Touch detection for a digitizer

• US 8,228,311 B2
• Filed: 05/16/2008
• Issued: 07/24/2012
• Est. Priority Date: 02/10/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: N-Trig Ltd (Microsoft Corporation)
• Inventors: Perski, Haim, Morag, Meir
• Primary Examiner(s): Patel, Nitin
• Application Number:
  US12/153,343
• Publication Number:
  US 20080218494A1
• Time in Patent Office: 1,530 Days
• Field of Search: 345156-173, 178 1801- 1803
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/02 Input arrangements using manually operated switches, e.g. using keyboards or dials
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• 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
• CPC Class Codes: G06F 3/046 by electromagnetic means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A detector for detecting touches of at least one object on a transparent sensor located over a display screen, the detector comprising. a display screen; a patterned arrangement of conductors extending into said sensor situated over said display screen; and detection circuitry adapted to detect capacitive coupling of said at least one object with said at least one conductor.

Claims

1. A detector for providing position detection of a first kind of user interaction together with position detection of a second kind of user interaction, the detector comprising:

a sensor,

a patterned arrangement of sensing conductors extending within said sensor, and

detection circuitry associated with said arrangement for detecting signals at same sensing conductors arising from said position detection of a first kind of user interaction and signals arising from said position detection of a second kind of user interaction, therefrom to detect positions at said sensor.

2. The detector of claim 1, wherein said position detection of a first kind of user interaction comprises electromagnetic-based object detection of an object able to produce an electromagnetic signal.

3. The detector of claim 2, comprises an excitation circuitry for providing an oscillating excitation signal capable of exciting said object, and wherein said object comprises a resonance circuit, and wherein said excitation signal is adapted to excite said resonance circuit, and said detection circuitry is adapted for detecting signals from said object at, at least one of the sensing conductors.

4. The detector of claim 2, wherein said object is a stylus.

5. The detector of claim 1, wherein said detection circuitry is capable of detecting interactions of said first kind of user interaction and said interactions of said second kind of user interaction simultaneously.

6. The detector of claim 1, wherein said detection circuitry is capable of detecting interactions of said first kind of user interaction and said interactions of said second kind of user interaction independently.

7. The detector of claim 1, wherein said sensor is substantially transparent and suitable for mounting over a display screen.

8. The detector of claim 1, wherein said detection circuitry comprises a differential detector arrangement associated with said sensing conductors for detecting differences between output signals at said conductors.

9. The detector of claim 8, wherein said sensing conductors are connected pairwise to differential amplifiers each having a positive input and a negative input, and wherein a first sensing conductor of said pair is connected to said positive input and a second sensing conductor of said pair is connected to said negative input.

10. The detector of claim 1, wherein said detection circuitry is configured for sensing a signal at, at least one of the sensing conductors induced by a touch of a conductive object.

11. The detector of claim 10, wherein said detection circuitry is adapted to detect a signal at said at least one sensing conductor for interpretation as a number of touching objects.

12. The detector of claim 1, wherein said position detection of a first kind of user interaction comprises electromagnetic-based object detection of multiple objects, each of the objects able to produce an electromagnetic signal.

13. The detector of claim 1, wherein said sensor comprises a matrix of first sensing conductors aligned in a first direction and second sensing conductors aligned in an orthogonal direction and said matrix of sensing conductors arranged within at least one layer.

14. The detector of claim 1 wherein said position detection of a first kind comprises capacitive-based touch detection, wherein said touch is a touch by a body part.

15. A method for providing position detection of a first kind of user interaction together with position detection of a second kind of user interaction, the method comprising:

providing a sensor including a patterned arrangement of sensing conductors;

detecting signals arising from said position detection of said first kind of user interaction and said second kind of user interaction at same sensing conductors; and

detecting position of said first kind of user interaction and said second kind of user interaction from said signals.

16. The method of claim 15, wherein said position detection of a first kind of user interaction comprises electromagnetic-based object detection of an object able to produce an electromagnetic signal.

17. The method of claim 16, wherein said object is a stylus.

18. The method according to claim 16 comprising:

providing an excitation signal capable of exciting said object, and

detecting signals from said object at least one of the sensing conductors.

19. The method according to claim 18, wherein said object comprises a resonance circuit, and said excitation signal is adapted to excite said resonance circuit.

20. The method of claim 15, wherein said position detection of a first kind of user interaction comprises capacitive-based touch detection.

21. The method according to claim 20 comprising:

providing an oscillating electrical signal; and

detecting a capacitive influence on at least one sensing conductor when said oscillating electrical signal is applied.

22. The method according to claim 21 comprising interpreting a property of the signals detected at, at least one sensing conductor in terms of a number of touching conductive objects.

23. The method according to claim 21, wherein said oscillating electrical signal is provided to at least one sensing conductor, said oscillating electrical signal oscillates with respect to a reference voltage level, thereby to permit a capacitive current flow between a touching object and said at least one sensing conductor.

24. The method according to claim 21, wherein said oscillating electrical signal is provided to an external transmitter to energize a touching capacitive object.

25. The method of claim 15, wherein said position detection of a first kind of user interaction comprises electromagnetic detection of an object able to produce an electromagnetic field and said position detection of a second kind of user interaction comprises capacitive-based touch detection.

26. The method of claim 15, wherein the detecting signals arising from said position detection of said first kind of user interaction and said second kind of user interaction is performed simultaneously.

27. The method of claim 15 wherein the detecting signals arising from said position detection of said first kind of user interaction and said second kind of user interaction is performed independently.

28. The method according to claim 15, wherein said sensor comprises a matrix of first sensing conductors aligned in a first direction and second sensing conductors aligned in an orthogonal direction and where the matrix is arranged within at least one layer thereof.

29. The method according to claim 28, comprising:

providing an oscillating electrical signal to at least one sensing conductor in said first direction; and

detecting a resulting signal at least one sensing conductor in said orthogonal direction, wherein said resulting signal is caused by a touch of an object.