Touch panel

• US 20070252825A1
• Filed: 04/24/2007
• Published: 11/01/2007
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Sugawara, Hideo, Nashiki, Tomotake
• Granted Patent: US 8,182,898 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H01H 13/704 characterised by the layers, e.g. by their material or structure H01H13/703 takes precedence
• CPC Class Codes: H01H 2201/00 Contacts
• CPC Class Codes: H01H 2201/016 Roughened contact surface, e.g. anti-adhering
• CPC Class Codes: H01H 2227/002 Layer thickness
• CPC Class Codes: H01H 2227/004 Membrane
• CPC Class Codes: H01H 2227/006 Spacer
• CPC Class Codes: H01H 2227/008 Substrate
• CPC Class Codes: H01H 2227/01 Adhesive
• CPC Class Codes: H01H 2227/03 Hardness
• CPC Class Codes: H01H 2227/034 Regulation of operating force
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24372 Particulate matter

Abstract

A touch panel of the invention comprises a first panel having a first film base with transparency and a first transparent conductive thin film provided on one surface of the first film base; and a second panel having a second film base with transparency and a second transparent conductive thin film provided on one surface of the second film base, wherein the first panel and the second panel are arranged so as to face each other with a spacer therebetween, in such a manner that the first conductive thin film and the second conductive thin film face each other, wherein the surface of the first conductive thin film has a hardness of 1 GPa or more and a modulus of elasticity of 5 GPa or more, the surface of the second conductive thin film has a center line average roughness (Ra) of 0.3 nm to 1.0 nm, and that of the center line average roughness (Ra) of the surface of the second conductive thin film is smaller than that of the surface of the first conductive thin film. The touch panel has good durability.

Claims

1. A touch panel, comprising:

a first panel having a first film base with transparency and a first transparent conductive thin film provided on one surface of the first film base; and

a second panel having a second film base with transparency and a second transparent conductive thin film provided on one surface of the second film base,

wherein the first panel and the second panel are arranged so as to face each other with a spacer therebetween, in such a manner that the first conductive thin film and the second conductive thin film face each other,

wherein the surface of the first conductive thin film has a hardness of 1 GPa or more and a modulus of elasticity of 5 GPa or more,

the surface of the second conductive thin film has a center line average roughness (Ra) of 0.3 nm to 1.0 nm, and

the value of the center line average roughness (Ra) of the surface of the second conductive thin film is smaller than that of the surface of the first conductive thin film.

2. The touch panel according to claim 1, wherein the center line average roughness (Ra) of the surface of the first conductive thin film is 0.7 nm to 2.0 nm.

3. The touch panel according to claim 1, wherein the values of the hardness and the modulus of elasticity of the surface of the second conductive thin film are both smaller than the values of the hardness and the modulus of elasticity of the surface of the first conductive thin film.

4. The touch panel according to claim 1, wherein the hardness of the surface of the second conductive thin film is 0.4 GPa to 2.0 GPa and the modulus of elasticity is 2.0 GPa to 8.0 GPa.

5. The touch panel according to claim 1, wherein the first film base is a multilayer body where two or more transparent film bases are laminated together with a transparent pressure-sensitive pressure-sensitive adhesive layer therebetween.

6. The touch panel according to claim 1, wherein the first conductive thin film is provided on the first film base with at least one layer of a transparent dielectric thin film therebetween.

7. The touch panel according to claim 6, wherein the dielectric thin film that is closest to the first conductive thin film is an SiO₂ film formed by a dry process.

8. The touch panel according to claim 1, wherein the second conductive thin film is provided on the second film base with at least one layer of a transparent dielectric thin film therebetween.

9. The touch panel according to claim 8, wherein the dielectric thin film that is closest to the second conductive thin film is an SiO₂ film formed by a wet application method.

10. The touch panel according to claim 1, wherein the second conductive thin film is provided on the second film base with a resin layer having a minute uneven form therebetween.