Touch sensor panels with reduced static capacitance

• US 8,507,811 B2
• Filed: 08/21/2009
• Issued: 08/13/2013
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steven Porter, Yousefpor, Marduke
• Primary Examiner(s): Tzeng, Fred
• Application Number:
  US12/545,741
• Publication Number:
  US 20100193257A1
• Time in Patent Office: 1,453 Days
• Field of Search: 178/18.06, 178/20.04, 345/84, 345/175, 345/204, 345/450
• US Class Current: 178/18.06
• 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 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard

Abstract

Capacitive touch panels may include a plurality of positive voltage lines that are driven at a first phase. These positive voltage lines may be used to provide the drive capacitance signal sensed by one or more sense regions. The touch panels may also include a plurality of negative phase voltage lines that are driven at a phase that is different than the first phase. Both the positive and negative voltage lines may cross-under one or more sense regions. The negative phase voltage lines are able to counter act and reduce the static capacitance in the sense regions.

Claims

1. A touch sensitive panel comprising:

a plurality of first voltage lines that are driven at a first phase;

a plurality of second voltage lines that are driven at a second phase that is different than the first phase;

a drive region coupled to the first voltage lines; and

a sense region, wherein the first voltage lines and the second voltage lines cross-under the sense region,

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.

2. The touch sensitive panel of claim 1, wherein the touch sensitive panel comprises a touch screen.

3. The touch sensitive panel of claim 1, wherein the touch sensitive panel comprises display pixels.

4. The touch sensitive panel of claim 1, the touch sensitive panel configured for having a touch phase and a display phase.

5. The touch sensitive panel of claim 1, wherein the second phase is opposite the first phase.

6. The touch sensitive panel of claim 1, wherein the second voltage lines cross-under the drive region.

7. The touch sensitive panel of claim 6, wherein the number of second voltage lines that cross-under the drive region is less than the number of second voltage lines that cross-under the sense region.

8. The touch sensitive panel of claim 1, wherein the drive region and the sense region comprise a plurality of capacitive elements of pixels.

9. The touch sensitive panel of claim 8, wherein all of the capacitive elements of pixels in a region are electrically connected together.

10. The touch sensitive panel of claim 9, comprising a conductive layer that electrically connects all the pixels in a region.

11. The touch sensitive panel of claim 1, further comprising a plurality of third voltage lines connected to the sense region.

12. A method of reducing static capacitance in a touch panel comprising:

driving a plurality of first voltage lines at a first phase;

driving a plurality of second voltage lines at a second phase that is different than the first phase, wherein the first voltage lines and the second voltage lines cross-under a sense region; and

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.

13. The method of claim 12, wherein the touch sensitive panel comprises a drive region electrically connected to the first voltage lines.

14. The method of claim 13, wherein the second voltage lines cross-under the drive region.

15. The method of claim 14, wherein the number of second voltage lines that cross-under the drive region is less than the number of second voltage lines that cross-under the sense region.

16. The method of claim 13, wherein the drive region and sense region comprise a plurality of capacitive elements of pixels.

17. The method of claim 16, wherein all of the capacitive elements of pixels in a region are electrically connected together.

18. The touch sensitive panel of claim 17, comprising a conductive layer that electrically connects all the pixels in a region.

19. The method of claim 12, wherein the touch sensitive panel comprises a touch screen.

20. The method of claim 12, wherein the touch sensitive panel comprises display pixels.

21. The method of claim 12, wherein the touch sensitive panel has a touch phase and a display phase.

22. The method of claim 12, wherein the second phase is opposite the first phase.

23. The touch sensitive panel of claim 12, further comprising a plurality of third voltage lines connected to the sense region.

24. A method of reducing the static capacitance in a sense region of a touch panel comprising:

providing a sense region comprising a plurality of capacitive elements of pixels,

providing a plurality of first voltage lines that are driven at a first phase and cross-under the sense region;

providing a drive region comprising a plurality of capacitive elements of pixels connected to the first voltage lines;

selecting a number of second voltage lines to be driven at a second phase that is different than the first phase; and

providing the selected number of second voltage lines that cross-under the sense region;

wherein the first and second phases of the first and selected number of second voltage lines respectively reduce static capacitance in the sense region.

25. A touch screen including display pixels with capacitive elements, the touch screen comprising:

a plurality of first voltage lines that are driven at a first phase;

a plurality of second voltage lines that are driven at a second phase that is different than the first phase;

a drive region comprising a plurality of capacitive elements of pixels connected to the first voltage lines;

a sense region, wherein the first voltage lines and the second voltage lines cross-under the sense region; and

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.

26. A digital media player comprising a touch screen comprising:

a plurality of first voltage lines that are driven at a first phase;

a plurality of second voltage lines that are driven at a second phase that is different than the first phase;

a drive region comprising a plurality of capacitive elements of pixels connected to the first voltage lines; and

a sense region, wherein the first voltage lines and the second voltage lines cross-under the sense region; and

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.

27. A mobile telephone comprising a touch screen comprising:

a plurality of first voltage lines that are driven at a first phase;

a plurality of second voltage lines that are driven at a second phase that is different than the first phase;

a drive region comprising a plurality of capacitive elements of pixels connected to the first voltage lines; and

a sense region comprising a plurality of capacitive elements of pixels, wherein the first voltage lines and the second voltage lines cross-under the sense region; and

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.

28. A personal computer comprising a touch screen comprising:

a plurality of first voltage lines that are driven at a first phase;

a plurality of second voltage lines that are driven at a second phase that is different than the first phase;

a drive region comprising a plurality of capacitive elements of pixels connected to the first voltage lines;

a sense region, wherein the first voltage lines and the second voltage lines cross-under the sense region; and

wherein the first and second phases of the first and second voltage lines respectively reduce static capacitance in the sense region.