Piezoelectric Shock Detection Using Induction Boosting

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Solution Overview

Problem

Conventional electronic apparatuses with separate piezoelectric elements for generating alarms and detecting shocks face challenges in reducing size while maintaining sensitivity, as they require multiple components, leading to reduced alarm sound volume and difficulty in detecting lower-frequency shocks.

Innovation Solution

An electronic apparatus with a piezoelectric element that generates oscillations and voltage due to deformation, an induction element for boosting voltage, and switches for controlling current flow and connection/disconnection between elements, allowing for sensitive shock detection by sampling voltage changes during disconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a second piezoelectric element is added for detecting shocks independently, then shock detection capability is improved, but the number of components increases and apparatus size increases

Engineering Contradiction:

Improveshock detection capabilityVSAvoidnumber of components

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The first piezoelectric element performs dual functions: generating alarm sound and detecting shocks. The control unit determines shock detection based on voltage signal changes during the alarm sound generation period, eliminating the need for a separate second piezoelectric element while maintaining shock detection capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention dynamically utilizes the alarm sound generation period for shock detection by monitoring voltage signal changes. The control unit detects shocks during the time when the alarm sound is being generated, transforming a static component into a dynamically multi-functional element

Inventive Principle:

Principle #15Dynamics

2Volume of stationary object

If piezoelectric elements are reduced in size to achieve compact apparatus, then apparatus size is reduced, but alarm sound volume decreases and shock detection sensitivity is reduced

Engineering Contradiction:

Improveapparatus sizeVSAvoidshock detection sensitivity

Core Design Contradiction:

Volume of stationary objectVSMeasurement precision

Solution Approach 1:

The invention changes the detection parameter from requiring large piezoelectric elements to monitoring voltage signal changes during alarm sound generation. By detecting the change in voltage signals rather than relying on absolute signal magnitude, small piezoelectric elements can maintain adequate detection sensitivity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The control unit monitors voltage signal changes from the piezoelectric element during alarm sound generation and uses this feedback to determine shock occurrence. This feedback mechanism allows effective shock detection even with reduced piezoelectric element size

Inventive Principle:

Principle #23Feedback

3Ease of operation

If a common electrode is provided extending over the entire first surface for both piezoelectric elements, then connection is simplified, but step-up coil conduction interferes with lower frequency shock detection

Engineering Contradiction:

Improveconnection simplicityVSAvoidlower frequency shock detection

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The invention segments the electrode configuration by providing separate second electrodes for the first and second piezoelectric elements instead of a single common electrode. This segmentation prevents the step-up coil from conducting during lower frequency shock detection while maintaining simplified connection through the shared first electrode

Inventive Principle:

Principle #1Segmentation

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 high-sensitivity shock detection and effective control of alarm sounds, reducing the number of components and improving detection of lower-frequency shocks, thereby enhancing the apparatus's sensitivity and efficiency.

Implementation Method 1

a piezoelectric element configured to impart an oscillation due to deformation in correspondence with an applied voltage to the oscillation unit, generating a voltage corresponding to deformation due to a shock imparted to the oscillation unit

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

an induction element for applying an increased voltage to the piezoelectric element

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9546919B2Electronic apparatus and shock detection method

Publication Date: 2017.01.17 SEIKO WATCH CORP

AI summary

An electronic apparatus includes an outer case, and a piezoelectric element mounted to an inner surface of the outer case and configured to impart vibration to the outer case due to deformation in correspondence with an applied voltage and to generate a voltage corresponding to deformation due to a shock imparted to the outer case. An induction element applies an increased voltage to the piezoelectric element, a first switch performs control as to whether or not to supply an electric current from a power source to the induction element, a second switch effects connection or disconnection between the induction element and the piezoelectric element, and a shock detection unit to detects a shock imparted to the outer case based on the voltage generated in the piezoelectric element.