LED Lens Aspheric Design for Uniform Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED light source devices for LCD displays face challenges in achieving uniform light distribution and scattering ability, leading to issues like bright spots, chromatic aberration, increased manufacturing costs, and heat accumulation due to high density layouts, which are difficult to address with conventional optical lenses.
Innovation Solution
An LED lens with a light incident surface and emitting surface designed to have specific aspheric and optically active areas, including recessions and convex portions, which refract light to achieve an effective divergence angle of at least 120° and improve illumination uniformity, reducing the need for high-density layouts and minimizing chromatic aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the refractive power of the light control emission face is enhanced to improve scattering ability, then the light distribution uniformity improves, but Fresnel reflection is generated and total flux decreases
Solution Approach 1:
The light control emission face is divided into different regions with different optical properties: a central first light emitting region with downwardly curved convex configuration and an outer second light emitting region with flat or upwardly curved configuration. This local differentiation allows the central region to provide scattering for uniformity while the outer region minimizes Fresnel reflection to preserve total flux.
Solution Approach 2:
The first light emitting region employs an asymmetric downwardly curved convex configuration that differs from the outer second light emitting region. This asymmetric design optimizes the light path in the central region to achieve scattering effect while reducing reflection losses compared to a symmetric design.
2Illumination intensity
If multiple light source devices are arranged closer to each other to ease uneven light pattern, then the light distribution uniformity improves, but the device complexity and manufacturing cost increase
Solution Approach 1:
Multiple light emitting regions (first and second light emitting regions) are merged into a single integrated light control emission face on one optical lens. This combining approach achieves uniform light distribution through the differential optical design of regions while avoiding the complexity of multiple separate light source devices.
3Length of stationary object
If the light emission angle is increased to reduce distance between light source device and LCD panel, then the device thickness reduces, but the light pattern uniformity deteriorates due to concentrated outgoing light flux
Solution Approach 1:
Different regions of the light control emission face provide different optical functions: the central first light emitting region with downwardly curved convex configuration scatters light to improve uniformity, while the outer second light emitting region controls light direction for wide emission angle. This local differentiation achieves both thinness and uniformity simultaneously.
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 LED lens provides improved illumination uniformity and scattering ability, reducing the number of LED devices required, minimizing heat accumulation and costs, while enhancing display quality and reducing thickness, thus addressing the limitations of conventional LED light source devices.
Implementation Method 1
An LED lens with a light incident surface and emitting surface designed to have specific aspheric and optically active areas, including recessions and convex portions, which refract light to achieve an effective divergence angle of at least 120°
Data Source
AI summary
An LED lens and a light emitting device using the same are disclosed. The LED lens comprises a light incident surface, a light emitting surface, and a bottom surface. The light emitting surface includes a first recession portion disposed at the central thereof and a protrusion portion connected to the outer periphery of the emitting recession portion. The light incident surface comprises a first optically active area and a second optically active area. The first optically active area is disposed at the central of the light incident surface, and has a second recession portion; the second optically active area is a concave surface connected to the first optically active area. The LED lens satisfies specific conditions. The LED lens distributes a light beam emitted from the light emitting device to form an even light pattern.