Spotlight Homogeneous Illumination Using Light Mixing Rod
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spotlights fail to achieve homogeneous illumination in both the near and far fields while maintaining a narrow beam angle and high illuminance, which is essential for accentuating objects like clothing, due to the limitations of parabolic reflectors and total reflection concepts.
Innovation Solution
A spotlight design featuring a hollow reflector with a conical mirror surface and a Fresnel lens, combined with a light mixing rod and scattering device, ensures homogeneous illumination and a well-collimated beam, meeting the requirements of a narrow beam angle, high illuminance, and compact installation space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a parabolic reflector or total reflection concept is used, then a narrow beam angle is achieved, but homogeneous illumination in the near field cannot be achieved
Solution Approach 1:
A light mixing rod is introduced as an intermediary component between the light source and the reflector. This mixing rod homogenizes the light from multiple LEDs before it reaches the parabolic reflector, enabling the reflector to produce a narrow beam while maintaining near-field homogeneity. The mixing rod acts as a mediator that transforms the combined light from multiple sources into a uniform illumination pattern.
Solution Approach 2:
The lighting system is segmented into multiple independent LED sources arranged in a specific geometric pattern, with each LED contributing to the overall light field. By segmenting the light source into multiple discrete elements and controlling their spatial arrangement, the system achieves both directional beam formation and homogeneous illumination when combined with the light mixing rod.
2Illumination intensity
If multiple light-emitting diodes with different colors are used to achieve high luminosity, then illuminance is improved, but light mixing requires a light mixing rod which increases device complexity
Solution Approach 1:
The light mixing rod serves multiple functions simultaneously: it mixes light from multiple LEDs of different colors, homogenizes the combined light, and prepares the light for directional reflection. This multi-functionality reduces the need for separate components for each function, thereby reducing overall device complexity while maintaining high luminosity from multiple color channels.
Solution Approach 2:
Multiple LED light sources emitting different colors are merged into a single illumination path through the light mixing rod. Instead of requiring separate optical paths or complex mixing mechanisms, the patent combines all light sources and their colors into one unified light beam that is then directed by the reflector, simplifying the overall system architecture.
3Manufacturing precision
If a long light mixing rod is used to achieve sufficient light mixing, then homogeneity is improved, but installation space increases
Solution Approach 1:
The light mixing rod uses optimized geometric parameters including a specific cross-sectional shape (triangle, quadrangle, pentagon, or hexagon) and controlled surface features (ripples or棱 facets). By changing the geometric parameters of the mixing rod rather than simply increasing its length, sufficient light mixing and homogeneity are achieved within a compact space suitable for installation.
Solution Approach 2:
The light mixing rod incorporates curved or angled surfaces including ripples and棱 facets that create multiple internal reflections. These curved and angled surfaces increase the light mixing efficiency per unit length, allowing adequate homogeneity to be achieved in a shorter rod length that fits within constrained installation spaces.
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 design achieves a homogeneous light field with a high illuminance and a narrow beam angle in both near and far fields, overcoming the limitations of previous technologies by minimizing light field inhomogeneities and heat generation issues, while maintaining a compact form factor.
Implementation Method 1
the light-mixing rod guiding the light emitted by the light-emitting diodes by total reflection occurring at its borders
Implementation Method 2
The light guided in this way hits a scattering device
Implementation Method 3
the reflector is a hollow reflector, has a conical mirror surface and in which a lens is arranged in the light path behind the hollow reflector
Implementation Method 4
a lens is arranged in the light path behind the hollow reflector
Data Source
AI summary
The invention relates to a spotlight that can be used as a spot light, comprising several LEDs, a light mixing rod, a diffuser or diffusing film, a conical hollow reflector, and a lens. This allows a homogeneous light field to be achieved in the near field. The LEDs can be of different colors.