Piezoelectric Pressure Sensing in Thin Display Panels

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Solution Overview

Problem

Existing touch screens with integrated actuators for pressure sensing increase the size of the device, contradicting the trend of thinness and portability in display technology.

Innovation Solution

Incorporating pressure sensing units with piezoelectric material layers and capacitive touch units into the display panel, allowing for pressure and touch input detection without significantly increasing the device's thickness, by using piezoelectric material layers that deform under stress to generate electric signals and dielectric material layers that change capacitance upon touch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If actuators are coupled as individual modules to the touch panel to enable pressure sensing, then pressure sensing capability is improved, but device thickness increases

Engineering Contradiction:

Improvepressure sensing capabilityVSAvoiddevice thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent integrates the actuator directly into the touch panel structure by forming the actuator electrode and touch electrode in the same layer or adjacent layers, eliminating the need for separate actuator modules. This merging of components enables pressure sensing while maintaining thin device profile, as the actuator functionality is combined with the existing touch panel layers rather than adding external modules.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from three-dimensional stacked module architecture to two-dimensional planar integration by forming both actuator and touch sensing functionalities within the same plane or closely spaced layers. This dimensional reorganization allows pressure sensing capability to be achieved without increasing device thickness, as the sensing elements are distributed across the surface area rather than stacked vertically.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If individual actuator modules are coupled to the touch panel, then pressure input sensing is enabled, but device size increases

Engineering Contradiction:

Improvepressure input sensingVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The actuator electrode and touch electrode are merged into the same structural layer or adjacent layers of the touch panel, eliminating the need for separate actuator modules. This integration enables pressure input sensing while maintaining compact device size, as the sensing functionality is combined with existing panel structures rather than adding external components.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touch panel structure is designed to perform multiple functions simultaneously - serving as both the touch sensing element and the actuator element. By making the touch electrode also function as the actuator electrode, the device achieves pressure sensing capability without requiring additional dedicated components, thereby maintaining small device size while enhancing functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables pressure and touch input sensing without increasing the device's size, facilitating thinness and portability while providing effective interaction capabilities.

Implementation Method 1

Each pressure sensing unit comprises a first upper electrode, a first lower electrode disposed opposite to the first upper electrode, and a piezoelectric material layer between the first upper electrode and the first lower electrode

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

each touch unit comprises a second upper electrode, a second lower electrode disposed opposite to the second upper electrode, and a dielectric material layer between the second upper electrode and the second lower electrode

Methodology Applied

Scientific EffectCapacitance change: Capacitance

Data Source

PatentUS11256348B2Display panel and display device

Publication Date: 2022.02.22 HEFEI BOE OPTOELECTRONIC TECH CO LTD

AI summary

The present disclosure provides a display panel include one or more pressure sensing units, the one or more pressure sensing units being configured to sense a pressure input on the display panel. Each of the pressure sensing units includes a first upper electrode, a first lower electrode disposed opposite to the first upper electrode, and a piezoelectric material layer between the first upper electrode and the first lower electrode. There is further provided a display device comprising the display panel described above.