Capacitive touch panel with low coupling capacitance and display device using the capacitive touch panel

• US 8,310,463 B2
• Filed: 09/29/2008
• Issued: 11/13/2012
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Yang, Tun-Chun, Lee, Seok-Lyul, Hu, Chih-Jen
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Lubit, Ryan A
• Application Number:
  US12/240,045
• Publication Number:
  US 20090084613A1
• Time in Patent Office: 1,506 Days
• Field of Search: 178 1801- 2004, 345173-178, 382115-127, 200/600
• US Class Current: 345/174
• 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 capacitive touch panel and a display device using the capacitive touch panel are provided. The capacitive touch panel includes a plurality of first direction electrode strings and second direction electrode strings. Each first direction electrode string has a plurality of first electrodes while each second direction electrode has a plurality of second electrodes. In order to reduce the lateral capacitance between adjacent electrodes, width of the first electrode is reduced from the middle to two sides of the electrode along a second direction. In addition, the first electrode has a perimeter surrounding itself. Each quarter of the perimeter of the first electrode facing the adjacent second electrode has a first slope change rate and a different second slope change rate.

Claims

1. A capacitive touch panel comprising:

a plurality of first direction electrode strings, wherein a plurality of first electrodes are disposed on each of the first direction electrode strings;

a plurality of second direction electrode strings, wherein a plurality of second electrodes are disposed on each of the second direction electrode strings, and each of the second electrodes is disposed between the first electrodes of the adjacent first direction electrode strings, the closest distance between the first electrode and the adjacent first electrode ranges from 10-100 micrometers; and

a dielectric layer disposed between the first direction electrode strings and the second direction electrode strings;

wherein the width of the first electrode decreases from middle of the first electrode to two sides of the first electrode, each of the first electrodes includes a perimeter, and a quarter of the perimeter closest to and facing a quarter of a perimeter of the second electrode has a first slope change rate and a different second slope change rate, the quarter of the perimeter of the first electrode includes a first line segment and a second line segment, the first line segment and the second line segment are not parallel to the quarter of the perimeter of the corresponding second electrode;

a first distance between the first line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies as a line segment of the quarter of the perimeter of the second electrode extends;

a second distance between the second line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies as a line segment of the quarter of the perimeter of the second electrode extends;

the first distance and the second distance have different change rate.

2. The capacitive touch panel of claim 1, wherein the second direction electrode strings cross the first direction electrode strings.

3. The capacitive touch panel of claim 1, wherein each of the second electrodes is disposed between the adjacent first electrodes.

4. The capacitive touch panel of claim 1, further comprising an overlapping a first electrode layer and a second electrode layer, wherein the first electrode strings and the second electrode strings belong to the first electrode layer and the second electrode layer respectively.

5. The capacitive touch panel of claim 1, wherein the first electrode is of a polygon with at least five sides.

6. The capacitive touch panel of claim 1, wherein the perimeter of first electrode includes a plurality of straight lines and each of the straight lines has a different slope.

7. The capacitive touch panel of claim 1, wherein the perimeter of the first electrode includes a plurality of arc-shaped lines and each of the arc-shaped lines has a different curvature.

8. The capacitive touch panel of claim 1, wherein each of the first electrodes is disposed between the adjacent second direction electrode strings, each of the second electrodes has a perimeter, and a quarter of the perimeter closest to and facing the first electrode has a first slope change rate and a different second slope change rate.

9. The capacitive touch panel of claim 8, wherein each of the second electrodes is a polygon of at least five sides.

10. The capacitive touch panel of claim 8, wherein the perimeter of second electrode includes a plurality of straight lines, and each of the straight lines has a different slope.

11. The capacitive touch panel of claim 1, wherein a closest distance between the first electrode and the adjacent second electrodes lies in between 1 and 1000 micrometers.

12. The capacitive touch panel of claim 11, wherein the closest distance between the first electrode and the adjacent second electrodes lies in between 10 and 100 micrometers.

