Self shielding capacitance sensing panel

• US 8,482,546 B2
• Filed: 06/29/2011
• Issued: 07/09/2013
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Polishchuk, Igor, Chai, Min Chin, Keiser, Fred
• Primary Examiner(s): Cheng, Joe H
• Application Number:
  US13/172,749
• Publication Number:
  US 20120044198A1
• Time in Patent Office: 741 Days
• Field of Search: 345/156, 345/173, 345/174, 178/18.01, 178/18.06, 178/19.03, 200/512, 340/407.1, 340/407.2
• US Class Current: 345/174
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A self-shielding capacitive sensor array may include a first plurality of sensor elements and a second plurality of sensor elements, where each of the second plurality of sensor elements intersects each of the first plurality of sensor elements, such that each of the first plurality of sensor elements may be capacitively coupled with each of the second plurality of sensor elements. The first plurality of sensor elements may be configured to shield each of the second plurality of sensor elements from a noise source.

Claims

1. An apparatus, comprising:

a first plurality of sensor elements;

a second plurality of sensor elements, wherein each of the second plurality of sensor elements intersects each of the first plurality of sensor elements, and wherein each of the first plurality of sensor elements is capacitively coupled with each of the second plurality of sensor elements; and

wherein the first plurality of sensor elements are configured to shield each of the second plurality of sensor elements from a noise source.

2. The apparatus of claim 1, wherein substantially all of the area of the second plurality of sensor elements overlaps an area of the first plurality of sensor elements.

3. The apparatus of claim 1, wherein the first plurality of sensor elements is situated between the second plurality of sensor elements and the noise source.

4. The apparatus of claim 1, wherein each of the first plurality of sensor elements is configured to transmit a signal and wherein each of the second plurality of sensor elements is configured to receive the transmitted signal.

5. The apparatus of claim 1, wherein the first plurality of sensor elements is separated by a first width between each of the first plurality of sensor elements, wherein the second plurality of sensor elements is separated by a second width between each of the second plurality of sensor elements, and wherein the first width is less than the second width.

6. The apparatus of claim 1, wherein a width of each of the second plurality of sensor elements is less than a width of each of the first plurality of sensor elements.

7. The apparatus of claim 1, wherein each of the second plurality of sensor elements comprises a plurality of sub-elements.

8. The apparatus of claim 1, wherein the noise source is a liquid crystal display (LCD) panel.

9. An apparatus, comprising:

a first plurality of sensor elements separated by a first width between each of the first plurality of sensor elements; and

a second plurality of sensor elements separated by a second width between each of the second plurality of sensor elements, wherein each of the second plurality of sensor elements intersects each of the first plurality of sensor elements, wherein the first width is less than the second width, and wherein the first plurality of sensor elements is situated between the second plurality of sensor elements and a noise source.

10. The apparatus of claim 9, wherein substantially all of the area of the second plurality of sensor elements overlaps an area of the first plurality of sensor elements.

11. The apparatus of claim 9, wherein each of the first plurality of sensor elements is capacitively coupled to each of the second plurality of sensor elements, wherein each of the first plurality of sensor elements is configured to transmit a signal, and wherein each of the second plurality of sensor elements is configured to receive the transmitted signal.

12. The apparatus of claim 9, wherein a surface area of each of the second plurality of sensor elements is less than a surface area of each of the first plurality of sensor elements.

13. The apparatus of claim 9, wherein each of the second plurality of sensor elements comprises a plurality of sub-elements.

14. The apparatus of claim 9, wherein the noise source is a liquid crystal display (LCD) panel.

15. An apparatus, comprising:

a first plurality of sensor elements;

a second plurality of sensor elements, wherein each of the second plurality of sensor elements intersects each of the first plurality of sensor elements, wherein the first plurality of sensor elements are configured to shield each of the second plurality of sensor elements from a noise source; and

a capacitance sensing system coupled with the first plurality of sensor elements and the second plurality of sensor elements, wherein the capacitive sensing system is configured to measure mutual capacitances between each of the first plurality of sensor elements and each of the second plurality of sensor elements.

16. The apparatus of claim 15, wherein at least some of the area of the first plurality of sensor elements is situated between substantially all of the area of the second plurality of sensor elements and the noise source.

17. The apparatus of claim 15, wherein the first plurality of sensor elements is situated between the second plurality of sensor elements and the noise source.

18. The apparatus of claim 15, wherein the capacitance sensing system is configured to measure the mutual capacitances by applying a transmit signal to each of the first plurality of sensor elements and measuring a receive signal at each of the second plurality of sensor elements.

19. The apparatus of claim 15, wherein each of the first plurality of sensor elements is separated by a first width between each of the first plurality of sensor elements, wherein each of the second plurality of sensor elements is separated by a second width between each of the second plurality of sensor elements, and wherein the first width is less than the second width.

20. The apparatus of claim 15, wherein a width of each of the second plurality of sensor elements is less than a width of each of the first plurality of sensor elements.