Selective Scanning for Touch-Sensitive Display Devices

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Solution Overview

Problem

Touch-sensitive display devices face high resource consumption when detecting inputs, especially with active styluses, due to the need to scan and track multiple electrodes simultaneously, leading to inefficiencies in power and processing usage.

Innovation Solution

The approach involves selectively scanning regions of interest on the touch-sensitive display based on predicted positions of stylus electrodes, reducing the number of electrodes that need to be actively scanned, thereby conserving electrical power and processing resources without compromising input detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all display electrodes are scanned to ensure detection of all touch inputs, then detection completeness is improved, but power consumption and processing resources increase

Engineering Contradiction:
Improvedetection completenessVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The display electrodes are divided into multiple groups, with different scanning frequencies assigned to different groups. Frequently touched regions are scanned more often while less active regions are scanned less frequently, reducing overall power consumption while maintaining detection completeness for active areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The scanning frequency of display electrodes is made dynamic rather than static. The system adjusts scanning frequencies based on detected touch patterns and regions of interest, allowing the scanning rate to adapt to user interaction needs and thereby reducing power consumption during periods of low activity.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple stylus electrodes are tracked simultaneously to enable precise input detection, then measurement precision is improved, but processing resources and complexity increase

Engineering Contradiction:
Improveinput detection accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The tracking of multiple stylus electrodes is segmented into sequential processing stages. Instead of simultaneously calculating positions and orientations of all electrodes, the system processes them in groups or sequences, reducing the computational burden while maintaining the ability to determine precise stylus state.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary actions by predicting future positions of stylus electrodes based on previous movements. This allows the system to prepare scanning and processing resources in advance for expected electrode positions, reducing the complexity of real-time tracking while maintaining precision.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method effectively reduces power and processing burdens while maintaining accurate touch input detection, allowing for efficient interaction with multiple input objects, including active styli, by predicting and targeting specific regions of interest for scanning.

Implementation Method 1

The touch sensor typically includes a plurality of touch-sensing electrodes distributed across the touch sensor to enable capacitance measurements at specific two-dimensional locations

Methodology Applied
Scientific EffectCapacitance measurement: Capacitance

Implementation Method 2

receiving a stylus excitation signal applied to a stylus electrode, and/or exchanging data with an active stylus via driving of display electrodes

Methodology Applied
Scientific EffectElectromagnetic signal transmission: Electromagnetic Induction

Data Source

PatentEP3676692B1Selective scanning for touch-sensitive display device
Publication Date: 2022.07.06 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3676692B1 patent drawingFigure 1
  • EP3676692B1 patent drawingFigure 2~3
  • EP3676692B1 patent drawingFigure 4

AI summary

Detecting touch input includes, over a series of touch-sensing time frames, interpreting electrical conditions of display electrodes of a touch-sensitive display device to estimate frame-by-frame positions of two or more stylus electrodes of an active stylus. Based on the estimated frame-by-frame positions, future positions of each of the two or more stylus electrodes during a future touch-sensing time frame are predicted. Regions of interest on the touch-sensitive display device are identified, each region of interest including a plurality of display electrodes surrounding the predicted future position of a stylus electrode of the two or more stylus electrodes. During the future touch-sensing time frame, display electrodes in the regions of interest are selectively scanned.