Display with dual-function capacitive elements

Patent metadata

Field	Value
Publication number	US-9075490-B2
Application number	US-201414275527-A
Country	US
Kind code	B2
Filing date	May 12, 2014
Priority date	Jul 3, 2008
Publication date	Jul 7, 2015
Grant date	Jul 7, 2015

Abstract

A touch screen including display pixels with capacitive elements is provided. The touch screen includes first common voltage lines connecting capacitive elements in adjacent display pixels, and a second common voltage line connecting first common voltage lines. Groups of pixels can be formed as electrically separated regions by including breaks in the common voltage lines. The regions can include a drive region that is stimulated by stimulation signals, a sense region that receives sense signals corresponding to the stimulation signals. A grounded region can also be included, for example, between a sense region and a drive region. A shield layer can be formed of a substantially high resistance material and disposed to shield a sense region. A black mask line and conductive line under the black mask line can be included, for example, to provide low-resistance paths between a region of pixels and touch circuitry outside the touch screen borders.

First claim

What is claimed is:

1. A touch screen including a display region having
display pixels and a non-display border region, the touch screen comprising:
a plurality of first common voltage lines disposed in rows including at least one row having a plurality of first portions that are electrically separate in the at least one row in the display region;
a plurality of second common voltage lines disposed in columns including at least one column having a plurality of second portions that are electrically separate in the at least one column in the display region;
a plurality of first and second regions, each region including a plurality of display pixels each having a capacitive element, wherein in each region, the capacitive elements are electrically connected together via one or more of the portions of each of the first and second common voltage lines, and the plurality of first regions are electrically separated from the plurality of second regions in the display region in a touch sensing mode of operation;
wherein capacitive elements within each region are configured to provide a display function in a display mode of operation of the touch screen and to provide capacitive coupling between at least one region of the plurality of first regions serving as one of a drive region or a sense region, and one region of the plurality of second regions serving as the other of the drive region or the sense region, in the touch sensing mode of operation; and
wherein the plurality of second regions extend substantially along columns and are zig-zag shaped.

2. The touch screen of claim 1 , further comprising at least one ground guard positioned adjacent each of the plurality of second regions.

3. The touch screen of claim 2 , wherein the at least one ground guard is zig-zag shaped.

4. The touch screen of claim 3 , wherein the at least one ground guard comprises a first ground guard positioned on one side of each of the plurality of second regions and a second ground guard positioned on the other side of each of the plurality of second regions, the first and second ground guards having a zig-zag shape.

5. The touch screen of claim 1 , wherein the plurality of first regions are substantially pentagonal in shape, and have a staggered orientation.

6. The touch screen of claim 5 , wherein the staggered orientation is such that a first row of first regions and a second row of first regions have portions thereof that are aligned in the row direction.

7. The touch screen of claim 6 , wherein at least two edges of each of the plurality of second regions follows the zig-zag shape of an adjacent second region.

8. The touch screen of claim 1 , wherein the plurality of first regions are substantially pentagonal in shape, and have a staggered orientation.

9. The touch screen of claim 8 , wherein the staggered orientation is such that a first row of first regions and a second row of first regions have portions thereof that are at aligned in the row direction.

10. The touch screen of claim 9 , wherein at least two edges of each of the plurality of second regions follows the zig-zag shape of an adjacent second region.

11. The touch screen of claim 1 , further comprising a plurality of third common voltage lines disposed in columns and positioned in channels between adjacent ones of the plurality of second regions.

12. The touch screen of claim 4 , further comprising a plurality of third common voltage lines disposed in columns and positioned in channels between adjacent ones of the plurality of second regions.

13. The touch screen of claim 4 , further comprising a plurality of third common voltage lines disposed in columns and positioned in channels between ground guards of adjacent ones of the plurality of second regions.

14. The touch screen of claim 1 , wherein the plurality of first regions are aligned along columns and the touch screen further comprising a plurality of third common voltage lines disposed in columns and positioned in channels between adjacent columns of the plurality of first regions.

15. The touch screen of claim 14 , wherein the plurality of third common voltage lines connect to the plurality of first regions.

16. The touch screen of claim 4 , wherein the plurality of first regions are aligned along columns and the touch screen further comprising a plurality of third common voltage lines disposed in columns and positioned in channels between adjacent columns of the plurality of first regions.

17. The touch screen of claim 16 , wherein the plurality of third common voltage lines connect to the plurality of first regions.

18. The touch screen of claim 1 , wherein during the touch sensing mode of operation, the plurality of first regions are electrically connected together in the non-display border region of the touch screen.

19. The touch screen of claim 1 , wherein the capacitive elements of each of the plurality of first regions emanates an electric field;
the plurality of second regions comprise sense regions and including capacitive elements that receive the electric field; and
a shield layer formed of a substantially high resistance material disposed such that the electric field passes through the shield layer before being received by the sense regions.

20. The touch screen of claim 19 , wherein the drive regions and the sense regions are disposed on a common substrate.

21. The touch screen of claim 20 , wherein the touch screen comprises a cover and the drive shield layer is disposed between the cover and the drive and sense regions.

22. The touch screen of claim 21 , wherein the plurality of first regions are electrically connected together in a non-display border region of the touch screen.

23. A method of operating a touch screen including a display region having display pixels and a non-display border region, the touch screen having a plurality of first common voltage lines disposed in rows including at least one row having a plurality of first portions that are electrically separate in the at least one row in the display region; a plurality of second common voltage lines disposed in columns including at least one column having a plurality of second portions that are electrically separate in the at least one column in the display region; a plurality of first and second regions, each region including a plurality of display pixels each having a capacitive element, wherein in each region, the capacitive elements are electrically connected together via one or more of the portions of each of the first and second common voltage lines, and the plurality of first regions are electrically separated from the plurality of second regions in the display region in a touch sensing mode of operation; wherein capacitive elements within each region are configured to provide a display function in a display mode of operation of the touch screen and to provide capacitive coupling between at least one region of the plurality of first regions serving as one of a drive region or a sense region, and one region of the plurality of second regions serving as the other of the drive region or the sense region in the touch sensing mode of operation, wherein the plurality of second regions extend substantially along columns and are zig-zag shaped; the method comprising:
operating the capacitive elements during the display mode of operation to produce an image on the touch screen;
operating the capacitive elements during the touch sensing mode of operation to sense a touch event on or near the touch

Assignees

• Apple Inc

Inventors

• Hotelling Steven P
• Chang Shih Chang
• Huang Lili
• Zhong John Z

Classifications

• G02F1/136286

  Wiring, e.g. gate line, drain line · CPC title

• G02F2001/136218

  Physics · mapped topic

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F2203/04112

  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 title

• G02F1/1393

  the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells (G02F1/1396, G02F1/141 take precedence) · CPC title