Touch panel, display device and method of producing touch panel

• US 7,184,027 B2
• Filed: 06/12/2002
• Issued: 02/27/2007
• Est. Priority Date: 10/13/2000
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sato, Koji, Uchida, Tsuneo, Mori, Kahoru, Muramatsu, Masayoshi, Suzuki, Harumi, Idogaki, Takaharu, Ozaki, Masaaki, Toyoda, Akito
• Primary Examiner(s): Mengistu; Amare
• Application Number:
  US10/166,605
• Publication Number:
  US 20020180712A1
• Time in Patent Office: 1,721 Days
• Field of Search: 345/87, 345/156, 345/173, 345/174, 345/175, 178/18.01, 178/18.03, 178 181- 183, 349/12, 349/122, 349/18.03, 349/153, 349/187, 349/190, 428/343, 428/345, 428/352
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia

Abstract

This invention provides a touch panel having excellent durability in a high-temperature high-moisture environment and a production method thereof. In a touch panel 1 including a pair of transparent glass substrates 1a and 2a each having a transparent electrode 1b, 2b and so arranged as to oppose each other through a seal portion 3, a thickness of the seal portion 3 is set to be not greater than 8 μm (exclusive of 0). In this way, moisture permeating through the seal portion 3 and entering a gap between the pair of transparent glass substrates 1a and 2a can be reduced.

Claims

1. A touch panel including a pair of transparent glass substrates each having a transparent conductive film, and arranged in such a fashion as to oppose each other on the side of said transparent conductive films and to be bonded to each other through a seal portion, wherein a thickness of said seal portion is set to be not greater than 5 μ

m (exclusive of

     0);

one of said glass substrates has a touch area, and a thickness of said one glass substrate is from 0.3 mm to 0.4 mm;

a Young'"'"'s modulus of said one glass substrate is from 730,000 kgf/cm² to 750,000 kgf/cm²;

said seal portion is formed of a thermosetting type epoxy resin having a moisture permeability not exceeding 8×

10<sup>−

12</sup> g·

cm/cm²·

sec·

cmHg when said seal portion is left standing under a condition of 65°

C. and 95% RH;

said touch panel further includes a wiring portion connected to said transparent conductive film of either one of said pair of glass substrates, and a wiring portion formed on the other of said glass substrates;

said touch panel further includes a transfer portion for electrically connecting both of said wiring portions, disposed between both of said wiring portions;

said transfer portion is positioned more inward than said seal portion between said pair of glass substrates; and

a sum of the thickness t1 of said transfer portion and both of said wiring portions and a thickness t2 of said seal portion satisfy the relation t1>

t2.

2. A touch panel according to claim 1, wherein the thickness of said one glass substrate is 0.4 mm.

3. A touch panel according to claim 1, wherein said one substrates having said touch area among said pair of glass substrates has an outwardly protruding shape as said relation t1>

t2 is satisfied.

4. A touch panel according to claim 1, wherein said transfer portion comprises electrically conductive particles being resin particles with metal films plated on the surfaces of said resin particles.

5. A touch panel according to claim 1, wherein said wiring portion comprises a baked body of an organic metal compound.

6. A touch panel according to claim 1, which is used for an automobile.

7. A touch panel according to claim 6, which is disposed on a display side of a display device for navigation.

8. A touch panel according to claim 7, wherein said display device is a liquid crystal display.

9. A display device including said touch panel according to claim 1 and a display device, wherein said touch panel is disposed on a display side of said display device.

10. A display device according to claim 9, wherein said display is a liquid crystal display device.

11. A method for producing a touch panel including a pair of transparent glass substrates each having a transparent conductive film, and arranged in such a fashion to oppose each other on the side of said transparent conductive films through a seal portion, one of said glass substrates having a touch area, said method comprising the steps of:

preparing a pair of glass substrates each having a transparent conductive film formed thereon, either one of said glass substrates having a seal material formed thereon;

pressing said pair of glass substrates and setting said seal material to not greater than 8 μ

m (exclusive of

     0) as a predetermined thickness;

expanding a gap between said pair of glass substrates; and

setting said seal material to provide the predetermined thickness thereof of not greater than 8 μ

m.

