroid of the area of contact and the centroid of force.

30. The computing device of claim 24, wherein a subset of the plurality of force sensors is arranged on sides of the display between the display and the housing, wherein the software held in the memory and run in the processor causes the processor to determine the shear force based on signals from the subset of the plurality of force sensors.

31. The computing device of claim 24, further comprising a motion sensor connected to the processor, wherein the software held in the memory and run in the processor causes the processor to detect motion of the computing device based on signals from the motion sensor, and to adjust a force threshold in response to the motion, wherein the force threshold is increased with greater motion of the computing device, to compare the magnitude of force to the force threshold, and to select a command when the magnitude of force is greater than the force threshold.

32. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to select a command to control a speed of scrolling data displayed on the display in response to the magnitude of force.

33. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to select a command to control a quantity of data on the display that is selected in response to the magnitude of force.

34. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to determine a rate of change in the magnitude of force, and to cause the processor to select a command to at least partially reverse a selected action in response to the rate of change of the magnitude of force being greater than a threshold.

35. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to select a command to select between a foreground object and a background object displayed on the display in response to the magnitude of force.

36. The computing device of claim 24, further comprising a camera with a selectable focal range, wherein the software held in the memory and run in the processor causes the processor to select a command to select a focal range for the camera in response to the magnitude of force.

37. The computing device of claim 24, wherein the touch screen display further comprises a touch sensor coupled to the display, the touch sensor being connected to the processor, wherein the software held in the memory and run in the processor causes the processor to determine an area of contact based on signals from the touch sensor and to select a command to produce an alarm indicating potential damage to the display in response to the magnitude of force over the area of contact being greater than a threshold.

38. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to select a command to lock the computing device in response to the magnitude of force being greater than a threshold and a location of contact on the touch screen display.

39. The computing device of claim 24, wherein the touch screen display further comprises a touch sensor coupled to the display, wherein the software held in the memory and run in the processor causes the processor to select a command to disable the touch sensor in response to the magnitude of force being greater than a threshold and a location of contact on the touch screen display.

40. The computing device of claim 39, wherein the touch sensor is at least one of a capacitive touch sensor and a resistive touch sensor.

41. The computing device of claim 24, wherein the touch screen display further comprises a touch sensor coupled to the display, wherein the software held in the memory and run in the processor causes the processor to control the computing device with the magnitude of force and the centroid of force while the touch sensor in the touch screen display is disabled.

42. The computing device of claim 24, wherein the software held in the memory and run in the processor causes the processor to adjust at least one of volume of a speaker, audio frequency equalization, active noise cancellation, dynamic range compression, limiting, and gain control in response to the magnitude of force applied to the touch screen display.

43. The computing device of claim 24, wherein the plurality of force sensors detect finger movement through a protective element.

44. The computing device of claim 43, wherein the protective element is a pocket of a garment or a holder.

45. A system comprising:

means for receiving force measurements from a plurality of locations of a touch screen display in response to contact with the touch screen display;

means for determining a characteristic of the contact with the touch screen display using force measurements from the plurality of locations, the characteristic of the contact comprising at least one of a magnitude of force applied normal to a plane defined by the touch screen display, a centroid of force of the contact, and a shear force parallel to the plane defined by the touch screen display;

means for selecting a command based on the characteristic of the contact;

means for processing the command.

46. A computer-readable medium including program code stored thereon, comprising:

program code to determine a characteristic of a contact with a touch screen display using signals received from a plurality of force sensors, the characteristic of the contact comprising at least one of a magnitude of force applied normal to a plane defined by the touch screen display, a centroid of force of the contact, and a shear force parallel to the plane defined by the touch screen display;

program code to use the characteristic of the contact to select a command; and

program code to process the command.