Inductive touch sensor and detecting method

• US 8,981,242 B2
• Filed: 09/13/2010
• Issued: 03/17/2015
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Original Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Inventors: Bayramoglu, Gokalp
• Primary Examiner(s): PATEL, PREMAL R
• Application Number:
  US12/880,159
• Publication Number:
  US 20110285454A1
• Time in Patent Office: 1,646 Days
• Field of Search: 345173-179, 178 1801- 1808, 178/19.03
• US Class Current: 178/18.07
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

An inductive touch sensor is provided. The inductive touch sensor comprises a driving layer for generating a magnetic field, an induced layer facing to the driving layer for identifying at least one induced electrical signal representing a change, in inductance corresponding to at least one touch location on the inductive touch sensor and at least one inductive circuit connected to the driving layer and the induced layer for detecting at least one induced electrical signal to determine at least one touch location on the inductive touch sensor. Furthermore, a detecting method of detecting at least one touch location on the inductive touch sensor is also provided.

Claims

1. An inductive touch sensor, comprising:

a driving layer to generate a magnetic field, wherein said driving layer comprises a plurality of driving electrodes, said driving electrodes are located on a plurality of driving lines;

an induced layer spaced apart from said driving layer, wherein said induced layer comprises a plurality of induced electrodes, said induced electrodes are located on a plurality of induced lines, and said magnetic field induces an induction on said induced layer, wherein when one of said driving layer and said induced layer is depressed, at least one change in said induction occurs; and

at least one inductive circuit connected to said driving layer and said induced layer;

wherein a driving current is applied to said driving layer by a controller, therefore generating said magnetic field which induces a current in said induced layer and when the distance between said driving layer and said induced layer changed as a result of a user'"'"'s touch, and said controller is capable of detecting the change in current in said induced layer to determine a touch location in two dimensional space.

2. The inductive touch sensor of claim 1, wherein said induced electrodes are connected to said at least one inductive circuit.

3. The inductive touch sensor of claim 2, wherein said induced layer further comprises an induced substrate with said induced electrodes placed on an inner surface of said induced substrate.

4. The inductive touch sensor as claimed in claim 2, wherein said induced layer further comprises an induced substrate with said induced electrodes placed on an outer surface of said induced substrate.

5. The inductive touch sensor of claim 2, wherein said driving electrodes are connected to said at least one inductive circuit.

6. The inductive touch sensor of claim 5, wherein said driving layer further comprises a driving substrate with said driving electrodes placed on an inner surface of said driving substrate.

7. The inductive touch sensor of claim 5, wherein said driving layer further comprises a driving substrate with said driving electrodes placed on an outer surface of said driving substrate.

8. The inductive touch sensor of claim 5, wherein said inductive circuit comprises:

said controller;

a plurality of driving conductor lines connecting said driving lines, wherein said driving electrodes connect to said controller through said driving conductor lines and said driving lines; and

a plurality of induced conductor lines connecting said induced lines, wherein said induced electrodes connect to said controller through said induced conductor lines and said induced lines.

9. The inductive touch sensor of claim 8, wherein said at least one driving conductor line extends along at least one direction from a point and said induced conductor lines distribute as concentric circles whose centre is a point on said induced layer.

10. The inductive touch sensor of claim 9, wherein said at least one driving conductor line further comprises at least two driving conductor lines extending along different directions from said point.

11. The inductive touch sensor of claim 10, wherein said driving layer further comprises a plurality of insulator pieces located at the intersection of said at least two driving conductor lines to insulate said driving conductor lines from each other.

12. The inductive touch sensor of claim 9, wherein said induced conductor lines comprises concentric arcs.

13. The inductive touch sensor of claim 8, wherein said at least one driving conductor line further comprises at least two driving conductor lines distributing as at least two concentric circles whose centre is a point and said induced conductor lines extend along different directions from a point on said induced layer.

