TOUCH MOTION DETECTION METHOD, CIRCUIT, AND SYSTEM

• US 20140028609A1
• Filed: 07/30/2012
• Published: 01/30/2014
• Est. Priority Date: 07/30/2012
• Status: Active Grant

• Current Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: Santos, Maria Rhea
• Granted Patent: US 9,235,289 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A touch controller includes a touch frame processing (TFP) component that receives sensor signals containing information about a touch point on a touch screen. The TFP component processes the sensor signals to generate touch information associated with each touch point. The touch information includes a location and the association of one of a touch-in, touch-out, and touch-motion event. A touch coordinate processing (TCP) component receives touch information from the TFP component and determines whether to report the touch information associated with a current touch point. The TCP component determines a difference between the location of the current touch point and a previously detected touch point and assigns a motion status to each touch event and reports the touch information when the difference is greater than a motion tolerance and when less than the motion tolerance selectively blocks or reports the touch information as a function of the corresponding motion status.

Claims

1. A touch controller, comprising:

a touch frame processing component adapted to receive sensor signals containing information about a touch point on a touch screen, the touch frame processing component operable to process the sensor signals to generate touch information associated with each touch point, the touch information including a location of the touch point and the association of one of a touch-in, touch-out, and touch-motion type of event with the touch point; and

a touch coordinate processing component coupled to receive touch information from the touch frame processing component and operable to determine whether to report touch information associated with a current touch point, the touch coordinate processing component operable to determine a difference between the location of the current touch point and the location of a previously detected touch point and to assign a motion status to each touch event, the touch coordinate processing component operable to report the touch information associated with the current touch point when the difference is greater than a motion tolerance threshold and further operable when the difference is less than the motion tolerance to selectively block or report the touch information as a function of the corresponding motion status.

2. The touch controller of claim 1, wherein the motion status comprises a stationary state and an in-motion state.

3. The touch controller of claim 2,

wherein the touch coordinate processing component is further operable, when the difference is less than the motion tolerance, to,

block reporting of the second touch event when the current motion status is the stationary state or when the current motion status is the in-motion state and a frame hysteresis value has reached a threshold value;

and

report the second touch event when the current motion status is the in-motion state and the frame hysteresis value has not reached the threshold value.

4. The touch controller of claim 1, wherein the touch coordinate processing component is operable to report a touch event when the touch event is a touch-in type of event.

5. The touch controller of claim 2, wherein the touch coordinate processing component is operable to report a touch event when the touch is a touch-out type of event.

6. The touch controller of claim 1 further comprising a FIFO buffer operable to store touch information being reported and to provide the stored touch information on a first-in-first-out basis.

7. The touch controller of claim 1, wherein each component comprises a software module executing on suitable digital circuitry.

8. The touch controller of claim 1, wherein the touch information further includes pressure and size information for each touch point.

12. The method of claim 1 further comprising when the difference is greater than or equal to a motion tolerance threshold:

resetting a frame count; and

setting a location of a reference touch point equal to the location of the second touch point.

13. The method of claim 2, wherein blocking reporting of the second touch event when the status is the in-motion state and a frame hysteresis value has reached a threshold value includes resetting the frame count.

14. The method of claim 3 further comprising detecting whether a touch event is a touch-in event or a touch-out event.

9. A method of determining whether to report the detection of a touch-motion event in an electronic device including a touch screen, the method comprising:

determining a difference between the location of a first touch point and the location of a subsequently detected second touch point;

when the difference is greater than or equal to a motion tolerance threshold, setting a status to an in-motion state and reporting a second touch event associated with the second touch point; and

when the difference is less than the motion tolerance threshold,

blocking reporting of the second touch event when the status is a stationary state or when the status is the in-motion state and a frame hysteresis value has reached a threshold value; and

reporting the second touch event when the status is the in-motion state and the frame hysteresis value has not reached the threshold value.

10. The method of claim 9, wherein the first touch point is a reference touch point corresponding to the location of a previous touch event.

11. The method of claim 10,

wherein the reference touch point is the location of a prior touch event when the prior touch event is a touch-in event;

and

wherein the reference touch point is the location of a prior touch event when the prior touch event is a touch-motion event and the difference is less than the motion tolerance threshold.

15. An electronic system, comprising:

processing circuitry;

a touch screen;

a touch controller coupled to the processing circuitry and the touch screen, the touch controller including a touch frame processing component adapted to receive sensor signals from the touch screen, the sensor signals containing information about a touch point on the touch screen, the touch frame processing component operable to process the sensor signals to generate touch information associated with each touch point, the touch information including a location of the touch point and the association of one of a touch-in, touch-out, and touch-motion type of event with the touch point; and

a touch coordinate processing component coupled to receive touch information from the touch frame processing component and operable to determine whether to report touch information associated with a current touch point to the processing circuitry, the touch coordinate processing component operable to determine a difference between the location of the current touch point and the location of a previously detected touch point and to assign a motion status to each touch event, and the touch coordinate processing component operable to report the touch information associated with the current touch point when the difference is greater than a motion tolerance threshold and further operable when the difference is less than the motion tolerance to selectively block or report the touch information as a function of the corresponding motion status.

16. The electronic system of claim 15, wherein the processing circuitry comprises cellular telephone processing circuitry.

17. The electronic system of claim 15, wherein the touch screen comprises a capacitive touch screen.

18. The electronic system of claim 15,

wherein the touch coordinate processing component is further operable, when the difference is less than the motion tolerance, to,

block reporting of the second touch event when the current motion status is the stationary state or when the current motion status is the in-motion state and a frame hysteresis value has reached a threshold value;

and

report the second touch event when the current motion status is the in-motion state and the frame hysteresis value has not reached the threshold value.

19. The electronic system of claim 15, wherein the touch coordinate processing component is operable to report a touch event when the touch event is a touch-in type of event.

20. The electronic system of claim 15, wherein the touch coordinate processing component is operable to report a touch event when the touch is a touch-out type of event.

21. The electronic system of claim 15 further comprising a FIFO buffer coupled to the processing circuitry and operable to store touch information being reported to the processing circuitry.

22. The electronic system of claim 15, wherein each component comprises a software module executing on suitable digital circuitry.

23. The electronic system of claim 15, wherein the touch information further includes identification, pressure and size information for each touch point.