Touch panel and display device using the same

• US 8,237,672 B2
• Filed: 09/29/2008
• Issued: 08/07/2012
• Est. Priority Date: 12/14/2007
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Original Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Inventors: Jiang, Kai-Li, Liu, Liang, Fan, Shou-Shan
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Bowman, Mary Ellen
• Application Number:
  US12/286,176
• Publication Number:
  US 20090153509A1
• Time in Patent Office: 1,408 Days
• Field of Search: 345/173, 524/496, 257/222, 349/12, 313/336, 428/339
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component

Abstract

An exemplary touch panel includes a substrate, transparent conductive layers, a capacitive sensing circuit, and conductive wires. The transparent conductive layers are disposed on a surface of the substrate and spaced apart from each other. Each transparent conductive layer includes a carbon nanotube layer. The carbon nanotube layer includes carbon nanotubes. The conductive wires respectively electrically connect the transparent conductive layers to the capacitive sensing circuit. A display device using the touch panel is also provided.

Claims

1. A touch panel comprising:

a substrate comprising a surface;

a plurality of transparent conductive layers disposed on the surface of the substrate and spaced apart from each other, at least one of the plurality of transparent conductive layers comprising a carbon nanotube layer;

at least one capacitive sensing circuit; and

a plurality of conductive wires respectively electrically connecting the plurality of transparent conductive layers to the at least one capacitive sensing circuit, the at least one capacitive sensing circuit measuring capacitive changes of the plurality of transparent conductive layers,

wherein the carbon nanotube layer comprises at least one carbon nanotube film, the at least one carbon nanotube film comprises a plurality of carbon nanotubes, and a majority of the plurality of carbon nanotubes of the carbon nanotube film are aligned along a same direction.

2. The touch panel as claimed in claim 1, wherein the at least one carbon nanotube film comprises a plurality of successive carbon nanotube segments joined end to end by van der Waals attractive force therebetween.

3. The touch panel as claimed in claim 2, wherein the carbon nanotube layer comprises a plurality of carbon nanotube films directly stacked with each other, the plurality of carbon nanotubes in each of the plurality of carbon nanotube films are aligned along a same direction, and an angle between the aligned direction of the carbon nanotubes in two adjacent stacked carbon nanotube films is greater than 0°

and up to 90°

.

4. The touch panel as claimed in claim 1, wherein a thickness of the at least one carbon nanotube film is in an approximate range from 0.5 nanometers to 100 microns.

5. The touch panel as claimed in claim 1, wherein the plurality of transparent conductive layers are arranged in an array of rows and columns or an array of concentric and radial segments.

6. The touch panel as claimed in claim 1, wherein the plurality of conductive wires comprise a material selected from the group consisting of indium tin oxide, antimony tin oxide, carbon nanotubes, and conductive resin.

7. The touch panel as claimed in claim 1, further comprising a filling layer located in gaps between the plurality of transparent conductive layers and the plurality of conductive wires.

8. The touch panel as claimed in claim 7, wherein the filling layer is formed of material with a refractive index and a transmissivity similar to those of the transparent conductive layers and the conductive wires.

9. The touch panel as claimed in claim 1, further comprising a transparent protective film disposed on surfaces of the plurality of transparent conductive layers facing away from the substrate, material of the transparent protective film being selected from the group consisting of silicon nitride, silicon dioxide, benzocyclobutene, polyester, acrylic resin, polyethylene terephthalate, and any combination thereof.

10. The touch panel as claimed in claim 1, further comprising a shielding layer disposed on another surface of the substrate that faces away from the plurality of transparent conductive layers, material of the shielding layer being selected from the group consisting of indium tin oxide film, antimony tin oxide film, conductive resin film, carbon nanotube film, and any combination thereof, the carbon nanotube film of the shielding layer comprises a plurality of carbon nanotubes aligned along a same direction.

11. A display device comprising:

a touch panel comprising a substrate, a plurality of transparent conductive layers disposed on a surface of the substrate, at least one capacitive sensing circuit, and a plurality of conductive wires respectively electrically connecting the plurality of transparent conductive layers to the at least one capacitive sensing circuit, at least one of the plurality of transparent conductive layers comprising a carbon nanotube layer, and the carbon nanotube layer comprising at least one carbon nanotube film, the at least one carbon nanotube film comprising a plurality of carbon nanotubes, a majority of the plurality of carbon nanotubes of the carbon nanotube film are aligned along the same direction and joined end to end by van der Waals attractive force; and

a display element is adjacent to the touch panel.

12. The display device as claimed in claim 11, further comprising a first controller configured for controlling the touch panel, a central processing unit, and a second controller configured for controlling the display element, the first controller, the central processing unit and the second controller being electrically connected with each other, the display element being connected to the second controller, and the touch panel being connected to the first controller.

13. The display device as claimed in claim 11, wherein the display element is selected from the group consisting of liquid crystal displays, field emission displays, plasma displays, electroluminescent displays, vacuum fluorescent displays, cathode ray tubes, e-papers, flexible liquid crystal displays, and flexible organic light emitting displays.

14. The display device as claimed in claim 11, wherein the touch panel is installed directly on the display element.

15. A touch panel comprising:

a substrate comprising a first surface and a second surface opposite to the first surface;

a plurality of transparent conductive layers disposed directly on the first surface of the substrate and spaced apart from each other, at least one of the plurality of transparent conductive layers comprising a first carbon nanotube film;

a shielding layer disposed directly on the second surface of the substrate, the shielding layer comprising a second carbon nanotube film;

at least one capacitive sensing circuit; and

a plurality of conductive wires electrically connecting the plurality of transparent conductive layers to the at least one capacitive sensing circuit, the at least one capacitive sensing circuit measuring capacitive changes of the plurality of transparent conductive layers,

wherein the first carbon nanotube film and the second carbon nanotube film each comprise a plurality of carbon nanotubes, and a majority of the plurality of carbon nanotubes of the first and second carbon nanotube films are aligned along a same direction.