Methods and devices for capacitive image sensing

• US 9,195,877 B2
• Filed: 12/19/2012
• Issued: 11/24/2015
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Erhart, Richard Alexander, Wickboldt, Paul
• Primary Examiner(s): Werner, Brian P
• Application Number:
  US13/720,508
• Publication Number:
  US 20130177220A1
• Time in Patent Office: 1,070 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

A sensing circuit and method is disclosed, which may comprise a plurality of transmitting or receiving elements each defining a pixel location defined by a gap between the respective one of the plurality of transmitting or receiving elements and a single element of the opposing type to the respective transmitting or receiving element, and a controller configured to provide or receive a probing signal to or from a group of at least two of the plurality of transmitting or receiving elements, at the same time, thereby increasing the effective area providing the transmitting of or the receiving of the probing signal for each pixel location imaged. The group of transmitting or receiving elements may form a symmetric pattern, which may be centered on the pixel location. The plurality of transmitting or receiving elements may form at least one linear pixel array with the respective single receiving or transmitting element.

Claims

1. A sensing circuit comprising:

a plurality of transmitting or receiving elements each defining a pixel location defined by a gap between the respective one of the plurality of transmitting or receiving elements and a single element of the opposing type to the respective transmitting or receiving element; and

a controller configured to provide or receive a probing signal to or from a group of at least two of the plurality of transmitting or receiving elements, at the same time, thereby increasing an effective area providing the transmitting of or the receiving of the probing signal for each pixel location imaged,

wherein at least two of the transmitting or receiving elements included in the group of at least two of the plurality of transmitting or receiving elements are separated by at least one transmitting or receiving element that is not energized by the probing signal.

2. The sensing circuit of claim 1 further wherein the group of at least two transmitting or receiving elements forms a symmetric pattern.

3. The sensing circuit of claim 2 wherein the symmetric pattern is centered on the pixel location.

4. The sensing circuit of claim 1 wherein the plurality of transmitting or receiving elements forms at least one linear pixel array with the single element of the opposing type.

5. The sensing circuit of claim 4 wherein the at least one linear pixel array comprises a first linear pixel array and a second linear pixel array, the sensing circuit further comprising:

an output signal generator combining an output of pixel locations in the first linear pixel array and in the second linear pixel array.

6. The sensing circuit of claim 4 wherein the controller is configured to transmit or receive the probing signal for respective pixel locations being imaged randomly along the respective linear pixel array.

7. A method of operating a sensing circuit comprising:

providing a plurality of transmitting or receiving elements each defining a pixel location defined by a gap between the respective one of the plurality of transmitting or receiving elements and a single element of the opposing type to the respective transmitting or receiving element; and

providing or receiving via a controller circuit a probing signal to or from a group of at least two of the plurality of transmitting or receiving elements, at the same time, thereby increasing an effective area providing the transmitting of or the receiving of the probing signal for each pixel location imaged,

wherein at least two of the transmitting or receiving elements included in the group of at least two of the plurality of transmitting or receiving elements are separated by at least one transmitting or receiving element that is not energized by the probing signal.

8. The method of claim 7 further wherein the group of at least two transmitting or receiving elements forms a symmetric pattern.

9. The method of claim 8 wherein the symmetric pattern is centered on the pixel location.

10. The method of claim 7 wherein the plurality of transmitting or receiving elements forms at least one linear pixel array with the single element of the opposing type.

11. The method of claim 10 wherein the at least one linear pixel array comprises a first linear pixel array and a second linear pixel array, the method further comprising:

providing an output signal generator combining an output of pixel locations in the first linear pixel array and in the second linear pixel array.

12. The method of claim 10 wherein the controller circuit is configured to transmit or receive the probing signal for respective pixel locations being imaged randomly along the respective linear pixel array.

13. A sensing circuit, comprising:

a plurality of transmitting elements each defining at least one pixel location defined by a gap between the respective one of the plurality of transmitting elements and at least one receiving element; and

a controller configured to receive a probing signal from a group of at least two of the plurality of transmitting elements, at the same time, to increase an effective area of the at least one pixel location,

wherein at least two of the transmitting elements included in the group of at least two of the plurality of transmitting elements are separated by at least one transmitting element that is not energized by the probing signal.

14. The sensing circuit of claim 13, wherein the at least one receiving element includes a plurality of receiving elements, and wherein the plurality of transmitting elements forms a 2D pixel array with the plurality of receiving elements.

15. A sensing circuit, comprising:

a plurality of receiving elements each defining at least one pixel location defined by a gap between the respective one of the plurality of receiving elements and at least one transmitting element; and

a controller configured to provide a probing signal to a group of at least two of the plurality of receiving elements, at the same time, to increase an effective area of the at least one pixel location,

wherein at least two of the receiving elements included in the group of at least two of the plurality of receiving elements are separated by at least one receiving element that is not energized by the probing signal.

16. The sensing circuit of claim 15, wherein the at least one transmitting element includes a plurality of transmitting elements, wherein the plurality of receiving elements forms a 2D pixel array with the plurality of transmitting elements.