MUTUAL CAPACITANCE SENSING ARRAY

• US 20110018829A1
• Filed: 07/23/2010
• Published: 01/27/2011
• Est. Priority Date: 07/24/2009
• Status: Abandoned Application

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Peng, Tao
• Application Number:
  US12/842,338
• Publication Number:
  US 20110018829A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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: Y10T 29/49002 Electrical device making

Abstract

A method and apparatus for sensing a conductive object by a mutual capacitance sensing array is described according to an embodiment of the present invention. The mutual capacitance sensing array comprises one or more sensor elements. Each sensor element comprises an outer frame including a conductive material. A cavity is formed within the interior of the outer frame.

Claims

1. An apparatus, comprising a mutual capacitance sensing array, the mutual capacitance sensing array comprising a plurality of sensor elements, each sensor element comprising an outer frame including a conductive material, the outer frame forming a cavity within the interior therein.

2. The apparatus of claim 1, wherein the conductive material is transparent.

3. The apparatus of claim 1, further comprising a non-conductive dielectric material disposed in the cavity.

4. The apparatus of claim 3, wherein the non-conductive dielectric material is electrically grounded.

5. The apparatus of claim 3, wherein the non-conductive dielectric material is co-planar with the outer frame.

6. The apparatus of claim 3, wherein the non-conductive dielectric material is non-co-planar with the outer frame, wherein the non-conductive dielectric material is connected to the outer frame with a non-conductive via.

7. The apparatus of claim 4, wherein the electrical grounding is a floating ground.

8. The apparatus of claim 1, wherein the outer frame has substantially a diamond shape.

9. The apparatus of claim 1, wherein an area of the cavity is substantially 50% to 90% of an area within the outer boundary of the sensor element.

10. The apparatus of claim 1, further comprising a processing device coupled to the mutual capacitance sensing array, wherein the processing device is operable to detect a presence of a conductive object on the mutual capacitance sensing array.

11. The apparatus of claim 10, wherein the mutual capacitance sensing array is disposed on a touch sensor screen.

12. The apparatus of claim 11, wherein the mutual capacitance sensing array is disposed on a trackpad.

13. A method, comprising:

forming an outer frame for a plurality of sensor elements, each outer frame comprising a conductive material, each outer frame forming a cavity within the interior therein; and

interconnecting the plurality of sensor elements to form a mutual capacitance sensor array.

14. The method of claim 13, wherein the outer frame has substantially a diamond shape.

15. The method of claim 13, further comprises providing a non-conductive material disposed in the cavity.

16. The method of claim 13, further comprising providing a processing device to detect a presence of a conductive object on the mutual capacitance sensing array.

17. The method of claim 16, further comprising disposing the mutual capacitance sensor array on a touch sensor screen.

18. A system, comprising:

a plurality of capacitive sensor elements configured in an array, each sensor element comprising an outer frame including a conductive material, the outer frame forming a cavity within the interior therein; and

a mutual capacitance sensing circuit coupled to the plurality of sensor elements to detect the presence of a conductive object on the plurality of sensor elements.

19. The system of claim 18 further comprising the plurality of sensor elements coupled to a touch screen.

20. The system of claim 18, wherein the area of the cavity is substantially 50% to 90% of an area within the outer boundary of the sensor element.