Piezoelectric Vibration Device for Mobile Terminals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vibration motors in mobile terminals have insufficient response speed to satisfy user demands for operational simultaneity and cannot transmit precise, slight vibrations to specific body parts like fingertips, limiting their effectiveness in haptic applications.
Innovation Solution
A piezoelectric vibration device using a bimorph piezoelectric vibrator with a voltage-boosting transformer and driving chip, combined with weights and insulation members, to achieve high response speed and precise control of vibration magnitude and speed, allowing for multi-position vibration and increased vibration intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional vibration motor using ERM or linear motor is employed, then the device can generate vibration, but the response speed is insufficient (about 200ms for ERM, about 50ms for linear motor) to satisfy user demand for operational simultaneity
Solution Approach 1:
The patent replaces the conventional mechanical vibration motor system (ERM or linear motor) with a piezoelectric vibration system. The piezoelectric element converts electrical signals directly into mechanical vibration through the piezoelectric effect, eliminating the need for rotating masses or complex coil-magnet assemblies. This substitution achieves a response speed of less than 0.002 seconds, dramatically improving operational simultaneity satisfaction while maintaining reliable vibration generation.
Solution Approach 2:
The patent changes the fundamental operating parameters of the vibration generation system by adopting piezoelectric materials with specific characteristics (high coupling coefficient, fast response). By selecting piezoelectric elements with optimized parameters and configuring them in a bimorph structure, the system achieves ultra-fast response speed (＜0.002s) while maintaining sufficient vibration intensity for mobile terminal applications.
2Speed
If a piezoelectric vibrator with high response speed is used, then operational simultaneity is satisfied, but the thickness increases which conflicts with slim mobile terminal design requirements
Solution Approach 1:
The patent employs a nested structure where the piezoelectric element is integrated within a compact housing that contains all necessary components (electrodes, insulation members, weights) in a layered configuration. The bimorph piezoelectric element consists of two piezoelectric layers with an intermediate electrode plate nested between them, maximizing space utilization. This nested arrangement achieves high response speed while minimizing the overall thickness to less than 3mm, satisfying both performance and slim design requirements.
Solution Approach 2:
The patent transitions from a conventional planar vibration motor layout to a three-dimensional layered structure. By stacking piezoelectric elements and insulation members in multiple layers with optimized thickness distribution, the system achieves fast response in the time dimension while keeping the overall thickness minimal. The vibration is generated through bending displacement in one direction while the structure is constrained in other dimensions, efficiently resolving the thickness-response speed contradiction.
3Force
If weights are attached to amplify vibration, then vibration intensity increases (over two times more than conventional motors), but the device complexity increases
Solution Approach 1:
The patent merges the weight amplification function with the existing housing structure. Instead of adding separate weight components, the housing itself is designed to incorporate weights that serve dual purposes: amplifying vibration intensity and providing structural support. The insulation members are also strategically positioned to function as part of the vibration transmission path, reducing the need for additional components and simplifying the overall structure while achieving over two times vibration intensity compared to conventional motors.
4Reliability
If insulation members are added to prevent electricity leakage, then safety is improved, but the internal space of mobile terminal is reduced
Solution Approach 1:
The patent designs insulation members that perform multiple functions simultaneously. The insulation members not only prevent electricity leakage from the piezoelectric element but also serve as vibration transmission paths, structural support elements, and spacing maintainers. By integrating these multiple functions into single components, the system achieves reliable electrical insulation without sacrificing internal space, maintaining compact dimensions suitable for mobile terminal integration.
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 piezoelectric vibration device achieves a response speed of less than 0.002 seconds, enabling precise and simultaneous vibration effects corresponding to sound and image, with increased vibration intensity and reduced thickness, suitable for slim mobile terminal designs and diverse haptic functions.
Implementation Method 1
a piezoelectric vibrator including a pair of piezoelectric element layers connected to one of positive and negative poles and a middle electrode plate interposed between the piezoelectric element layers and connected to the other pole, the piezoelectric vibrator being configured to generate vibration due to up/down bending displacement
Data Source
AI summary
A piezoelectric vibration device for a mobile terminal is disclosed. A bimorph piezoelectric vibrator includes a pair of piezoelectric element layers connected to one of positive and negative poles and a middle electrode plate interposed between the piezoelectric element layers and connected to the other pole. The piezoelectric vibrator generates vibration due to up/down bending displacement by fixing both end portions thereof to an inner surface of a casing of a mobile terminal. A voltage-boosting transformer raises a power source voltage of a mobile terminal to a driving voltage. A driving chip receives the raised driving voltage from the voltage-boosting transformer and drives the piezoelectric vibrator. Weights are attached to at least one of both sides of the piezoelectric vibrator to amplify vibration. Insulation members are provided at both end portions of the piezoelectric vibrator to prevent electricity applied to the piezoelectric vibrator from leaking to the casing.