Segmented LED Arrays with Diffusing Elements for Uniform Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Segmented LED arrays with walls between segments can produce discernible patterned illumination due to imaging by optical elements, which is undesirable, and defocusing may not completely eliminate this pattern.
Innovation Solution
Incorporating diffusing elements such as continuous layers or dome-shaped structures of diffuser material over the LEDs, positioned between the light emitter or wavelength-converter structures and optical elements, to diffuse light and achieve more uniform illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If walls are added between LED segments to separate them optically, then light leakage between segments is reduced, but discernible patterned illumination appears in the far-field image
Solution Approach 1:
A diffuser layer is introduced as an intermediary element between the LED segments and the far-field imaging plane. This diffuser mediates the light propagation by scattering the light rays, thereby preventing the formation of discernible patterns while maintaining optical separation between segments. The diffuser acts as a mediator that transforms the directed light from walls into scattered light that eliminates patterning.
2Illumination intensity
If optical elements are used to collect light from LEDs, then illumination intensity is improved, but patterned illumination from segmented structure becomes visible
Solution Approach 1:
The diffuser layer serves as an intermediary positioned between the optical elements and the illuminated target. It receives the collected light from optical elements and redistributes it through scattering, thereby maintaining high illumination intensity while eliminating the patterned structure that would otherwise be visible in the far-field image.
3Object-generated harmful factors
If defocusing is applied to eliminate patterned illumination, then discernible patterns are reduced, but illumination uniformity is not fully achieved
Solution Approach 1:
Instead of changing the focus parameter of optical elements, the invention changes the scattering parameter by introducing a diffuser layer. This parameter change in light propagation characteristics achieves superior illumination uniformity compared to simple defocusing, as the diffuser actively scatters light to fill in dark regions while maintaining overall brightness.
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 use of diffusing elements in segmented LED arrays effectively blurs out patterning in the far-field image, approximating a diffuse extended light source and reducing discernible patterns, thereby improving illumination uniformity.
Implementation Method 1
a plurality of columns of a diffuser material provided over the light emitter arrangement or the wavelength-converter structure and configured to diffuse light emerging from the light emitter arrangement or the wavelength-converter structure
Data Source
AI summary
LED arrays with diffusing elements are disclosed. In various embodiments, diffusing elements in the form of one or more structures of a diffuser material may be provided between an LED array and an optical element that collects light emitted by the array and directs the light to an optical far field. The optical element may image or approximately image the LED array. The diffusing elements at least partially blur patterning in the far field illumination that may otherwise arise from the optical element imaging the array. Each LED may be a wavelength-converting LED in that it may include a light emitter arrangement and a wavelength-converter structure.