Foam Diffuser Plate with Porous Core for Light Uniformity

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Solution Overview

Problem

Conventional light diffuser plates are heavy and have low diffusion due to poor refractive index, failing to meet the needs of modern display screens for better light distribution and uniformity.

Innovation Solution

A foam diffuser plate with a foam core layer and protective layers made of specific materials, including PS and GPPS, with a foaming agent to create holes for improved light reflection and a quantum dot layer for enhanced optical performance, reducing weight and irregularity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional diffuser plates use solid substrate materials with inorganic or organic light diffusing agents, then light diffusion is achieved through refraction and scattering, but the plates become heavy in weight and have low diffusion performance due to poor refractive index

Engineering Contradiction:
Improvelight diffusion performanceVSAvoidweight of diffuser plate
Core Design Contradiction:
Illumination intensityVSWeight of moving object

Solution Approach 1:

The patent applies porous materials by incorporating a foam core layer with controlled cell structure into the diffuser plate. The foam core layer contains numerous closed cells that create internal surfaces for light scattering and reflection, achieving effective light diffusion while maintaining low weight. The porosity of the foam structure provides multiple light interaction paths without requiring heavy inorganic diffusing agents.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses composite materials by combining foam core layer (polystyrene-based foam) with protective layers containing inorganic diffusing agents (TiO2, SiO2). This composite structure leverages the low weight and internal scattering of the foam core while the protective layers provide additional surface-level diffusion. The combination achieves superior light diffusion performance with reduced overall weight compared to conventional solid substrate plates.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If conventional diffuser plates process surfaces with concave and convex dots or stripes to improve light dispersion, then light distribution uniformity is enhanced, but the structure becomes complex and diffusion performance remains limited due to poor refractive index

Engineering Contradiction:
Improvelight distribution uniformityVSAvoidstructural complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The foam core layer's cellular structure provides inherent light scattering capabilities through its three-dimensional network of cells. This porous structure naturally creates multiple light interaction paths and scattering centers throughout the bulk material, achieving uniform light distribution without requiring complex surface patterning. The internal foam structure replaces the need for surface concave-convex features.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent changes the refractive index parameter by using polystyrene-based foam material with appropriate refractive index properties. By adjusting the foam density, cell size, and composition, the optical parameters are optimized to enhance light scattering efficiency. This parameter optimization achieves good light distribution uniformity without adding structural complexity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If conventional diffuser plates use solid structure without foam, then structural strength is maintained, but total light reflection performance is poor and Mura effects occur due to insufficient diffusion

Engineering Contradiction:
Improvetotal light reflection performanceVSAvoidMura effects
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The foam core layer with its cellular structure provides extensive internal surfaces that scatter and reflect light in multiple directions. This porous structure significantly enhances total light reflection performance by creating numerous light-bouncing surfaces within the material bulk. The scattered light paths reduce direct transmission and enhance diffusion, preventing Mura effects caused by insufficient light scattering.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The foam core layer acts as an intermediary between the light source and the protective layers. It receives incident light, scatters it through its cellular structure, and redirects light toward the protective layers for further diffusion. This intermediary foam structure enhances overall light reflection performance and ensures uniform light distribution, reducing Mura effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 diffuser plate achieves better light reflection, uniformity, and reduced Mura effects, with improved brightness and color gamut, while being lighter and more heat-resistant.

Implementation Method 1

the light can be refracted, reflected, and scattered in different directions

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

the light can be refracted, reflected, and scattered in different directions

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

the light can be refracted, reflected, and scattered in different directions

Methodology Applied
Scientific EffectScattering: Scattering

Implementation Method 4

a quantum dot layer is also arranged between the two protective layers

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 5

by adding a foaming agent, several holes are formed inside the foam core layer

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 6

by adding inorganic or organic light diffusing agents to the base... the light can be refracted, reflected, and scattered in different directions

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4296725A1Foam diffuser plate and a manufacturing method thereof
Publication Date: 2023.12.27 REGENCY OPTICS ELECTRON CORP
  • EP4296725A1 patent drawingFigure 1~2
  • EP4296725A1 patent drawingFigure 3~4
  • EP4296725A1 patent drawingFigure 5~6

AI summary

The present invention provides a foam diffuser plate, including a foam core layer (10), the upper surface and the lower surface of the foam core layer (10) are covered with a protective layer (20), and the thickness ratio of the foam core layer (10) to the upper and lower surfaces of the protective layer (20) is 1:7-9:1. The mass percentage of each raw material of the protective layer (20) is PS raw material 90-99%, stabilizer 0.01-1%, organosilicon 0.1-3%, inorganic diffusing agent 0.1-3%, diffusing oil 0.1-3%, styrene-butadiene copolymer 0.1-2%, and magnesium silicate mineral 0.1-6%. The mass percentage of each raw material of the foam core layer (10) is GPPS raw material 95-99%, antioxidant 0.3-0.6%, silicone diffusing agent 0.6-1%, foaming agent 0.5-2%, anti-UV agent 0.3-0.6%, toughening agent 0.5-2%, stabilizer 0.3-0.6%, and nucleating agent 1-5%. A manufacturing method of the foam diffuser plate is provided in the present invention as well.