Light Guide Lens for Uniform LED Backlight Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LED backlight modules for liquid crystal displays suffer from non-uniform illumination due to the point source nature of LEDs, leading to hot spots and increased production and assembly costs, with existing lens structures being complex and inefficient in lateral light emission, resulting in energy loss and bulky designs.
Innovation Solution
A light guide lens with a lens body featuring refraction structures to refract incident light into parallel rays and reflection structures to facilitate lateral emission, minimizing energy loss and simplifying assembly, made from resin or transparent polymer with convex refraction and inclined plane reflection surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional LED point source is used for backlight illumination, then the LED provides high brightness and energy efficiency, but the illumination becomes non-uniform with visible hot spots
Solution Approach 1:
The lens surface is segmented into multiple functional zones: a spherical refraction surface for converting divergent light into parallel beams, and planar reflection surfaces for redirecting light laterally. This segmentation allows different portions of the lens to perform specific optical functions, transforming the point source emission pattern into a uniform lateral emission pattern without compromising energy efficiency
Solution Approach 2:
The invention transitions the light emission from a vertical point-source pattern to a lateral planar emission pattern by using the refraction surface to create parallel beams and the reflection surfaces to redirect them horizontally. This dimensional transformation eliminates hot spots while maintaining the energy efficiency of LED sources
2Illumination intensity
If a serrate lens structure is used to achieve lateral light emission, then some uniform illumination is improved, but the structure becomes complex and increases manufacturing costs
Solution Approach 1:
Instead of using a complex serrate structure, the invention segments the lens into a spherical refraction surface and multiple planar reflection surfaces. This simpler segmentation achieves the same lateral emission function with reduced manufacturing complexity and lower production costs
Solution Approach 2:
Rather than using a serrate outer surface to refract light laterally as in conventional lenses, the invention inverts the approach by using a spherical inner surface to create parallel beams and planar surfaces to reflect light laterally. This inverted design simplifies the outer surface to a smooth contour while achieving the desired optical effect
3Speed
If a serrate outer surface lens cap is used for lateral emission, then light direction is controlled, but production costs increase due to combination of dies requirement
Solution Approach 1:
The invention inverts the conventional lens design by placing the complex refraction function on the spherical inner surface and using simple planar reflection surfaces for lateral emission. This allows the outer surface to be a smooth contour that can be manufactured as a single piece, eliminating the need for combination of dies and reducing production costs while maintaining precise light direction control
4Speed
If light is refracted multiple times in a conventional lens cap, then lateral emission is achieved, but light energy loss increases
Solution Approach 1:
The lens is segmented into a spherical refraction surface for single-pass beam collimation and planar reflection surfaces for single-pass lateral redirection. This segmentation ensures that light undergoes only one refraction and one reflection, minimizing energy loss while achieving efficient lateral emission
Solution Approach 2:
The invention converts the potentially harmful effect of multiple refractions (which cause energy loss) into a beneficial single refraction-single reflection path. The spherical refraction surface efficiently collimates light in one pass, and the planar reflection surfaces redirect it laterally in one pass, transforming what would be a multi-step energy-loss-prone process into a streamlined single-refraction single-reflection system
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 achieves efficient lateral light emission with minimal energy loss, reducing manufacturing costs and eliminating the need for auxiliary structures, providing uniform illumination and a more compact design.
Implementation Method 1
The plurality of refraction structures are formed on the light incidence surface and configured to refract the incident light such that the incident light travels toward the light emission surface. Each of the refraction structures turns incident light rays coming in all directions into parallel light rays by refraction.
Implementation Method 2
The plurality of reflection structures are formed on the light emission surface such that light rays from the refraction structures reflect off the reflection structures and laterally exit the lens body.
Data Source
AI summary
A light guide lens includes a lens body having a light incidence surface and a light emission surface, a plurality of refraction structures formed on the light incidence surface, and a plurality of reflection structures formed on the light emission surface. The refraction structures send incoming light rays to the light emission surface by refraction. Each of the refraction structures turns incoming light rays coming in all directions into refracted parallel light rays. The refracted parallel light rays arriving from the refraction structures reflect off the corresponding reflection structures and then laterally exit the lens body. The refracted parallel light rays arriving from each of the refraction structures travel to a corresponding one of the reflection structures, such that eventually the incoming light rays exit laterally. The present invention further provides a light emitting diode package structure having the light guide lens.