Lens Array with Color-Mixing Rods for Low Etendue LED Lighting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LED-based lighting devices for stage lighting face challenges in achieving low etendue while providing uniform color and brightness, as existing optical systems often increase etendue to achieve directed beams, compromising their effectiveness.
Innovation Solution
The development of an optical system for multi-color, multi-emitter LED-based lighting devices that includes a lens array with color-mixing rod members and a beam-forming section, optimized to align with emitters on a printed circuit board, which combines light from multiple LEDs to produce a uniform beam with low etendue and high color uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If secondary optical systems are used to provide directed beams, then beam directionality is improved, but etendue increases
Solution Approach 1:
The optical system is divided into multiple lens elements, each associated with a specific emitter, arranged in a segmented array configuration. Each lens element independently processes light from its corresponding emitter, maintaining low etendue while achieving collective beam directionality through the segmented structure.
Solution Approach 2:
The patent transitions from conventional single-element optics to a two-dimensional array of lens elements, adding spatial dimensionality to the optical system. This dimensional expansion allows simultaneous control of multiple emitters while preserving low etendue characteristics through the structured arrangement in the array plane.
2Power
If multiple LED emitters are combined to increase light output, then luminous flux is improved, but color uniformity deteriorates
Solution Approach 1:
The optical system segments the multi-emitter array into individual emitter-lens pairs, where each lens element processes light from a specific emitter. This segmentation maintains color integrity from each emitter while combining multiple emitters to increase total luminous flux, preventing color mixing that would degrade uniformity.
Solution Approach 2:
Each lens element in the array is optimized for its specific emitter with local quality characteristics, including emitter-specific optical parameters and positioning. This local optimization ensures that each emitter's unique color characteristics are preserved while the overall array achieves high total luminous flux through the coordinated operation of multiple locally-optimized elements.
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 enables the creation of a uniform, controllable light beam with optimized etendue and color mixing, enhancing the ability to spotlight specific areas and achieve desired lighting effects without increasing etendue, thus improving the efficiency and effectiveness of LED-based stage lighting.
Implementation Method 1
a lens array that can be formed as a unitary structure made of a material that is transparent to optical wavelengths
Implementation Method 2
The lens array can include a number of color-mixing rod members extending parallel to each other along an optical axis, with the color-mixing rod members being arranged and spaced so that the rear end of each color-mixing rod member aligns with a different one of the emitters on the emitter plate
Data Source
AI summary
An optical system for a multi-color, multi-emitter LED-based lighting device can include a lens array. The lens array can include a number of color-mixing rod members extending parallel to each other along an optical axis, the color-mixing rod members being arranged and spaced so that the rear end of each color-mixing rod member aligns with a different one of the emitters. A beam-forming section can be formed at the front ends of the color mixing rod members. The beam-forming section can include nonplanar (e.g., convex or concave) front surface features, each nonplanar front surface feature being aligned with a front end of a corresponding one of the color-mixing rod members. The beam-forming section and color-mixing rod members can be formed as a unitary structure.