Waveguide Illumination Panels with Alternating-Density Extraction Patterns
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Solution Overview
Problem
Conventional wide-area light emitting devices face challenges in efficiently coupling, decoupling, and distributing light, leading to optical losses and suboptimal performance in achieving desired angular distribution and uniformity.
Innovation Solution
A wide-area solid-state illumination device employing a light guiding sheet with a two-dimensional pattern of discrete surface microstructures, including alternating light extraction and separation areas, and a grid of optically opaque members to enhance light extraction and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional edge-lit illumination systems are used, then light can be coupled into the waveguide, but light extraction and distribution efficiency deteriorates leading to optical losses
Solution Approach 1:
The waveguide surface is segmented into multiple discrete light extraction features arranged in a two-dimensional pattern, including light extraction areas and separation areas. This segmentation allows controlled light extraction at specific locations rather than uniform extraction, improving light distribution efficiency and reducing optical losses.
Solution Approach 2:
Different regions of the waveguide surface are given different optical properties through alternating light extraction areas and separation areas. The light extraction areas have high extraction efficiency while separation areas provide regions for light redistribution, creating local quality variations that optimize overall light extraction and distribution.
2Illumination intensity
If conventional waveguide illumination systems are used, then light can be distributed across the waveguide, but achieving desired angular distribution and uniformity deteriorates
Solution Approach 1:
The illumination system is segmented into distinct light extraction areas and separation areas arranged in a periodic two-dimensional pattern. This segmentation enables independent optimization of light extraction and angular distribution without requiring complex optical components, achieving desired uniformity through geometric arrangement.
3Productivity
If light extraction features are added to the waveguide surface, then light extraction efficiency improves, but manufacturing complexity increases
Solution Approach 1:
The light extraction features are formed using a mask or template that can be replicated across the waveguide surface. This copying approach allows consistent reproduction of the two-dimensional pattern of light extraction and separation areas, simplifying manufacturing while maintaining high light extraction efficiency.
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 solution improves light extraction and distribution efficiency, achieving uniform luminance and reduced energy waste, with the ability to create visually distinct patterns and enhance overall illumination performance.
Implementation Method 1
The light guiding sheet is configured for guiding light between opposing edges using optical transmission and a total internal reflection
Implementation Method 2
The light scattering material is disposed in optical contact with the surface and configured for extracting light from the light guiding sheet
Data Source
AI summary
A method of making a wide-area waveguide illumination system includes providing a sheet of optically transmissive material having first and second broad-area surfaces and at least one light input edge, the sheet configured to guide light using total internal reflection. A two-dimensional pattern of light extraction features with variable areal density is formed on at least one of the surfaces, including alternating higher-density and lower-density light extraction areas across at least one dimension of the sheet. Distances between light extraction features in higher-density areas are generally less than distances between features in lower-density areas. One or more solid-state light sources are provided to illuminate the light input edge such that emitted light is guided within the sheet and partially extracted through the pattern of light extraction features. An image print may be disposed in an energy-receiving relationship with respect to the sheet such that extracted light illuminates the print.