SCREEN WITH CAPACITIVE TOUCH ZONES

• US 20090167721A1
• Filed: 12/18/2008
• Published: 07/02/2009
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Original Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Inventors: Hamm, Alain, Grosjacques, Emile
• Granted Patent: US 8,125,466 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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

Abstract

Capacitive touch screen including first and second substrates (2, 4) that extend parallel to and at a distance from each other, said first and second substrates (2, 4) being made of a transparent, dielectric material, a first series of electrodes (6), made of a transparent, electrically conductive material, being arranged on at least the surface (2a) of the first substrate (2) that faces the second substrate (4), said touch screen being characterized in that it includes means for keeping the space between the two substrates (2, 4) constant.

Claims

1. A capacitive touch screen including first and second substrates extending parallel to and at a distance from each other, said first and second substrates being made of a transparent, dielectric material, a first series of electrodes made of a transparent, electrically conductive material being arranged on at least the surface of the first substrate that faces the second substrate, wherein said touch screen includes means for keeping the space between the two substrates constant.

2. The touch screen according to claim 1, wherein a second series of electrodes, made of a transparent, electrically conductive material, is arranged on the surface of the second substrate that faces the first substrate.

3. The touch screen according to claim 1, wherein the first and second substrates are joined to each other by means of a sealing frame, which extends along the outer perimeter of said two substrates and which defines a volume for containing a fluid, whose optical refractive index is substantially equal to that of the first substrate.

4. The touch screen according to claim 2, wherein the first and second substrates are joined to each other by means of a sealing frame, which extends along the outer perimeter of said two substrates and which defines a volume for containing a fluid, whose optical refractive index is substantially equal to that of the first substrate.

5. The touch screen according to claim 3, wherein the first series of electrodes which are carried by first substrate are transferred onto second substrate next to the second series of electrodes which are carried by second substrate.

6. The touch screen according to claim 4, wherein the first series of electrodes which are carried by first substrate are transferred onto second substrate next to the second series of electrodes which are carried by second substrate.

7. The touch screen according to claim 3, wherein spacers are dispersed in the volume delimited by the sealing frame.

8. The touch screen according to claim 4, wherein spacers are dispersed in the volume delimited by the sealing frame.

9. The touch screen according to claim 5, wherein spacers are dispersed in the volume delimited by the sealing frame.

10. The touch screen according to claim 6, wherein spacers are dispersed in the volume delimited by the sealing frame.

11. The touch screen according to claim 3, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

12. The touch screen according to claim 4, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

13. The touch screen according to claim 5, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

14. The touch screen according to claim 6, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

15. The touch screen according to claim 7, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

16. The touch screen according to claim 8, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

17. The touch screen according to claim 9, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

18. The touch screen according to claim 10, wherein the fluid confined in the volume delimited by the sealing frame is a liquid crystal or a transparent, isotropic or anisotropic fluid, whose optical refractive index is substantially equal to that of the first substrate.

19. The touch screen according to claim 1, wherein an intermediate layer, made of a transparent, dielectric material, is arranged on the surface of at least one of the first and second substrates, which carries the first, respectively the second, series of electrodes so as to cover said electrodes.

20. The touch screen according to claim 1, wherein the first and second substrates are joined to each other by means of an adhesive layer, formed of optical adhesive, in which spacers are dispersed.

21. The touch screen according to claim 2, wherein the first and second substrates are joined to each other by means of an adhesive layer, formed of optical adhesive, in which spacers are dispersed.

22. The touch screen according to claim 19, wherein the first and second substrates are joined to each other by means of an adhesive layer, formed of optical adhesive, in which spacers are dispersed.

23. The touch screen according to claim 19, wherein the intermediate layer of transparent, dielectric material has an optical refractive index comprised between the optical refractive index of the first substrate and the optical refractive index of the electrically conductive material of which the electrodes are made.

24. The touch screen according to claim 20, wherein the intermediate layer of transparent, dielectric material has an optical refractive index comprised between the optical refractive index of the first substrate and the optical refractive index of the electrically conductive material of which the electrodes are made.

25. The touch screen according to claim 23, wherein the intermediate layer of transparent, dielectric material is made of a polyimide with an optical refractive index that is substantially equal to 1.68.

26. The touch screen according to claim 1, wherein the thickness of the electrodes is less than or equal to fifteen nanometres.

27. The touch screen according to claim 26, wherein the electrodes are made of indium and tin oxide.