Device and method for parallel-scanning differential touch detection

• US 8,564,557 B2
• Filed: 10/11/2010
• Issued: 10/22/2013
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu, Lee, Cheng-Han, Tang, Chi-Hao, Ho, Shun-Lung
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): ABDIN, SHAHEDA A
• Application Number:
  US12/901,896
• Publication Number:
  US 20110084923A1
• Time in Patent Office: 1,107 Days
• Field of Search: 345173-178, 341 33- 34, 178/18.01, 178/18.05, 178/18.06
• US Class Current: 345/173
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• 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 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A method for parallel-scanning differential touch detection is disclosed herein. The method includes generating a plurality of first outputs by a differential unit according to a plurality of first inputs provided by a plurality of sensors of a touch panel in each scan of total i scans, herein, the kth first output in the jth scan of the total i scans is the (i*(k−1)+j)th output in the continuous first outputs, i≧2, j≧1, k≧1, and i, j, k are natural numbers. Wherein, the differential unit has a plurality of subtractors and the inputs of the subtractors are connected in series. By doing so, the noises between a touch panel and a display can be eliminated.

Claims

1. A device for parallel-scanning (Horizontal scanning) differential touch detection, comprising:

a differential unit for generating a plurality of first outputs based on a plurality of first inputs in each scan of total i scans, wherein the kth first output in the jth scan of the total i scans is the (i*(k−

1)+j) th first output in a continuous plurality of first outputs, wherein

i≧

2, j≧

1, k≧

1

and i, j, k are natural numbers; and

a first selecting unit operatively coupled to a plurality of sensors of a touch panel for providing the first inputs, wherein each of the first inputs is operatively coupled to one of i continuous of the plurality of sensors in the total i scans;

wherein the differential unit includes a plurality of dual-differential subtractors, and the first inputs include plurality sets of three inputs, each of the dual-differential subtractors generating one of the first outputs based on one of the plurality sets of three inputs, wherein each of the dual-differential subtractors includes;

two first subtractors, inputs of which being connected in series; and

one second subtractor for receiving outputs of the two first subtractors and generating one of the first outputs.

2. The device of claim 1, further comprising:

an analog-to-digital converting (ADC) unit for simultaneously generating a plurality of digital values based on the first outputs, wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

3. The device of claim 1, further comprising:

at least one second selecting unit for providing a second input by operatively coupling to one of the first outputs in each scan; and

at least one ADC unit for generating a digital value of the second input,

wherein the at least one ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

4. The device of claim 1, wherein the differential unit includes a plurality of subtractors, and the first inputs include plurality pairs of inputs, each of the subtractors generating one of the first outputs based on one of the plurality pairs of inputs.

5. The device of claim 1, further comprising an amplifying unit including a plurality of amplifiers, each of the first inputs being coupled to the differential unit via one of the amplifiers.

6. A device for parallel-scanning differential touch detection, comprising:

a differential unit for generating a plurality of first outputs based on a plurality of first inputs provided by a plurality of sensors of a touch panel in each scan of total i scans, wherein the kth first output in the jth scan of the total i scans is the (i*(k−

1)+j)th first output in a continuous plurality of first outputs, wherein i≧

2, j≧

1, k≧

1

and i, j, k are natural numbers;

wherein the differential unit includes a plurality of dual-differential subtractors, and the first inputs include plurality sets of three inputs, each of the dual-differential subtractors generating one of the first outputs based on one of the plurality sets of three inputs, wherein each of the dual-differential subtractors includes;

a plurality of first subtractors, inputs of which being connected in series; and

a plurality of second subtractors for respectively receiving outputs of the first subtractors, inputs of the second subtractors being connected in series.

7. The device of claim 6, further comprising:

an analog-to-digital converting (ADC) unit for simultaneously generating a plurality of digital values based on the first outputs, wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

8. The device of claim 6, further comprising:

a selecting unit for providing a second input by operatively coupling to one of the first outputs in each scan; and

an ADC unit for generating a digital value of the second input,

wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

9. The device of claim 6, wherein the differential unit includes a plurality of subtractors, and the first inputs include plurality pairs of inputs, each of the subtractors generating one of the first outputs based on one of the plurality pairs of inputs, wherein inputs of the subtractors are connected in series.

10. The device of claim 6, further comprising an amplifying unit including a plurality of amplifiers, each of the first inputs being coupled to the differential unit via one of the amplifiers.

