Airguide Backlight Assembly Using Reflective Pan Curvature
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Solution Overview
Problem
Conventional backlight assemblies, particularly edge-lit systems, face challenges in achieving uniform light distribution and efficiency due to the limitations of traditional light guides, which often fail to effectively homogenize and out-couple light from non-uniform light sources.
Innovation Solution
The use of air as a light guide, combined with a lens to capture light and a reflective pan with optimized curvature or varying reflectivity to homogenize and out-couple light, along with optional blinders for further control, replaces traditional light guides, allowing for improved light distribution and emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional light guides are used in edge-lit backlight assemblies, then the structure is simple and easy to manufacture, but the light distribution is non-uniform and homogenization is insufficient
Solution Approach 1:
The patent removes the traditional light guide component from the backlight assembly and replaces it with air as the light transmission medium. This extraction of the solid light guide material eliminates the complexity associated with manufacturing and integrating traditional light guides while maintaining the essential light transmission function. The airgap between the light source and diffuser serves as the light guide, simplifying the overall structure.
Solution Approach 2:
The patent changes the physical state of the light guide from solid (traditional light guide material) to gas (air). This parameter change from solid to gas phase eliminates manufacturing complexity associated with solid light guides while enabling effective light homogenization through the airgap configuration combined with diffuser elements.
2Ease of manufacture
If traditional light guides are used, then manufacturing is easier, but light homogenization and out-coupling efficiency are insufficient
Solution Approach 1:
The patent introduces air as an intermediary medium between the light source and the diffuser element. This airgap acts as a mediator that facilitates efficient light transmission and homogenization without requiring complex solid light guide structures. The air intermediary enables effective light distribution while maintaining manufacturing simplicity.
3Illumination intensity
If air is used as the light guide instead of traditional light guides, then light homogenization and distribution are improved, but the device complexity increases due to lens and pan components
Solution Approach 1:
The patent employs a reflective pan with optimized curvature that uses the natural reflection properties of light to achieve homogenization without requiring additional active control mechanisms. The pan's geometry is designed to passively redirect and distribute light uniformly, allowing the system to self-regulate light distribution through geometric optics rather than complex electronic control systems.
Solution Approach 2:
The patent utilizes a reflective pan with optimized curvature (spheroidal or parabolic surfaces) to control and homogenize light distribution. The curved geometry of the pan naturally redirects light rays from the edge-mounted LED source to achieve uniform illumination across the display area, leveraging geometric optics principles to reduce the need for additional homogenization components.
4Volume of moving object
If edge-lit configuration with traditional light guides is used, then the assembly is compact, but light extraction and out-coupling are inefficient
Solution Approach 1:
The patent utilizes thin film diffusers positioned in the airgap to enhance light out-coupling efficiency. These thin film elements are integrated into the compact edge-lit structure without significantly increasing volume, yet they dramatically improve light extraction and distribution by scattering and homogenizing the light as it passes through the airgap to the display surface.
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 solution enables efficient and uniform light distribution in various display applications, including LCDs and static displays, using diverse light sources like LEDs and fluorescent tubes, enhancing the overall performance of backlight assemblies.
Implementation Method 1
a lens is used to capture the light
Implementation Method 2
a pan is used to homogenize and out-couple the light. The pan can have constant reflectivity, or reflectivity which changes based on the location within the pan
Implementation Method 3
backlight assembly using only air as the light guide ('airguide')
Data Source
AI summary
The exemplary embodiments herein provide an airguide backlight assembly having an anterior element, a reflective pan positioned posterior to the anterior element, and a light source positioned to direct light towards the reflective pan. A lens element may be placed in front of each light source. The reflective pan preferably contains a slope or curve so that light emitted from the light sources can be reflected and/or refracted to distribute the light uniformly to the anterior element. In some embodiments, blinders may be positioned between the light sources and the anterior element as well as between the light sources and the reflective pan.