Short-Throw Illumination Lens Geometry for Uniform Wide-Angle Light
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Solution Overview
Problem
Existing wide-angle illumination systems for short-throw lighting, such as in LCD backlights and refrigerator cabinets, face challenges in achieving uniformity and efficiency due to the small size of LEDs and the difficulty in producing precise illumination lenses, especially with fewer LEDs required by advancements in LED flux output.
Innovation Solution
The development of a design method using photometric nonimaging optics to generate numerically specific lens configurations that provide uniform illumination patterns, compensating for distortions caused by volume scattering and Fresnel reflections, and employing elliptical and aspheric surfaces to achieve the required source magnification and demagnification for efficient light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fewer LEDs are used to reduce power consumption, then power savings are achieved, but uniformity of illumination becomes more difficult to achieve
Solution Approach 1:
The patent changes the optical parameters of the lens system by introducing an aspheric surface with specific curvature variations. This allows the lens to redistribute light from fewer LEDs more uniformly across the target area, compensating for the reduced number of light sources while maintaining illumination uniformity.
Solution Approach 2:
The patent employs an aspheric lens surface instead of a simple spherical or flat surface. The aspheric curvature profile is specifically designed to control light ray paths, ensuring uniform illumination distribution across the target area even when fewer LEDs are used as light sources.
2Device complexity
If the distance between LEDs is increased to reduce the number of LEDs, then device complexity is reduced, but the difficulty of achieving uniform illumination increases
Solution Approach 1:
The patent modifies the lens parameters including aspheric coefficients and surface curvatures to optimize light distribution. These parameter changes enable the lens to compensate for the increased spacing between LEDs, redistributing light paths to achieve uniform illumination coverage across the target area.
3Ease of manufacture
If conventional spherical lenses are used, then ease of manufacture is improved, but the ability to achieve precise illumination patterns and compensate for scattering is reduced
Solution Approach 1:
The patent transitions from simple spherical or flat lens surfaces to aspheric surfaces with precisely controlled curvature profiles. The aspheric design allows for better control of light ray paths and compensation of optical aberrations including scattering effects, while still being manufacturable using modern molding techniques.
4Length of moving object
If the lens size is reduced to fit thin display backlights, then device thickness is reduced, but the difficulty of achieving sufficient light distribution increases
Solution Approach 1:
The patent uses aspheric surface geometry to maximize the light distribution capability within a compact lens size. The aspheric curvature profile is optimized to spread light uniformly across the target area, achieving sufficient illumination coverage in thin backlight applications where conventional spherical lenses would fail.
Solution Approach 2:
The patent optimizes lens parameters including aspheric coefficients, surface curvatures, and thickness distribution to achieve effective light distribution in a reduced-size lens. These parameter adjustments enable the compact lens to maintain uniform illumination performance despite the reduced overall dimensions required for thin display backlights.
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 approach enables the use of fewer LEDs while maintaining uniformity and efficiency, reducing the size of illumination lenses, and effectively compensating for scattering issues, resulting in improved lighting patterns and reduced manufacturing costs.
Implementation Method 1
Illumination lenses to do the job
Implementation Method 2
compensating for distortions caused by volume scattering and Fresnel reflections
Data Source
AI summary
An illumination tens includes a light incident surface that defines a cavity and has a flat top surface and lateral flanks, the light incident surface configured to receive light from an underlying light emitting element, a light exiting surface having a central indentation and surrounding toroid, and a bottom surface connecting the light incident surface and the light exiting surface. The lateral flank includes a first region extending from the top surface and a second region extended from the first region, the second region is a curved surface, of which the center of the curvature thereof lies on the illumination lens, an intersection of the second region and a horizontal optical axis forms a first point, and the first point is disposed lower than a second point where the bottom surface and the light exiting surface intersect.