Transcapacitive input object sensing

• US 9,274,659 B2
• Filed: 09/27/2013
• Issued: 03/01/2016
• Est. Priority Date: 09/27/2013
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Tanemura, Tetsuo, Shimura, Hiroshi, Chen, Wenchang
• Primary Examiner(s): Okebato, Sahlu
• Application Number:
  US14/039,281
• Publication Number:
  US 20150091838A1
• Time in Patent Office: 886 Days
• Field of Search: 345/173
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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

Abstract

In a method of input object sensing, a plurality of transmitter electrodes are driven in a first way to acquire a first sub-frame image with the plurality of transmitter electrodes and a plurality of receiver electrodes of a sensor electrode pattern during a first sub-frame of a transcapacitive sensing frame. The plurality of transmitter electrodes is also driven in a second way to acquire a second sub-frame image with the plurality of transmitter electrodes and the plurality of receiver electrodes during a second sub-frame of the transcapacitive sensing frame, wherein the first way and the second way differ. A capacitive image is determined by combining the first sub-frame image with the second sub-frame image such that a motion artifact associated with an input object and present in at least one of the sub-frame images is suppressed by the combining.

Claims

1. A method of input object sensing, said method comprising:

driving a plurality of transmitter electrodes in a first way to acquire a first sub-frame image with said plurality of transmitter electrodes and a plurality of receiver electrodes of a sensor electrode pattern during a first sub-frame of a transcapacitive sensing frame;

driving said plurality of transmitter electrodes in a second way to acquire a second sub-frame image with said plurality of transmitter electrodes and said plurality of receiver electrodes during a second sub-frame of said transcapacitive sensing frame, wherein said first way and said second way differ; and

determining a capacitive image by combining said first sub-frame image with said second sub-frame image such that a motion artifact associated with an input object and present in at least one of said acquired sub-frame images is suppressed by said combining.

2. The method as recited in claim 1, wherein said driving a plurality of transmitter electrodes in a first way to acquire a first sub-frame image comprises:

driving said plurality of transmitter electrodes based on a coding technique to acquire said first sub-frame image, wherein at least two of said plurality of transmitter electrodes are driven simultaneously using said coding technique; and

wherein said driving said plurality of transmitter electrodes in a second way to acquire a second sub-frame image comprises;

driving said plurality of transmitter electrodes based on a progressive scanning scheme to acquire said second sub-frame image, wherein only one transmitter electrode of said transmitter electrodes is driven at a time using said progressive scanning scheme.

3. The method as recited in claim 1, wherein said driving a plurality of transmitter electrodes in a first way to acquire a first sub-frame image comprises:

driving said plurality of transmitter electrodes based on a coding technique to acquire said first sub-frame image, beginning said coding technique at a first transmitter electrode of said plurality of transmitter electrodes; and

wherein said driving said plurality of transmitter electrodes in a second way to acquire a second sub-frame image comprises;

driving said plurality of transmitter electrodes based on said coding technique to acquire said second sub-frame image, beginning said coding technique at a second transmitter electrode of said plurality of transmitter electrodes, wherein said first and second transmitter electrodes are different from one another and located at different locations within said sensor electrode pattern.

4. The method as recited in claim 1, wherein said driving a plurality of transmitter electrodes in a first way to acquire a first sub-frame image comprises:

driving said plurality of transmitter electrodes based on a coding technique to acquire said first sub-frame image; and

wherein said driving said plurality of transmitter electrodes in a second way to acquire a second sub-frame image comprises;

driving said plurality of transmitter electrodes based a second coding technique to acquire said second sub-frame image, wherein codes of said first coding technique and said second coding techniques are different.

5. The method as recited in claim 4, wherein said driving said plurality of transmitter electrodes based a second coding technique to acquire said second sub-frame image, comprises:

driving said plurality of transmitter electrodes based on said second coding technique to acquire said second sub-frame image, wherein said second coding technique is the complementary pair of said first coding technique.

6. The method as recited in claim 1, wherein said driving a plurality of transmitter electrodes in a first way to acquire a first sub-frame image with said plurality of transmitter electrodes and a plurality of receiver electrodes of a sensor electrode pattern during a first sub-frame of a transcapacitive sensing frame comprises:

driving all of said plurality of transmitter electrodes simultaneously in said first way.

7. The method as recited in claim 1, wherein said determining a capacitive image by combining said first sub-frame image with said second sub-frame image such that a motion artifact associated with an input object and present in at least one of said acquired sub-frame images is suppressed by said combining comprises:

determining said capacitive image by combining said first sub-frame image with said second sub-frame image through one of addition, subtraction, multiplication, masking, averaging, Boolean operation, and spatial filtering.

