Piezoelectric Polylactic Acid Touch Panel for Position and Pressure Detection

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Solution Overview

Problem

Current touch panels face challenges in achieving high transparency, cost-effectiveness, and simplicity while simultaneously detecting position and pressure information, often resulting in complex structures and reduced light transmissivity due to multiple layers and complicated signal processing.

Innovation Solution

A touch panel using a molecule-oriented polylactic acid film with transparent electrodes, which exhibits piezoelectric properties, allowing for the simultaneous detection of position and pressure information with high transparency and reduced complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple films and electrode layers are stacked to achieve both position detection and pressure sensitivity, then detection functionality is improved, but light transmissivity is reduced and structure becomes complex

Engineering Contradiction:
Improvedetection functionalityVSAvoidlight transmissivity
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent merges the position detection function and pressure sensitivity function into a single integrated touch panel structure. The piezoelectric film serves dual purposes: detecting pressure through piezoelectric effect and enabling position detection through its integration with transparent electrodes. This eliminates the need for separate stacked layers for each function, thereby maintaining high light transmissivity while achieving both detection capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piezoelectric film is designed to perform multiple functions simultaneously: it acts as a pressure-sensitive element, a structural component, and an integral part of the position detection system. By making the piezoelectric film serve multiple roles, the patent reduces the total number of layers needed, thus improving light transmissivity while maintaining versatile detection functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple films and electrode layers are stacked to achieve both position detection and pressure sensitivity, then detection functionality is improved, but device structure becomes complex

Engineering Contradiction:
Improvedetection functionalityVSAvoidstructure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple detection functions into a unified structure where the piezoelectric film and transparent electrodes work together as an integrated system. This merging approach eliminates redundant layers and simplifies the overall device structure while maintaining the ability to detect both position and pressure information.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piezoelectric film is designed as a multi-functional component that simultaneously contributes to pressure detection, structural integrity, and position detection when combined with transparent electrodes. This multi-functionality reduces the number of separate components needed, thereby simplifying the device structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If lattice-shaped fine wire electrodes are formed on piezoelectric film to detect position information, then position detection capability is improved, but structure becomes significantly complicated

Engineering Contradiction:
Improveposition detection capabilityVSAvoidstructure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by forming transparent electrode patterns specifically in regions where position detection is needed, rather than using a uniform lattice structure across the entire piezoelectric film. This allows position detection capability to be achieved in critical areas while maintaining simplicity in other regions, thus reducing overall structural complexity.

Inventive Principle:
Principle #3Local quality

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 enables a touch panel with high transparency, cost-effectiveness, and simplicity in structure, effectively improving operability by providing accurate position and pressure information detection without compromising light transmissivity or increasing environmental impact.

Implementation Method 1

a touch panel using a molecule-oriented polylactic acid film with transparent electrodes, which exhibits piezoelectric properties

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2442213B1Touch screen and touch-type input device
Publication Date: 2022.05.18 MURATA MFG CO LTD
  • EP2442213B1 patent drawingFigure 1
  • EP2442213B1 patent drawingFigure 2(a)~2(c)
  • EP2442213B1 patent drawingFigure 3

AI summary

A touch panel and a touch panel device, which have a simple structure, a high transparency, and a reduced environmental load are provided. A touch panel (1) which includes a molecule oriented polylactic acid film, the polylactic acid film has a first principal plane and a second principal plane formed with electrodes, and the electrode on the first principal plane includes divided electrodes (3a to 3d) which are electrically divided into at least four. In addition, a touch panel input device having the touch panel, wherein the respective divided electrodes are connected to a processor (101) which outputs position information and/or pressed information based on voltages detected independently from the divided electrodes.