14. The inductive touch sensor of claim 13, wherein said at least two driving conductor lines comprises concentric arcs.

15. The inductive touch sensor of claim 13, wherein said induced layer further comprises a plurality of insulator pieces located at the intersection of said induced conductor lines to insulate said induced conductor lines from each other.

16. The inductive touch sensor of claim 8, wherein said induced conductor lines connect each said induced electrode to said controller respectively.

17. The inductive touch sensor of claim 8, wherein said induced electrodes comprise a plurality of first induced electrodes and a plurality of second induced electrodes.

18. The inductive touch, sensor of claim 17, wherein said induced conductor lines comprise a plurality of first induced conductor lines connecting said first induced electrodes to said controller in a first direction and a plurality of second induced conductor lines connecting said second induced electrodes to said controller in a second direction different to said first direction.

19. The inductive touch sensor of claim 18, wherein said first induced electrodes are placed on an inner surface of said induced substrate and said second induced electrodes are placed on an outer surface of said induced substrate.

20. The inductive touch sensor of claim 18, wherein said inductive layer further comprises a plurality of insulator pieces located between said first induced conductor lines and said second induced conductor lines at the intersection of said first induced conductor lines and said second induced conductor lines.

21. The inductive touch sensor of claim 1, wherein said driving lines are disposed in a first direction and said induced lines are disposed in a second direction different to said first direction, and each of said driving electrodes is located on a corresponding intersection of said driving line and said induced line, and said induced electrodes align to said driving electrodes.

22. The inductive touch sensor of claim 1, wherein said driving layer and said induced layer are spaced by insulating medium.

23. The inductive touch sensor of claim 22, wherein said insulating medium is made of deformable material.

24. A detecting method of detecting at least one touch location on an inductive touch sensor, comprising steps of:

applying a driving current to a driving layer to generate a magnetic field which induces an inductance on an induced layer, wherein said driving layer comprises a plurality of driving electrodes located on a plurality of driving lines, wherein said driving current is applied to one driving line at a time; and

wherein said induced layer comprises a plurality of induced electrodes located on a plurality of induced lines; and

wherein said plurality of induced lines are sensed in sequence by a controller circuit when said driving current is applied to said driving lines such a way that one driving line is driven at any time by applying said driving current to said driving line, while all said sensing lines are sensed sequentially when one driving line is driven by said driving current;

identifying at least one change in said inductance when the distance between said driving lines and said induced lines change as a result of a user'"'"'s touch; and

determining said at least one touch location in two dimensional space by processing said at least one change in said inductance.

25. The detecting method of claim 24, further comprising a step of providing at least one inductive circuit, wherein said inductive circuit comprises a controller, a plurality of driving conductor lines connecting said driving lines to said controller and a plurality of induced conductor lines connecting said induced lines to said controller.

26. The detecting method of claim 25, wherein said driving current is applied to said driving lines by said driving conductor lines in turn in the step of applying a driving current.

27. The detecting method of claim 26, wherein said induced layer comprises an induced substrate and said induced electrodes and said induced lines are placed on said induced substrate, and wherein said driving layer comprises a driving substrate and said driving electrodes and said driving lines are placed on said driving substrate.

28. The detecting method of claim 24, wherein said inductive touch sensor further comprises a plurality of first induced conductor lines and a plurality of second induced conductor lines connecting said induced layer to said controller.

29. The detecting method of claim 28, wherein determining said at least one touch location is based on both said first induced conductor lines and said second induced conductor lines.

30. The detecting method of claim 24, wherein an outer surface of said driving layer is depressed in the step of identifying at least one change in said inductance.

31. The detecting method of claim 24, wherein said change in said inductance is reflected in change in distance between said driving layer and said induced layer when one of said driving layer and said induced layer is depressed.

32. The detecting method of claim 24, wherein in the step of identifying at least one change in said inductance, one of said driving layer and said induced layer is depressed by a conductive object or an dielectric object.