Head-Mounted Device Speaker Module Counter-Vibration Noise Reduction

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Solution Overview

Problem

Existing head-mounted devices suffer from mechanical vibration of the shell caused by the speaker, which interferes with the voice input quality of the bone conduction microphone by mixing noise with the voice signal.

Innovation Solution

The head-mounted device incorporates a speaker module with two speaker units having opposite vibration directions of their sound diaphragms in specific frequency bands to offset shell vibrations, combined with air conduction microphones and a voice control module for signal processing to enhance voice quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a speaker is provided in the head-mounted device for sound output, then sound output function is achieved, but mechanical vibration of the shell is caused which interferes with voice input quality

Engineering Contradiction:

Improvemechanical vibration noiseVSAvoidvoice input quality

Core Design Contradiction:

Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The patent employs a counter-vibration mechanism where a counter-vibration speaker generates vibrations opposite to those produced by the main speaker. This counter-vibration speaker is driven with an inverted signal to create equal and opposite mechanical vibrations, thereby canceling out the shell vibrations that interfere with the bone conduction microphone's voice input quality.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent converts the harmful mechanical vibrations into a beneficial effect by using the same vibration source (speaker) to generate both the sound output and the counter-vibration. The vibration that was previously purely harmful is now utilized as a control signal to drive the counter-vibration speaker, transforming the problem into a solution.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Measurement precision

If a bone conduction microphone is used for voice input, then voice input function is achieved, but voice quality is degraded by noise from shell vibration

Engineering Contradiction:

Improvevoice input qualityVSAvoidnoise from shell vibration

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The counter-vibration speaker acts as an active damping mechanism that generates forces to counterbalance the shell vibrations. By positioning the counter-vibration speaker strategically and driving it with the inverted audio signal, the system creates opposing vibrations that neutralize the harmful effects on the bone conduction microphone's performance.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The system uses feedback by monitoring the vibrations caused by the main speaker and using this information to drive the counter-vibration speaker. The inverted signal serves as a feedback mechanism that automatically adjusts the counter-vibration in real-time to maintain optimal voice input quality throughout the frequency range.

Inventive Principle:

Principle #23Feedback

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 design significantly reduces mechanical vibration noise, improving the voice quality input by the bone conduction microphone and enhancing sound quality of the speaker module while maintaining effective noise reduction and echo cancellation.

Implementation Method 1

vibration directions of the sound diaphragms of the two speaker units are opposite at a first frequency band

Methodology Applied

Scientific EffectMechanical vibration: Vibration

Implementation Method 2

offset the forces exerted by the sound diaphragms of the two speaker units on the shell, thereby greatly reducing the intensity of mechanical vibration generated by the shell

Methodology Applied

Scientific EffectVibration offset: Damping

Implementation Method 3

each speaker unit includes a magnetic circuit structure, a voice coil and a sound diaphragm

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS20250211887A1Head-mounted device

Publication Date: 2025.06.26 GEER TECH CO LTD

AI summary

Disclosed is a head-mounted device, which includes a device body, a wearing portion, a bone conduction microphone and a speaker module. The wearing portion is connected to an end of the device body, the bone conduction microphone is provided at the wearing portion, and the speaker module is provided at the wearing portion. The speaker module includes two speaker units. Each speaker unit includes a magnetic circuit structure, a voice coil and a sound diaphragm. The distribution directions of the two speaker units are parallel to the distribution directions of the magnetic circuit structure and the sound diaphragm of at least one of the speaker units, and vibration directions of the sound diaphragms of the two speaker units are opposite at a first frequency band.