INTERDIGITATED TOUCHSCREEN ELECTRODES

• US 20110095990A1
• Filed: 10/23/2009
• Published: 04/28/2011
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Philipp, Harald, Yilmaz, Esat
• Granted Patent: US 9,632,628 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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

A device includes a plurality of adjacent electrodes for a touch sensitive device. The electrodes run generally in a first direction. Adjacent electrodes are interdigitated to provide one or more interpolation sections of the electrodes. Touch sensitive devices may utilize such interdigitated electrodes as drive electrodes, along with transverse sense electrodes formed over a display.

Claims

1. A device comprising:

a plurality of adjacent electrodes for a touch sensitive device, the electrodes running generally in a first direction, wherein adjacent electrodes are interdigitated to provide one or more interpolated sections of the drive electrodes.

2. The device of claim 1 wherein the electrodes are drive electrodes that are interdigitated in a stepped manner to provide one interpolated section between each pair of adjacent electrodes.

3. The device of claim 1 wherein the electrodes are interdigitated in a stepped manner to provide multiple interpolated sections for each pair of adjacent electrodes.

4. The device of claim 1 wherein the electrodes are interdigitated in a sloped manner.

5. The device of claim 1 wherein the electrodes are formed of a solid filled transparent conductor.

6. The device of claim 5 wherein the conductor comprises indium tin oxide.

7. The device of claim 1 wherein the electrodes are formed of metal lines that are thin enough to not be easily visually perceptible.

8. The device of claim 7 wherein the thin metal lines comprise box lines and cross lines coupled to the box lines running in a different direction from the box lines, and wherein an interpolation of a drive electrode comprises passive box line replicators and cross lines running in a different direction from the box lines that are alternately connected to adjacent drive electrode box lines.

9. The device of claim 8 wherein the cross lines coupled to the box lines run diagonally from the box lines such that a moiré

effect is reduced.

10. The device of claim 8 wherein a cross line is formed of redundant conductive metal lines coupled to each other in multiple places.

12. The device of claim 10 wherein the crossbars have a one to one correspondence with the primary drive sections and interpolated sections of the drive electrodes.

14. The device of claim 10 wherein the electrodes are interdigitated in a stepped manner.

15. The device of claim 10 wherein the electrodes are formed of a solid filled transparent conductor.

16. The device of claim 10 wherein the electrodes are formed of thin metal lines.

17. The device of claim 15 wherein the thin metal lines comprise box lines and lines running in a different direction from the box lines and wherein an interpolated section comprises passive box line replicators and lines alternately connected to adjacent drive electrodes.

11. A sensing device comprising:

a drive electrode layer comprising a plurality of adjacent drive electrodes, the drive electrodes running generally in a first direction, wherein adjacent electrodes are interdigitated to provide one or more interpolated sections of the drive electrodes and primary drive sections;

a dielectric layer; and

a sense electrode layer separated from the drive electrode layer by the dielectric layer and having a plurality of spines running in a second direction substantially transverse to the first direction and a plurality of crossbars coupled to the spine and running generally in the first direction.

13. The device of claim 11 wherein the crossbars extend approximately seventy five percent of the distance toward adjacent spines such that crossbars from adjacent spines overlap one half the distance between spines.

18. A sensing device comprising:

a drive electrode layer comprising a plurality of adjacent drive electrodes, the drive electrodes running generally in a first direction, wherein adjacent electrodes are interdigitated such that the drive electrode layer has drive sections and interpolated drive sections;

a dielectric layer;

a sense electrode layer separated from the drive electrode layer by the dielectric layer and having a plurality of spines running in a second direction substantially transverse to the first direction; and

a display layer beneath the drive electrode layer, wherein the display layer is visible through the second electrode layer, the dielectric layer and the first electrode layer.

19. The sensing device of claim 18 wherein the sense electrode layer further comprises a plurality of crossbars coupled to each spine and running generally in the first direction.

20. The device of claim 19 wherein the crossbars have a one to one correspondence with the drive sections and interpolated drive sections of the drive electrodes.

21. The device of claim 20 wherein the crossbars extend approximately seventy five percent of the distance toward adjacent spines such that crossbars from adjacent spines overlap about one half the distance between spines.

22. The device of claim 18 wherein the electrodes are interdigitated in a stepped manner.

23. The device of claim 18 wherein the electrodes are formed of a solid filled transparent conductor.

24. The device of claim 18 wherein the electrodes are formed of metal lines, wherein the thin metal lines comprise box lines and lines running in a different direction from the box lines and wherein an interpolation of a drive electrode comprises passive box line replicators and lines alternately connected to adjacent drive electrodes.

25. A method comprising:

forming a plurality of adjacent drive electrodes on a substrate, the drive electrodes running generally in a first direction, wherein adjacent electrodes are interdigitated to provide at least one interpolation of the drive electrodes.