Touch Sensing Device Grip Detection Algorithm
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Solution Overview
Problem
Display devices equipped with touch panels often misinterpret touches on the edge area as actual touches, leading to touch malfunctions.
Innovation Solution
A touch sensing device and method that includes a first circuit to supply a driving signal to a touch electrode, a second circuit to sense changes in capacitance, and a third circuit to calculate touch coordinates, determine touch areas, and differentiate between normal and grip touches based on a touch ratio between touch nodes on multiple lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If touch sensing is performed on the entire panel area, then touch detection coverage is improved, but false detection of grip touches as normal touches increases
Solution Approach 1:
The patent applies different touch detection criteria to different regions of the panel. Edge regions use grip touch detection algorithms that analyze touch ratio across multiple lines, while central regions use standard touch detection. This local differentiation allows the system to maintain high detection coverage while reducing false positives from grip touches on the edges.
Solution Approach 2:
The panel is segmented into multiple detection lines, and touch detection is performed independently on each line. By calculating touch ratios across these segmented lines and comparing against threshold values, the system can distinguish between grip touches (which typically affect only edge lines) and normal touches (which affect central lines).
2Measurement precision
If touch detection threshold is lowered to detect small touches, then sensitivity to normal touches is improved, but false detection of grip touches increases
Solution Approach 1:
The system dynamically adjusts touch detection thresholds based on the detected touch ratio. When the touch ratio indicates a grip touch pattern (high ratio on edge lines), the system raises the threshold for normal touch detection. When the touch ratio indicates a normal touch pattern (low ratio on edge lines), the system uses lower thresholds to detect small touches. This dynamic adjustment maintains sensitivity while preventing false detections.
3Measurement precision
If touch ratio calculation uses multiple lines, then grip touch identification accuracy is improved, but processing complexity increases
Solution Approach 1:
The system calculates touch ratios for all detection lines but only performs detailed grip touch analysis on edge lines where grip touches are most likely to occur. For central lines, the system uses simpler detection criteria. This partial application of the complex touch ratio algorithm reduces processing complexity while maintaining high grip touch identification accuracy where it is most needed.
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
Accurately identifies intended touches by users, preventing touch malfunctions and providing stable touch information even with sudden data changes, by considering the touch ratio and historical touch data.
Implementation Method 1
a second circuit configured to sense a change in capacitance of the touch electrode
Data Source
AI summary
In an aspect of the present disclosure, a touch sensing device is provided. The touch sensing device includes: a first circuit configured to supply a driving signal to a touch electrode of a panel; a second circuit configured to sense a change in capacitance of the touch electrode caused by a user touch; and a third circuit configured to: calculate a touch coordinate based on the sensed capacitance change; determine a touch area based on the touch coordinate; and determine the user touch as either a normal touch or a grip touch based on a touch ratio between touch nodes placed on each of a plurality of lines of the panel and the touch area.