Integrated Touch Screen Panel Using Liquid Crystal Electrodes

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Solution Overview

Problem

Conventional touch screen panels have increased thickness and production costs due to the separation of touch sensing and display electrodes, which complicates their design and functionality.

Innovation Solution

A touch screen panel with a simple structure and thin thickness is achieved by using a pair of transparent electrodes that serve both display and touch sensing functions, integrated with a liquid crystal layer to change optical properties based on voltage, allowing for both image display and touch detection with a single layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate electrodes are used for touch sensing and display functions, then the touch screen panel can perform both functions, but the thickness and production costs increase

Engineering Contradiction:

Improvedual function capabilityVSAvoidpanel thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent merges the touch sensing electrode and display electrode into a single integrated electrode structure. The liquid crystal layer itself serves as the touch sensing element, eliminating the need for separate touch sensing electrodes and reducing overall panel thickness while maintaining both display and touch functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The liquid crystal layer is designed to perform multiple functions simultaneously: it serves as both the display medium that modulates light for image formation and the touch sensing element that detects capacitance changes when touched. This multi-functional design eliminates redundant components and reduces thickness.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate electrodes are used for touch sensing and display functions, then the touch screen panel can perform both functions, but production costs increase

Engineering Contradiction:

Improvedual function capabilityVSAvoidproduction cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By combining the display electrode and touch sensing electrode into a single integrated structure, the patent reduces the number of manufacturing steps, materials required, and assembly operations. This simplification directly lowers production costs while maintaining dual functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The liquid crystal layer's dual role as both display medium and touch sensor eliminates the need for separate touch sensing layers and their associated manufacturing processes, thereby reducing material costs and production complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Length of stationary object

If a single pair of electrodes is used for both display and touch sensing, then thickness and production costs are reduced, but the structure becomes more complex

Engineering Contradiction:

Improvepanel thicknessVSAvoidstructural complexity

Core Design Contradiction:

Length of stationary objectVSDevice complexity

Solution Approach 1:

The liquid crystal layer is designed to inherently provide both display and touch sensing functions through its electro-optic properties and capacitance characteristics, eliminating the need for additional structural layers and simplifying the overall device architecture despite the multi-functional requirement.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Ease of manufacture

If a single pair of electrodes is used for both display and touch sensing, then production costs are reduced, but the manufacturing process becomes more difficult

Engineering Contradiction:

Improveproduction costVSAvoidmanufacturing difficulty

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The integration of display and touch sensing functions into the liquid crystal layer itself eliminates the need for precise alignment and bonding of multiple separate electrode layers, thereby reducing manufacturing precision requirements and simplifying the production process while lowering costs.

Inventive Principle:

Principle #5Merging (Combining)

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 solution enables a compact and cost-effective touch screen panel that efficiently displays images and senses touches using a single pair of electrodes, reducing thickness and production costs while maintaining effective functionality.

Implementation Method 1

integrated with a liquid crystal layer to change optical properties based on voltage

Methodology Applied

Scientific EffectElectro-optic effect: Electro-Optic Effects

Implementation Method 2

the capacitance type touch screen panel senses a user's touch by sensing a change of a capacitance between the two electrodes

Methodology Applied

Scientific EffectCapacitance sensing: Capacitance

Data Source

PatentEP3190494B1Touch screen panel, electronic notebook and mobile terminal

Publication Date: 2021.02.17 SAMSUNG ELECTRONICS CO LTD

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AI summary

A touch screen panel may include a liquid crystal, a first transparent electrode and a second transparent electrode provided at both sides of the liquid crystal, and a controller configured to transfer image data to the first transparent electrode and the second transparent electrode in a first mode and sense a touch of a user on at least one of the first transparent electrode and the second transparent electrode in a second mode.