Batwing LED Optical System for Uniform Illuminance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing batwing optical systems are not designed for light-emitting diodes (LEDs), which have different emission characteristics compared to incandescent and discharge lamps, limiting their ability to achieve uniform illuminance beyond 20-25° angles in lighting applications like roadway lighting.
Innovation Solution
A radiation distribution system featuring a dielectric lens with a tapered center and rounded end sections, combined with elongated reflective surfaces, redirects light from LEDs to produce a batwing distribution pattern, enhancing illuminance uniformity up to 30° or more.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional collimators are used, then acceptable uniformity is achieved for angles up to 20-25°, but illuminance uniformity deteriorates sharply for angles of 30° or more due to the 1/cos³(φ) factor
Solution Approach 1:
The patent applies parameter changes by designing a batwing intensity distribution P(φ) that specifically compensates for the 1/cos³(φ) factor. The luminous intensity is engineered to increase with angle according to a predetermined batwing curve, transforming the optical parameters to achieve uniform illuminance at large angles (30° or more) where conventional collimators fail.
Solution Approach 2:
The patent employs asymmetry in the light emitting element array configuration, where LEDs are positioned at different locations and orientations to create an asymmetric intensity distribution that produces the desired batwing pattern. This asymmetric arrangement allows different parts of the array to contribute differently to various angular regions, achieving uniform illuminance across the required angular range.
2Adaptability or versatility
If batwing optical systems designed for incandescent and discharge lamps are used, then those systems work for spherical emission sources, but they cannot achieve uniform illuminance beyond 20-25° when applied to LEDs with different emission characteristics
Solution Approach 1:
The patent fundamentally changes the optical parameters by designing a batwing intensity distribution P(φ) tailored specifically for LED emission characteristics. Unlike prior art optimized for spherical incandescent sources, this system uses a predetermined intensity curve that accounts for LED's directional emission, enabling uniform illuminance at angles of 30° or more.
Solution Approach 2:
The patent segments the light source into multiple discrete LEDs arranged in specific patterns (such as rectangular or circular arrays). Each LED contributes to the overall intensity distribution, and by controlling the individual positions and emission characteristics of these segmented sources, the system achieves the desired batwing distribution that works specifically for LED arrays rather than single point sources.
3Device complexity
If the luminous intensity P(φ) follows a conventional uniform distribution, then the system is simple to design, but the illuminance becomes non-uniform at angles beyond 20-25° due to the cosine effect
Solution Approach 1:
The patent intentionally complicates the intensity distribution parameter by implementing a batwing P(φ) curve instead of uniform distribution. This deliberate parameter change increases design complexity but is necessary to counteract the 1/cos³(φ) factor and achieve uniform illuminance at large angles. The predetermined intensity profile is calculated to specifically compensate for angular cosine effects.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and pre-designing the batwing intensity distribution P(φ) to anticipate and compensate for the 1/cos³(φ) factor before light reaches the target surface. The optical system is configured in advance with specific LED positions and emission characteristics that will produce the required intensity variation, so that when light arrives at the surface, uniform illuminance is achieved without requiring additional corrective 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
The system effectively generates a batwing distribution pattern suitable for LEDs, improving illuminance uniformity and coverage in applications such as roadway lighting, architectural lighting, and surface street lighting.
Implementation Method 1
A lens is disposed on a mount surface. The lens has a dielectric surface comprising a middle section having a center region that is tapered in from both sides and two rounded end sections
Implementation Method 2
At least one elongated reflective surface is disposed external to the lens and proximate to the lens
Data Source
AI summary
A radiation distribution system designed to produce a batwing distribution. The system may be used with radiative sources emitting in the visible spectrum or in other spectra. The system comprises a specially shaped lens disposed over a radiative source, such as an LED, for example. The lens and source are arranged between two reflector bodies, both of which have an elongated reflective surface that faces the source. The reflector bodies each have two different reflective surfaces that face outward and away from each other. The lens and both reflective surfaces work in concert to redirect a portion of the emitted radiation to create the desired batwing distribution. Several sources may be arranged linearly between a single pair of reflector bodies on a common surface to create a linear array of sources. Likewise, multiple linear arrays may be combined to form a two-dimensional array. In the two-dimensional configuration, linear arrays of sources are disposed on both sides of a reflector body, so that both of the reflective surfaces are utilized.