Dual Panel Audio Actuators for Dynamic Sweet Spot Control

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Solution Overview

Problem

Panel audio loudspeakers in mobile devices lack a natural orientation fiducial due to uniform sound radiation, and their 'sweet spot' for optimal sound quality is not consistently located, making it difficult to direct sound effectively.

Innovation Solution

Incorporating two actuators at opposite ends of the panel, with adjustable amplitude and phase, and using sensors to align the drive signals for constructive interference at a specific location, allowing for manipulation of the sweet spot's position and size based on user proximity and device status.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If panel audio loudspeakers radiate sound uniformly across the entire panel, then the sound distribution is even, but there is no natural fiducial for orienting the device and the sweet spot is not consistently located

Engineering Contradiction:
Improvenatural fiducial for orienting deviceVSAvoidsound radiation uniformity
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent divides the panel audio loudspeaker into multiple independent actuator zones (first actuator and second actuator at opposite ends of the panel). Each actuator can be independently controlled to generate bending waves with adjustable amplitude and phase, allowing the system to create a consistent sweet spot location by coordinating the segmented actuator regions rather than relying on uniform radiation from the entire panel.

Inventive Principle:
Principle #1Segmentation

2Area of stationary object

If a single actuator is used in the panel audio loudspeaker, then the device complexity is low, but the sweet spot size and loudness are limited

Engineering Contradiction:
Improvesweet spot sizeVSAvoidnumber of actuators
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent combines multiple actuators (first actuator and second actuator) into a single panel audio loudspeaker system where they work cooperatively. The actuators are positioned at opposite ends of the panel and driven with coordinated signals to generate bending waves that constructively interfere at a specific sweet spot location. This merging of multiple actuator functions allows the system to achieve a larger and louder sweet spot while maintaining manageable complexity through integrated control.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If the sweet spot is focused at a particular location, then sound quality is maximized, but sound is also emitted from other areas of the panel which may compromise privacy

Engineering Contradiction:
Improvesound quality at sweet spotVSAvoidunwanted sound emission
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent implements local quality by using independent control of each actuator zone to concentrate acoustic energy specifically at the desired sweet spot location. By adjusting the amplitude and phase of bending waves from the first and second actuators, the system maximizes sound quality at the target location while minimizing sound emission from other areas of the panel, thereby addressing privacy concerns through spatially selective acoustic output.

Inventive Principle:
Principle #3Local quality

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 solution enhances the size and loudness of the sweet spot, enabling dynamic audio output direction and mode switching between near-field and far-field modes, improving sound quality and privacy by minimizing unwanted sound emission.

Implementation Method 1

Typically, the actuators are electromagnetic or piezoelectric actuators

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 2

Typically, the actuators are electromagnetic or piezoelectric actuators

Methodology Applied
Scientific EffectPiezoelectric actuation: Piezoelectric Effect

Implementation Method 3

the drive signals can be time aligned such that vibrations generated by the actuators constructively interfere at a particular coordinate on the panel

Methodology Applied
Scientific EffectConstructive interference: Interference

Implementation Method 4

panel audio loudspeakers operate by exciting a distribution of vibration modes in a panel using an electro-acoustic actuator

Methodology Applied
Scientific EffectAcoustic radiation: Sound

Data Source

PatentEP3794841B1Dual panel audio actuators and mobile devices including the same
Publication Date: 2024.06.26 GOOGLE LLC
  • EP3794841B1 patent drawingFigure 1
  • EP3794841B1 patent drawingFigure 2
  • EP3794841B1 patent drawingFigure 3

AI summary

A method for producing an audio signal from a panel audio loudspeaker in a mobile device includes receiving information about a status of the mobile device from one or more sensors of the mobile device. The method further includes driving, with a first drive signal, a first actuator coupled to a display panel of the panel audio loudspeaker at a first location and simultaneously driving, with a second drive signal, a second actuator coupled to the display panel at a second location different from the first location. The method also includes varying a relative timing of the first and second drive signals based on the information about the status of the mobile device to vary a direction of an audio signal and/or a source location of the audio signal on the display panel.