Light Guide Plate Microstructures for Backlight Brightness Uniformity
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Solution Overview
Problem
Conventional backlight modules with point light sources, such as LEDs, suffer from light leakage and uneven brightness due to the directional nature of these sources, leading to poor appearance brightness uniformity and hot spots on the light incidence side.
Innovation Solution
A light guide plate with microstructure regions on its light-emitting surface, featuring stripe or dot microstructures parallel or perpendicular to the light incidence surface, which scatter incident light to blur leakage and improve brightness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If point light sources (LEDs) are used in backlight modules, then energy efficiency and lifespan are improved, but light leakage and uneven brightness occur due to the directional nature of these sources
Solution Approach 1:
The patent applies local quality by creating microstructure regions with different surface characteristics at specific locations on the light guide plate. The light-emitting surface includes a first region with first microstructures and a second region with second microstructures, where each region has tailored optical properties to control light distribution locally, thereby improving overall brightness uniformity while maintaining energy efficiency of LED sources
Solution Approach 2:
The patent introduces dimensional complexity by adding microstructures that extend in multiple directions and orientations on the light guide plate surface. The first and second microstructures are arranged with different orientations and extend in different directions, creating a multi-dimensional light scattering pattern that effectively distributes directional LED light across the display area, resolving the brightness uniformity issue
2Illumination intensity
If the cover's covering range is extended to prevent light leakage, then appearance uniformity improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the light control function from the cover structure and transfers it to the light guide plate itself through microstructure regions. By incorporating optical control features directly into the light guide plate, the cover can maintain a simpler design with extended covering range for better appearance uniformity, while the complex light distribution function is handled by the integrated microstructures rather than requiring complex cover geometry
Solution Approach 2:
The light guide plate is designed to perform multiple functions: it guides light from LEDs, distributes light uniformly through microstructure regions, and integrates optical control features that previously would have required separate components. The first and second microstructure regions work together to simultaneously address different aspects of light distribution, reducing overall device complexity
3Illumination intensity
If microstructure regions with stripe or dot microstructures are added to the light guide plate, then brightness uniformity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent segments the light-emitting surface into distinct microstructure regions with different characteristics. The first microstructure region contains first microstructures with specific orientations, while the second microstructure region contains second microstructures with different orientations. This segmentation allows for targeted light control in different areas and can be implemented through modular manufacturing processes, reducing overall manufacturing complexity compared to creating entirely new uniform structures across the entire surface
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 microstructures effectively scatter light, enhancing brightness uniformity and reducing the spray phenomenon caused by directional point light sources, resulting in a more uniform and improved appearance brightness distribution.
Implementation Method 1
The stripe microstructures can scatter incident light of a non-visible region, so that leakage light on the non-visible region can be effectively blurred
Implementation Method 2
The dot microstructures can blur light reflected back to a light-emitting surface of the light guide plate, so that a spray phenomenon caused by point light sources with high directionality can be greatly improved
Data Source
AI summary
A light guide plate and a backlight module are described. The light guide plate includes a main body and a plurality of stripe microstructures. The main body includes a light incidence surface, a light-emitting surface and a light reflective surface. The light-emitting surface is opposite to the light reflective surface, and the light incidence surface is connected between the light-emitting surface and the light reflective surface. The light-emitting surface includes a microstructure region adjacent to the light incidence surface. The stripe microstructures are arranged in the microstructure region, and parallel to a normal line of the light incidence surface.