TOUCH PANEL

• US 20100320009A1
• Filed: 11/24/2009
• Published: 12/23/2010
• Est. Priority Date: 06/18/2009
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Kuo, Jing-Tin, Lin, Yu-Chuan, Chen, Pei-Yu, Chang, Wei-Jen, Cheng, Kuo-Hsing
• Granted Patent: US 8,269,118 B2
• Time in Patent Office: Days
• US Class Current: 178/18.06
• 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 touch panel includes a substrate, a touch-sensing circuit, a plurality of sensing signal transmission wires, a capacitance compensation conductor, and a sensing signal readout circuit. The touch-sensing circuit is disposed on the substrate. The sensing signal transmission wires are disposed on the substrate and electrically connected to the touch-sensing circuit. The capacitance compensation conductor is disposed over the sensing signal transmission wires. Capacitance of each sensing signal transmission wire is C1, and coupling capacitance between each sensing signal transmission wire and the capacitance compensation conductor is C2. The sensing signal readout circuit is electrically connected to the sensing signal transmission wires. In each sensing signal transmission wire, variation of summation of C1 and C2 is less than a readout resolution of the sensing signal readout circuit. Another touch panel using an electrostatic discharge conductor to adjust varied capacitances of sensing signal transmission wires is also provided.

Claims

1. A touch panel, comprising:

a substrate;

a touch-sensing circuit disposed on the substrate;

a plurality of sensing signal transmission wires disposed on the substrate and electrically connected to the touch-sensing circuit;

a capacitance compensation conductor disposed over the sensing signal transmission wires, wherein capacitance of each of the sensing signal transmission wires is C1, and coupling capacitance between each of the sensing signal transmission wires and the capacitance compensation conductor is C2; and

a sensing signal readout circuit electrically connected to the sensing signal transmission wires, wherein in each of the sensing signal transmission wires, variation of summation of the capacitances C1 and C2 is less than a readout resolution of the sensing signal readout circuit.

2. The touch panel as claimed in claim 1, wherein the capacitance C1 of each of the sensing signal transmission wires is substantially different, and the coupling capacitance C2 between each of the sensing signal transmission wires and the capacitance compensation conductor is substantially different.

3. The touch panel as claimed in claim 1, the touch-sensing circuit comprising:

a plurality of first sensing series disposed on the substrate, wherein each of the first sensing series extends along a first direction and is electrically insulated from one another; and

a plurality of second sensing series disposed on the substrate, wherein each of the second sensing series extends along a second direction and is electrically insulated from one another.

4. The touch panel as claimed in claim 3, wherein each of the first sensing series comprises a plurality of first sensing pads and a plurality of first bridge portions, each of the first bridge portions is electrically connected to the adjacent first sensing pads, each of the second sensing series comprises a plurality of second sensing pads and a plurality of second bridge portions, and each of the second bridge portions is electrically connected to the adjacent second sensing pads.

5. The touch panel as claimed in claim 1, wherein width of each of the sensing signal transmission wires is substantially the same, while length of each of the sensing signal transmission wires is different.

6. The touch panel as claimed in claim 1, wherein the readout resolution of the sensing signal readout circuit ranges from −

1 pF to 1 pF.

7. The touch panel as claimed in claim 1, wherein an overlapping area between each of the sensing signal transmission wires and the capacitance compensation conductor is substantially different.

8. The touch panel as claimed in claim 1, further comprising a dielectric layer disposed on the substrate to cover the sensing signal transmission wires, wherein the capacitance compensation conductor is disposed on the dielectric layer.

10. The touch panel as claimed in claim 1, wherein the coupling capacitance C3 between each of the electrostatic discharge conductors and the electrostatic charge releasing wire is substantially different.

9. A touch panel, comprising:

a substrate;

a touch-sensing circuit disposed on the substrate, wherein the touch-sensing circuit comprises a plurality of sensing series;

a plurality of sensing signal transmission wires disposed on the substrate and electrically connected to the sensing series;

a plurality of electrostatic discharge conductors disposed on the substrate and electrically connected to the sensing series;

an electrostatic charge releasing wire disposed on the substrate, wherein capacitance of each of the sensing signal transmission wires is C1, and coupling capacitance between each of the electrostatic discharge conductors and the electrostatic charge releasing wire is C3; and

a sensing signal readout circuit electrically connected to the sensing signal transmission wires, wherein in each of the electrostatic discharge conductors and each of the sensing signal transmission wires connected to one of the sensing series, variation of summation of the capacitances C1 and C3 is less than a readout resolution of the sensing signal readout circuit.

11. The touch panel as claimed in claim 9, the sensing series comprising:

a plurality of first sensing series extending along a first direction and electrically insulated from one another; and

a plurality of second sensing series extending along a second direction and electrically insulated from one another.

12. The touch panel as claimed in claim 11, wherein each of the first sensing series comprises a plurality of first sensing pads and a plurality of first bridge portions, each of the first bridge portions is electrically connected between two of the first sensing pads adjacent to each other, each of the second sensing series comprises a plurality of second sensing pads and a plurality of second bridge portions, and each of the second bridge portions is electrically connected between two of the second sensing pads adjacent to each other.

13. The touch panel as claimed in claim 9, wherein width of each of the sensing signal transmission wires is substantially the same, while length of each of the sensing signal transmission wires is different.

14. The touch panel as claimed in claim 9, wherein the readout resolution of the sensing signal readout circuit ranges from −

1 pF to 1 pF.

15. The touch panel as claimed in claim 9, wherein each of the electrostatic discharge conductors has a first protrusion, the electrostatic charge releasing wire has a plurality of second protrusions, and each of the first protrusions is aligned to one of the second protrusions.

16. The touch panel as claimed in claim 15, wherein an overlapping area between each of the first protrusions and the corresponding second protrusion is substantially different.

17. The touch panel as claimed in claim 16, wherein one or more of the overlapping areas between the aligned first protrusions and second protrusions is 0.