Piezoelectric Audio Output Device Wiring Complexity
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Solution Overview
Problem
Existing audio output devices using MEMS technology face challenges in cost reduction, precision processing, internal voltage maintenance, and excessive wiring complexity, making them unsuitable for mass production and mobile device applications.
Innovation Solution
The audio output device employs a piezoelectric layer and support layer configuration with electrode layers on either side, allowing for a passive matrix drive mechanism that simplifies wiring and facilitates precise sound pressure generation with reduced component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If MEMS technology is used to create a digital speaker, then sound pressure level can be achieved, but manufacturing cost and complexity increase significantly
Solution Approach 1:
The patent replaces the complex MEMS mechanical system with a simpler piezoelectric actuator system. The piezoelectric element converts electrical signals directly to mechanical vibrations of the diaphragm, eliminating the need for complex MEMS fabrication processes while achieving comparable sound pressure levels.
Solution Approach 2:
The patent changes the actuation mechanism from electrostatic (MEMS) to piezoelectric, fundamentally altering the physical principle used to drive the diaphragm. This parameter change simplifies the manufacturing process while maintaining the ability to generate high sound pressure levels.
2Force
If high voltage is applied to drive the diaphragm with electrostatic force, then vibration can be achieved, but internal voltage is lost due to electrical leakage through the insulating layer
Solution Approach 1:
The patent substitutes the electrostatic actuation system with a piezoelectric actuation system. The piezoelectric element generates mechanical stress directly in response to applied voltage, eliminating the need for thick insulating layers and preventing electrical leakage while maintaining the ability to generate sufficient force for diaphragm vibration.
3Reliability
If the thickness of the insulating layer is increased to prevent electrical leakage, then insulation performance improves, but the amplitude of diaphragm vibration decreases
Solution Approach 1:
The patent replaces the electrostatic actuation system that requires thick insulating layers with a piezoelectric system. The piezoelectric element is coupled directly to the diaphragm, eliminating the insulating layer requirement and allowing full transmission of actuation force to the diaphragm, thereby maximizing vibration amplitude.
4Measurement precision
If driver circuits are provided for each diaphragm unit to enable independent driving, then control precision improves, but the number of wires increases making physical connection impossible
Solution Approach 1:
The patent merges multiple driver circuits into a single integrated driver circuit that controls all piezoelectric elements. The piezoelectric elements are connected in arrays (series/parallel combinations), allowing a single driver circuit to independently control each diaphragm unit through coordinated activation of different element groups, thereby reducing wiring complexity while maintaining control precision.
Solution Approach 2:
The single driver circuit performs multiple functions by selectively activating different combinations of piezoelectric elements to control individual diaphragm units. This universal controller replaces the need for dedicated driver circuits for each diaphragm unit, significantly reducing the number of wires required while maintaining the ability to independently control each diaphragm.
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
This configuration enables downsized, cost-effective, and efficiently processed audio output devices with reduced wiring complexity, suitable for both TV and mobile applications, while maintaining high sound pressure levels.
Implementation Method 1
a piezoelectric layer and support layer configuration with electrode layers on either side
Data Source
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AI summary
In order to solve problems with an audio device that is difficult to machine and has an increased amount of wiring, the present invention provides an audio output device comprising: a first electrode layer including a plurality of rows of electrodes arranged in a first direction; a second electrode layer disposed on the back surface of the first electrode layer and including a plurality of rows of electrodes arranged in a second direction; a driving layer including a piezoelectric layer disposed between the first electrode layer and the second electrode layer and a support layer coupled to one of the front surface and the back surface of the piezoelectric layer; and a support plate coupled to the back surface of the driving layer and having a hollow portion formed in a region corresponding to each of intersections between the plurality of rows of electrodes in the first electrode layer and the plurality of rows of electrodes in the second electrode layer intersect.