Planar Light Source Asymmetric Unit Spacing for Luminance Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Planar light sources often suffer from luminance unevenness due to variations in light distribution across their surface, which can affect the performance of applications such as liquid crystal displays.
Innovation Solution
A planar light source design featuring a light guide member with grooves separating light-emitting units, where the number and arrangement of light-emitting units are optimized to ensure uniform brightness, using a combination of light-emitting elements and reflective members to control light transmission and reflection, thereby reducing luminance disparities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light sources are arranged in a regular grid pattern, then the structure is simple and easy to manufacture, but luminance unevenness occurs due to different numbers of adjacent light-emitting units
Solution Approach 1:
The patent applies asymmetry by intentionally creating non-uniform spacing between light-emitting units. Specifically, the distance between adjacent light-emitting units is made different in different regions of the light guide plate. This asymmetric arrangement compensates for the natural luminance decay and ensures that outer portions (which have fewer adjacent units) receive sufficient light while inner portions (which have more adjacent units) do not become overly bright, thereby achieving uniform overall luminance distribution.
2Device complexity
If outer portions have fewer adjacent light-emitting units, then the structure is simpler, but brightness becomes higher causing luminance unevenness
Solution Approach 1:
The patent applies local quality by making the spacing between light-emitting units position-dependent. Different regions of the light guide plate have different spacing characteristics: regions with fewer adjacent light-emitting units (outer portions) have smaller distances to neighboring units, while regions with more adjacent units (inner portions) have larger distances. This localized adjustment of spacing ensures that each region receives appropriate light intensity, achieving uniform luminance across the entire plate despite structural simplicity.
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 achieves a more uniform luminance distribution across the planar light source, enhancing its performance and reducing luminance unevenness, which is critical for applications like liquid crystal display backlights.
Implementation Method 1
a light guide member (10), one or more light sources (20A)
Implementation Method 2
using a combination of light-emitting elements and reflective members to control light transmission and reflection
Data Source
AI summary
A planar light source includes a light guide member including light-emitting units separated by a groove and one or more light sources disposed in one or more of the light-emitting units. The light-emitting units include outer portions and at least one inner portion located in a region surrounded by the outer portions in a plan view. In the plan view, at least one of the outer portions is adjacent to a smaller number of light-emitting units than a number of light-emitting units to which one of the at least one inner portion is adjacent. In a state in which the same power is supplied and one of the outer portions and one of the at least one inner portion are allowed to individually emit light, brightness of the one of the outer portions is higher than brightness of the one of the at least one inner portion.