CONTROL SURFACE FOR TOUCH AND MULTI-TOUCH CONTROL OF A CURSOR USING A MICRO ELECTRO MECHANICAL SYSTEM (MEMS) SENSOR

• US 20120154273A1
• Filed: 03/01/2011
• Published: 06/21/2012
• Est. Priority Date: 12/21/2010
• Status: Active Grant

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: McDade, Darryn D. Sr., Mohammadi, Hamid
• Granted Patent: US 8,749,486 B2
• Time in Patent Office: Days
• US Class Current: 345/157
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means

Abstract

A method and apparatus for touch detection, multi-touch detection and cursor control in which the acceleration of a control surface is sensed to provide sensed signals. The control surface is supported at one or more support positions and moves in response to a force applied by a user at a touch position. The sensed signals are received in a processing unit where they are used to estimate a change in the position of force application. A touch control signal is generated from the estimated change in touch position. The touch control signal may be output to a graphical user interface, where it may be used, for example, to control various elements such as mouse clicks, scroll controls, control of single or multiple cursors, or manipulation of views of an object on a visual display unit, or remote control manipulation of objects themselves.

Claims

1. An apparatus for providing touch control information, the apparatus comprising:

a control surface supported at one or more support positions and adapted to move in response to pressure applied at a first touch position on the control surface;

a first MEMS-based sensor, coupled to the control surface at a first sensing position and operable to produce a first sensed signal in response to motion of the control surface at the first sensing position; and

a processing unit operable to receive the first sensed signal and to compute a change in the first touch position over a time interval from changes in the first sensed signal over the time interval,

wherein the touch control information is derived from the change in the first sensing position.

2. An apparatus in accordance with claim 1, wherein the first MEMS-based sensor comprises an accelerometer and wherein the processing unit is operable to compute the change in the first touch position dependent upon a double time integration of the first sensed signal.

3. An apparatus in accordance with claim 2, wherein the first MEMS-based sensor is operable to sense motion in a plurality of directions.

4. An apparatus in accordance with claim 1, wherein the processing unit is operable to compute at least one position coordinate of the first touch position dependent upon the first sensed signal, and wherein the touch control information is derived from the at least one position coordinate of the first touch position.

5. An apparatus in accordance with claim 1, wherein the control surface comprises a flexible control surface supported at its periphery, the apparatus further comprising:

second, third and fourth MEMS-based sensors coupled to the control surface and operable to produce sensed signal in response to motion of the control surface due to pressure applied at the first touch position on the control surface,

wherein the processing unit is operable to receive sensed signals from the first, second, third and fourth MEMS-based sensors and to compute a change in the first touch position over a time interval from changes in the sensed signals from the first, second, third and fourth MEMS-based sensors.

6. An apparatus in accordance with claim 1, further comprising a fulcrum, wherein the control surface is supported at a pivot point by the fulcrum and is adapted to pivot about the pivot point when pressure is applied at the first position on the control surface.

7. An apparatus in accordance with claim 6, wherein the control surface is flexible and bends about a line though the pivot point when pressure is applied at first and second touch positions on the control surface, the apparatus further comprising:

a second MEMS-based sensor, coupled to the control surface at a second sensing position and operable to produce a second sensed signal in response to motion of the control surface at the second sensing position,

wherein the processing unit is operable to receive the second sensed signals and to compute a change in the second touch position over the time interval from changes in the second sensed signal over the time interval, and

wherein the touch control information is derived from the change in the first touch position and the change in the second touch position.

8. An apparatus in accordance with claim 6, wherein the control surface is flexible and bends about a plurality of lines though the pivot point when pressure is applied at a plurality of touch positions on the control surface, the apparatus further comprising:

a plurality of MEMS-based sensors, coupled to the control surface and operable to produce a plurality of second sensed signal in response to motion of the control surface,

wherein the processing unit is operable to receive the plurality of sensed signals and to compute changes in the plurality of touch positions over the time interval from changes in the plurality of sensed signal over the time interval, and

wherein the touch control information is derived from the changes in the plurality of touch positions and comprises control information for a plurality of cursors.

9. An apparatus in accordance with claim 6, wherein the control surface is substantially rigid, the apparatus further comprising:

a spring element acting on the control surface at one or more positions and configured to bias the control surface to an equilibrium position, such that motion of the control surface is dependent upon the force applied to the control surface at the first touch position and upon the distance from the first touch position from the pivot point,

wherein the touch control information comprises information for control of a scrolling function.

10. An apparatus in accordance with claim 6, wherein the touch control information comprises one or more signals selected from the group of signals consisting of:

a cursor control signal;

a scroll control signal;

a mouse ‘

click’

signal; and

a mouse ‘

double-click’

signal.

11. A method for touch control of a remote apparatus, the method comprising:

sensing acceleration of a control surface supported at one or more support positions and adapted to move in response to a force applied by a user at a first touch position on the control surface to provide a sensed signal;

receiving the sensed signals in a processing unit;

doubly integrating the sensed signals in the processing unit to estimate a change in the first touch position on the control surface;

generating a touch control signal from the estimated change in the first touch position; and

outputting the touch control signal to the graphical user interface.

12. A method in accordance with claim 11, wherein the one or more support positions comprise a pivot point at which the control surface contacts a fulcrum.

13. A method in accordance with claim 12, wherein sensing the acceleration vector of the control surface comprises sensing an acceleration vector at one or more sensing positions on the control surface using one or more MEMS-based accelerometers.

14. A method in accordance with claim 12, wherein the control surface is supported by a spring such that the change in the first touch position is related to the force applied at the first touch position, and wherein the touch control signal comprises a signal for controlling a scroll function.

15. A method in accordance with claim 12, wherein the control surface is supported by a spring such that the change in the first touch position is related the distance between the first touch position and the pivot point, and wherein the touch control signal comprises a signal for controlling a scroll function.

16. A method in accordance with claim 11, wherein the one or more support positions are located at the periphery of the control surface and wherein the control surface is flexible.

17. A method in accordance with claim 16, wherein sensing acceleration of the control surface comprises sensing acceleration vectors at a plurality of sensing positions on the control surface using a plurality of MEMS-based accelerometers.

18. A method in accordance with claim 16, wherein sensing acceleration of the control surface comprises sensing motion of the control surface perpendicular to the control surface over successive time intervals, and wherein the touch control signal comprises a mouse click signal.

19. A method in accordance with claim 16, wherein sensing acceleration of the control surface comprises sensing motion of the control surface perpendicular to the control surface over successive time intervals, and wherein the touch control signal comprises a mouse double-click signal.

20. A method in accordance with claim 11, wherein the touch control signal comprises a plurality of cursor control signals for controlling a view of an object on a visual display screen.

21. A method in accordance with claim 11, wherein the remote apparatus comprises a graphical user interface.

22. A method in accordance with claim 11, wherein the touch control signal comprises a plurality of manipulation controls for controlling the remote apparatus.