Waveguide Sub-Assembly for Reducing Light Loss in Illumination Devices

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Solution Overview

Problem

Existing illumination devices using discrete light sources, such as LEDs, face inefficiencies due to light obstruction and absorption by structural components and neighboring light sources, leading to reduced illumination efficiency, especially in devices with multiple light sources.

Innovation Solution

The development of sub-assemblies that position discrete light sources above other components and incorporate a waveguide for controlled light propagation, with a geometric contour complementary to the waveguide recess, providing mechanical support, electrical connectivity, and thermal management, while minimizing light obstruction and absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If discrete light sources are positioned within the waveguide using a complementary contour structure, then light coupling efficiency is improved and light loss is reduced, but device complexity increases due to the specialized structure

Engineering Contradiction:

Improvelight lossVSAvoidstructure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The sub-assembly structure is nested within the waveguide recess, with the carrier containing the discrete light source positioned inside the waveguide body. This nesting arrangement allows the light source to be embedded within the optical path without requiring external mounting structures, thereby improving light coupling efficiency while containing the complexity within a compact nested configuration.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention transitions from positioning light sources at the waveguide edge (two-dimensional surface mounting) to embedding them within the waveguide volume (three-dimensional internal positioning). The complementary contour structure enables this dimensional transition by providing a shaped recess that accommodates the sub-assembly, allowing light to be coupled from within the waveguide volume rather than from the surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Productivity

If discrete light sources are positioned above other components to minimize light obstruction, then illumination efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveillumination efficiencyVSAvoidfabrication process

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The sub-assembly is pre-configured with the discrete light source mounted on the carrier in the correct elevated position before integration into the waveguide. The complementary contour structure is pre-formed in the waveguide recess to receive this pre-assembled unit, allowing the light source to be positioned above other components for optimal illumination efficiency while simplifying the final assembly process through pre-integrated sub-components.

Inventive Principle:

Principle #10Preliminary action

3Area of stationary object

If multiple discrete light sources are used to create large illumination devices, then illumination coverage is improved, but light absorption by neighboring sources and structures increases

Engineering Contradiction:

Improveillumination coverageVSAvoidlight absorption

Core Design Contradiction:

Area of stationary objectVSLoss of energy

Solution Approach 1:

The illumination device is segmented into multiple independent sub-assemblies, each containing a discrete light source on its own carrier. These modular segments are distributed within the waveguide structure, allowing each light source to operate independently with its own optimized optical path. This segmentation prevents light from one source being absorbed by neighboring sources while collectively providing broad illumination coverage through the combined output of multiple segments.

Inventive Principle:

Principle #1Segmentation

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 light coupling efficiency by positioning discrete light sources within the waveguide, reducing light loss and absorption, and allowing for efficient emission, thereby improving the overall illumination efficiency of the devices.

Implementation Method 1

a waveguide for the controlled propagation and emission of light

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The top surface of the carrier may be reflective

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS8231237B2Sub-assembly and methods for forming the same

Publication Date: 2012.07.31 OREE ADVANCED ILLUMINATION SOLUTIONS LTD

AI summary

A sub-assembly matable to a waveguide having a recess therein includes a structure comprising a discrete light source disposed on a carrier, and a substrate and a heat spreader disposed beneath the structure. The structure has a contour complementary to the recess, such that, when the sub-assembly is joined to the waveguide, the discrete light source is within the waveguide.