Fiber-Coupled Light Engine Layout for Compact HMD Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional HMD light engines have a cumbersome footprint due to the orthogonal arrangement of discrete components, requiring significant space that is not available in wearable devices.
Innovation Solution
The use of fiber optic strands and wavelength-specific channels to optically couple light sources with collimating lenses, reducing the overall footprint by combining and collimating light within a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If discrete components are combined in an orthogonal manner, then light combination and projection capabilities are achieved, but the footprint becomes cumbersome and too large for wearable devices
Solution Approach 1:
The patent merges multiple discrete optical components (laser diodes, collimating lenses, combiner) into an integrated waveguide structure. The waveguide combines wavelength-specific channels for different laser sources within a single component, eliminating the need for separate discrete components and their complex orthogonal arrangement, thereby significantly reducing the light engine footprint while maintaining light combination capabilities
Solution Approach 2:
The patent transitions from a planar orthogonal arrangement of discrete components to a three-dimensional waveguide structure with multiple wavelength-specific channels. This dimensional change allows light from multiple sources to be combined within the volume of the waveguide rather than requiring extended planar space, reducing the overall footprint while preserving optical functionality
2Volume of moving object
If the light engine size is reduced for wearable devices, then space efficiency improves, but the ability to accommodate necessary optical components becomes limited
Solution Approach 1:
The waveguide structure serves multiple functions simultaneously: it acts as a light transmission medium, a combiner for multiple wavelength sources, and a spatial organization structure for optical components. This multi-functionality allows the reduced-size light engine to maintain full optical capabilities without requiring separate dedicated components for each function
Solution Approach 2:
The waveguide is segmented into multiple wavelength-specific channels, each optimized for a particular laser source. This segmentation allows different optical paths to coexist within the compact waveguide volume, enabling the integration of multiple optical functions in a reduced-size configuration while maintaining the versatility needed for various optical components
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 significantly reduces the size of the light engine, allowing it to be housed efficiently within the limited space of wearable devices while maintaining optical performance.
Implementation Method 1
The fiber optic strands are bundled and terminate at a ferrule containing lens elements to combine the light from the individual fiber optic strands
Implementation Method 2
a ferrule containing lens elements to combine the light from the individual fiber optic strands into a combined beam
Implementation Method 3
to collimate the combined beam of light
Implementation Method 4
a lightguide having wavelength-specific channels (also referred to as a 'channeled lightguide'), where each of the channels is optically coupled to a light source
Data Source
AI summary
A light engine includes multiple laser diodes, each configured to emit laser light, and a light source unit having multiple channels, each of the channels is associated with one of the laser diodes and configured to transmit the laser light emitted from the corresponding laser diode. The channels may be, for example, fiber optic strands or optical pathways within a channeled lightguide. The light engine further includes a ferrule coupled to the light source unit and configured to receive the laser light from the light source unit and to output a collimated beam of laser light comprising each wavelength of laser light emitted by the laser diodes.