Single Layer Mutual Capacitance Sensing Systems, Device, Components and Methods

• US 20090194344A1
• Filed: 01/31/2008
• Published: 08/06/2009
• Est. Priority Date: 01/31/2008
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Orsley, Timothy J., Harley, Jonah A.
• Application Number:
  US12/024,057
• Publication Number:
  US 20090194344A1
• Time in Patent Office: Days
• US Class Current: 178/18.06
• 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 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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

Abstract

According to one embodiment, there is provided a mutual capacitance sensing system comprising at least one substrate comprising an electrode array mounting surface. A plurality of drive electrodes are disposed in a first plurality of rows or columns positioned upon the electrode array mounting surface, where the drive electrodes in each row or column are electrically connected to one another. A plurality of sense electrodes are disposed in a second plurality of rows or columns positioned upon the electrode array mounting surface that is substantially perpendicular to the first plurality of rows or columns, and the sense electrodes in each column are electrically connected to one another. The sense and drive electrodes form an array disposed substantially in a single plane that is configured to permit at least one location corresponding to at least one finger placed in proximity thereto to be detected thereby.

Claims

1. A mutual capacitance sensing system, comprising:

at least one substrate comprising an outer touch surface and an inner surface disposed substantially in a single plane, the outer touch and inner surfaces forming opposing substantially planar and substantially parallel surfaces;

a plurality of drive electrodes disposed in a first plurality of rows or columns positioned upon the inner surface substantially in the single plane, the drive electrodes in each row or column being electrically connected to one another;

a plurality of sense electrodes disposed in a second plurality of rows or columns also positioned upon the inner surface substantially in the single plane, the sense electrodes in each column being electrically connected to one another;

wherein the first plurality of rows or columns is substantially perpendicular to the second plurality of rows or columns, the outer touch surface is configured for a user to place at least one finger thereon and move the at least one finger thereacross, and the drive and sense electrodes form an array configured in respect of the outer touch surface to permit at least one location corresponding to the at least one finger on the outer touch surface to be detected by the array.

2. The mutual capacitance touchscreen of claim 1, wherein the plurality of drive electrodes in each row are interleaved with corresponding sense electrodes intersecting therewith.

3. The mutual capacitance touchscreen of claim 1, wherein the plurality of sense electrodes in each column are interleaved with corresponding drive electrodes intersecting therewith.

4. The mutual capacitance sensing system of claim 1, wherein at least one of the plurality of drive electrodes and the plurality of sense electrodes comprises indium tin oxide (ITO).

5. The mutual capacitance sensing system of claim 1, wherein the substrate comprises at least one of glass and plastic.

6. The mutual capacitance sensing system of claim 1, wherein the substrate is substantially optically transparent.

7. The mutual capacitance sensing system of claim 1, further comprising a ground layer disposed beneath the inner surface of the substrate.

8. The mutual capacitance sensing system of claim 1, wherein at least one electrically conductive fixed potential or ground conductor is disposed between at least portions of the plurality of drive electrodes and the plurality of sense electrodes.

9. The mutual capacitance sensing system of claim 1, further comprising a drive signal circuit configured to provide an electrical drive signal to the plurality of drive electrodes and operably connected thereto.

10. The mutual capacitance sensing system of claim 1, further comprising a capacitance sensing circuit operably coupled to the plurality of sense electrodes and configured to detect changes in capacitance occurring therein or thereabout.

11. The mutual capacitance sensing system of claim 1, wherein at least one of the drive signal circuit and the capacitance sensing circuit is incorporated into an integrated circuit.

12. The mutual capacitance sensing system of claim 1, further comprising at least one polarizer layer.

13. The mutual capacitance sensing system of claim 1, wherein the polarizer layer comprises polyvinylalcohol (PVA).

14. The mutual capacitance sensing system of claim 1, further comprising at least one of a triacetyl cellulose (TAC) film layer, a glue layer, an optical retarder layer and a backlighting layer.

15. The mutual capacitance sensing system of claim 1, wherein the system is incorporated into or forms a portion of an LCD, a computer display, a laptop computer, a personal data assistant (PDA), a mobile telephone, a radio, an MP3 player, a portable music player, a stationary device, a television, a stereo, an exercise machine, an industrial control, a control panel, an outdoor control device and a washing machine.

16. The mutual capacitance sensing system of claim 1, wherein the system forms a portion of a touchscreen or a touchpad.

17. The mutual capacitance sensing system of claim 1, wherein the system is configured to scan the first and second pluralities of rows and columns thereby to detect the at least one location.

18. The mutual capacitance sensing system of claim 1, wherein the system is configured to multiplex signals provided by at least one of the first and second pluralities of rows and the columns.

19. The mutual capacitance sensing system of claim 1, wherein the system is configured to sense multiple locations in the array simultaneously.

35. The mutual capacitance sensing system of claim 16, further comprising at least one of a triacetyl cellulose (TAC) film layer, a glue layer, an optical retarder layer and a backlighting layer.

