Transparent touch panel and electronic apparatus using the same

• US 6,781,642 B2
• Filed: 04/11/2003
• Issued: 08/24/2004
• Est. Priority Date: 01/18/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nakanishi, Akira, Fukui, Toshiharu
• Primary Examiner(s): TON, MINH TOAN T
• Application Number:
  US10/412,551
• Publication Number:
  US 20030197813A1
• Time in Patent Office: 501 Days
• Field of Search: 349/12, 349/122, 349/137, 349/158, 345/104, 345/173-175, 345/179
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A transparent touch panel (TTP) comprising a fixed substrate of transparent resin, an adhesion layer disposed on the fixed substrate, an antireflection layer disposed on the adhesion layer, a first transparent conductive layer disposed on the antireflection layer, a second transparent conductive layer opposed to and spaced apart from the first transparent conductive layer, and a flexible transparent film disposed on the upper surface of the second transparent conductive layer. In one embodiment, rather than having a separate adhesion layer and antireflection layer, the adhesion layer may also serve as the antireflection layer, the rest of the above components remaining the same. The use of transparent resin in the TTP of the present invention reduces weight and increases resistance to breaking. The antireflection layer decreases the light reflection at respective boundary surfaces, thus increasing light transmittance. The adhesion layer strengthens adhesion of the antireflection layer and the first transparent conductive layer onto the fixed substrate, thus providing for even and uniform electrical resistance in the transparent conductive layer. An electronic apparatus thus comprises at least a control circuit, an LCD device for display, and a TTP disposed on the display surface of the LCD device. The TTP may comprise the TTP described above and/or may comprise a polarizing plate on an operating surface of the transparent touch panel.

Claims

1. A transparent touch panel comprising:

a fixed substrate comprising a transparent plastic and having an upper surface;

a first adhesion layer disposed on the upper surface of said fixed substrate, the first adhesion layer having adhesive properties at both an upper and a lower surface of said adhesion layer and having an antireflective properties;

a first transparent conductive layer disposed on said first adhesion layer,

a second transparent conductive layer opposed to and spaced apart from said first transparent conductive layer; and

a flexible transparent film disposed on said second transparent conductive layer.

2. The transparent touch panel of claim 1, further comprising:

a second adhesion layer having adhesive properties at both an upper surface and a lower surface of said adhesion layer; and

a second antireflection layer disposed on a bottom surface of said fixed substrate.

3. The transparent touch panel of claim 2, wherein said first adhesion layer and said second adhesion layer each comprises silica formed under atmospheric pressure as a main component.

4. The transparent touch panel of claim 1, further comprising a second adhesion layer on a bottom surface of said fixed substrate, said second adhesion layer having adhesive properties at both an upper surface and a lower surface of said adhesion layer and having antireflective properties.

5. The transparent touch panel of claim 1, further comprising on an upper surface of said flexible transparent film:

a hard coat layer; and

a third antireflection layer.

6. The transparent touch panel of claim 1, wherein said flexible transparent film further comprises a fourth antireflection layer and the second transparent conductive layer at a bottom surface of said flexible transparent film.

7. The transparent touch panel of claim 1, further comprising a polarizing plate on the upper surface of said flexible transparent film.

8. The transparent touch panel of claim 7, further comprising a hard coat layer and a third antireflection layer on the upper surface of said polarizing plate.

9. The transparent touch panel of claim 1, wherein said flexible transparent film comprises a polarizing film.

10. The transparent touch panel of claim 1, wherein said first adhesion layers contains as a main component a resin selected from the group consisting of:

an acrylic resin, an urethane resin, an epoxy resin, and a combination thereof.

11. The transparent touch panel of claim 1, wherein said first antireflection layer comprises a laminated layer comprising a layer of low refractive index and a layer of high refractive index.

12. The transparent touch panel of claim 1, wherein at least one of said first antireflection layers or said first adhesion layers comprises a transparent layer having a thickness of not less than about 0.05 μ

m and not more than about 0.15 μ

m and having a refractive index not more than about 1.5.

13. The transparent touch panel of claim 1, wherein the fixed substrate comprises a resin having a bending modulus of not less than about 30,000 kg/cm².

14. An electronic apparatus comprising at least a control circuit, a display device, and a transparent touch panel disposed on a display surface of said display device, wherein said transparent touch panel comprises:

a fixed substrate comprising a transparent resin;

a first adhesion layer disposed on said fixed substrate and having adhesive properties at both an upper surface and a lower surface of said adhesion layer and having antireflective properties;

a first transparent conductive layer formed on said first adhesion layer;

a second transparent conductive layer opposed to and spaced apart from said first transparent conductive layer; and

a flexible transparent film disposed on an upper surface of said second transparent conductive layer.

15. The electronic apparatus of claim 14, wherein said display device is a reflection type LCD device.

16. The electronic apparatus of claim 14, wherein a polarizing plate is provided on an operating surface of said transparent touch panel.