Apparatus and method for recognizing a tap gesture on a touch sensing device

• US 8,111,243 B2
• Filed: 03/30/2006
• Issued: 02/07/2012
• Est. Priority Date: 03/30/2006
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Peng, Tao, Qin, Zheng
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US11/395,674
• Publication Number:
  US 20070229466A1
• Time in Patent Office: 2,140 Days
• Field of Search: 345156-178, 178/18.03, 178/18.06, 704/272
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

A method and apparatus to recognize a tap gesture on a sensing device. The method may include detecting a presence of a conductive object on a sensing device, determining a velocity of the detected presence of the conductive object, and recognizing a tap gesture based on the velocity. The velocity may be determined by determining a differential of the capacitance over time on a sensing device. The sensing device may include a plurality of sensor elements to detect the presence of the conductive object, and a processing device may be used to determine the velocity of the presence of the conductive object, and to recognize a tap gesture based on the velocity of the presence of the conductive object.

Claims

1. A method, comprising:

detecting a presence of a conductive object on a sensing device;

determining a velocity of the detected presence of the conductive object in a direction substantially orthogonal to that of the sensing device, wherein the determining the velocity comprises;

determining a capacitance of the conductive object on the sensing device over time, and

determining a differential of the capacitance over the time, wherein the differential is representative of the velocity of the presence, and;

recognizing a tap gesture based on the velocity, wherein recognizing the tap gesture based on the velocity comprises recognizing the tap gesture based on the differential of the capacitance.

2. The method of claim 1, wherein determining the capacitance further comprises:

determining a capacitance of each of the plurality of sensor elements of the sensing device; and

determining an average capacitance based on the capacitance of each of the plurality of sensor elements, wherein recognizing the tap gesture is based on the average capacitance.

3. The method of claim 1, wherein recognizing the tap gesture based on the differential of the capacitance comprises:

detecting a first peak of the differential at a first time;

detecting a second peak of the differential at a second time; and

determining a difference between the first time and the second time, wherein the tap gesture is recognized when the difference between the first time and the second time is less than a time threshold.

4. The method of claim 3, wherein detecting the first peak at the first time comprises detecting a rising edge of the capacitance in a positive direction, and wherein detecting the second peak at the second time comprises detecting a falling edge of the capacitance in a negative direction.

5. The method of claim 3, wherein detecting the first and second peaks each comprise:

determining a peak height;

determining a peak width;

determining a sharpness factor using the peak height and peak width; and

comparing the sharpness factor with a sharpness threshold, wherein the peak is detected when the sharpness factor is less than the sharpness threshold.

6. An apparatus, comprising:

a sensing device having a plurality of sensor elements to detect a presence of a conductive object on the sensing device; and

a processing device coupled to the sensing device, wherein the processing device is;

configured to measure a capacitance on each sensor element over time, and configured to calculate a differential of the capacitance over the time, wherein the differential is representative of a velocity of the presence in a direction substantially orthogonal to that of the sensing device, and

configured to recognize a tap gesture based on the velocity.

7. The apparatus of claim 6, wherein the capacitance sensor comprises a relaxation oscillator coupled to the plurality of sensor elements, wherein the relaxation oscillator comprises:

a current source to provide a charge current to the plurality of sensor elements;

a selection circuit coupled to the plurality of sensor elements and the current source, wherein the selection circuit is configured to sequentially select a sensor element of the plurality of sensor elements to provide the charge current and to measure the capacitance of each sensor element of the sensing device;

a comparator coupled to the current source and the selection circuit, wherein the comparator is configured to compare a voltage on the selected sensor element and a threshold voltage; and

a reset switch coupled to the comparator, current source, and selection circuit, wherein the reset switch is configured to reset the charge current on the selected sensor element.

8. The apparatus of claim 7, wherein the capacitance sensor comprises a digital counter coupled to the relaxation oscillator, and wherein the digital counter is configured to count at least one of a frequency or a period of a relaxation oscillator output received from the relaxation oscillator.

9. The apparatus of claim 6, further comprising a component external to the processing device, wherein the processing device is configured to send data to the component when the tap gesture is recognized.

10. The apparatus of claim 9, wherein the component external to the processing device is a processor.

11. The apparatus of claim 9, wherein the component external to the processing device is a driver of a processor.

12. The apparatus of claim 9, wherein the component external to the processing device is an embedded controller.

13. The apparatus of claim 9, wherein the data is a command.

14. The apparatus of claim 9, wherein the data is a signal.

15. The apparatus of claim 6, wherein the conductive object is a finger.

16. The apparatus of claim 6, wherein the sensing device comprise a multi-dimension sensor array comprising the plurality of sensor elements.

17. The apparatus of claim 6, wherein the sensing device is a touch-sensor pad.

18. The apparatus of claim 6, wherein the sensing device is at least one of a touch-sensor pad or a touch-sensor button.

19. The apparatus of claim 6, wherein the sensing device is mounted on a mobile handset.

20. An apparatus, comprising:

a sensing device;

means for detecting a presence of a conductive object on the sensing device;

means for determining a velocity of the detected presence of the conductive object in a direction substantially orthogonal to that of the sensing device; and

means for recognizing a tap gesture based on the velocity

wherein the determining a velocity comprises;

determining a capacitance of the conductive object on the sensing device over time; and

determining a differential of the capacitance over the time, wherein the differential is representative of the velocity of the presence, and wherein recognizing the tap gesture based on the velocity comprises recognizing the tap gesture based on the differential of the capacitance.

21. The apparatus of claim 20, wherein the sensing device is a touch-sensor pad.

22. The apparatus of claim 20, wherein the sensing device is at least one of a touch-sensor slider or a touch-sensor button.