Conductive film for touch panel, and touch panel and display apparatus including the same

• US 10,198,138 B2
• Filed: 06/17/2016
• Issued: 02/05/2019
• Est. Priority Date: 06/19/2015
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Hur, Yangwook, Lee, Junghoon, Kim, Minchul
• Primary Examiner(s): Ketema, Benyam
• Application Number:
  US15/185,936
• Publication Number:
  US 20160370903A1
• Time in Patent Office: 963 Days
• Field of Search: 345174
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04112 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 Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

Discussed is a touch panel including a base film, a first electrode formed on one surface of the base film, the first electrode being provided with a first sensor part including a first conductor, and a second electrode formed on the other surface of the base film, the second electrode being provided with a second sensor part including a second conductor different from the first conductor. The first sensor part has a higher resistance than a resistance of the second sensor part. A first area ratio, which is a ratio of an area, in which the first sensor part is formed, to an area inside an outer edge of the first sensor part is greater than a second area ratio, which is a ratio of an area, in which the second sensor part is formed, to an area inside an outer edge of the second sensor part.

Claims

1. A touch panel comprising:

a base film;

a first electrode formed on one surface of the base film, the first electrode being provided with a first sensor part including a first conductor; and

a second electrode formed on the other surface of the base film, the second electrode being provided with a second sensor part including a second conductor different from the first conductor,

wherein the first sensor part has a higher resistance than a resistance of the second sensor part,

wherein a first area ratio, which is a ratio of an area, in which the first sensor part is formed, to an area inside an outer edge of the first sensor part is greater than a second area ratio, which is a ratio of an area, in which the second sensor part is formed, to an area inside an outer edge of the second sensor part,

wherein the first conductor includes a metal nano-material configuring a network structure,

wherein the touch panel further comprises a first hard coating layer located between the base film and the first electrode,

wherein the first electrode includes a residual portion having a smaller thickness than a thickness of the first conductor, the residual portion containing a resin, and

wherein the touch panel further comprises an over-coating layer disposed on the first electrode, the over-coating layer having a smaller thickness than a thickness of the first hard coating layer and being configured to enclose and cover the first conductor protruding upward from the residual portion.

2. The touch panel according to claim 1, wherein the first conductor within the first sensor part has a lower filling density than a filling density of the second conductor within the second sensor part.

3. The touch panel according to claim 1, wherein the first conductor includes a transparent conductive oxide, and

wherein the second conductor includes metal particles.

4. The touch panel according to claim 1, wherein the first conductor has a width within a range from 10 nm to 35 nm and a length within a range from 20 μ

m to 40 μ

m, and

wherein the second conductor has a diameter within a range from 100 nm to 300 nm.

5. The touch panel according to claim 1, wherein the first conductor includes a plurality of nano-wires as the metal nano-material, and having a plurality of contact points, and

wherein the number of the contact points of the first conductor within the first sensor part is 1,000 per mm² or more.

6. The touch panel according to claim 1, wherein the first sensor part has a sheet resistance within a range from 10 Ω

/sq. to 270 Ω

/sq., and

wherein the second sensor has a sheet resistance within a range from 1 Ω

/sq. to 50 Ω

/sq.

7. The touch panel according to claim 1, wherein the first sensor part is formed, without an opening, in the entire area inside the outer edge of the first sensor part, and

wherein the second sensor part includes a plurality of electrode portions crossing each other at intersections such that at least one opening is formed in the area inside the outer edge of the second sensor part.

8. The touch panel according to claim 7, wherein the first area ratio is 95% or more, and

wherein the second area ratio is within a range from 0.01% to 5%.

9. The touch panel according to claim 7, wherein the number of the intersections, at which the electrode portions cross each other, in the second sensor part is within a range from 3 to 50 per mm².

10. The touch panel according to claim 1, wherein the first sensor part is thinner than the second sensor part.

11. The touch panel according to claim 10, wherein the first sensor part has a thickness of 200 nm or less, and

wherein the second sensor part has a thickness within a range from 0.5 μ

m to 2 μ

m.

