Uniform threshold for capacitive sensing

• US 8,063,330 B2
• Filed: 06/22/2007
• Issued: 11/22/2011
• Est. Priority Date: 06/22/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Nousiainen, Jari, Karhiniemi, Marko
• Primary Examiner(s): Luebke; Renee
• Assistant Examiner(s): Caroc; Lheiren Mae
• Application Number:
  US11/821,205
• Publication Number:
  US 20080314725A1
• Time in Patent Office: 1,614 Days
• Field of Search: 200/600
• US Class Current: 200/600
• CPC Class Codes: G06F 2203/04809 Textured surface identifying touch areas, e.g. overlay structure for a virtual keyboard
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

The specification and drawings present a new apparatus and method for providing and using a uniform threshold for capacitive touch sensing in a user interface having a non-flat touch surface. The capacitive touch sensor can to provide a sensor signal using the uniform capacitance threshold level as a function of a location of an object (e.g., finger, stylus, etc.) on or near the non-flat touch surface of a user interface module using a substantially uniform distance between the non-flat touch surface and a capacitive touch sensor layer, and/or using a gradient of a dielectric constant of materials between the non-flat touch surface and the capacitive touch sensor layer according to a predetermined criterion.

Claims

1. An apparatus, comprising:

a user interface layer comprising a non-flat touch surface;

a capacitive touch sensor layer, located outside of and non-touching said user interface layer along portions of the capacitive touch sensor layer, and configured to provide a sensor signal using a uniform capacitance threshold level for capacitive touch sensing at the non-flat touch surface; and

material between said non-flat touch surface and said capacitive touch sensor layer, wherein the combination of said capacitive touch sensor layer and said material is configured to provide a uniform capacitance level at the non-flat touch surface, wherein said uniform capacitance level is provided, at least partly, by modulating a distance between said non-flat touch surface and said capacitive touch sensor layer by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface.

2. The apparatus of claim 1, wherein said user interface layer and said capacitive touch sensor layer are parts of a user interface module.

3. The apparatus of claim 1, wherein said capacitive touch sensor layer is made of a semiconducting material.

4. The apparatus of claim 1, wherein said capacitive touch sensor layer is manufactured by molding.

5. The apparatus of claim 1, wherein said apparatus is an electronic device configured for wireless communications.

6. An apparatus of claim 1, wherein said uniform capacitance level is further provided by modulating a dielectric constant of said material between said non-flat touch surface and said capacitive touch sensor layer.

7. The apparatus of claim 6, wherein said modulating the dielectric constant is provided by using a higher dielectric constant material between said non-flat touch surface and said capacitive touch sensor layer in corresponding areas if a distance between said non-flat touch surface and said capacitive touch sensor layer in said corresponding areas is larger than in other areas between said non-flat touch surface and said capacitive touch sensor layer.

8. The apparatus of claim 6, wherein said uniform capacitance level is provided by using simultaneously said modulating the distance between said non-flat touch surface and said capacitive touch sensor layer and said modulating the dielectric constant.

9. The apparatus of claim 1, wherein said material comprises materials with a dielectric constant.

10. A user interface module, comprising:

a user interface layer comprising a non-flat touch surface;

a capacitive touch sensor layer, located outside of and non-touching said user interface layer along portions of the capacitive touch sensor layer, and configured to provide a sensor signal using a uniform capacitance threshold level for capacitive touch sensing at the non-flat touch surface; and

material between said non-flat touch surface and said capacitive touch sensor layer, wherein the combination of said capacitive touch sensor layer and said material is configured to provide a uniform capacitance level at the non-flat touch surface, wherein said uniform capacitance level is provided, at least partly, by modulating a distance between said non-flat touch surface and said capacitive touch sensor layer by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface, and

wherein said user interface module is configured to be used with an electronic device.

11. The user interface module of claim 10, wherein said user interface module is a part of said electronic device.

12. The user interface module of claim 10, wherein said user interface module is connected to said electronic device by an electrical or a wireless connection.

13. The user interface module of claim 10, wherein said capacitive touch sensor layer is made of a semiconducting material.

14. The user interface module of claim 10, wherein said capacitive touch sensor layer is manufactured by molding.

15. The user interface module of claim 10, wherein said uniform capacitance level is further provided by modulating a dielectric constant of said material between said non-flat touch surface and said capacitive touch sensor layer.

16. The user interface module of claim 15, wherein said modulating the dielectric constant is provided by using a higher dielectric constant material between said non-flat touch surface and said capacitive touch sensor layer in corresponding areas if a distance between said non-flat touch surface and said capacitive touch sensor layer in said corresponding areas is larger than in other areas between said non-flat touch surface and said capacitive touch sensor layer.

17. The user interface module of claim 15, wherein said uniform capacitance level is provided by using simultaneously said modulating the distance between said non-flat touch surface and said capacitive touch sensor layer and said modulating the dielectric constant.

18. The user interface module of claim 10, wherein said material comprises materials with a dielectric constant.

19. A method, comprising:

detecting a touch on or near proximity to a non-flat touch surface of a user interface layer by an object; and

providing by a capacitive touch sensor layer a sensor signal using a uniform capacitance threshold level for capacitive touch sensing at the non-flat touch surface, wherein

the combination of said capacitive touch sensor layer and material between said non-flat touch surface and capacitive touch sensor layer is configured to provide a uniform capacitance level at the non-flat touch surface, wherein said uniform capacitance level is provided, at least partly, by modulating a distance between said non-flat touch surface and said capacitive touch sensor layer by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface; and

said capacitive touch sensor layer being located outside of and non-touching said user interface layer along portions of the capacitive touch sensor layer.

20. The method of claim 19, wherein said user interface layer and capacitive touch sensor layer are parts of a user interface module.

21. A method of claim 19, wherein said uniform capacitance level is further provided by modulating a dielectric constant of said material between said non-flat touch surface and said capacitive touch sensor layer according to a predetermined criterion.

22. The method of claim 21, wherein said modulating the dielectric constant is provided by using a higher dielectric constant material between said non-flat touch surface and said capacitive touch sensor layer in corresponding areas if a distance between said non-flat touch surface and said capacitive touch sensor layer in said corresponding areas is larger than in other areas between said non-flat touch surface and said capacitive touch sensor layer.

23. The method of claim 21, wherein said uniform capacitance level is provided by using simultaneously said modulating the distance between said non-flat touch surface and said capacitive touch sensor layer and said modulating the dielectric constant.

24. The method of claim 19, wherein said material comprises materials with a dielectric constant.