Uniform threshold for capacitive sensing

• US 20080314725A1
• Filed: 06/22/2007
• Published: 12/25/2008
• Est. Priority Date: 06/22/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Karhiniemi, Marko, Nouslainen, Jari
• Granted Patent: US 8,063,330 B2
• Time in Patent Office: Days
• 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; and

a capacitive touch sensor layer, configured to provide a sensor signal using a uniform capacitance threshold level as a function of a location of an object on or near said non-flat touch surface when said object touches or is in a close proximity to said 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 25, wherein

said substantially uniform distance is provided by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface.

4. The apparatus of claim 1, wherein said

capacitive touch sensor layer is inserted inside of said user interface layer.

5. The apparatus of claim 1, wherein said

capacitive touch sensor layer is made of a semiconducting material.

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

7. The apparatus of claim 25, wherein

said gradient of a 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 25, wherein

said uniform capacitance threshold level is provided by using simultaneously said substantially uniform distance and said gradient of the dielectric constant.

9. The apparatus of claim 1, wherein said

apparatus is an electronic device configured for wireless communications.

25. An apparatus of claim 1, wherein said uniform capacitance threshold level is provided by at least one of:

a substantially uniform distance between said non-flat touch surface and said capacitive touch sensor layer, and

a gradient of a dielectric constant of materials between said non-flat touch surface and said capacitive touch sensor layer according to a predetermined criterion.

10. A user interface module, comprising:

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

a capacitive touch sensor layer, configured to provide a sensor signal using a uniform capacitance threshold level as a function of a location of an object on or near said non-flat touch surface when said object touches or is in a close proximity to said non-flat touch surface,

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.

15. The user interface module of claim 10, wherein

said capacitive touch sensor layer is made of a semiconducting material.

16. The user interface module of claim 10, wherein

said capacitive touch sensor layer is manufactured by molding.

19. A method, comprising:

touching a non-flat touch surface of a user interface layer by an object; and

providing by a capacitive touch sensor layer a sensor signal with a uniform capacitance threshold level as a function of a location on said non-flat touch surface when an object touches or is in a close proximity to said non-flat touch surface.

20. The method of claim 27, wherein

said substantially uniform distance is provided by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface.

21. The method of claim 20, wherein said

capacitive touch sensor layer is inserted inside of said user interface layer.

22. The method of claim 27, wherein

said gradient of a 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 27, wherein

said uniform capacitance threshold level is provided by using simultaneously said substantially uniform distance and said gradient of the dielectric constant.

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

27. A method of claim 19, wherein said uniform capacitance threshold level is provided by at least one of:

a substantially uniform distance between said non-flat touch surface and said capacitive touch sensor layer, and

a gradient of a dielectric constant of materials between said non-flat touch surface and said capacitive touch sensor layer according to a predetermined criterion.

26. The user interface module, wherein said uniform capacitance threshold level is provided by at least one of:

a substantially uniform distance between said non-flat touch surface and said capacitive touch sensor layer, and

a gradient of a dielectric constant of materials between said non-flat touch surface and said capacitive touch sensor layer according to a predetermined criterion.

13. The user interface module of claim 26, wherein said substantially uniform distance is provided by bending said capacitive touch sensor layer to follow a shape of the non-flat touch surface.

14. The user interface module of claim 13, wherein

said capacitive touch sensor layer is inserted inside of said user interface layer.

17. The user interface module of claim 26, wherein said gradient of a 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.

18. The user interface module of claim 26, wherein said uniform capacitance threshold level is provided by using simultaneously said substantially uniform distance and said gradient of the dielectric constant.