wherein said step of preparing said pair of glass substrates includes the steps of;

preparing a pair of glass substrates each having said transparent conductive film in advance formed thereon;

forming a wiring portion to be connected to said transparent conductive film of either one of said pair of glass substrates;

forming a wiring portion on the other of said glass substrates; and

forming a seal material on said one glass substrate in such a fashion as to be positioned between said pair of glass substrates more outside than both of said wiring portions and said transparent conductive films;

wherein said transparent conductive film on each of said pair of glass substrates is directly exposed to said space on the entire surface with the exception of the connection portion with said wiring portions;

wherein said step of preparing said pair of glass substrates includes the step of forming a seal material on said pair of glass substrates and forming a transfer portion on said wiring portion of said one glass substrate;

said transfer portion is formed of conductive particles comprising resin particles and metal films plated onto surface of said resin particles; and

said wiring portions of said pair of glass substrates are electrically connected through said transfer portion when said pair of glass substrates are so arranged as to oppose each other through said seal material.

12. A method for producing a touch panel according to claim 11, wherein said gap is charged into said space between said pair of glass substrates to expand said gap.

13. A method for producing a touch panel according to claim 11, wherein a gas is charged into said space under the state where a pressing force is not imparted to said pair of glass substrates.

14. A method for producing a touch panel according to claim 11, wherein setting of said seal material is conducted under the state where a pressing force is not imparted to said pair of glass substrates.

15. A touch panel for an automobile, comprising first and second transparent glass substrates each having a transparent conductive film, and arranged in such a fashion as to oppose each other on the side of the transparent conductive films and to form a space between them, and to be bonded to each other through a seal portion, wherein

the first glass substrate has a touch area;

a thickness glass substrate is from 0.3 mm to 0.4 mm;

a Young'"'"'s modulus of the first glass substrates is from 730,000 kgf/cm² to 750,000 kgf/cm².

an operation load at the touch area is set to 110 gf±

90 gf;

a thickness of the seal portion is set to a range of from 4 μ

m; and

the seal portion has a moisture permeability not exceeding 8 ×

10^-12 g.cm/cm².sec.cmHg when said seal portion is left standing under a condition of 65°

C. and 95% RH.

16. A touch panel for an automobile according to claim 15, wherein said touch panel further comprises

a first wiring portion connected to said transparent conductive film of a first glass substrates, and

a second wiring portion formed on the second glass substrates;

said touch panel further comprises a fransfer portion for electrically connecting both the first and second wiring portions, disposed between the first and second wiring portions;

said transfer portion is positioned more inward as compared to said seal portion between the first and second glass substrates; and

a sum of the thickness t1 of said transfer portion and the first and second wiring portions and thickness t2 of said seal portion satisifies the relation (t1>

t2).

17. A touch panel for an automobile according to claim 16, wherein the first substrate has an outwardly protruding shape when said relation (t1>

t2) is satisfied.

18. A touch panel for an automobile according to claim 16, wherein said transparent conductive film on each of the first and second glass substrates is directly exposed to a space defined between the first and second glass substrates on the entire surface with the exception of a connection portion with said wiring portions.

19. A touch panel for an automobile according to claim 16, wherein said transfer portion comprises electrically conductive particles being resin particles with metal films plated on the surfaces of said resin particles.

20. A touch panel for an automobile according to claim 16, wherein said wiring portion is covered with said seal portion.

21. A touch panel for an automobile according to claim 16, wherein said wiring comprises a baked body of an organic metal compound.

22. A touch panel for an automobile according to claim 15, wherein the thickness of the first glass substrate is about 0.4 mm, and the thickness of said seal portion is set to a range of from 2 μ

m to 8 μ

m.

23. A touch panel for an automobile according to claim 15, wherein said seal portion is formed of a thermosetting type epoxy resin.

24. A touch panel for an automobile according to claim 15, wherein the touch panel is disposed on a display side device for navigation.

25. A touch panel for an automobile according to claim 24, wherein said display device is a liquid crystal display device.

26. A device including said touch panel according to claim 15 and a display device, wherein said touch panel is disposed on a display side of said display device.

27. A display device according to claim 26, wherein said display is a liquid crystal display device.