Hybrid capacitive baseline management

Patent metadata

Field	Value
Publication number	US-9507472-B2
Application number	US-201414327530-A
Country	US
Kind code	B2
Filing date	Jul 9, 2014
Priority date	Jul 10, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

In a method of managing baselines of a capacitive sensing input device, a transcapacitive baseline, a first absolute capacitive baseline, and a second absolute capacitive baseline are acquired with a plurality of sensor electrodes of the capacitive sensing input device. A transcapacitive image, a first absolute capacitive profile, and a second absolute capacitive profile are acquired with the plurality of sensor electrodes. The transcapacitive baseline, the first absolute capacitive baseline, and the second absolute capacitive baseline are managed based on a value of at least one of the first absolute capacitive profile and the second absolute capacitive profile.

First claim

What is claimed is:

1. A method of managing baselines of a capacitive sensing input device, said method comprising:
acquiring a transcapacitive baseline, a first absolute capacitive baseline, and a second absolute capacitive baseline with a plurality of sensor electrodes of the capacitive sensing input device;
acquiring a transcapacitive image with said plurality of sensor electrodes, a first absolute capacitive profile with a first subset of sensor electrodes of said plurality of sensor electrodes, and a second absolute capacitive profile with a second subset of sensor electrodes of said plurality of sensor electrodes, wherein sensor electrodes of said first subset are different from sensor electrodes of said second subset;
determining an absolute capacitive image as a function of said first absolute capacitive profile and said second absolute capacitive profile;
determining a hybrid capacitive image as a function of said absolute capacitive image and said transcapacitive image; and
managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a value of at least one of said first absolute capacitive profile and said second absolute capacitive profile.

2. The method as recited in claim 1 , further comprising:
managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a comparison of said transcapacitive image with at least one of said first absolute capacitive profile and said second absolute capacitive profile.

3. The method as recited in claim 2 , wherein said managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a comparison of said transcapacitive image with at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
updating said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on detection of an input object in one of said transcapacitive image but not in both of said first absolute capacitive profile and said second absolute capacitive profile.

4. The method as recited in claim 2 , wherein said managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a comparison of said transcapacitive image with at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
freezing said transcapacitive baseline, said absolute capacitive baseline, and said second absolute capacitive baseline.

5. The method as recited in claim 1 , wherein said managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a value of at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
updating said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline when said value based on negativity of the value.

6. The method as recited in claim 1 , wherein said managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a value of at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
performing slow relaxation on said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline.

7. The method as recited in claim 1 , wherein said managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a value of at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
performing fast relaxation on said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline.

8. The method as recited in claim 1 , wherein managing said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a value of at least one of said first absolute capacitive profile and said second absolute capacitive profile comprises:
acquiring a new transcapacitive baseline, a new absolute capacitive baseline, and a new second absolute capacitive baseline.

9. A processing system for a capacitive sensing input device, said processing system comprising:
a sensor module configured to acquire transcapacitive resulting signals by transmitting with a first one of a plurality of sensor electrodes and receiving with a second one of said plurality of sensor electrodes and acquire absolute capacitive resulting signals by modulating and receiving with a first subset of sensor electrodes of said plurality of sensor electrodes that include said first one of said plurality of sensor electrodes and modulating and receiving with a second subset of sensor electrodes of said plurality of sensor electrodes that include said second one of said plurality of sensor electrodes, wherein sensor electrodes of said first subset are different from sensor electrodes of said second subset;
a determination module configured to:
determine a transcapacitive image from said transcapacitive resulting signals; and
determine a first absolute capacitive profile and a second absolute capacitive profile from said absolute capacitive resulting signals;
determine an absolute capacitive image as a function of said first absolute capacitive profile and said second absolute capacitive profile;
determine a hybrid capacitive image as a function of said absolute capacitive image and said transcapacitive image; and
a baseline management module configured to utilize said transcapacitive image, said first absolute capacitive profile, and said second absolute capacitive profile to manage a transcapacitive baseline associated with said capacitive sensing input device, a first absolute capacitive baseline associated with said capacitive sensing input device, and a second absolute capacitive baseline associated with said capacitive sensing input device.

10. The processing system of claim 9 , wherein said baseline management module is further configured to:
manage said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on a comparison of said transcapacitive image with at least one of said first absolute capacitive profile and said second absolute capacitive profile.

11. The processing system of claim 10 , wherein said baseline management module is further configured to:
manage said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on detection of an input object in one of said transcapacitive image but not in both of said first absolute capacitive profile and said second absolute capacitive profile.

12. The processing system of claim 10 , wherein said management of said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline based on detection of an input object comprises:
applying a like management action to each of said transcapacitive baseline, said first absolute capacitive baseline, and said second absolute capacitive baseline, wherein said like management action is selected from the list of management actions consisting of fast relaxation, slow relaxation, freezing, and reacquisition.

13. The processing system of c

Assignees

• Synaptics Inc

Inventors

• Fotopoulos Nickolas
• Reynolds Joseph Kurth
• Vandermeijden Tom

Classifications

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F3/041662

  using alternate mutual and self-capacitive scanning · CPC title

• G06F3/0443 Primary

  using a single layer of sensing electrodes · CPC title