8. A processing system comprising:

a sensor module configured to;

drive a plurality of transmitter electrodes in a first way to acquire a first sub-frame image with said plurality of transmitter electrodes and a plurality of receiver electrodes of a sensor electrode pattern during a first sub-frame of a transcapacitive sensing frame;

drive said plurality of transmitter electrodes in a second way to acquire a second sub-frame image with said plurality of transmitter electrodes and said plurality of receiver electrodes during a second sub-frame of said transcapacitive sensing frame, wherein said first way and said second way differ; and

a determination module configured to;

determine a capacitive image from said acquired sub-frame images of said transcapacitive sensing frame such that a motion artifact associated with an input object and present in at least one of said acquired sub-frame images is suppressed; and

determine a position of said input object within said capacitive image.

9. The processing system of claim 8, wherein said first way comprises a coding technique to drive a code on said plurality of transmitter electrodes to acquire said first sub-frame image, wherein at least two of said plurality of transmitter electrodes are driven simultaneously using said coding technique;

and

wherein said second way comprises a progressive scanning scheme to acquire said second sub-frame image, wherein only one transmitter electrode of said transmitter electrodes is driven at a time using said progressive scanning scheme.

10. The processing system of claim 8, wherein said first way comprises a coding technique to drive a code on said plurality of transmitter electrodes to acquire said first sub-frame image, said code beginning at a first transmitter electrode of said plurality of transmitter electrodes;

and

wherein said second way comprises beginning said code at a second transmitter electrode of said plurality of transmitter electrodes, wherein said first and second transmitter electrodes are different from one another and located at different locations within said sensor electrode pattern.

11. The processing system of claim 8, wherein said first way comprises a coding technique to drive a first code on said plurality of transmitter electrodes to acquire said first sub-frame image;

and

wherein said second way comprises a second coding technique to drive a second code on said plurality of transmitter electrodes to acquire said second sub-frame image, wherein said first coding technique and said second coding technique are different and said first code and said second code are different.

12. The processing system of claim 11, wherein said second coding technique has low auto-correlation with said first coding technique.

13. The processing system of claim 8, wherein said first way comprises:

all of said plurality of transmitter electrodes being driven simultaneously.

14. A capacitive sensing input device, said capacitive sensing input device comprising:

a plurality of sensor electrodes disposed in a sensor electrode pattern; and

a processing system coupled with said plurality of sensor electrodes, said processing system configured to;

drive a plurality of transmitter electrodes of said sensor electrode pattern in a first way to acquire a first sub-frame image with said plurality of transmitter electrodes and a plurality of receiver electrodes of said sensor electrode pattern during a first sub-frame of a transcapacitive sensing frame;

drive said plurality of transmitter electrodes in a second way to acquire a second sub-frame image with said plurality of transmitter electrodes and said plurality of receiver electrodes during a second sub-frame of said transcapacitive sensing frame, wherein said first way and said second way differ; and

determine a capacitive image through combination of said acquired sub-frame images of said transcapacitive sensing frame such that a motion artifact associated with an input object and present in at least one of said acquired sub-frame images is suppressed by said combining; and

determine a position of said input object within said capacitive image.

15. The capacitive sensing input device of claim 14, wherein said first way comprises a coding technique to drive a code on said plurality of transmitter electrodes to acquire said first sub-frame image, wherein at least two of said plurality of transmitter electrodes are driven simultaneously using said coding technique;

and

wherein said second way comprises a progressive scanning scheme to acquire said second sub-frame image, wherein only one transmitter electrode of said transmitter electrodes is driven at a time using said progressive scanning scheme.

16. The capacitive sensing input device of claim 14, wherein said first way comprises a coding technique to drive a code on said plurality of transmitter electrodes to acquire said first sub-frame image, said code beginning at a first transmitter electrode of said plurality of transmitter electrodes;

and

wherein said second way comprises beginning said code at a second transmitter electrode of said plurality of transmitter electrodes, wherein said first and second transmitter electrodes are different from one another and located at different locations within said sensor electrode pattern.

17. The capacitive sensing input device of claim 14, wherein said first way comprises a coding technique to drive a first code on said plurality of transmitter electrodes to acquire said first sub-frame image;

and

wherein said second way comprises a second coding technique to drive a second code on said plurality of transmitter electrodes to acquire said second sub-frame image, wherein said first coding technique and said second coding technique are different and said first code and said second code are different.

18. The processing system of claim 17, wherein said second coding technique is the complementary pair of said first coding technique.

19. The capacitive sensing input device of claim 14, wherein said first way comprises:

all of said plurality of transmitter electrodes being driven simultaneously.

20. The capacitive sensing input device of claim 14, wherein said combining said first sub-frame image with said second sub-frame image consists of combining portions of said first and second sub-frames through at least one of addition, subtraction, multiplication, masking, averaging, Boolean operation, and spatial filtering.