Method for gesture detection on a capacitive touchpad

• US 8,013,842 B2
• Filed: 10/23/2006
• Issued: 09/06/2011
• Est. Priority Date: 10/25/2005
• Status: Expired due to Fees

• Current Assignee: Elan Microelectronics Corporation
• Original Assignee: Elan Microelectronics Corporation
• Inventors: Chien, Yung-Lieh, Lii, Jia-Yih
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Edwards; Carolyn R
• Application Number:
  US11/584,615
• Publication Number:
  US 20070091077A1
• Time in Patent Office: 1,779 Days
• Field of Search: 345156-175, 178/18.01, 178/19.03, 463/37
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

In a gesture detection method for a capacitive touchpad, various gesture operations are determined by detecting the touching on the touchpad, leaving from the touchpad, and moving on the touchpad.

Claims

1. A method for object detection on a capacitive touchpad, comprising the steps of:

(a) verifying that an object touches the touchpad for the first time, a sensed value being monitored for a predefined set of points in a region of the touchpad;

(b) determining whether the object moves on the touchpad;

(c) verifying that the object leaves the touchpad for the first time if the object does not move on the touchpad;

(d) sending a first gesture signal;

(e) counting a departure time after the object leaves the touchpad;

(f) verifying that the object touches the touchpad for the second time if the departure time is shorter than a first reference time;

(g) determining whether the object moves on the touchpad;

(h) calculating a position information of the object if the object moves on the touchpad;

(i) maintaining the first gesture signal to produce a second gesture signal;

(j) verifying that the object leaves the touchpad for the second time to terminate the second gesture signal;

(k) counting a second departure time after the object leaves the touchpad for the second time;

(l) verifying that the object touches the touchpad for the third time if the second departure time is shorter than a second reference time;

(m) determining whether the object moves on the touchpad; and

(n) if the object does not move on the touchpad, verifying that the object leaves the touchpad for the third time and sending a third gesture signal to terminate the first gesture signal, and if the object moves on the touchpad, repeating the previous steps from the step (h);

wherein the first gesture signal is determined independent of when the object touches the touchpad for the first time and when the object leaves the touchpad;

at least one of the object movement, object touching, and object leaving determinations being made based on a trend indicated by a difference between the sensed values at different times for the predefined set of points within the region of the touchpad.

2. The method of claim 1, wherein the steps of verifying that the object touches the touchpad for the first time, the second time, and the third time comprise the steps of:

monitoring a variation in the sensed value when the sensed value is greater than a threshold, the variation being a calculated difference between a present time sensed capacitive value and a last time sensed capacitive value; and

determining that the object touches the touchpad if the sensed value maintains an increasing trend within a third reference time.

3. The method of claim 1, wherein the step (g) and the step (m) comprise the steps of:

monitoring a variation in the sensed value; and

determining that the object moves on the touchpad if the sensed value maintains an increasing trend in a first direction and a decreasing trend in a second direction opposite to the first direction within a third reference time.

4. The method of claim 1, wherein the steps of verifying that the object leaves the touchpad for the first time, the second time, and the third time comprise the steps of:

monitoring a variation in the sensed value when the sensed value is less than a threshold; and

determining that the object leaves the touchpad if the sensed value maintains a decreasing trend within a third reference time.

5. The method of claim 1, wherein the first gesture signal comprises a key-press signal.

6. The method of claim 1, wherein the first gesture signal comprises a key-press and zero-displacement signal.

7. The method of claim 1, wherein the second gesture signal comprises a combined signal of a key-press signal and the position information.

8. The method of claim 1, wherein the third gesture signal comprises a key-release signal.

9. The method of claim 1, wherein the position information comprises an absolute coordinate or a relative coordinate.

10. The method of claim 1, wherein the position information comprises a relative displacement of the object on the touchpad.

11. A method for object detection on a capacitive touchpad, comprising the steps of:

(a) verifying that an object touches the touchpad for the first time, a sensed value being monitored for a predefined set of points in a region of the touchpad;

(b) determining whether the object moves on the touchpad;

(c) verifying that the object leaves the touchpad for the first time if the object does not move on the touchpad;

(d) sending a first gesture signal;

(e) counting a first departure time after the object leaves the touchpad;

(f) verifying that the object touches the touchpad for the second time if the first departure time is shorter than a first reference time;

(g) determining whether the object moves on the touchpad;

(h) calculating a position information of the object if the object moves on the touchpad;

(i) maintaining the first gesture signal to produce a second gesture signal;

(j) verifying that the object leaves the touchpad for the second time to terminate the second gesture signal;

(k) counting a second departure time after the object leaves the touchpad for the second time;

(l) verifying that the object touches the touchpad for the third time if the second departure time is shorter than a second reference time;

(m) determining whether the object moves on the touchpad;

(n) calculating the position information of the object if the object moves on the touchpad;

(o) maintaining the first gesture signal to produce a third gesture signal;

(p) verifying that the object leaves the touchpad for the third time to terminate the third gesture signal;

(q) counting a third departure time after the object leaves the touchpad for the third time; and

(r) if the third departure time is longer than second reference time, initiating a fourth gesture signal to terminate the first gesture signal, and if the third departure time is shorter than second reference time, repeating the previous steps from the step (1);

wherein the first gesture signal is determined independent of when the object touches the touchpad for the first time and when the object leaves the touchpad;

at least one of the object movement, object touching, and object leaving determinations being made based on a trend indicated by a difference between the sensed values at different times for the predefined set of points within the region of the touchpad.

12. The method of claim 11, wherein the steps of verifying that the object touches the touchpad for the first time, the second time, and the third time comprise the steps of:

monitoring a variation in the sensed value when the sensed value is greater than a threshold, the variation being a calculated difference between a present time sensed capacitive value and a last time sensed capacitive value; and

determining that the object touches the touchpad if the sensed value maintains an increasing trend within a third reference time.

13. The method of claim 11, wherein the step (g) and the step (m) comprise the steps of:

monitoring a variation in the sensed value; and

determining that the object moves on the touchpad if the sensed value maintains an increasing trend in a first direction and a decreasing trend in a second direction opposite to the first direction within a third reference time.

14. The method of claim 11, wherein the steps of verifying that the object leaves the touchpad for the first time, the second time, and the third time comprise the steps of:

monitoring a variation in the sensed value when the sensed value is less than a threshold; and

determining that the object leaves the touchpad if the sensed value maintains a decreasing trend within a third reference time.

15. The method of claim 11, wherein the first gesture signal comprises a key-press signal.

16. The method of claim 11, wherein the first gesture signal comprises a key-press and zero-displacement signal.

17. The method of claim 11, wherein the second gesture signal comprises a combined signal of a key-press signal and the position information.

18. The method of claim 11, wherein the third gesture signal comprises a combined signal of a key-press signal and the position information.

19. The method of claim 11, wherein the fourth gesture signal comprises a key-release signal.

20. The method of claim 11, wherein the position information comprises an absolute coordinate or a relative coordinate.

21. The method of claim 11, wherein the position information comprises a relative displacement of the object on the touchpad.