Compact Lighting Device Using Nested Solid State Emitters
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Solution Overview
Problem
Current lighting technologies face challenges in achieving efficient energy use, long operational lifetimes, and good color rendering index (CRI) in general illumination, particularly with solid state light emitters, as they often require complex heat management and struggle with uniform color mixing in compact designs.
Innovation Solution
A lighting device incorporating a light mixing element that reflects a specified percentage of light emitted by solid state light emitters, ensuring efficient light distribution and uniform color output, with a compact design that maintains high brightness and color mixing capabilities, using a light mixing element with a small size and specific surface area ratios to optimize light exit and entrance regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional lighting device uses multiple solid state light emitters to provide bright light, then the brightness increases, but the device size increases and light mixing becomes difficult
Solution Approach 1:
The patent places multiple solid state light emitters and the light mixing element within a compact, nested configuration where the light mixing element is positioned between the emitters and the exit aperture. This nesting allows multiple light sources to be integrated into a small volume without increasing the overall device size proportionally, achieving bright light output in a compact form factor.
Solution Approach 2:
The patent uses a light mixing element with specific geometric features (such as a hemispherical or dome-shaped structure) that utilizes three-dimensional light propagation and reflection. By designing the mixing element with curved surfaces and specific optical paths, the patent achieves effective light mixing in a compact volume by exploiting spatial dimensionality rather than simply increasing the device footprint.
2Stability of the object's composition
If a light mixing element is made larger to improve light mixing, then color uniformity improves, but the device complexity and size increase
Solution Approach 1:
The patent applies different optical properties to different regions of the light mixing element. The mixing element includes a light incident surface facing the solid state light emitters and a light exit surface with specific geometric features. This local differentiation of optical properties allows effective light mixing and color uniformity to be achieved in a compact structure without requiring the entire device to be complex or large.
Solution Approach 2:
The light mixing element features curved surfaces, such as a hemispherical or dome-shaped structure, that utilize spherical geometry to achieve uniform light distribution. The curved surfaces naturally redirect light rays from multiple emitters through total internal reflection and refraction, creating uniform color output without requiring complex mechanical mixing structures or large device dimensions.
3Use of energy by moving object
If solid state light emitters are used to improve energy efficiency, then energy consumption decreases, but heat management becomes more critical
Solution Approach 1:
The light mixing element serves as an intermediary component that also functions as a thermal management element. While its primary optical function is to mix light from multiple emitters, its physical presence and thermal conductivity properties help distribute and dissipate heat away from the light emitting diodes, providing passive thermal management that supports the high energy efficiency of solid state lighting.
4Stability of the object's composition
If the light mixing element reflects more light to improve mixing efficiency, then color uniformity improves, but light loss through absorption increases
Solution Approach 1:
The curved, hemispherical geometry of the light mixing element utilizes total internal reflection at the curved interfaces to redirect light rays without requiring additional reflective coatings. This geometric design achieves efficient light mixing through multiple internal reflections while minimizing absorption losses that would occur with flat surfaces or coated reflectors, thereby maintaining high light output 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 enables a compact lighting device to achieve high brightness and uniform color mixing with improved energy efficiency and extended operational lifetimes, addressing the limitations of existing technologies in solid state lighting systems.
Implementation Method 1
at least about 10 percent of light emitted by the first solid state light emitter that enters the light mixing element is reflected at least once within the light mixing element
Data Source
AI summary
A lighting device comprising a solid state light emitter and a light mixing element, in which at least ten of light emitted by the emitter that enters the mixing element is reflected within the mixing element, and the mixing element is not larger than 16 mm. Also, a lighting device comprising an emitter and a mixing element comprising first and second regions. Also, a lighting device comprising a light emitter and a mixing element, in which a light exit region of the mixing element has a surface area between about 50% to about 300% of a surface area of a light entrance region of the mixing element. Also, a lighting device comprising a light emitter, a mixing element and a light output shaping element which defines an exit aperture having a dimension that is at least three times a largest dimension of the first light mixing element.