Display Input Sensor Trace Layout for Parasitic Capacitance

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Solution Overview

Problem

Existing display devices lack sufficient design freedom in the arrangement of sensing electrodes and trace lines, leading to inefficiencies in touch sensitivity and capacitance issues.

Innovation Solution

A display device with an input sensor design that includes overlapping sensing regions, featuring group electrodes and trace lines arranged in specific patterns to optimize sensing and reduce parasitic capacitance, with varying trace line lengths and resistances to enhance touch sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If trace lines are arranged in a regular grid pattern, then manufacturing is simplified, but parasitic capacitance increases and touch sensitivity decreases

Engineering Contradiction:
Improvetrace line arrangementVSAvoidtouch sensitivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by making trace line lengths unequal in the first direction. Specifically, trace lines extending from different sensing electrodes have different lengths, with at least one trace line being longer than others. This asymmetric arrangement reduces the overlap area between trace lines and sensing electrodes, thereby reducing parasitic capacitance and improving touch sensitivity while maintaining manufacturability through a systematic design approach.

Inventive Principle:
Principle #4Asymmetry

2Measurement precision

If sensing electrodes are densely arranged, then sensing resolution improves, but parasitic capacitance between electrodes increases

Engineering Contradiction:
Improvesensing resolutionVSAvoidparasitic capacitance
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by varying the characteristics of trace lines connected to different sensing electrodes. Specifically, trace lines have different lengths and configurations depending on their position and the sensing electrode they connect to. This localized optimization allows dense electrode arrangement for high resolution while managing parasitic capacitance through tailored trace line designs for each electrode.

Inventive Principle:
Principle #3Local quality

3Area of stationary object

If trace line length is increased to cover larger sensing regions, then sensing area expands, but resistance increases and touch sensitivity decreases

Engineering Contradiction:
Improvesensing region coverageVSAvoidtouch sensitivity
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent applies parameter changes by systematically varying trace line parameters (length, width, configuration) to optimize performance. Longer trace lines are designed with specific width adjustments or routing optimizations to maintain acceptable resistance levels. The parameter variations allow coverage of larger sensing regions while preserving touch sensitivity through compensated design parameters.

Inventive Principle:
Principle #35Parameter changes

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

The solution provides a display device with improved touch sensitivity and reduced parasitic capacitance, offering enhanced design flexibility and performance in touch sensing.

Implementation Method 1

reduced parasitic capacitance between touch electrode lines and touch electrodes by having openings in the touch electrodes lines so that the overlap area is reduced

Methodology Applied
Scientific EffectParasitic capacitance: Parasitic Capacitance

Implementation Method 2

Respective resistances of the (i+1) th trace line and the (i+2) th trace line are different from each other

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP4404036B1Display device
Publication Date: 2025.10.29 SAMSUNG DISPLAY CO LTD
  • EP4404036B1 patent drawingFigure 1~2
  • EP4404036B1 patent drawingFigure 3
  • EP4404036B1 patent drawingFigure 4A

AI summary

Disclosed is a display device (DD) including an input sensor (200). The input sensor (200) includes a first group electrode (E1) and a second group electrode (E2) that overlap a sensing region (200-SA). A first group line (TL1) is connected to the first group line (TL1), and overlaps the sensing region (200-SA). The first group line (TL1) is substantially uniformly located in a first region of the sensing region (200-SA), and is located more densely in a second region of the sensing region (200-SA) than in the first region. A length of the first group line (TL1) located in the second region is less than that of the first group line (TL1) located in the first region.