Touch Sensor Dummy Pattern Area Variation for Low Temperature Accuracy
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Solution Overview
Problem
Existing touch sensors in display devices face challenges in accurately recognizing touch inputs, especially in low temperature environments, due to touch misrecognition and sensitivity issues.
Innovation Solution
The touch sensor design includes multiple touch sensing areas with varying dummy pattern areas and touch pattern areas, where the second touch sensing area has a larger RC delay to reduce touch misrecognition, and a sensor driver uses a baseline tracking method to update capacitance values based on temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the touch sensor uses a uniform design across all sensing areas, then the manufacturing process is simple, but touch recognition accuracy deteriorates in low temperature environments
Solution Approach 1:
The patent applies local quality by configuring different dummy pattern areas for different touch sensing areas. Specifically, the first touch sensing area has a first dummy pattern area with a first area, while the second touch sensing area has a second dummy pattern area with a second area that is greater than the first area. This localized differentiation optimizes touch recognition accuracy in low temperature environments for specific regions without requiring complete redesign of the entire touch sensor, thus maintaining manufacturing simplicity while improving measurement precision where needed.
2Measurement precision
If the dummy pattern area is increased to reduce touch misrecognition, then touch recognition accuracy is improved, but the touch pattern area available for sensing is reduced
Solution Approach 1:
The patent implements local quality by strategically placing larger dummy pattern areas in specific touch sensing regions rather than uniformly across the entire sensor. The second touch sensing area, which is more susceptible to low temperature effects, receives a larger dummy pattern area (second area) compared to the first touch sensing area (first area). This localized approach improves touch recognition accuracy in critical regions while preserving sufficient touch pattern area in other regions for normal operation.
3Adaptability or versatility
If the touch sensor is designed with different RC delay characteristics for different areas, then resilience to temperature changes is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by creating different RC delay characteristics in different touch sensing areas through geometric modifications rather than complex circuitry. The second touch sensing area is configured with a larger dummy pattern area (second area greater than first area), which naturally creates a different RC delay characteristic. This geometric-based differentiation provides temperature resilience across different regions without introducing complex additional components or control mechanisms, thus improving adaptability while minimizing device complexity.
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 design enhances touch recognition accuracy and resilience to temperature changes, minimizing touch sensitivity loss and reducing hardware modifications needed for low temperature environments.
Implementation Method 1
a sensor driver configured to determine a touch position, based on a difference between raw data provided from the first touch cells and the second touch cells and a value of a baseline corresponding to a base capacitance of the first and second touch cells
Data Source
AI summary
A touch sensor includes first touch cells disposed in a first touch sensing area, the first touch cells each including a first touch pattern and a first dummy pattern, and second touch cells disposed in a second touch sensing area, the second touch cells each including a second touch pattern and a second dummy pattern. An area of a first dummy pattern area in which the first dummy pattern is disposed is greater than an area of a second dummy pattern area in which the second dummy pattern is disposed.