Patent ID: 8013842

Claim:
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.