Touch Substrate With Interlocking Electrode Limbs

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Solution Overview

Problem

Mutual capacitance touch structures in touch displays suffer from low touch signal amount, reduced touch accuracy, and decreased sensitivity due to the thinning of film layers, leading to increased touch noise and decreased interaction area between driving and sensing electrodes.

Innovation Solution

The touch substrate design includes driving electrodes and sensing electrodes with limb portions that are alternately engaged on a base, increasing the interaction area and capacitance sensing signal variation, along with bridge portions and connecting bridges to enhance touch signal amount and sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If film layers are thinned to reduce device thickness, then device thickness is reduced, but touch signal amount decreases and touch noise increases

Engineering Contradiction:

Improvedevice thicknessVSAvoidtouch signal amount

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

The electrodes are divided into multiple limb portions that extend toward adjacent electrodes, creating multiple interaction zones. This segmentation increases the effective interaction area between driving and sensing electrodes, compensating for the reduced film thickness and maintaining touch signal strength.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electrode design transitions from simple planar structures to three-dimensional limb portions that extend in multiple directions. This dimensional enhancement increases the interaction volume and capacitance coupling between electrodes, offsetting the losses from thinning the film layers.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Length of stationary object

If film layers are thinned, then device thickness is reduced, but touch accuracy and sensitivity decrease

Engineering Contradiction:

Improvedevice thicknessVSAvoidtouch accuracy

Core Design Contradiction:

Length of stationary objectVSMeasurement precision

Solution Approach 1:

The limb portions create multiple discrete interaction zones that improve the resolution of touch detection. By having multiple limb portions extending in different directions, the system can more precisely locate touch positions and distinguish between multiple touch points, thereby improving touch accuracy despite reduced film thickness.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If simple electrode structures are used, then device complexity is reduced, but interaction area between electrodes decreases

Engineering Contradiction:

Improveelectrode structure complexityVSAvoidinteraction area

Core Design Contradiction:

Device complexityVSArea of stationary object

Solution Approach 1:

The electrode structure is segmented into limb portions that are extensions of the main electrode body. These limb portions are simple in form but strategically positioned to maximize interaction with adjacent electrodes, thereby increasing the effective interaction area without significantly increasing overall device complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The limb portions are designed with arcuate edges that substantially match the arcuate profiles of adjacent electrode limb portions. This curved geometry maximizes the contact area and electromagnetic coupling between interacting electrodes, enhancing the interaction area while maintaining manufacturing simplicity.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 improves touch accuracy and sensitivity by increasing the interaction area between electrodes, enhancing the touch signal amount and reducing impedance, thus addressing the limitations of existing mutual capacitance touch structures.

Implementation Method 1

each touch unit includes a driving electrode and a sensing electrode... mutual capacitance touch has higher touch accuracy... can support a real multi-point touch

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11340729B2Touch substrate and display panel

Publication Date: 2022.05.24 CHENGDU BOE OPTOELECTRONICS TECH CO LTD

AI summary

Provided are a touch substrate and a display panel. The touch substrate includes a base; multiple touch units provided on the base, each touch unit includes a driving electrode and a sensing electrode, the driving electrode includes a first main body portion and multiple first limb portions positioned on an edge of the first main body portion, the first limb portions are connected to the first main body portion; the sensing electrode includes a second main body portion and multiple second limb portions positioned on an edge of the second main body portion, the second limb portions are connected with the second main body portion; orthographic projections of the first and second limb portions on the base are alternately engaged with each other, at least parts of profiles of opposite edges of the first limb portions and the second limb portions are arcuate and substantially consistent with each other.