Touch Sensor and Method for Operating a Touch Sensor

• US 20080316182A1
• Filed: 06/21/2007
• Published: 12/25/2008
• Est. Priority Date: 06/21/2007
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Karhiniemi, Marko, Antila, Mika, Ramo, Teemu
• Application Number:
  US11/766,568
• Publication Number:
  US 20080316182A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

Touch detection within display devices with a first conductive layer with first and second electrodes, a second conductive layer with third electrodes, a spacer spatially spacing the first conductive layer from the second conductive layer, the first electrodes being arranged for capacitive touch detection, and the second and third electrodes being arranged for resistive touch detection.

Claims

1. An apparatus with

a first conductive layer with first and second electrodes,

a second conductive layer with third electrodes,

a spacer spatially spacing the first conductive layer from the second conductive layer,

the first electrodes being arranged at least for capacitive touch detection,

the second and third electrodes being arranged for resistive touch detection.

2. The apparatus of claim 1, wherein the first electrodes are arranged at opposing positions on the first conductive layer.

3. The apparatus of claim 2, wherein the first electrodes are arranged at the corners of the first conductive layer.

4. The apparatus of claim 1, wherein the first conductive layer is curved or plane.

5. The apparatus of claim 1, wherein the first electrodes are supplied with an equal potential.

6. The apparatus of claim 1, wherein the first electrodes are connected to first current sensors arranged for sensing current changes within the electrodes.

7. The apparatus of claim 1, wherein the second electrodes are connected to first current sensors arranged for sensing current changes within the electrodes.

8. The apparatus of claim 7, wherein the first and/or the second electrodes are connected to sensors arranged for selectively sensing either current changes within the electrodes or a voltage applied by the third electrodes on the second conductive layer upon contact between the first and the second conductive layer.

9. The apparatus of claim 1, wherein the second electrodes are one electrode.

10. The apparatus of claim 1, wherein the second electrodes are arranged spatially apart from the first electrodes on the first conductive layer.

11. The apparatus of claim 1, wherein the second electrode is arranged on an edge of the first conductive layer.

12. The apparatus of claim 1, wherein the second electrode connected to a second current sensor arranged for sensing a voltage applied by the third electrodes on the second conductive layer upon contact between the first and the second conductive layer.

13. The apparatus of claim 1, wherein the third electrodes are arranged at opposing positions on the second conductive layer.

14. The apparatus of claim 1, wherein the third electrodes are arranged at the corners of the second conductive layer.

15. The apparatus of claim 1, wherein the first conductive layer is larger than the second conductive layer, such that the area of capacitive touch sensing overlaps the area of resistive touch sensing.

16. The apparatus of claim 1, wherein the second conductive layer is formed equal to the first conductive layer.

17. The apparatus of claim 1, wherein the third electrodes are connected to a switching unit such that field lines of the electrical field on the second conducive layer are successively substantially orthogonal to each other.

18. The apparatus of claim 1, wherein the third electrodes are connected to a switch such that successively sets of the third electrodes are at an equal potential.

19. The apparatus of claim 1, wherein the third electrodes are connected to a switch such that a first set of the third electrodes is at a first potential and a second set of the third electrodes is at a second potential.

20. The apparatus of claim 1, wherein the first and the second conductive layers are transparent.

21. The apparatus of claim 1, wherein the first and the second conductive layers are made of at least one of:

A) Indium-Tin-Oxide,

B) Antimony-Tin-Oxide,

C) PEDOT,

D) Orgacon,

E) conductive organic materials,

F) conductive inks,

G) carbon nanotube coatings,

H) conductive plastics,

I) conductive paints,

J) metal meshes

22. The apparatus of claim 1, wherein the first conductive layer is arranged on top of the second conductive layer.

23. The apparatus of claim 1, wherein the first conductive layer and/or the second conductive layer is a flexible layer.

24. The apparatus of claim 1, wherein the second conductive layer is a stable layer.

25. A touch sensitive display panel comprising a apparatus of claim 1.

26. A mobile multimedia device comprising a memory, a processor, a display and a apparatus of claim 1.

27. A method comprising:

applying a first potential onto a first conductive layer comprising first electrodes,

applying a second potential onto a second conductive layer comprising third electrodes,

providing capacitive touch detection using the first electrodes on the first conductive layer, and

providing resistive touch detection using at least second electrodes arranged on the first conductive layer for sensing contact between the first and the second conductive layer.

28. The method of claim 27, wherein the first conductive layer is applied with an electro static potential.

29. The method of claim 27, wherein the second conductive layer is applied with a temporally changing potential.

30. The method of claim 27, wherein the potential applied to the second conductive layer temporally changes the direction of field lines of the electrical field such that first field lines are substantially orthogonal temporally following second field lines.

31. The method of claim 27, wherein sensing a conductive piece in the proximity of the first conductive layer due to a current change activates a user interface of a display panel.

32. The method of claim 27, wherein the first conductive layer provides for browsing through a user interface.

33. The method of claim 27, wherein sensing the first and the second conductive layers being in contact activates a user interface of a display panel.

34. The method of claim 27, wherein when the first and the second conductive layers are brought into contact by pressing the first conductive layer onto the second conductive layer, resistive touch detection is activated.

35. The method of claim 27, wherein in an idle mode of the user interface only resistive touch detection is activated

36. The method of claim 27, wherein the voltage applied to the first conductive layer is switched off upon sensing the voltage applied from the second conductive layer onto the first conductive layer.

37. The method of claim 27, wherein the voltage applied to the first conductive layer is switched on upon sensing that no voltage is applied from the second conductive layer onto the first conductive layer.

38. An apparatus with

first conductive means arranged for forming a first conductive layer with first and second electrodes,

second conductive means arranged for forming a second conductive layer with third electrodes,

spacer means arranged for spatially spacing the first conductive means from the second conductive means,

the first electrodes being arranged at least for capacitive touch detection, and

the second and third electrodes being arranged for resistive touch detection.