11. A device for differential touch detection, comprising:

a first selecting unit for simultaneously receiving signals of a plurality of adjacent first axial wires of a touch panel, and outputting the signals of these adjacent first axial wires according to a first selecting signal in a time-sharing manner S1 times, wherein the first selecting unit includes a plurality of outputs and each output outputs next of the signals of the adjacent first axial wires each time after the first time of output, wherein S1≧

2 and S1 is a natural number;

a first differential unit for receiving the signals of the adjacent first axial wires output from the first selecting unit, and subtracting two adjacent signals of the signals of the adjacent first axial wires from one another to obtain X results, wherein X≧

1 and X is a natural number; and

a detection controlling unit for receiving the X results and controlling the first selecting signal;

wherein the first differential unit includes a plurality of first dual-differential subtractors, wherein each of the first dual-differential subtractors includes;

two first subtractors, inputs of which being connected in series; and

one second subtractor for receiving outputs of the two first subtractors and generating one of the X results.

12. The device of claim 11, wherein the first selecting unit includes a plurality of electronically actuated switches with n₁-bit outputs in m₁ segments, wherein m₁≧

2, n₁≧

1, and m₁ and n₁ are natural numbers.

13. The device of claim 11, wherein the first selecting unit includes a plurality of data shifters with m₂ inputs and n₂ outputs, wherein m₂≧

2, n₂≧

1, and m₂ and n₂ are natural numbers.

14. The device of claim 11, wherein the first selecting unit includes a plurality of m₃-to-1 multiplexers, wherein m₃≧

2 and m₃ is a natural number.

15. The device of claim 11, wherein the first differential unit includes a plurality of first subtractors.

16. The device of claim 11, further comprising:

a second selecting unit for simultaneously receiving signals of a plurality of adjacent second axial wires of the touch panel, and outputting the signals of these adjacent second axial wires according to a second selecting signal in a time-sharing manner S₂ times, wherein the second selecting unit includes a plurality of outputs and each output outputs next of the signals of the adjacent second axial wires each time after the first time of output, wherein S₂≧

2 and S₂ is a natural number;

a second differential unit for receiving the signals of the adjacent second axial wires output from the second selecting unit, and subtracting two adjacent signals of the signals of the adjacent second axial wires from one another to obtain Y results, wherein Y≧

1 and Y is a natural number; and

the detection controlling unit for receiving the Y results and controlling the second selecting signal.

17. The device of claim 16, wherein the first selecting unit includes a plurality of electronically actuated switches with n₄-bit outputs in m₄ segments, wherein m₄≧

2, n₄≧

1, and m₄ and n₄ are natural numbers.

18. The device of claim 16, wherein the second selecting unit includes a plurality of data shifters with m₅ inputs and n₅ outputs, wherein m₅≧

2, n₅≧

1, and m₅ and n₅ are natural numbers.

19. The device of claim 16, wherein the second selecting unit includes a plurality of m₆-to-1 multiplexers, wherein m₆≧

2 and m₆ is a natural number.

20. The device of claim 16, wherein the second differential unit includes a plurality of third subtractors.

21. The device of claim 16, wherein the second differential unit includes a plurality of second dual-differential subtractors, wherein each of the second dual-differential subtractors includes:

two third subtractors, inputs of which being connected in series; and

one fourth subtractor for receiving outputs of the two third subtractors and generating one of the Y results.

22. A method for parallel-scanning differential touch detection, comprising:

providing a plurality of first inputs by operatively coupling a first selecting unit to a plurality of sensors of a touch panel, wherein each of the first inputs operatively coupling to i continuous of the plurality of sensors in total i scans; and

generating a plurality of first outputs based on the first inputs by a differential unit in each scan of the total i scans, wherein the kth first output in the jth scan of the total i scans is the (i*(k−

1)+j)th first output in a continuous plurality of first outputs, wherein

i≧

2, j≧

1, k≧

1

and i, j, k are natural numbers;

wherein the differential unit includes a plurality of dual-differential subtractors, and the first inputs include plurality sets of three inputs, each of the dual-differential subtractors generating one of the first outputs based on one of the plurality sets of three inputs, wherein each of the dual-differential subtractors includes;

two first subtractors, inputs of which being connected in series; and

one second subtractor for receiving outputs of the two first subtractors and generating one of the first outputs.

23. The method of claim 22, further comprising:

simultaneously generating a plurality of digital values by an analog-to-digital converting (ADC) unit based on the first outputs, wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

24. The method of claim 22, further comprising:

providing a second input by at least one second selecting unit operatively coupling to one of the first outputs in each scan; and

generating a digital value of the second input by at least one ADC unit,

wherein the at least one ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

25. The method of claim 22, wherein the differential unit includes a plurality of subtractors, and the first inputs include plurality pairs of inputs, each of the subtractors generating one of the first outputs based on one of the plurality pairs of inputs.

26. The method of claim 22, further comprising amplifying each of the first inputs before coupling it to the differential unit by an amplifying unit including a plurality of amplifiers.

