Diffuser Plate Structure for Slim Displays With Uniform Brightness

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Solution Overview

Problem

Existing display apparatuses face challenges in achieving a slim design while maintaining brightness uniformity on the front surface due to reduced distance between the light source and the diffuser plate, leading to irregular light distribution.

Innovation Solution

A display apparatus with a diffuser plate featuring a two-layer structure comprising a pattern layer and a reflective layer, utilizing diffusion patterns and total reflection at the boundary surface to enhance light diffusion, and scattering by beads within the reflective layer, reducing the need for a large number of beads to achieve uniform light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the distance between the light source and the diffuser plate is reduced to achieve a slim design, then the thickness of the backlight unit is decreased, but the front brightness uniformity deteriorates and irregularity occurs

Engineering Contradiction:
Improvethickness of backlight unitVSAvoidfront brightness uniformity
Core Design Contradiction:
Length of stationary objectVSIllumination intensity

Solution Approach 1:

The diffuser plate is segmented into a two-layer structure: a pattern layer with diffusion patterns and a reflective layer with beads. This segmentation allows each layer to perform a specific light diffusion function, achieving uniform brightness even at reduced thickness by distributing the diffusion function across multiple specialized layers rather than relying on a single thick layer

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The diffuser plate uses a composite structure combining a pattern layer (with refractive index differences for diffusion) and a reflective layer (with beads for scattering). This composite material approach enables effective light diffusion in a thin configuration by leveraging the complementary light-modifying properties of both layers

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If a large number of beads are used in the diffuser plate to improve light diffusion, then brightness uniformity is improved, but light loss increases and brightness efficiency decreases

Engineering Contradiction:
Improvebrightness uniformityVSAvoidlight loss
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The light diffusion function is segmented between the pattern layer (which diffuses light through refractive index differences at the diffusion patterns) and the reflective layer (which scatters light through beads). This segmentation reduces the reliance on a large number of beads, thereby reducing light loss while maintaining brightness uniformity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pattern layer acts as an intermediary between the light source and the reflective layer, performing initial light diffusion before light reaches the beads. This intermediary function reduces the burden on the beads to achieve uniformity, allowing fewer beads to be used and reducing light loss

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 solution improves light diffusion performance, reduces light loss, and increases brightness efficiency, allowing for a slim design without compromising on uniformity.

Implementation Method 1

Light is diffused by refraction of light by diffusion patterns of a pattern layer

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

total reflection of light at a boundary surface between the pattern layer and a reflective layer

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

scattering of light by beads inside the reflective layer

Methodology Applied
Scientific EffectScattering: Scattering

Data Source

PatentEP3956722B1Display apparatus and diffuser plate thereof
Publication Date: 2026.04.01 SAMSUNG ELECTRONICS CO LTD
  • EP3956722B1 patent drawingFigure 1
  • EP3956722B1 patent drawingFigure 2~3
  • EP3956722B1 patent drawingFigure 4~5

AI summary

A display apparatus includes a chassis, a light source provided on the chassis and configured to emit light; a diffuser plate disposed in front of the light source and configured to diffuse the light emitted from the light source, and a liquid crystal panel disposed in front of the diffuser plate and configured to displaying an image. The diffuser plate includes a pattern layer including diffusion patterns protruding toward the light source, and a reflective layer provided in contact with the pattern layer such that portion of light traveling through the pattern layer is totally reflected at a boundary surface between the reflective layer and the pattern layer.