13. A capacitive touch panel comprising:

a plurality of first direction electrode strings, wherein each of the first direction electrodes strings includes a plurality of first electrodes;

a plurality of second direction electrode strings, wherein each of the second direction electrode strings includes a plurality of second electrodes disposed between the adjacent first direction electrode strings, the closest distance between the first electrode and the adjacent first electrode ranges from 10-100 micrometers; and

a dielectric layer disposed between the first direction electrode strings and the second direction electrode strings;

wherein the first electrodes are polygons except for quadrilaterals, each of the first electrodes includes a perimeter, and a quarter of the perimeter closest to and facing a quarter of a perimeter of the second electrode has a first line segment and a second line segment, the first line segment and the second line segment are not parallel to the quarter of the perimeter of the corresponding second electrode;

a first distance between the first line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies as a line segment of the quarter of the perimeter of the second electrode extends;

a second distance between the second line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies as a line segment of the quarter of the perimeter of the second electrode extends;

the first distance and the second distance have different change rate.

14. The capacitive touch panel of claim 13, wherein the second direction electrode strings cross the first direction electrode strings.

15. The capacitive touch panel of claim 13, wherein the second electrode is disposed between the adjacent first electrodes.

16. The capacitive touch panel of claim 13, further comprising a first electrode layer overlapping a second electrode layer, wherein the first direction electrode strings and the second direction electrode strings belong to the first electrode layer and the second electrode layer respectively.

17. The capacitive touch panel of claim 13, wherein the first electrode is of a polygon with at least five sides.

18. The capacitive touch panel of claim 13, wherein each of the first electrodes is disposed between the adjacent second direction electrode strings, the second electrodes are polygons except for quadrilaterals.

19. The capacitive touch panel of claim 18, wherein the second electrode is a polygon of at least five sides.

20. The capacitive touch panel of claim 13, wherein the closest distance between the first electrode and the adjacent second electrodes lies in between 1 and 1000 micrometers.

21. The capacitive touch panel of claim 20, wherein the closest distance between the first electrode and the adjacent second electrodes lies in between 10 and 100 micrometers.

22. A capacitive touch panel comprising:

a plurality of first direction electrode strings, wherein a plurality of first electrodes are disposed on each of the first direction electrode strings;

a plurality of second direction electrode strings, wherein a plurality of second electrodes are disposed on each of the second direction electrode strings, and each of the second electrodes is disposed between the first electrodes of the adjacent first direction electrode strings; and

a dielectric layer disposed between the first direction electrode strings and the second direction electrode strings;

wherein width of the first electrode decreases from middle of the first electrode to two sides of the first electrode along the second direction, each of the first electrodes includes a perimeter, and a quarter of the perimeter closest to and facing a quarter of a perimeter of the second electrode has a first slope change rate and a different second slope change rate, a projection of the quarter of the perimeter of the first electrode and a projection of the quarter of the perimeter of the second electrode on the dielectric layer are asymmetrical, wherein the first electrodes are polygons except for quadrilaterals;

a distance between a line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies and has different change rate as a line segment of the quarter of the perimeter of the second electrode extends.

23. A capacitive touch panel comprising:

a plurality of first direction electrode strings, wherein each of the first direction electrodes strings includes a plurality of first electrodes;

a plurality of second direction electrode strings, wherein each of the second direction electrode strings includes a plurality of second electrodes disposed between the adjacent first direction electrode strings; and

a dielectric layer disposed between the first direction electrode strings and the second direction electrode strings;

wherein the first electrodes are polygons except for quadrilaterals, each of the first electrodes includes a perimeter, a quarter of the perimeter of the first electrode faces a quarter of a perimeter of the second electrode, a projection of the quarter of the perimeter of the first electrode and a projection of the quarter of the perimeter of the second electrode on the dielectric layer are asymmetrical, wherein a distance between a line segment of the quarter of the perimeter of the first electrode and the nearest quarter of the perimeter of the adjacent second electrode varies and has different change rate as a line segment of the quarter of the perimeter of the second electrode extends.