Edge-Lit Light Source Bending Region for Narrow Bezel and Hotspot Reduction
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Solution Overview
Problem
Edge-lit light sources for display devices face challenges in achieving a narrow bezel design while minimizing hotspot defects, as the short light-mixing distance can lead to increased bezel size and poor light utilization, resulting in alternating light and dark images due to inefficient light scattering within the light guide plate.
Innovation Solution
The edge-lit light source incorporates a light guide layer with a bending region between the light incident and exit surfaces, enhancing light mixing and scattering by arranging light guide bars and extending portions to increase the light-mixing distance, and using a light-guide-layer shaping member and reflective adhesives to maintain total reflection and prevent light leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the light guide plate uses a short light-mixing distance design, then the bezel size is reduced, but the light scattering efficiency deteriorates causing hotspot defects and alternating light and dark images
Solution Approach 1:
The light guide plate incorporates a bending region with a specific curvature radius (R1) between the light incident surface and light exit surface. This curved structure extends the light-mixing distance within a compact bezel space, enabling effective light scattering without increasing the overall device size. The curvature causes light rays to traverse a longer path through the light guide plate, improving uniformity and eliminating hotspot defects.
2Productivity
If the light guide plate extends the light-mixing distance, then the light scattering efficiency is improved, but the bezel size increases
Solution Approach 1:
The bending region is positioned at a specific location within the light guide plate structure, utilizing the thickness dimension (with thickness T satisfying 0.1mm < T ≤ 0.5mm) to create the curvature. This allows the light-mixing distance to be extended in three-dimensional space without increasing the two-dimensional footprint or bezel size, effectively decoupling light scattering performance from device dimensions.
3Productivity
If multiple light guide layers are stacked, then the light guide efficiency is improved, but the device complexity increases
Solution Approach 1:
Multiple light guide layers are stacked in the thickness direction with their bending regions aligned, forming an integrated light guide structure. This merging approach allows light to be distributed across multiple layers, improving light guide efficiency and uniformity. The aligned bending regions work together to scatter light effectively, achieving high performance without requiring complex independent structures for each layer.
Solution Approach 2:
The multiple light guide layers are arranged in a nested stack configuration, with each layer containing the same bending region structure. This nested arrangement allows the light guide system to achieve enhanced light mixing and scattering capabilities through layer multiplication, while maintaining a compact overall structure that does not linearly increase 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
This design reduces the bezel size, improves light guide efficiency, and minimizes hotspot defects by ensuring complete light mixing and uniform brightness distribution across the display area, thereby achieving a narrow bezel design without compromising image quality.
Implementation Method 1
the bending region includes all of the bending portions of the light guide layer
Implementation Method 2
enhancing light mixing and scattering by arranging light guide bars and extending portions to increase the light-mixing distance
Data Source
AI summary
An edge-lit light source includes at least two light guide layers and one or more light-emitting elements. Side surfaces of each layer include a light incident surface and a light exit surface. The layer includes a bending region. A light-emitting surface of each element faces a light incident surface of at least one layer. The layer includes first and second light guide portions. An end surface of the first light guide portion is the light exit surface. The second light guide portion includes at least two light guide bars each including a bending portion and an extending portion. A surface of the extending portion is a light incident sub-surface. The light-emitting surface of each element faces at least one light incident sub-surface. Second light guide portions of the at least two layers are arranged in a second direction perpendicular to a thickness direction of the first light guide portion.