12. The touch panel according to claim 1, wherein the first sensor part has a smaller surface roughness than a surface roughness of the second sensor part.

13. The touch panel according to claim 1, wherein the first sensor part has a smaller specular reflectance than a specular reflectance of the second sensor part.

14. The touch panel according to claim 13,

wherein the first sensor part has a greater diffuse reflectance than a diffuse reflectance of the second sensor part.

15. The touch panel according to claim 1, wherein the first sensor part has a higher transmissivity than a transmissivity of the second sensor part.

16. The touch panel according to claim 15, wherein the transmissivity of the first sensor part is within a range from 88% to 92%, and

wherein the transmissivity of the second sensor part is within a range from 87% to 91%.

17. The touch panel according to claim 1, wherein the first electrode includes a first wiring part connected to the first sensor part,

wherein the second electrode includes a second wiring part connected to the second sensor part, and

wherein the first and second wiring parts have higher filling densities than that of the first sensor part and greater area ratios than the second area ratio.

18. The touch panel according to claim 1, further comprising a second hard coating layer located between the base film and the second electrode.

19. The touch panel according to claim 1, further comprising an insulation layer configured to cover the second electrode,

wherein the insulation layer has a smaller dielectric coefficient than a dielectric coefficient of the over-coating layer.

20. The touch panel according to claim 1, further comprising:

a cover substrate disposed on a front surface of the touch panel; and

a transparent adhesive layer disposed between the touch panel and the cover substrate to bond the touch panel to the cover substrate.

21. A conductive film for a touch panel, the conductive film comprising:

a base film;

a first electrode formed on one surface of the base film, the first electrode being provided with a first sensor part including a first conductor; and

a second electrode formed on the other surface of the base film, the second electrode being provided with a second sensor part including a second conductor different from the first conductor,

wherein the first sensor part has a higher resistance than a resistance of the second sensor part,

wherein a first area ratio, which is a ratio of an area, in which the first sensor part is formed, to an area inside an outer edge of the first sensor part is greater than a second area ratio, which is a ratio of an area, in which the second sensor part is formed, to an area inside an outer edge of the second sensor part,

wherein the first conductor includes a metal nano-material configuring a network structure,

wherein the conductive film for the touch panel further comprises a first hard coating layer located between the base film and the first electrode,

wherein the first electrode includes a residual portion having a smaller thickness than a thickness of the first conductor, the residual portion containing a resin, and

wherein the conductive film for the touch panel further comprises an over-coating layer disposed on the first electrode, the over-coating layer having a smaller thickness than a thickness of the first hard coating layer and being configured to enclose and cover the first conductor protruding upward from the residual portion.

22. A display apparatus comprising:

a display panel; and

a touch panel integrated with the display panel,

wherein the touch panel includes;

a base film;

a first electrode formed on one surface of the base film, the first electrode being provided with a first sensor part including a first conductor; and

a second electrode formed on the other surface of the base film, the second electrode being provided with a second sensor part including a second conductor different from the first conductor,

wherein the first sensor part has a higher resistance than a resistance of the second sensor part,

wherein a first area ratio, which is a ratio of an area, in which the first sensor part is formed, to an area inside an outer edge of the first sensor part is greater than a second area ratio, which is a ratio of an area, in which the second sensor part is formed, to an area inside an outer edge of the second sensor part,

wherein the first conductor includes a metal nano-material configuring a network structure,

wherein the touch panel further comprises a first hard coating layer located between the base film and the first electrode,

wherein the first electrode includes a residual portion having a smaller thickness than a thickness of the first conductor, the residual portion containing a resin, and

wherein the touch panel further comprises an over-coating layer disposed on the first electrode, the over-coating layer having a smaller thickness than a thickness of the first hard coating layer and being configured to enclose and cover the first conductor protruding upward from the residual portion.

23. The display apparatus according to claim 22, wherein the touch panel is located at a front side of the display panel, or located inside the display panel.