Touch panel and display device including the smae

• US 20160188082A1
• Filed: 12/23/2015
• Published: 06/30/2016
• Est. Priority Date: 12/29/2014
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lim, MyungJin, Choi, Seulgi, Ham, Yong-Su, Choi, SuSeok, Kim, Taeheon, Lee, YongWoo
• Granted Patent: US 10,444,891 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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

Provided is a touch panel. The touch panel includes a first substrate, a second substrate, a first electrode, a second electrode, a third electrode, and a dielectric layer. The second substrate faces the first substrate. The first electrode is on one surface of the first substrate. The second electrode is spaced apart from the first electrode on a same plane as the first electrode. The third electrode is on one surface of the second substrate and overlaps the first electrode and the second electrode. The dielectric layer is between the first electrode and the third electrode and between the second electrode and the third electrode and includes an anisotropic dielectric material.

Claims

1. A touch panel, comprising:

a first substrate;

a second substrate facing the first substrate;

a first electrode on one surface of the first substrate;

a second electrode spaced apart from the first electrode on a same plane as the first electrode;

a third electrode on one surface of the second substrate and overlapping the first electrode and the second electrode; and

a dielectric layer between the first electrode and the third electrode and between the second electrode and the third electrode and including an anisotropic dielectric material.

2. The touch panel according to claim 1, wherein the third electrode includes a plurality of pattern electrodes.

3. The touch panel according to claim 2, wherein:

the first electrode includes a plurality of first sub electrodes,

the second electrode includes a plurality of second sub electrodes, and

the plurality of respective pattern electrodes of the third electrode overlap with at least one first sub electrode among the plurality of first sub electrodes and at least one second sub electrode among the plurality of second sub electrodes.

4. The touch panel according to claim 3, wherein a capacitance between the pattern electrode which overlaps with at least one first sub electrode among the plurality of pattern electrodes and at least one first sub electrode is determined based on the arrangement direction of the anisotropic dielectric material.

5. The touch panel according to claim 3, wherein:

the first electrode and the second electrode extend in different directions from each other, and

the plurality of first sub electrodes are electrically connected to each other through a first connection electrode disposed on a plane different from the first sub electrode and the plurality of second sub electrodes are connected to each other through a second connection electrode disposed on the same plane as the second sub electrode.

6. The touch panel according to claim 3, the touch panel further comprising a plurality of partitions between the first substrate and the second substrate, wherein the plurality of partitions are along outlines of the plurality of respective pattern electrodes.

7. The touch panel according to claim 1, wherein the anisotropic dielectric material has a non-cubic crystal structure.

8. The touch panel according to claim 7, wherein the anisotropic dielectric material is a liquid crystal.

9. The touch panel according to claim 8, wherein a difference between a maximum relative permittivity and a minimum relative permittivity of the liquid crystal is 2 or more.

10. A display device, comprising:

a display panel;

a touch panel on the display panel; and

a touch controller configured to detect coordinates of a touch input applied to the touch panel and force of the touch input,

wherein the touch panel includes;

a lower electrode;

a dielectric layer on the lower electrode and including an anisotropic dielectric material; and

an upper electrode on the dielectric layer, overlapped with the lower electrode, and including a first electrode and a second electrode spaced apart from each other.

11. The display device according to claim 10, wherein:

the first electrode includes a plurality of first sub electrodes,

the second electrode includes a plurality of second sub electrodes, and

the lower electrode includes pattern electrodes which overlap with at least one first sub electrode among the plurality of first sub electrodes and at least one second sub electrode among the plurality of second sub electrodes.

12. The display device according to claim 11, wherein:

the first electrode extends in a first direction,

the second electrode extends in a second direction different from the first direction, and

the first electrode and the second electrode cross each other to be disposed in a matrix pattern.

13. The display device according to claim 12, wherein at least one first sub electrode and at least one second sub electrode which overlap with the pattern electrode are positioned in line with each other.

14. The display device according to claim 10, wherein the touch controller is configured to apply first voltage to the first electrode, apply second voltage different from the first voltage to the second electrode, and apply third voltage different from the first voltage to the lower electrode.

15. The display device according to claim 14, wherein:

the anisotropic dielectric material is a liquid crystal,

the arrangement directions of the liquid crystal is determined by an electric field between the first electrode and the second electrode, and

a capacitance between the upper electrode and the lower electrode is determined based on the number of the liquid crystals of which the arrangement direction is changed.

16. The display device according to claim 15, wherein the touch controller includes:

a touch coordinate detecting unit configured to detect coordinates of the touch input by sensing a change of the electric field between the first electrode and the second electrode, and

a touch force detecting unit configured to detect the force of the touch input by sensing the change of the capacitance between the upper electrode and the lower electrode.

17. The display device according to claim 10, further comprising:

a polarizer between the display panel and the touch panel; and

a cover glass on the touch panel.

18. The display device according to claim 10, wherein when the touch input is applied to the touch panel, a thickness of the dielectric layer is maintained to be the same.