Position-filtering for land-lift events

• US 9,753,582 B2
• Filed: 06/30/2015
• Issued: 09/05/2017
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Manca, Gian Mario
• Primary Examiner(s): Patel, Sanjiv D
• Application Number:
  US14/788,460
• Publication Number:
  US 20170003819A1
• Time in Patent Office: 798 Days
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

A processing system for position-filtering includes a sensor module and a determination module. The sensor module includes sensor circuitry coupled to sensor electrodes, and is configured to transmit transmitter signals and receive resulting signals with at least a portion of the sensor electrodes. The determination module is configured to determine first positional information for an input object in a sensing region based on the resulting signals, the first positional information including a detected displacement of the input object from a preceding frame, and determine second positional information from the first positional information. The second positional information includes a revised displacement determined by applying a correction factor to the detected displacement, the correction factor being based on a number of frames of the input object being detected in the sensing region, a noise scale, and a finger scale. The determination module is further configured to report the second positional information.

Claims

1. A processing system for position-filtering, comprising:

sensor circuitry configured to be coupled to a plurality of sensor electrodes, the sensor circuitry configured to transmit transmitter signals and receive resulting signals with at least a portion of the plurality of sensor electrodes; and

determination circuitry configured to;

determine first positional information for an input object in a sensing region based on the resulting signals, the first positional information comprising a detected displacement of the input object from a preceding frame,

determine, using a piecewise function and based on a number of frames of the input object being present in the sensing region, a correction factor for the detected displacement, wherein the piecewise function comprises a first interval for displacement to a noise scale value, a second interval for displacement to a finger scale value, and a third interval for displacement starting after the finger scale value and ending at a threshold displacement value,

apply, the correction factor to the detected displacement to obtain a revised displacement, wherein the revised displacement is less than the detected displacement in the third interval,

determine second positional information comprising the revised displacement, and

report the second positional information.

2. The processing system of claim 1, wherein the correction factor resets after the input object leaves the sensing region.

3. The processing system of claim 1, wherein the correction factor decreases over the number of frames, and wherein the input object is continually detected as being present in the sensing region over the number of frames.

4. The processing system of claim 1, wherein the revised displacement is equal to the detected displacement when the detected displacement is greater than the threshold displacement value.

5. The processing system of claim 1, wherein determining using the piecewise function and based on the number of frames comprises:

determining, from a plurality of displacement reporting functions, a displacement reporting function according to the number of frames, wherein the piecewise function is the displacement reporting function.

6. The processing system of claim 5, wherein, when the detected displacement is less than the noise scale, the determining the displacement reporting function produces a same correction factor regardless of the number of frames.

7. The processing system of claim 5, wherein, when the detected displacement is less than the noise scale, the determining the displacement reporting function produces heterogeneous correction factors dependent on the number of frames.

8. The processing system of claim 5, wherein determining the displacement reporting function based on the number of frames comprises:

selecting an initial displacement reporting function as the determined displacement reporting function when the number of frames is less than a threshold number.

9. The processing system of claim 1, wherein the finger scale value compensates for displacement due to a compression of a finger.

10. A method for baseline management comprising:

determining first positional information for an input object in a sensing region based on resulting signals, the first positional information comprising a detected displacement of the input object from a preceding frame;

determining, using a piecewise function and based on a number of frames of the input object being present in the sensing region, a correction factor for the detected displacement, wherein the piecewise function comprises a first interval for displacement to a noise scale value, a second interval for displacement to a finger scale value, and a third interval for displacement starting after the finger scale value and ending at a threshold displacement value;

applying, the correction factor to the detected displacement to obtain a revised displacement, wherein the revised displacement is less than the detected displacement in the third interval;

determining second positional information comprising the revised displacement; and

reporting the second positional information.

11. The method of claim 10, wherein the correction factor resets after the input object leaves the sensing region.

12. The method of claim 10, wherein the correction factor decreases over the number of frames, and wherein the input object is continually detected as being present in the sensing region over the number of frames.

13. The method of claim 10, wherein the revised displacement is equal to the detected displacement when the detected displacement is greater than the threshold displacement value.

14. The method of claim 10, wherein determining using the piecewise function and based on the number of frames comprises:

determining, from a plurality of displacement reporting functions, a displacement reporting function according to the number of frames, wherein the piecewise function is the displacement reporting function.

15. The method of claim 14, wherein, when the detected displacement is less than the noise scale, the determining the displacement reporting function produces a same correction factor regardless of the number of frames.

16. The method of claim 14, wherein, when the detected displacement is less than the noise scale, the determining the displacement reporting function produces heterogeneous correction factors dependent on the number of frames.

17. The method of claim 14, wherein determining the displacement reporting function based on the number of frames comprises:

selecting an initial displacement reporting function as the determined displacement reporting function when the number of frames is less than a threshold number.

18. The method of claim 10, wherein the finger scale value compensates for displacement due to a compression of a finger.

19. An input device comprising:

a plurality of sensor electrodes configured to generate sensing signals; and

a processing circuitry connected to the plurality of sensor electrodes and configured to;

determine first positional information for an input object in a sensing region based on the sensing signals, the first positional information comprising a detected displacement of the input object from a preceding frame,

determine, using a piecewise function and based on a number of frames of the input object being present in the sensing region, a correction factor for the detected displacement, wherein the piecewise function comprises a first interval for displacement to a noise scale value, a second interval for displacement to a finger scale value, and a third interval for displacement starting after the finger scale value and ending at a threshold displacement value,

apply, the correction factor to the detected displacement to obtain a revised displacement, wherein the revised displacement is less than the detected displacement in the third interval,

determine second positional information comprising the revised displacement and

report the second positional information.

20. The input device of claim 19, wherein determining using the piecewise function and based on the number of frames comprises:

determining, from a plurality of displacement reporting, a displacement reporting function according to the number of frames, wherein the piecewise function is the displacement reporting function.