Foam Light Diffuser for Uniform Illumination
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Solution Overview
Problem
Existing direct illumination devices for transmissive display devices face challenges in maintaining a uniform surface light source due to the instability of diffusion plates, which can deform under temperature changes, vibration, and weight, leading to inconsistent light distribution and reduced display quality.
Innovation Solution
Incorporating a foam layer between the light emitting elements and the optical sheet in the illumination device, which diffuses light through repeated refraction, scattering, and reflection, eliminating the need for a diffusion plate and maintaining a stable distance for uniform light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a diffusion plate is used to diffuse light from point light sources, then light distribution is improved, but the diffusion plate deforms under temperature changes, vibration, and weight, leading to instability
Solution Approach 1:
The patent introduces a foam material as an intermediary substance between the light emitting elements and the optical sheet. This foam serves as a mediator that diffuses light through its cellular structure while maintaining dimensional stability, replacing the unstable diffusion plate in the optical path.
Solution Approach 2:
The patent utilizes a foam material with a porous cellular structure to diffuse light. The foam's three-dimensional network of cells acts as a light-diffusing medium, scattering light rays as they pass through the porous structure, thereby achieving uniform illumination without requiring a separate diffusion plate.
2Illumination intensity
If a diffusion plate is provided to convert point light sources to surface light sources, then light uniformity is improved, but the device structure becomes more complex and manufacturing costs increase
Solution Approach 1:
The patent combines the light-diffusing function with the spacing function into a single foam element. The foam simultaneously serves as the diffusion medium and as the spacer that maintains the optical distance between the light emitting elements and the optical sheet, eliminating the need for separate diffusion plate and spacer components.
Solution Approach 2:
The foam material performs multiple functions within the illumination device: it acts as a light diffuser, a structural spacer, and a cushioning element. This multi-functional approach simplifies the overall device structure by replacing multiple specialized components with a single versatile foam element.
3Illumination intensity
If an optical distance is provided between light emitting elements and optical sheet, then light diffusion is improved, but the device thickness increases
Solution Approach 1:
The patent employs a foam material with a compressed cellular structure that provides significant light-diffusing capability within a thin profile. The three-dimensional network of cells in the foam creates multiple light scattering events over a short distance, achieving effective diffusion without requiring large thickness.
Solution Approach 2:
The patent optimizes the foam's physical parameters including cell size, cell density, and compression ratio to achieve the desired light diffusion effect within a minimized thickness. By adjusting these parameters, the foam provides adequate optical distance for diffusion while maintaining a compact overall device structure.
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 foam layer ensures a stable and uniform surface light source is formed, preventing deformation of the optical sheet and bezel, allowing for thinner device designs and improved display quality with reduced manufacturing costs.
Implementation Method 1
diffuses light through repeated refraction, scattering, and reflection
Implementation Method 2
diffuses light through repeated refraction, scattering, and reflection
Implementation Method 3
diffuses light through repeated refraction, scattering, and reflection
Data Source
AI summary
According to one embodiment, an illumination device includes a substrate, a plurality of light emitting elements mounted on the substrate, an optical sheet located on the light emitting elements, and a foam located between the light emitting elements and the optical sheet and overlapping the light emitting elements.