Distributed Mode Loudspeaker Actuator with Patterned Electrodes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Distributed mode loudspeakers face challenges in efficiently generating sound across a wide frequency range while minimizing power usage and reducing capacitance, as existing technologies often require extensive energization of all electrode pairs for full frequency coverage.

Innovation Solution

A distributed mode loudspeaker system that selectively energizes multiple electrode pairs based on determined frequency subsets, using a piezoelectric transducer with layers of ceramic material, where a drive module provides current to specific electrode pairs to generate sound within targeted frequency ranges, optimizing power usage and impedance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If all electrode pairs are energized to cover the full frequency range, then the frequency coverage is improved, but power consumption increases

Engineering Contradiction:
Improvefrequency coverageVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The electrode pairs are divided into multiple groups, each group responsible for specific frequency ranges. The drive module can selectively energize only the required groups based on the desired frequency output, rather than energizing all electrode pairs simultaneously. This segmentation enables partial frequency coverage with reduced power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects which electrode pairs to energize based on the required frequency range. The drive module adjusts the configuration of active electrode pairs in real-time, transitioning between different energization states to match the desired audio output, optimizing power usage for each operating condition.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If all electrode pairs are energized for full frequency coverage, then the frequency range is improved, but capacitance increases

Engineering Contradiction:
Improvefrequency rangeVSAvoidcapacitance
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

By segmenting the electrode pairs into multiple groups with different capacitance characteristics, the system can select only the necessary groups for the current frequency range. This reduces the total capacitance that must be charged and discharged, improving electrical efficiency while maintaining the ability to cover the full frequency range when needed.

Inventive Principle:
Principle #1Segmentation

3Use of energy by moving object

If multiple electrode pairs are selectively energized for different frequencies, then power efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidcontrol complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The drive module serves multiple functions: it controls the piezoelectric transducer, selects which electrode pairs to energize, determines the frequency range, and manages power distribution. This multi-functionality consolidates what could be separate complex systems into a single controller, reducing overall device complexity while maintaining power efficiency benefits.

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

This approach reduces power consumption, increases impedance, and minimizes capacitance, enabling more efficient sound generation across a range of frequencies with improved sound reproduction accuracy.

Implementation Method 1

A DML may use a distributed mode actuator ('DMA'), e.g., a piezoelectric transducer, to cause the panel to vibrate and generate sound

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4109926B1Distributed mode loudspeaker actuator including patterned electrodes
Publication Date: 2024.11.27 GOOGLE LLC
  • EP4109926B1 patent drawingFigure 1A~1C
  • EP4109926B1 patent drawingFigure 2A~2C
  • EP4109926B1 patent drawingFigure 3

AI summary

A distributed mode loudspeaker comprising: a display panel; a support attached to the display panel; a piezoelectric transducer comprising a layer of piezoelectric material, the piezoelectric transducer being attached to the support at one end and extending parallel to the display panel to a free end opposite the end attached to the support, the piezoelectric transducer further comprising electrode layers arranged on opposing sides of the layer of piezoelectric material, the electrode layers comprising two or more electrode pairs, each electrode pair comprising a first electrode on a first side of the opposing sides and a second electrode on a second side of the opposing sides; and a drive module connected to each of the two or more electrode pairs and adapted to selectively provide current to the piezoelectric transducer to generate a force that, when provided to the display panel, causes the display panel to generate sound waves.