Light Guide Plate with Concentric Scattering Dots for Uniform Illumination
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Solution Overview
Problem
Direct-type backlight modules suffer from non-uniform illumination due to the random arrangement of scattering dots on light guide plates, which leads to inconsistent light output from point light sources.
Innovation Solution
A light guide plate with a scattering structure featuring concentrically arranged scattering dots on both the bottom and light output surfaces, along with a reflective plate and additional optical components like microprism, polarization, and diffusing plates, to uniformly distribute light from a point source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If scattering dots are arranged randomly on the light guide plate, then the manufacturing process is simple, but the illumination uniformity deteriorates
Solution Approach 1:
The patent applies local quality by arranging scattering dots with different densities in different regions of the light guide plate. Specifically, the first scattering dots are arranged in a first region and the second scattering dots are arranged in a second region, with each region having optimized local dot density and distribution patterns. This localized optimization ensures uniform light output across different areas while maintaining manufacturing feasibility.
Solution Approach 2:
The patent changes the parameters of scattering dot arrangement by specifying different density ranges for different regions. The first scattering dots have a density of 0.5-2 dots/mm² in the first region, while the second scattering dots have a density of 0.3-1.5 dots/mm² in the second region. These parameter optimizations improve illumination uniformity while keeping the manufacturing process practical.
2Device complexity
If point light sources are used in the backlight module, then the device structure is compact, but the light output uniformity deteriorates
Solution Approach 1:
The patent addresses the non-uniform light output from point light sources by implementing region-specific scattering dot arrangements. The light guide plate is divided into a first region containing a first light source and a second region containing a second light source, with each region having optimized scattering dot density and distribution patterns tailored to its specific light source characteristics, achieving overall uniformity despite using compact point sources.
Solution Approach 2:
The scattering dots on the light guide plate serve as an intermediary between the point light sources and the display panel. By carefully controlling the density and distribution of these scattering dots in different regions, the patent transforms the non-uniform point source emission into uniform diffuse light output, effectively mediating the optical characteristics without requiring complex additional optical components.
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 solution achieves greater than 85% uniformity of illumination, enhancing the performance of direct-type backlight modules by ensuring consistent light distribution across the display panel.
Implementation Method 1
The scattering structure is configured to scatter incident light propagating within the light guide plate
Implementation Method 2
The reflective plate 204 is located between the light source 200 and the bottom surface 212 of the light guide plate 202
Data Source
AI summary
A light guide plate includes a body having a bottom surface and a light output surface opposite to the bottom surface. A scattering structure is formed on the bottom surface. The scattering structure includes a plurality of scattering dots located in the form of a plurality of concentric shapes about the center. A backlight module using the light guide plate is also provided.