Stretchable Touch Panel Capacitance Correction for Accurate Touch Sensing

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Solution Overview

Problem

Existing display devices, particularly those with stretchable and flexible substrates, face challenges in maintaining effective touch performance when stretched or deformed, leading to inaccuracies in touch data detection.

Innovation Solution

A display device incorporating a stretchable touch panel with touch electrodes, a stretchable display panel, and an actuator that deforms the panels to correct touch data values, utilizing a touch driver with electric charge removing capacitors to enhance touch performance in both stretched and non-stretched states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the touch panel is stretched to enable flexible display applications, then the adaptability and shape variability are improved, but the touch performance and measurement precision deteriorate due to inaccuracies in touch data detection

Engineering Contradiction:

Improveshape variabilityVSAvoidtouch data detection accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the capacitance values of compensation capacitors based on the stretchable area ratio of the touch panel. When the panel is stretched, the system calculates the stretchable area ratio and modifies the capacitance parameters to compensate for the deformation, thereby maintaining accurate touch data detection across different deformation states

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by continuously monitoring the touch data uniformity across different regions of the touch panel and using this information to adjust the compensation capacitor settings. The system calculates the stretchable area ratio based on detected touch data variations and feeds this information back to the capacitance correction unit, which then adjusts the capacitance values to maintain measurement precision

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If the touch panel is stretched to enable stereoscopic display, then the adaptability is improved, but the touch performance deteriorates due to non-uniform touch data across different areas

Engineering Contradiction:

Improvestereoscopic display capabilityVSAvoidtouch performance consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by dividing the touch panel into different regions (first area, second area, third area) and applying different capacitance compensation values to each region based on its specific deformation characteristics. The system identifies the stretchable area ratio for different regions and adjusts the capacitance of compensation capacitors locally to compensate for region-specific deformation effects, thereby maintaining uniform touch performance across the entire panel

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the capacitance parameters of compensation capacitors based on the calculated stretchable area ratio. When the panel is stretched into a stereoscopic configuration, the system detects the deformation, calculates the stretchable area ratio for different regions, and adjusts the capacitance values accordingly to maintain reliable and uniform touch performance across all areas of the deformed panel

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If capacitance correction is applied to improve touch performance in stretched areas, then the touch data uniformity is improved, but the device complexity increases due to additional compensation capacitors and control logic

Engineering Contradiction:

Improvetouch data uniformityVSAvoidcompensation circuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the touch panel into multiple distinct areas (first area, second area, third area) with different deformation characteristics. Compensation capacitors are assigned to each region, allowing independent capacitance adjustment for each segment. This segmented approach enables precise local compensation without requiring a completely complex global correction system

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by applying capacitance compensation only to the stretchable areas of the touch panel where deformation occurs, rather than uniformly across the entire panel. The system calculates the stretchable area ratio and applies correction primarily to affected regions, reducing the overall complexity compared to a full-panel compensation approach while still achieving sufficient touch data uniformity

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS20250306712A1Display device and method to correct touch data of stretchable touch panel

Publication Date: 2025.10.02 LG DISPLAY CO LTD

AI summary

According to an aspect of the present disclosure, a display device includes: a stretchable touch panel having a plurality of touch electrodes; a stretchable display panel configured to display an image; and a touch driver configured to operate the stretchable touch panel, in which the touch driver recognizes a stretchable area of the stretchable touch panel and corrects a touch data value of the stretchable area of the stretchable touch panel, thereby improving touch performance of the stretchable touch panel.