Light Guide Plate Stripe 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 the light sources, leading to poor appearance brightness uniformity and hot spots on the light incidence side.
Innovation Solution
A light guide plate with microstructures, including stripe and dot microstructures, is introduced near the light incidence surface to scatter incident light and blur leakage light, improving brightness uniformity by distributing light more evenly across the light-emitting surface.
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 the light sources
Solution Approach 1:
The patent applies local quality by introducing microstructures (prisms, gratings, or roughened surfaces) at specific locations on the light guide plate - particularly near the light incidence surface and at edges where light leakage occurs. These localized structural modifications selectively scatter and redirect light in problem areas without affecting the overall directional lighting efficiency of the LED sources, thus maintaining energy efficiency while improving brightness uniformity.
Solution Approach 2:
The light guide plate serves as an intermediary element between the directional LED light sources and the display panel. By incorporating microstructures into the light guide plate, it mediates the light transmission process by scattering and redistributing the directional light from LEDs into more uniform illumination across the display area, effectively decoupling the directional nature of LEDs from the uniformity requirement of the display backlight.
2Volume of moving object
If the cover length is reduced to improve module compactness, then the backlight module becomes more compact, but appearance light leakage increases in the non-visible region
Solution Approach 1:
The patent converts the potentially harmful light leakage phenomenon into a beneficial effect by using microstructures to intentionally scatter and redirect light that would otherwise leak. The microstructures transform the harmful direct light leakage into beneficial diffuse light distribution, improving appearance uniformity while allowing for compact module design with shorter covers.
Solution Approach 2:
The patent addresses the light leakage problem by adding structural complexity in the micro-scale dimension (microstructures on the light guide plate surface) rather than increasing the macro-scale cover length. This dimensional approach allows compact module design while effectively controlling light distribution through surface-level optical modifications.
3Illumination intensity
If microstructures are added to the light guide plate to improve brightness uniformity, then light scattering and brightness distribution are enhanced, but device complexity increases
Solution Approach 1:
The patent implements brightness uniformity improvement by modifying the physical parameters of the light guide plate through microstructures - changing the surface morphology at the micro-scale (prisms, gratings, or roughened surfaces). These parameter changes alter the optical path and scattering characteristics of light without requiring fundamental redesign of the entire backlight module architecture, thus enhancing brightness uniformity with minimal added complexity.
Solution Approach 2:
The patent merges the light guiding function and the light scattering function into a single integrated component - the light guide plate itself. By incorporating microstructures directly into the light guide plate, it simultaneously performs light transmission from LEDs and light scattering for uniformity, eliminating the need for separate scattering elements and reducing overall device complexity.
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 incident light, reducing light leakage and enhancing brightness uniformity, resulting in a more uniform and improved appearance brightness distribution in the backlight module.
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.