Rear Piezoelectric Input Device for Clean Display Operation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional information display devices with touch panels on the surface are prone to dirtiness from finger oils, leading to reduced visibility and require frequent cleaning, and struggle with complex operation inputs when using touch pads on the back surface, which require complex detection mechanisms and result in larger device sizes.

Innovation Solution

An operation input device with a piezoelectric element of a flat film shape is integrated into the back surface of the information display device, capable of detecting pressing position and force, using a polylactic acid piezoelectric film for high sensitivity and reliability, and a housing design that allows for precise detection of touch position and force without the need for complex temperature compensation mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a touch panel is used on the surface for operation input, then operation input is simple and direct, but the display screen becomes dirty frequently and visibility decreases

Engineering Contradiction:

Improveoperation inputVSAvoidstains on display screen

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional touch panel arrangement by placing the piezoelectric sensing element on the back surface of the device instead of on the front display surface. This allows users to input operations on the clean back surface while the display screen remains protected from direct contact and staining.

Inventive Principle:

Principle #13The other way round (Inversion)

2Object-affected harmful factors

If a touch pad on the back surface is used for operation input, then the display screen is protected from stains, but complex detection mechanisms are required and device size increases

Engineering Contradiction:

Improvestains on display screenVSAvoiddetection mechanism

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical or capacitive detection mechanisms with a piezoelectric sensing system. The piezoelectric film directly converts mechanical pressure from finger contact into electrical signals, providing a simpler and more reliable detection mechanism that reduces device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If a touch pad on the back surface is used for operation input, then the display screen is protected from stains, but the device size becomes larger

Engineering Contradiction:

Improvestains on display screenVSAvoiddevice size

Core Design Contradiction:

Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The patent employs a thin piezoelectric film as the sensing element on the back surface. This thin-film approach allows for operation detection without adding significant bulk or volume to the device, maintaining a compact form factor while protecting the display screen from stains.

Inventive Principle:

Principle #30Flexible shells and thin films

4Measurement precision

If a piezoelectric element is used on the back surface for operation input, then operation detection sensitivity is high and device size is compact, but temperature influence from body heat may affect detection

Engineering Contradiction:

Improvedetection sensitivityVSAvoidbody temperature influence

Core Design Contradiction:

Measurement precisionVSTemperature

Solution Approach 1:

The patent introduces a housing structure as an intermediary thermal barrier between the user's finger and the piezoelectric element. This housing layer isolates the temperature-sensitive piezoelectric sensor from direct body heat contact, allowing high detection sensitivity to be maintained without temperature interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively reduces stains on the display screen and enables complex operation inputs similar to surface-based inputs, while maintaining a compact device size and high detection sensitivity, without being influenced by body temperature.

Implementation Method 1

a piezoelectric element of a flat film shape... the piezoelectric element of the flat film shape which generates a detection signal corresponding to a pressing position

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9904382B2Rear piezoelectric operation input device and front information display device

Publication Date: 2018.02.27 MURATA MFG CO LTD

AI summary

An operation input device has a housing including a concave portion in which an information display device is accommodated. A piezoelectric element of a flat film shape and a control IC connected to the piezoelectric element are built in a base portion of the housing. The control IC is connected to a device IC of the information display device. When a user's finger touches an attachment region of the piezoelectric element in the base portion of the housing, a detection signal corresponding to the touch position and a pressing amount is outputted from the piezoelectric element. The control IC generates operation information based on the detection signal, and outputs the operation information to the device IC of the information display device. The device IC shows display corresponding to the operation information.