Noise-adapting touch sensing window
First Claim
1. A processing system for a display device having an integrated capacitive sensing device, the display device comprising a plurality of common electrodes configured for display updating and capacitive sensing, the processing system comprising:
- a driver module comprising driver circuitry configured for coupling to the plurality of common electrodes and configured to drive the plurality of common electrodes for display updating and capacitive sensing;
wherein the driver module is configured to drive the plurality of common electrodes for capacitive sensing during a first capacitive sensing period of a first display frame and a second capacitive sensing period, wherein the first capacitive sensing period comprises a first plurality of non-display update periods, wherein the driver module is further configured to operate the plurality of common electrodes for interference sensing;
a receiver module configured to receive first resulting signals during the first capacitive sensing period, second resulting signals during the second capacitive sensing period, and a third resulting signal when the plurality of common electrodes are operated for interference sensing; and
a determination module configured to acquire a first capacitive image based on the first resulting signals, a second capacitive image based on the second resulting signals, and an interference measurement based on the third resulting signals;
wherein the determination module is configured to determine positional information based on the first capacitive image responsive to the interference measurement being less than a threshold value; and
wherein the determination module is configured to determine positional information based on the second capacitive image responsive to the interference measurement exceeding the threshold value.
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Accused Products
Abstract
Embodiments of the invention generally provide an input device with display screens that periodically update (refresh) the screen by selectively driving electrodes corresponding to pixels in a display line, while also using the display screen as a touch area for capacitive sensing. To do this, the input device uses common electrodes for both updating the display and performing capacitive sensing, and interleaves periods of capacitive sensing between periods of updating the display lines (and pixels) based on a display frame. To avoid noise and mitigate interference during capacitive sensing, the input device may switch which windows of time in a display frame are used as capacitive sensing periods based on measurements of interference.
73 Citations
20 Claims
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1. A processing system for a display device having an integrated capacitive sensing device, the display device comprising a plurality of common electrodes configured for display updating and capacitive sensing, the processing system comprising:
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a driver module comprising driver circuitry configured for coupling to the plurality of common electrodes and configured to drive the plurality of common electrodes for display updating and capacitive sensing; wherein the driver module is configured to drive the plurality of common electrodes for capacitive sensing during a first capacitive sensing period of a first display frame and a second capacitive sensing period, wherein the first capacitive sensing period comprises a first plurality of non-display update periods, wherein the driver module is further configured to operate the plurality of common electrodes for interference sensing; a receiver module configured to receive first resulting signals during the first capacitive sensing period, second resulting signals during the second capacitive sensing period, and a third resulting signal when the plurality of common electrodes are operated for interference sensing; and a determination module configured to acquire a first capacitive image based on the first resulting signals, a second capacitive image based on the second resulting signals, and an interference measurement based on the third resulting signals; wherein the determination module is configured to determine positional information based on the first capacitive image responsive to the interference measurement being less than a threshold value; and wherein the determination module is configured to determine positional information based on the second capacitive image responsive to the interference measurement exceeding the threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for operating a display device having an integrated capacitive sensing device, the method comprising:
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driving a plurality of common electrodes for capacitive sensing during a first capacitive sensing period of a first display frame and a second capacitive sensing period, wherein the first capacitive sensing period comprises a first plurality of non-display update periods; operating the plurality of common electrodes for interference sensing; receiving, from a plurality of receiver electrodes, first resulting signals during the first capacitive sensing period, second resulting signals during the second capacitive sensing period, and a third resulting signal when the plurality of common electrodes are operated for interference sensing; determining a first capacitive image based on the first resulting signals, a second capacitive image based on the second resulting signals, and an interference measurement based on the third resulting signals; responsive to the interference measurement being less than a threshold value, determining positional information based on the first capacitive image; and responsive to the interference measurement exceeding the threshold value, determining positional information based on the second capacitive image. - View Dependent Claims (13, 14, 15, 16)
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17. A display device having an integrated capacitive sensing device, the display device comprising:
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a plurality of common electrodes configured to be driven for display updating a plurality of display lines of a display screen of the display device and performing capacitive sensing; a plurality of receiver electrodes; and a processor coupled to the plurality of common electrodes and to the plurality of receiver electrodes, wherein the processor is configured to; drive the plurality of common electrodes for capacitive sensing during a first capacitive sensing period of a first display frame and a second capacitive sensing period, wherein the first capacitive sensing period comprises a first plurality of non-display update periods; operate the plurality of common electrodes for interference sensing; receive first resulting signals on at least one of the plurality of receiver electrodes while driving during the first capacitive sensing period, second resulting signals during the second capacitive sensing period, and a third resulting signal when the plurality of common electrodes are operated for interference sensing; acquire a first capacitive image based on the first resulting signals, a second capacitive image based on the second resulting signals, and an interference measurement based on the third resulting signals; determine positional information based on the first capacitive image responsive to the interference measurement being less than a threshold value; and determine positional information based on the second capacitive image responsive to the interference measurement exceeding the threshold value. - View Dependent Claims (18, 19, 20)
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Specification