Optimizing pixel settling in an integrated display and capacitive sensing device

Patent metadata

Field	Value
Publication number	US-2017192581-A1
Application number	US-201514986079-A
Country	US
Kind code	A1
Filing date	Dec 31, 2015
Priority date	Dec 31, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

An example method of performing capacitive sensing and display updating in an integrated capacitive sensing device and display device includes driving a plurality of display electrodes with one or more display voltages from one or more supplies during a first time period, the one or more voltages configured to drive the display pixels. The method further includes initiating a long horizontal blanking interval during a second time period. The method further includes driving a plurality of sensor electrodes with one or more sensing voltages from the one or more supplies during the second time period to perform capacitive sensing. The method further includes activating first circuitry during one of the first time period or the second time period to draw current to equalize power drawn from the one or more supplies during the first and second time periods within a threshold.

First claim

We claim:

1 . A method of performing capacitive sensing and display updating in an integrated capacitive sensing device and display device, the method comprising:
driving a plurality of display electrodes with one or more display voltages from one or more supplies during a first time period, the one or more voltages configured to drive the display pixels; initiating a long horizontal blanking interval during a second time period; driving a plurality of sensor electrodes with one or more sensing voltages from the one or more supplies during the second time period to perform capacitive sensing; and activating first circuitry during one of the first time period or the second time period to draw current to equalize power drawn from the one or more supplies during the first and second time periods within a threshold.

2 . The method of claim 1 , wherein the power drawn from the one or more supplies is higher during the first time period than during the second time period, and wherein the first circuitry is activated during the second time period.

3 . The method of claim 1 , wherein the power drawn from the one or more supplies is higher during the second time period than during the first time period, and wherein the first circuitry is activated during the first time period.

4 . The method of claim 1 , wherein activating the first circuitry comprises driving one or more source drivers during the second time period while the one or more source drivers are disconnected from the display device.

5 . The method of claim 1 , wherein activating the first circuitry comprises driving one or more current consumption circuits during either the first time period or the second time period.

6 . The method of claim 1 , further comprising:
controlling second circuitry during the other of the first time period or the second time period to further equalize power drawn from the one or more supplies during the first and second time periods within the threshold.

7 . The method of claim 6 , wherein controlling the second circuitry comprises reducing current consumed by one or more source drivers during the first time period while the one or more source drivers are coupled to the display device.

8 . A processing system for a capacitive sensing device and a display device, comprising:
source drivers configured to drive a plurality of display electrodes with one or more display voltages from one or more supplies to drive display pixels of the display device during a first time period; sensing circuitry configured to drive a plurality of sensor electrodes with one or more sensing voltages from the one or more supplies during a second time period to perform capacitive sensing; a controller configured to initiate a long horizontal blanking interval during the second time period; and an equalizer configured to activate first circuitry during one of the first time period or the second time period to draw current to equalize power drawn from the one or more supplies during the first and second time periods within a threshold.

9 . The processing system of claim 8 , wherein the power drawn from the one or more supplies is higher during the first time period than during the second time period, and wherein the equalizer is configured to activate the first circuitry during the second time period.

10 . The processing system of claim 8 , wherein the power drawn from the one or more supplies is higher during the second time period than during the first time period, and wherein the equalizer is configured to activate the first circuitry during the first time period.

11 . The processing system of claim 8 , wherein the equalizer is configured to activate the first circuitry by driving one or more source drivers during the second time period while the one or more source drivers are disconnected from the display device.

12 . The processing system of claim 8 , wherein the equalizer is configured to activate the first circuitry by driving one or more current consumption circuits during either the first time period or the second time period.

13 . The processing system of claim 8 , wherein the equalizer is further configured to:
control second circuitry during the other of the first time period or the second time period to further equalize power drawn from the one or more supplies during the first and second time periods within the threshold.

14 . The processing system of claim 13 , wherein the equalizer is configured to control the second circuitry by reducing current consumed by one or more source drivers during the first time period while the one or more source drivers are coupled to the display device.

15 . The processing system of claim 8 , wherein the equalizer comprises an equalizer circuit coupled to the first circuitry.

16 . An input device comprising a capacitive sensing device and a display device, the input device comprising:
a plurality of sensor electrodes; a plurality of display electrodes; and a processing system, coupled to the plurality of sensor electrodes and the plurality of display electrodes, the processing system including:
source drivers configured to drive the plurality of display electrodes with one or more voltages from one or more supplies to drive display pixels of the display device during a first time period;
sensing circuitry configured to drive the plurality of sensor electrodes with one or more sensing voltages from the one or more supplies during a second time period to perform capacitive sensing;
a controller configured to initiate a long horizontal blanking interval during the second time period; and
an equalizer configured to activate first circuitry during one of the first time period or the second time period to draw current to equalize power drawn from the one or more supplies during the first and second time periods within a threshold.

17 . The input device of claim 16 , wherein the power drawn from the one or more supplies is higher during the first time period than during the second time period, and wherein the equalizer is configured to activate the first circuitry during the second time period.

18 . The input device of claim 16 , wherein the power drawn from the one or more supplies is higher during the second time period than during the first time period, and wherein the equalizer is configured to activate the first circuitry during the first time period.

19 . The input device of claim 16 , wherein the equalizer is configured to activate the first circuitry by driving one or more source drivers during the second time period while the one or more source drivers are disconnected from the display device.

20 . The input device of claim 16 , wherein the equalizer is configured to activate the first circuitry by driving one or more current consumption circuits during either the first time period or the second time period.

Assignees

• Synaptics Inc

Inventors

• Shamarao Prashant
• Reynolds Joseph Kurth
• Morein Stephen L

Classifications

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• G02F1/13338

  Input devices, e.g. touch panels · CPC title

• G06F2203/04106

  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 title

• G06F3/0416 Primary

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044

  by capacitive means · CPC title