27. A method for parallel-scanning differential touch detection, comprising:

generating a plurality of first outputs by a differential unit based on a plurality of first inputs provided by a plurality of sensors of a touch panel in each scan of total i scans, wherein the kth first output in the jth scan of the total i scans is the (i*(k−

1)+j)th first output in a continuous plurality of first outputs, wherein

i≧

2, j≧

1, k≧

1

and i, j, k are natural numbers;

wherein the differential unit includes a plurality of dual-differential subtractors, and the first inputs include plurality sets of three inputs, each of the dual-differential subtractors generating one of the first outputs based on one of the plurality sets of three inputs, wherein each of the dual-differential subtractors includes;

a plurality of first subtractors, inputs of which being connected in series; and

a plurality of second subtractors for respectively receiving outputs of the first subtractors, inputs of the second subtractors being connected in series.

28. The method of claim 27, further comprising:

simultaneously generating a plurality of digital values by an analog-to-digital converting (ADC) unit based on the first outputs, wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

29. The method of claim 27, further comprising:

providing a second input by a selecting unit operatively coupling to one of the first outputs in each scan; and

generating a digital value of the second input by an ADC unit,

wherein the ADC unit generates the digital values of the continuous plurality of first outputs in the total i scans.

30. The method of claim 27, wherein the differential unit includes a plurality of subtractors, and the first inputs include plurality pairs of inputs, each of the subtractors generating one of the first outputs based on one of the plurality pairs of inputs, wherein inputs of the subtractors are connected in series.

31. The method of claim 27, further comprising amplifying each of the first inputs before coupling it to the differential unit by an amplifying unit including a plurality of amplifiers.

32. A method for differential touch detection, comprising:

a first selecting unit simultaneously receiving signals of a plurality of adjacent first axial wires of a touch panel, and outputting the signals of these adjacent first axial wires according to a first selecting signal in a time-sharing manner S.sub.1 times, wherein the first selecting unit includes a plurality of outputs and each output outputs next of the signals of the adjacent first axial wires each time after the first time of output, wherein S1≧

2, and S1 is a natural number;

a first differential unit receiving the signals of the adjacent first axial wires output from the first selecting unit, and subtracting two adjacent signals of the signals of the adjacent first axial wires from one another to obtain X results, wherein X≧

1 and X is a natural number; and

a detection controlling unit receiving the X results and controlling the first selecting signal;

wherein the first differential unit includes a plurality of first dual-differential subtractors, wherein each of the first dual-differential subtractors includes;

two first subtractors, inputs of which being connected in series; and

one second subtractor for receiving outputs of the two first subtractors and generating one of the X results.

33. The method of claim 32, wherein the first selecting unit includes one of followings:

a plurality of electronically actuated switches with n₁-bit outputs in m₁ segments, a plurality of data shifters with m₂ inputs and n₂ outputs and a plurality of m₃-to-1 multiplexer, wherein m₁≧

2, n₁≧

1, m₂≧

2, n₂≧

1 and m₃≧

2, and m₁, n₁, m₂, n₂ and m₃ are natural numbers.

34. The method of claim 32, wherein the first differential unit includes a plurality of first subtractors.

35. The method of claim 32, further comprising:

a second selecting unit simultaneously receiving signals of a plurality of adjacent second axial wires of the touch panel, and outputting the signals of these adjacent second axial wires according to a second selecting signal in a time-sharing manner S₂ times, wherein the second selecting unit includes a plurality of outputs and each output outputs next of the signals of the adjacent second axial wires each time after the first time of output, wherein S₂≧

2 and S₂ is a natural number;

a second differential unit receiving the signals of the adjacent second axial wires output from the second selecting unit, and subtracting two adjacent signals of the signals of the adjacent second axial wires from one another to obtain Y results, wherein Y≧

1 and Y is a natural number; and

the detection controlling unit receiving the Y results and controlling the second selecting signal.

36. The method of claim 35, wherein the first selecting unit includes one of followings:

a plurality of electronically actuated switches with n₄-bit outputs in m₄ segments, a plurality of data shifters with m₅ inputs and n₅ outputs and a plurality of m₆-to-1 multiplexer, wherein m₄≧

2, n₄≧

1, m₅≧

2, n₅≅

1 and m₆≧

2, and m₄, n₄, m₅, n₅ and m₆ are natural numbers.

37. The method of claim 35, wherein the second differential unit includes a plurality of third subtractors.

38. The method of claim 35, wherein the second differential unit includes a plurality of second dual-differential subtractors, wherein each of the second dual-differential subtractors includes:

two third subtractors, inputs of which being connected in series; and

one fourth subtractor for receiving outputs of the two third subtractors and generating one of the Y results.