Hollow Light Recycling Backlight with Semi-Specular Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing backlights, particularly edge-lit and direct-lit types, face challenges such as large mass and weight, non-uniform illumination, high component costs, heat generation, and limitations in thinness due to the use of solid light guides and diffusing plates, which affect brightness and uniformity, especially in larger displays.
Innovation Solution
The implementation of a hollow light recycling cavity with semi-specular and reflective components that provide a balance of specular and diffuse characteristics, characterized by a transport ratio, and the use of LED sources with collimated light injection to achieve efficient lateral transport and mixing of light, reducing the need for multiple light sources and enhancing brightness and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If solid light guides and diffusing plates are used in backlights, then light transport and distribution are achieved, but mass and weight increase significantly
Solution Approach 1:
The patent extracts and removes the solid light guide and diffusing plate components from the backlight system, replacing them with a hollow cavity structure. This extraction eliminates the heavy solid materials while maintaining light distribution functionality through reflective surfaces and direct LED illumination in the hollow space.
Solution Approach 2:
The patent employs thin reflective films and shells to line the hollow cavity, replacing bulky solid light guides. These thin films provide the necessary optical reflection and light distribution properties with minimal mass, achieving weight reduction while maintaining illumination performance.
2Illumination intensity
If multiple light sources are used to achieve uniform illumination across large areas, then brightness uniformity improves, but device complexity and component costs increase
Solution Approach 1:
The patent transitions from a planar arrangement of multiple light sources to a three-dimensional hollow cavity structure. By utilizing the vertical dimension and reflective surfaces within the cavity, a single LED can illuminate the entire display area uniformly through multiple reflections, eliminating the need for arrays of light sources.
Solution Approach 2:
The hollow cavity with reflective surfaces acts as an intermediary between the single LED and the display panel. The reflective surfaces distribute and redirect light throughout the cavity, enabling uniform illumination across the entire display area from a single light source without requiring complex multi-source configurations.
3Illumination intensity
If solid light guides are used for light transport, then light distribution is achieved, but the backlight thickness increases
Solution Approach 1:
The patent extracts the solid light guide component and replaces it with a hollow cavity structure. This removal eliminates the thickness required for solid light transport materials while achieving light distribution through reflective surfaces and direct illumination within the hollow space.
Solution Approach 2:
The patent employs a hollow (air-filled) cavity structure instead of solid light guides. The air or vacuum within the hollow cavity eliminates the need for thick solid materials, achieving thin-profile construction while maintaining light distribution functionality through reflective surfaces.
4Illumination intensity
If conventional backlight components are used, then illumination is provided, but heat generation and component costs increase
Solution Approach 1:
The patent extracts and removes conventional heat-generating components such as solid light guides and diffusing plates, replacing them with a hollow cavity structure. This elimination reduces the material mass that absorbs and generates heat, leading to lower operating temperatures and reduced thermal management requirements.
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 approach results in thinner, lighter, and more uniform backlights with improved brightness and spatial uniformity, reducing component costs and heat issues while maintaining efficient light distribution across large areas.
Implementation Method 1
semi-specular and reflective components that provide a balance of specular and diffuse characteristics
Implementation Method 2
semi-specular and reflective components that provide a balance of specular and diffuse characteristics
Implementation Method 3
use of LED sources with collimated light injection to achieve efficient lateral transport and mixing of light
Implementation Method 4
characterized by a transport ratio, and the use of LED sources with collimated light injection to achieve efficient lateral transport and mixing of light
Data Source
AI summary
A hollow light-recycling backlight has a “semi-specular” component providing a balance of specularly and diffusely reflected light improving the uniformity of the light output. The component may be arranged on the reflectors (1021), (1014) or inside the cavity (1016). This balance is achieved by designing the component's “transport ratio” defined by (F−B)/(F+B), (F and B are the amounts of incident light scattered forwards and backwards respectively by the component in the plane of the cavity) to lie in a certain range. Furthermore, the product of the front and back reflector “hemispherical” reflectivities should also lie in a given range. Alternatively, the “cavity transport value”, a measure of how well the cavity can spread injected light from the injection point to distant points in the cavity should lie in a further range and the “hemispherical” reflectivity of the back reflector should be >0.7.