HMD Audio Output Assembly with Rear Sound Conduit

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional head-mounted displays (HMDs) face challenges in generating high-quality audio output due to limited housing size, requiring separate audio devices rather than integrated components.

Innovation Solution

The HMD incorporates a housing with a speaker positioned within an enclosure, defining a back volume for sound enhancement, and a sound conduit that transmits sound from the speaker to the rear, allowing for integrated audio output assemblies that direct sound towards the user's ears.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a speaker is integrated within the HMD housing, then audio output quality is improved, but the housing size and complexity increase

Engineering Contradiction:
Improveaudio output qualityVSAvoidhousing structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The speaker is nested within an enclosure formed by the housing, with the back volume defined between the housing and the back side of the speaker. The sound conduit is nested within the housing structure, extending through the aperture to transmit sound. This nesting approach integrates audio components within the limited HMD housing space without significantly increasing external dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The sound conduit extends in a rear direction from the speaker enclosure through the housing aperture, utilizing the depth dimension of the housing to route sound toward the user's ear. This dimensional approach allows sound transmission without requiring lateral expansion of the housing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the HMD housing is kept compact, then ease of wearing is improved, but integrated audio components cannot be accommodated

Engineering Contradiction:
Improveease of wearingVSAvoidintegrated audio capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The sound conduit extends rearward from the speaker through the housing aperture in the depth direction, utilizing available space within the compact housing to route sound toward the user's ear without increasing the front-to-back profile significantly. This allows integrated audio while maintaining a compact form factor suitable for wearing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The housing includes a specific aperture positioned to allow sound conduit penetration, creating a localized opening for audio output. The enclosure is specifically configured to position the speaker with its front side facing away from the interior surface, optimizing sound direction toward the user's ear while maintaining overall housing compactness.

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 design enables high-quality, integrated audio output within the HMD, enhancing sound generation and transmission while maintaining a compact form factor, suitable for virtual, augmented, or mixed reality systems.

Implementation Method 1

A back volume is defined between at least a portion of the housing and the back side of the speaker for enhancing sound generated by the speaker

Methodology Applied
Scientific EffectAcoustic resonance: Resonance

Implementation Method 2

The sound conduit having an end open to the enclosure and extends outside the housing through the aperture. The sound conduit has another end open toward a rear direction to transmit the sound generated by the speaker

Methodology Applied
Scientific EffectAcoustic wave propagation: Sound

Data Source

PatentEP3439322B1Audio output assembly for a head-mounted display
Publication Date: 2022.03.16 META PLATFORMS TECHNOLOGIES LLC
  • EP3439322B1 patent drawingFigure 1
  • EP3439322B1 patent drawingFigure 2A
  • EP3439322B1 patent drawingFigure 2B

AI summary

A head-mounted display (HMD) includes a housing defining an enclosure having an aperture. A is speaker positioned within the enclosure, the speaker having a back side facing an interior surface of the housing and a front side facing away from the interior surface of the housing, a back volume defined between at least a portion of the housing and the back side of the speaker for enhancing sound generated by the speaker. A sound conduit having an end open to the enclosure and extends outside the housing through the aperture. The sound conduit has another end open toward a rear direction to transmit the sound generated by the speaker.