Correcting touch interference for active pen
A method of capacitive sensing includes obtaining a capacitive touch profile from multiple receiver electrodes disposed in a sensing region of an input device and obtaining an active pen profile, different from the capacitive touch profile, from the multiple receiver electrodes. The method also includes adjusting, using the capacitive touch profile, the active pen profile to obtain a corrected active pen profile and determining a position of an active pen in the sensing region, using the corrected active pen profile.
1 . A method, comprising:
obtaining, by an input device, a first capacitive touch profile via a first plurality of electrodes disposed in a sensing region of the input device, wherein the first capacitive touch profile corresponds to a first axis of the sensing region;
obtaining, by the input device, a second capacitive touch profile via a second plurality of electrodes disposed in the sensing region of the input device, wherein the second capacitive touch profile corresponds to a second axis of the sensing region;
obtaining, by the input device, an active pen profile;
obtaining, by the input device, a corrected active pen profile by adjusting the active pen profile using the second capacitive touch profile, wherein the second capacitive touch profile includes touch information corresponding to a palm or finger disposed in the sensing region of the input device; and
determining, by the input device, a position of an active pen in the sensing region using the corrected active pen profile.
2 . The method according to claim 1 , further comprising:
selecting, by the input device, the second capacitive touch profile for use in adjusting the active pen profile.
3 . The method according to claim 2 , further comprising:
determining, by the input device, that each capacitive measurement in the first capacitive touch profile affected by an input object is also affected by the active pen;
wherein selecting the second capacitive touch profile for use in adjusting the active pen profile is based on the determination that each capacitive measurement in the first capacitive touch profile affected by the input object is also affected by the active pen.
4 . The method according to claim 2 , further comprising:
determining, by the input device, that at least one capacitive measurement corresponding to a location of an input object in the second capacitive touch profile is not affected by the active pen.
5 . The method according to claim 1 , wherein the active pen profile corresponds to the first axis of the sensing region.
6 . The method according to claim 5 , wherein adjusting the active pen profile corresponding to the first axis using the second capacitive touch profile corresponding to the second axis includes application of a scaling ratio to a second tuning value corresponding to the second axis to obtain a first tuning value corresponding to the first axis.
7 . The method according to claim 1 , wherein adjusting the active pen profile using the second capacitive touch profile takes into account both the active pen profile and the second capacitive touch profile along with a gain.
8 . The method according to claim 7 , wherein the gain is applied to the second capacitive touch profile.
9 . The method according to claim 1 , wherein obtaining the active pen profile comprises receiving pen signal emissions of the active pen via the first plurality of electrodes or the second plurality of electrodes.
10 . The method according to claim 9 , wherein a pen body of the active pen emits an inverted pen signal; and
wherein adjusting the active pen profile using the second capacitive touch profile corrects for touch interference associated with the inverted pen signal.
11 . An input device, comprising:
a plurality of electrodes disposed in a sensing region of the input device, wherein the plurality of electrodes includes a first plurality of electrodes and a second plurality of electrodes; and
a processing system configured to:
obtain a first capacitive touch profile via the first plurality of electrodes, wherein the first capacitive touch profile corresponds to a first axis of the sensing region;
obtain a second capacitive touch profile via the second plurality of electrodes, wherein the second capacitive touch profile corresponds to a second axis of the sensing region, wherein the second capacitive touch profile includes touch information corresponding to a palm or finger disposed in the sensing region of the input device;
obtain an active pen profile;
obtain a corrected active pen profile by adjusting the active pen profile using the second capacitive touch profile; and
determine a position of an active pen in the sensing region using the corrected active pen profile.
12 . The input device according to claim 11 , wherein the processing system is further configured to select the second capacitive touch profile for use in adjusting the active pen profile.
13 . The input device according to claim 12 , wherein the processing system is further configured to determine that each capacitive measurement in the first capacitive touch profile affected by an input object is also affected by the active pen; and
wherein selecting the second capacitive touch profile for use in adjusting the active pen profile is based on the determination that each capacitive measurement in the first capacitive touch profile affected by the input object is also affected by the active pen.
14 . The input device according to claim 12 , wherein the processing system is further configured to determine that at least one capacitive measurement corresponding to a location of an input object in the second capacitive touch profile is not affected by the active pen.
15 . The input device according to claim 11 , wherein the active pen profile corresponds to the first axis of the sensing region.
16 . The input device according to claim 15 , wherein adjusting the active pen profile corresponding to the first axis using the second capacitive touch profile corresponding to the second axis includes application of a scaling ratio to a second tuning value corresponding to the second axis to obtain a first tuning value corresponding to the first axis.
17 . The input device according to claim 11 , wherein adjusting the active pen profile using the second capacitive touch profile takes into account both the active pen profile and the second capacitive touch profile along with a gain.
18 . The input device according to claim 17 , wherein the gain is applied to the second capacitive touch profile.
19 . The input device according to claim 11 , wherein obtaining the active pen profile comprises receiving pen signal emissions of the active pen via the first plurality of electrodes or the second plurality of electrodes; and
wherein adjusting the active pen profile using the second capacitive touch profile corrects for touch interference associated with an inverted pen signal emitted by a pen body of the active pen.
20 . A non-transitory computer-readable medium having processor-executable instructions stored thereon, wherein the processor-executable instructions, when executed, facilitate performance of the following:
obtaining, by an input device, a first capacitive touch profile via a first plurality of electrodes disposed in a sensing region of the input device, wherein the first capacitive touch profile corresponds to a first axis of the sensing region;
obtaining, by the input device, a second capacitive touch profile via a second plurality of electrodes disposed in the sensing region of the input device, wherein the second capacitive touch profile corresponds to a second axis of the sensing region;
obtaining, by the input device, an active pen profile;
obtaining, by the input device, a corrected active pen profile by adjusting the active pen profile using the second capacitive touch profile, wherein the second capacitive touch profile includes touch information corresponding to a palm or finger disposed in the sensing region of the input device; and
determining, by the input device, a position of an active pen in the sensing region using the corrected active pen profile.