Light Guide Panel Reflective Grooves for Uniform Edge-Lit Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light guide panels in edge light type backlight units suffer from the generation of dark portions due to inadequate light distribution, leading to irregular brightness and reduced display quality, particularly in small-sized displays.
Innovation Solution
A light guide panel with dark portion reducing units, such as oblique grooves, curved, or semi-conical surfaces, positioned along the incidence surface adjacent to light sources, which reflect light to enhance uniformity and reduce dark areas, combined with diffusion units to diffuse incident light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If light sources are installed at lateral sides of light guide panel (edge light type), then the backlight unit size is reduced and is suitable for small/medium displays, but dark portions are created near the light sources due to insufficient lateral light emission
Solution Approach 1:
The patent applies local quality by introducing dark portion reducing units with specific reflective properties at the lateral sides of the light guide panel where dark portions occur. These units have different optical characteristics (higher reflectivity) compared to other regions, specifically addressing the local brightness deficiency near light sources while maintaining overall system compactness
Solution Approach 2:
The dark portion reducing units act as intermediary elements between the light sources and the display panel. They mediate the light distribution by reflecting lateral light emissions from LEDs toward the display panel, thereby converting the harmful concentrated lateral light into useful distributed illumination that reduces dark portions
2Illumination intensity
If light sources are installed directly under liquid crystal display (direct light type), then brightness uniformity is improved, but the backlight unit size increases making it unsuitable for small displays
Solution Approach 1:
The patent transitions from a direct light configuration (light sources below the panel) to an edge light configuration with dimensional redistribution of light paths. By positioning light sources at lateral edges and using the light guide panel to distribute light across the surface, the system achieves compactness in the vertical dimension while maintaining brightness uniformity through optical path extension in horizontal dimensions
3Use of energy by moving object
If LED emits most light forward with decreasing efficiency from 0° to 90°, then light emitting efficiency is improved in forward direction, but lateral light emission is insufficient creating dark portions
Solution Approach 1:
The patent converts the harmful effect of concentrated forward light emission (which causes dark portions at lateral regions) into a benefit by using dark portion reducing units to reflect the excess lateral light. The units capture light that would otherwise be wasted or create dark spots and redirect it to illuminate dark portions, thereby utilizing the LED's directional emission characteristic productively
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 effectively minimizes dark portions, ensuring uniform brightness and increasing the usable screen area by redirecting lateral light emissions, thus improving display quality and enabling miniaturization of backlight units for smaller displays.
Implementation Method 1
at least one dark portion reducing unit formed in the incidence surface below the upper surface and positioned along the incidence surface adjacent to a position of the light source, and which reflects light toward the upper surface
Implementation Method 2
a lower surface facing the upper surface and reflecting the light incident from the incident surfaces and dark portion reducing units
Implementation Method 3
Diffusion units that are disposed on the incidence surface facing the light sources and diffuse the incident light from the light sources
Data Source
AI summary
Provided are a light guide panel and a display device employing the same. The light guide panel includes: an incidence surface facing a plurality of light sources separated apart a predetermined distance; at least one dark portion reducing unit that is formed on the incidence surface between adjacent pairs of the slight sources and at both edges of the incidence surface, and reflects the light incident from the light sources to reduce the creation of dark portion units; an upper surface transmitting a portion of incident light and reflecting the rest of the incident light; and a lower surface facing the upper surface and reflecting the light incident from the incidence surfaces and dark portion reducing units.