20. A mutual capacitance sensing system, comprising:

at least one substrate comprising an electrode array mounting surface disposed substantially in the single plane;

a plurality of drive electrodes disposed in a first plurality of rows or columns positioned upon the electrode array mounting surface substantially in the single plane, the drive electrodes in each row being electrically connected to one another;

a plurality of sense electrodes disposed in a second plurality of rows or columns positioned upon the electrode array mounting surface substantially in the single plane, the sense electrodes in each column being electrically connected to one another;

wherein the first plurality of rows or columns is substantially perpendicular to the second plurality of rows or columns, and the drive and sense electrodes form an array configured to permit at least one location corresponding to at least one finger placed in proximity to the electrode array mounting surface to be detected by the array.

21. The mutual capacitance sensing system of claim 20, wherein an electrically insulative touch layer is disposed over the electrode array mounting surface.

22. The mutual capacitance sensing system of claim 20, wherein the electrically insulative touch layer comprises glass or plastic.

23. The mutual capacitance sensing system of claim 20, wherein the plurality of drive electrodes in each row are interleaved with corresponding sense electrodes intersecting therewith.

24. The mutual capacitance sensing system of claim 20, wherein the plurality of sense electrodes in each column are interleaved with corresponding drive electrodes intersecting therewith.

25. The mutual capacitance sensing system of claim 20, wherein at least one of the plurality of drive electrodes and the plurality of sense electrodes comprises indium tin oxide (ITO).

26. The mutual capacitance sensing system of claim 20, wherein the substrate comprises at least one of glass and plastic.

27. The mutual capacitance sensing system of claim 20, wherein the substrate is substantially optically transparent.

28. The mutual capacitance sensing system of claim 20, further comprising a ground layer.

29. The mutual capacitance sensing system of claim 20, wherein at least one electrically conductive fixed potential or ground conductor is disposed between at least portions of the plurality of drive electrodes and the plurality of sense electrodes.

30. The mutual capacitance sensing system of claim 20, further comprising a drive signal circuit configured to provide an electrical drive signal to the plurality of drive electrodes and operably connected thereto.

31. The mutual capacitance sensing system of claim 20, further comprising a capacitance sensing circuit operably coupled to the plurality of sense electrodes and configured to detect changes in capacitance occurring therein or thereabout.

32. The mutual capacitance sensing system of claim 20, wherein at least one of the drive signal circuit and the capacitance sensing circuit is incorporated into an integrated circuit.

33. The mutual capacitance sensing system of claim 20, further comprising at least one polarizer layer.

34. The mutual capacitance sensing system of claim 33, wherein the polarizer layer comprises polyvinylalcohol (PVA).

36. The mutual capacitance sensing system of claim 20, wherein the system is incorporated into or forms a portion of an LCD, a computer display, a laptop computer, a personal data assistant (PDA), a mobile telephone, a radio, an MP3 player, a portable music player, a stationary device, a television, a stereo, an exercise machine, an industrial control, a control panel, an outdoor control device and a washing machine.

37. The mutual capacitance sensing system of claim 20, wherein the system is configured to scan the first and second pluralities of rows and columns thereby to detect the at least one location.

38. The mutual capacitance sensing system of claim 20, wherein the system is configured to multiplex signals provided by at least one of the first and second pluralities of rows and columns.

39. The mutual capacitance sensing system of claim 20, wherein the system is configured to sense multiple locations in the array simultaneously.

40. A method of making a mutual capacitance sensing system, comprising:

providing at least one substrate comprising an outer touch surface and an inner surface disposed in a single plane, the outer touch and inner surfaces forming opposing substantially planar and substantially parallel surfaces;

disposing a plurality of drive electrodes in a first plurality of rows or columns upon the inner surface substantially in the single plane, and electrically connecting the drive electrodes in each row or column to one another, and

disposing a plurality of sense electrodes in a second plurality of rows or columns upon the inner surface substantially in the single plane and electrically connecting the sense electrodes in each row or column, the second plurality of rows or columns being substantially perpendicular to the first plurality of rows or columns;

wherein the drive and sense electrodes form an array that is configured to permit at least one location corresponding to at least one finger placed on the outer touch surface to be detected by the array.

41. A method of making a mutual capacitance sensing system, comprising:

providing at least one substrate comprising an electrode array mounting surface disposed in a single plane;

disposing a plurality of drive electrodes in a first plurality of rows or columns upon the electrode array mounting surface substantially in the single plane, and electrically connecting the drive electrodes in each row or column to one another;

disposing a plurality of sense electrodes in a second plurality of rows or columns upon the electrode array mounting surface substantially in the single plane, and electrically connecting the sense electrodes in each column to one another, the second plurality of rows or columns being substantially perpendicular to the first plurality of rows or columns;

wherein the drive and sense electrodes form an array that is configured to permit at least one location of at least one finger placed in proximity to the electrode array mounting surface to be detected using by the array.