Light Guide Plate Microstructures for Uniform Backlight Illumination
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Solution Overview
Problem
In liquid crystal displays, the light exiting from a light guide plate is non-uniform due to specific light source angles creating dark zones and light leakage occurs as some incident light is directed to the side surfaces of the plate.
Innovation Solution
A light guide plate with first and second minute projection structures coated with high reflectivity material, where the first structures define included angles towards the light incidence surface to redirect light to gap areas and the second structures reflect light back into the plate to prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If light sources are positioned at specific angles in the backlight module, then the light guide plate can be simplified in structure, but dark zones appear at gap locations between light sources causing non-uniform light distribution
Solution Approach 1:
The invention applies local quality by creating different microstructures at different locations on the light guide plate. First minute projection structures are positioned at light source locations to control light extraction, while second minute projection structures are positioned at gap locations to prevent dark zones. Each location has optimized microstructure characteristics tailored to its specific function, achieving uniform light distribution without complicating the overall structure.
2Illumination intensity
If microstructures are added to the light guide plate to improve light uniformity, then light distribution becomes more even, but light leakage occurs at side surfaces reducing light utilization
Solution Approach 1:
The invention uses local quality by implementing different microstructure types at different locations. First minute projection structures with specific angular orientations control light extraction at light source positions, while second minute projection structures at side surface locations reflect stray light back into the light guide plate, preventing light leakage and improving overall light utilization.
Solution Approach 2:
The invention converts the harmful effect of stray light that would otherwise leak at side surfaces into a beneficial effect. The second minute projection structures intercept light that would leak and redirect it back into the light guide plate, transforming light loss into useful light that contributes to uniform illumination.
3Loss of energy
If minute projection structures are introduced to control light direction, then light leakage is reduced, but the manufacturing complexity of the light guide plate increases
Solution Approach 1:
The invention applies parameter changes by optimizing the geometric parameters of the minute projection structures, including their size, shape, and angular orientation. By carefully selecting these parameters, the structures achieve effective light control while maintaining compatibility with existing manufacturing processes, balancing performance improvement with manufacturing ease.
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
Enhances light uniformity by preventing dark zones and increases light utilization by reflecting stray light back into the plate, improving overall light distribution and reducing optic loss.
Implementation Method 1
the first minute projection structures each comprise at least two side faces coated with a high reflectivity material and the at least two high reflectivity material coated side faces of the first minute projection structure define at least one included angle pointing toward the at least one light incidence surface
Implementation Method 2
the second minute projection structures each comprise a side face that is coated with a high reflectivity material and the side face of the second minute projection structure defines two angles, which are less than 90°, with respect to a closest light incidence surface and a closest light guide plate side surface
Data Source
AI summary
A light guide plate includes a light exit surface, a reflection surface opposite to the light exit surface, at least one light incidence surface connecting to the light exit surface and the reflection surface, and two side surfaces. The reflection surface includes first and second minute projection structures projecting toward interior of the light guide plate, the second minute projection structures being arranged between the first minute projection structures and the two side surfaces of the light guide plate. The first minute projection structures each include at least two side faces coated with a high reflectivity material and forming at least one included angle pointing toward the at least one light incidence surface. The second minute projection structures each include a side face coated with a high reflectivity material and defining two angles, which are less than 90°, with respect to a light incidence surface and a side surface.