Touch Screen Controller Donut Pattern Validation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch sensing techniques often incorrectly interpret a single large finger touch as multiple touches, especially under weak ground conditions, leading to unwanted touch separation, breaks, or ghost touches, particularly when multiple large fingers interact with the screen along the same force line.
Innovation Solution
A touch screen controller that utilizes both mutual capacitance and self capacitance sensing to identify a 'donut touch pattern' by analyzing touch strength values, validating single touches and distinguishing them from multiple touches by large fingers through the detection of singular peak values within defined bounds, and separating candidate patterns based on valleys in self capacitance touch strength values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional touch sensing techniques are used to detect multiple touches, then multiple touches by small fingers can be detected, but single large finger touches are incorrectly interpreted as multiple touches
Solution Approach 1:
The patent segments the touch detection process into two distinct phases: pre-validation phase using mutual capacitance to identify donut-shaped patterns, and validation phase using self capacitance to confirm single touch status. This segmentation allows the system to first detect potential multi-touch patterns and then validate whether they represent actual multiple touches or single large finger touches, thereby resolving the contradiction between detecting multiple touches and avoiding false positives.
Solution Approach 2:
The patent introduces self capacitance sensing as an intermediary validation mechanism between the initial mutual capacitance detection and the final touch recognition decision. This intermediary step analyzes the touch strength profile within the donut pattern bounds to determine if multiple peaks are present, serving as a mediator that resolves the ambiguity between single and multiple touch interpretations.
2Reliability
If techniques are developed to distinguish single large finger touch from multiple small finger touches, then false touch separation is reduced, but multiple touches by large fingers along the same force line cannot be accurately determined
Solution Approach 1:
The patent changes the sensing parameter from mutual capacitance alone to a combination of mutual capacitance and self capacitance. By switching between these two sensing modes and analyzing their respective outputs (donut pattern detection in mutual capacitance, peak analysis in self capacitance), the system can adaptively distinguish between single large finger touches and multiple large finger touches, thereby maintaining reliability while improving adaptability to different touch scenarios.
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 differentiates single large finger touches from multiple touches by large fingers, reducing errors in touch recognition and preventing unwanted separation or merging, thereby enhancing the reliability of touch input detection on touch screens.
Implementation Method 1
acquire mutual capacitance touch strength values from the touch screen
Implementation Method 2
read self capacitance touch strength values for lines that are contained within bounds of the pre-validated donut touch pattern
Data Source
AI summary
Disclosed herein is a touch screen controller operable with a touch screen. The touch screen controller includes input circuitry to receive touch data from the touch screen, and processing circuitry. The processing circuitry acquires mutual capacitance touch strength values from the touch screen, determines when the mutual capacitance touch strength values define a pre-validated donut touch pattern, and reads self capacitance touch strength values for lines that are contained within bounds of the pre-validated donut touch pattern. If the self capacitance touch strength values for lines contained within bounds of the pre-validate donut touch pattern contain a singular peak value, the processing circuitry validates the pre-validated donut touch pattern as representing a single touch.