Capacitive Key Structure for Electronic Device Button Sensitivity

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Solution Overview

Problem

Buttons in electronic devices often lose sensitivity over time, leading to reduced functionality.

Innovation Solution

A key structure with electrode plates and a filler material, where the capacitance between the plates changes when pressed, generating a signal through a signal generating device, allowing for improved sensitivity and functionality by using different materials and configurations for the key column and filler to produce varied key signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional mechanical buttons are used in electronic devices, then the device can detect key presses, but the buttons lose sensitivity and function over time due to wear and tear

Engineering Contradiction:

Improvebutton sensitivityVSAvoidservice life

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent replaces the traditional mechanical button structure with a capacitive sensing mechanism. Instead of relying on mechanical movement and contact, the system uses changes in capacitance values between electrode plates to detect key presses. This eliminates mechanical wear and maintains sensitivity throughout the device's service life, directly resolving the contradiction between reliability and duration of action.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a capacitive key structure with multiple electrode plates is used, then key press detection accuracy is improved, but the device complexity increases

Engineering Contradiction:

Improvekey press detection accuracyVSAvoidstructure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the sensing area into multiple electrode plates arranged in arrays, allowing independent measurement of capacitance changes at different locations. This segmentation enables precise detection of which key is pressed and with what force, improving measurement precision while maintaining a relatively simple overall structure through modular electrode arrangement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The same electrode plate array structure serves multiple functions: detecting key press location, determining press depth, and identifying different keys. This multi-functionality reduces the need for separate sensing mechanisms for each parameter, thereby improving measurement precision without proportionally increasing device complexity.

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

The solution maintains or enhances the sensitivity of electronic device buttons, enabling consistent and reliable operation by utilizing changes in capacitance to generate key signals, addressing the issue of reduced functionality due to wear and tear.

Implementation Method 1

the capacitance between the plates changes when pressed, generating a signal through a signal generating device

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10516395B2Key structure of electronic device

Publication Date: 2019.12.24 FU TAI HUA IND SHENZHEN

AI summary

A key structure of an electronic device includes a connecting portion and a key portion. The connecting portion includes two electrode plates cooperatively defining an accommodating space. The key portion, when pressed, is moved toward the accommodating space and partially received within the accommodating space, thereby changing a capacitance between the two electrode plates. The key portion partially protrudes from the housing.