Force Touch Electronic Device With Capacitance Sensing

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Solution Overview

Problem

Existing organic light emitting display devices with force touch functions face challenges due to increased thickness and complexity, including the need for separate force sensors and driving ICs, which complicate the structure and increase manufacturing costs.

Innovation Solution

An electronic device with a force touch function is designed, featuring a substrate with a light emitting device layer, a second electrode, and a touch electrode part, where a thickness variation member between the second electrode and the touch electrode allows capacitance variation sensing based on touch force, eliminating the need for separate force sensors and ICs by using an elastic barrier film or dielectric material to change distance and sense touch force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate force sensor and force touch driving IC are added to sense touch force, then force touch function is achieved, but device thickness increases and structure becomes complicated

Engineering Contradiction:

Improveforce touch functionVSAvoidstructure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the force sensing function with the existing touch electrode structure by utilizing capacitance variation between the touch electrode and a second electrode. This integration eliminates the need for separate force sensors and dedicated force touch driving ICs, as the same electrode structure serves both touch detection and force sensing purposes through capacitance measurement.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touch electrode structure is designed to perform multiple functions: it detects both touch position (through capacitance coupling with the second electrode) and touch force (through capacitance variation of the touch electrode itself). This multi-functionality reduces the number of separate components needed while maintaining comprehensive touch sensing capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a separate force sensor and force touch driving IC are added to sense touch force, then force touch function is achieved, but manufacturing cost increases

Engineering Contradiction:

Improveforce touch functionVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If thickness variation member is introduced to enable capacitance variation sensing, then force touch sensing is achieved without additional sensors, but device structure becomes more complex

Engineering Contradiction:

Improvenumber of elementsVSAvoidtouch force sensing precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent utilizes changes in capacitance parameters to detect touch force. The thickness variation member modifies the distance between electrodes, which directly changes the capacitance value. By measuring this capacitance variation, the system can precisely detect touch force without requiring additional sensors, as the physical parameter change (distance) translates directly into an electrical signal change (capacitance).

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

This design achieves a thin form factor while enabling effective force touch sensing without additional sensors or ICs, reducing the number of elements and manufacturing costs, and enhancing touch sensitivity and precision.

Implementation Method 1

a thickness variation member between the second electrode and the touch electrode part so that a distance between the second electrode and the touch electrode part is changeable according to a touch force applied to the touch electrode part, wherein the electronic device is configured to sense a touch force applied to the touch electrode part by sensing a variation of a capacitance generated between the second electrode and the touch electrode part

Methodology Applied

Scientific EffectCapacitance variation: Capacitance

Implementation Method 2

using an elastic barrier film or dielectric material to change distance and sense touch force

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3316088B1Electronic device having force touch function

Publication Date: 2024.05.01 LG DISPLAY CO LTD

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AI summary

Disclosed is an electronic device having a force touch function, which has a thin thickness despite having the force touch function. The electronic device includes a substrate (110), first and second electrodes (E1, E2) and a light emitting device layer including a light emitting layer provided on the substrate (110), and a touch electrode part (170) on the second electrode (E2). A distance between the second electrode and the touch electrode part (170) is changeable according to a touch force applied to the touch electrode part (170).