Method and device for signal detection

• US 8,816,987 B2
• Filed: 10/11/2010
• Issued: 08/26/2014
• 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): ABDIN, SHAHEDA A
• Application Number:
  US12/901,905
• Publication Number:
  US 20110084924A1
• Time in Patent Office: 1,415 Days
• Field of Search: 345173-174, 345/50, 345/83, 345/520, 345/521, 178/18.01, 178/18.06, 327/52, 327/53, 327/96
• US Class Current: 345/174
• 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 and device for signal detection is disclosed. At least one detection period is predefined for detecting a signal of a signal source, a differential signal of a pair of signal sources, or a dual-differential signal of three signal sources during at least one clock cycle.

Claims

1. A method for signal detection, comprising:

defining at least one detection period in a clock cycle with an enable signal;

defining a prior half cycle and a latter half cycle of the clock cycle with a synchronizing signal, wherein time duration of the at least one detection period is less than the time duration of the prior half cycle and less than the time duration of the latter half cycle;

performing an integration detection on a signal difference of a pair of inputs in the at least one detection period according to the enable signal; and

switching signal sources of the pair of inputs according to the synchronizing signal.

2. The method of claim 1, wherein signals of the pair of inputs are alternating signals.

3. The method of claim 1, wherein the prior half cycle and the latter half cycle each has at least one detection period.

4. The method of claim 1, wherein the integration detection includes detecting the signal differences of a pair of signal sources in the at least one detection period in at least one clock cycle.

5. The method of claim 1, wherein a first signal source and a second signal source of the pair of signal sources are coupled to a first input and a second input of the pair of inputs in the prior half cycle, respectively, and coupled to the second input and the first input of the pair of inputs in the latter half cycle, respectively.

6. The method of claim 1, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal differences in the at least one detection period is greater than an accumulation of the signal differences in the same number of other time slots.

7. The method of claim 1, wherein the signal sources of the pair of inputs are a pair of sensors in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information.

8. A device for signal detection, comprising:

a device for providing an enable signal which defines at least one detection period in a clock cycle;

a device for providing a synchronizing signal which defines a prior half cycle and a latter half cycle of the clock cycle, wherein time duration of the at least one detection period is less than the time duration of the prior half cycle and less than the time duration of the latter half cycle;

a device for performing an integration detection on a signal difference of a pair of inputs in the at least one detection period according to the enable signal; and

a device for switching signal sources of the pair of inputs according to the synchronizing signal.

9. The device of claim 8, wherein signals of the pair of inputs are alternating signals.

10. The device of claim 8, wherein the prior half cycle and the latter half cycle each has at least one detection period.

11. The device of claim 8, wherein the integration detection includes detecting the signal differences of a pair of signal sources in the at least one detection period in at least one clock cycle.

12. The device of claim 8, wherein a first signal source and a second signal source of the pair of signal sources are coupled to a first input and a second input of the pair of inputs in the prior half cycle, respectively, and coupled to the second input and the first input of the pair of inputs in the latter half cycle, respectively.

13. The device of claim 8, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal differences in the at least one detection period is greater than an accumulation of the signal differences in the same number of other time slots.

14. The device of claim 8, wherein the signal sources of the pair of inputs are a pair of sensors in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information.

15. A method for signal detection, comprising:

defining at least one detection period in a clock cycle with an enable signal;

defining a prior half cycle and a latter half cycle of the clock cycle with a synchronizing signal;

switching signal sources of a first pair of inputs of a first subtractor according to the synchronizing signal, a first output of the first subtractor providing a signal difference of the first pair of inputs;

switching signal sources of a second pair of inputs of a second subtractor according to the synchronizing signal, a second output of the second subtractor providing a signal difference of the second pair of inputs; and

performing an integration detection on a signal difference of the first output and the second output in the at least one detection period according to the enable signal.

16. The method of claim 15, wherein signals of the first pair of inputs and the second pair of inputs are alternating signals.

17. The method of claim 15, wherein the prior half cycle and the latter half cycle each has at least one detection period.

18. The method of claim 15, wherein the integration detection includes detecting the signal differences of the first output and the second output in the at least one detection period in at least one clock cycle.

19. The method of claim 15, wherein a first signal source and a second signal source of the signal sources of the first pair of inputs are coupled to a first input and a second input of the first pair of inputs in the prior half cycle, respectively, and coupled to the second input and the first input in the latter half cycle, respectively.

20. The method of claim 19, wherein the second signal source and a third signal source of the signal sources of the second pair of inputs are coupled to a third input and a fourth input of the second pair of inputs in the prior half cycle, respectively, and coupled to the fourth input and the third input in the latter half cycle, respectively.

21. The method of claim 15, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal differences of the first output and the second output in the at least one detection period is greater than an accumulation of the signal differences of the first output and the second output in the same number of other time slots.

22. The method of claim 15, wherein the signal sources of the first pair of inputs and the signal sources of the second pair of inputs are three sensors in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information, wherein the three sensors are adjacent or non-adjacent.

