Head-Mounted Infrared Illumination for Low-Light Tracking

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Solution Overview

Problem

Head-mounted devices struggle to provide adequate illumination for cameras in low-light conditions, which affects the performance of hand and body tracking, visual inertial odometry, and other camera-based functions.

Innovation Solution

A supplemental infrared illumination system with adjustable light sources is integrated into the head-mounted device, providing targeted and power-efficient infrared illumination to enhance camera performance in low-light environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a camera is positioned low to the ground for wildlife photography, then the ability to capture animals in their natural habitat is improved, but the available natural light is insufficient

Engineering Contradiction:
Improveability to capture animals in natural habitatVSAvoidavailable natural light
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

A light guide acts as an intermediary between the distant light source and the camera position. The light guide captures light from the environment and transports it through a fiber optic bundle to illuminate the camera sensor, enabling low-angle photography with sufficient illumination without directly positioning lights near the camera.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If supplemental lighting is added to improve illumination, then the illumination intensity is improved, but the natural appearance of the image deteriorates

Engineering Contradiction:
Improveillumination intensityVSAvoidunnatural appearance
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The light guide system serves as an intermediary that collects and redirects ambient light rather than introducing artificial light sources. This preserves the natural quality and color temperature of the illumination while providing sufficient brightness for low-angle photography.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the spatial parameters of light delivery by transporting light through a flexible fiber optic bundle from a distant collection point to the camera position. This allows the light to appear as if it comes from the natural environment rather than an artificial source.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a remote light guide is used to transport light from a distance, then the adaptability to low-angle positioning is improved, but the light intensity loss over distance increases

Engineering Contradiction:
Improvelow-angle positioning capabilityVSAvoidlight intensity loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The lighting system is segmented into multiple fiber optic bundles that can be arranged in parallel. Each bundle carries a portion of the total light requirement, allowing the system to scale to meet illumination demands while maintaining flexibility for remote positioning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light guide utilizes the third dimension (vertical space) by routing the fiber optic bundle along the camera housing or tripod structure. This allows light to be transported from a horizontal distance while minimizing bending losses by using gentle curves rather than sharp angles.

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

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

The system ensures effective tracking and imaging capabilities in low-light conditions without disturbing those around the user, conserving power, and maintaining seamless operation of the device.

Implementation Method 1

A supplemental illumination system includes a light guide and an optical fiber bundle. The optical fiber bundle transmits light through its length to a position near the camera lens.

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Data Source

PatentEP4229468B1Systems with supplemental illumination
Publication Date: 2026.05.20 APPLE INC
  • EP4229468B1 patent drawingFigure 1
  • EP4229468B1 patent drawingFigure 2
  • EP4229468B1 patent drawingFigure 3

AI summary

A head-mounted device may have a head-mounted support structure. Displays may present images to eye boxes at the rear of the head-mounted support structure. Cameras and other sensors may be supported by the head-mounted support structure. Tracking cameras may be used to track the movement of a user's hands or other external objects. In dim ambient lighting conditions, a supplemental illumination system may be activated to provide supplemental illumination for the tracking cameras. A single beam of supplemental illumination may be emitted over a given coverage area or a smaller beam of supplemental illumination may be steered across the given coverage area. Light-emitting devices such as infrared light-emitting diodes and infrared lasers may be used to form infrared light sources for the supplemental illumination system.