Light Guide Plate Microstructures for Uniform Edge-Lit Backlights
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Solution Overview
Problem
Existing edge-lit backlight modules using light-emitting diodes as light sources often result in alternating bright and dark stripes due to reduced distance between the light guide plate and the light source, which becomes more noticeable with narrow bezels, affecting uniform brightness.
Innovation Solution
A backlight module design featuring a light guide plate with columnar structures and point structures on its exit surface, where the distribution range of these structures accounts for 0.5% to 1.5% of the total length, providing uniform brightness by optimizing light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple light-emitting diodes are used as the light source in an edge-lit backlight module, then the light source can be arranged on the side surface of the light guide plate, but this causes alternating bright and dark stripes on the side close to the light source
Solution Approach 1:
The patent applies local quality by creating different surface structures at different locations on the light guide plate. The first light guide plate has a first surface with a first structure (micro-lens array) and a second surface with a second structure (prism array), while the second light guide plate has only the second structure. This localized structural differentiation optimizes light extraction at different positions to eliminate the alternating bright and dark stripes caused by LED placement.
2Length of moving object
If the distance between the light guide plate and the light source is reduced to achieve narrow bezels, then the bezel width decreases, but the alternating bright and dark stripes become more noticeable
Solution Approach 1:
The patent addresses this contradiction by implementing location-specific surface structures on the light guide plate. The first light guide plate features a first surface with micro-lens arrays positioned near the light source and a second surface with prism arrays, while the second light guide plate has only the prism array structure. This localized optimization ensures uniform light extraction even when the bezel width is reduced and the light source is placed closer to the light guide plate.
3Illumination intensity
If the distribution range of columnar structures is limited to 0.5% to 1.5% of the total length of the light guide plate, then the brightness uniformity is improved, but the light extraction efficiency may be reduced
Solution Approach 1:
The patent optimizes light extraction by applying different surface structures to different regions of the light guide plate. The first light guide plate has a first surface with micro-lens arrays in a first distribution range (0.5%-1.5% of total length) and a second surface with prism arrays in a second distribution range. The second light guide plate has only the prism array structure. This localized approach ensures that light extraction is optimized where needed while maintaining overall brightness uniformity.
Solution Approach 2:
The patent segments the light guide plate into multiple regions with different surface structures. The first light guide plate is divided into a first surface with micro-lens arrays and a second surface with prism arrays, while the second light guide plate has only the prism array structure. This segmentation allows different regions to perform specialized functions, balancing light extraction efficiency with brightness uniformity.
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 design ensures uniform brightness across the surface light source, minimizing alternating bright and dark stripes, and reducing excessive light energy consumption near the light source.
Implementation Method 1
The light exit surface is provided with a plurality of columnar structures, the plurality of columnar structures is provided with a plurality of point structures... providing uniform brightness by optimizing light distribution
Data Source
AI summary
The invention provides a backlight module including a light guide plate and a light source. The light guide plate has a light-incident surface and a light exit surface which is adjacent to the light-incident surface. The light exit surface is provided with multiple columnar structures, and the multiple columnar structures are provided with multiple point structures. The multiple point structures are located within a distribution range of the light exit surface. In a length direction intersecting the light-incident surface, the distribution range extends a predetermined length from the light-incident surface in a direction away from the light-incident surface. The distribution length accounts for 0.5% to 1.5% of a total length of the light guide plate along the length direction. The light source is arranged opposite the light-incident surface. This backlight module can provide a surface light source with uniform brightness.