23. The method of claim 15, wherein time duration of the at least one detection period is less than time duration of the prior half cycle and the latter half cycle.

24. A device for signal detection, comprising:

a device for providing an enable signal which defines at least one detection period in a clock cycle;

a device for providing a synchronizing signal which defines a prior half cycle and a latter half cycle of the clock cycle;

a device for switching signal sources of a first pair of inputs of a first subtractor according to the synchronizing signal, a first output of the first subtractor providing a signal difference of the first pair of inputs;

a device for switching signal sources of a second pair of inputs of a second subtractor according to the synchronizing signal, a second output of the second subtractor providing a signal difference of the second pair of inputs; and

a device for performing an integration detection on a signal difference of the first output and the second output in the at least one detection period according to the enable signal.

25. The device of claim 24, wherein signals of the first pair of inputs and the second pair of inputs are alternating signals.

26. The device of claim 24, wherein the prior half cycle and the latter half cycle each has at least one detection period.

27. The method of claim 24, wherein the integration detection includes detecting the signal differences of the first output and the second output in the at least one detection period in at least one clock cycle.

28. The device of claim 24, wherein a first signal source and a second signal source of the signal sources of the first pair of inputs are coupled to a first input and a second input of the first pair of inputs in the prior half cycle, respectively, and coupled to the second input and the first input in the latter half cycle, respectively.

29. The device of claim 28, wherein the second signal source and a third signal source of the signal sources of the second pair of inputs are coupled to a third input and a fourth input of the second pair of inputs in the prior half cycle, respectively, and coupled to the fourth input and the third input in the latter half cycle, respectively.

30. The device of claim 24, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal differences of the first output and the second output in the at least one detection period is greater than an accumulation of the signal differences of the first output and the second output in the same number of other time slots.

31. The device of claim 24, wherein the signal sources of the first pair of inputs and the signal sources of the second pair of inputs are three sensors in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information, wherein the three sensors are adjacent or non-adjacent.

32. The device of claim 24, wherein time duration of the at least one detection period is less than time duration of the prior half cycle and the latter half cycle.

33. A method for signal detection, comprising:

defining at least one detection period in a clock cycle with an enable signal;

defining a prior half cycle and a latter half cycle of the clock cycle with a synchronizing signal, wherein time duration of the at least one detection period is less than the time duration of the prior half cycle and less than the time duration of the latter half cycle;

providing one of a signal of a signal source and an inverse of the signal according to the synchronizing signal; and

performing an integration detection on the signal or the inverse of the signal in the at least one detection period according to the enable signal.

34. The method of claim 33, wherein the signal of the signal source is an alternating signal.

35. The method of claim 33, wherein the prior half cycle and the latter half cycle each has at least one detection period.

36. The method of claim 33, wherein the integration detection includes detecting the signal or the inverse of the signal in the at least one detection period in at least one clock cycle.

37. The method of claim 33, wherein the integration detection is performed on one of the signal and the inverse of the signal in the at least one detection period in the prior half cycle, and performed on the other one of the signal and the inverse of the signal in the at least one detection period in the latter half cycle.

38. The method of claim 33, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal or the inverse of the signal in the at least one detection period is greater than an accumulation of the signal or the inverse of the signal in the same number of other time slots.

39. The method of claim 33, wherein the signal source is a sensor in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information.

40. The method of claim 33, wherein there are a plurality of detection periods within the prior half cycle or the latter half cycle.

41. A device for signal detection, comprising:

a device for providing an enable signal which defines at least one detection period in a clock cycle;

a device for providing a synchronizing signal which defines a prior half cycle and a latter half cycle of the clock cycle, wherein time duration of the at least one detection period is less than the time duration of the prior half cycle and less than the time duration of the latter half cycle;

a device for providing one of a signal of a signal source and an inverse of the signal according to the synchronizing signal; and

a device for performing an integration detection on the signal or the inverse of the signal in the at least one detection period according to the enable signal.

42. The device of claim 41, wherein the signal of the signal source is an alternating signal.

43. The device of claim 41, wherein the prior half cycle and the latter half cycle each has at least one detection period.

44. The device of claim 41, wherein the integration detection includes detecting the signal or the inverse of the signal in the at least one detection period in at least one clock cycle.

45. The device of claim 41, wherein the integration detection is performed on one of the signal and the inverse of the signal in the at least one detection period in the prior half cycle, and performed on the other one of the signal and the inverse of the signal in the at least one detection period in the latter half cycle.

46. The device of claim 41, wherein the clock cycle includes a plurality of time slots, and the at least one detection period includes a number of time slots, wherein an accumulation of the signal or the inverse of the signal in the at least one detection period is greater than an accumulation of the signal or the inverse of the signal in the same number of other time slots.

47. The device of claim 41, wherein the signal source is a sensor in a sensing device having a plurality of sensors, wherein these sensors provide a touch-related sensing information.