Display Optical Stack with Deformation Preventing Layer

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Solution Overview

Problem

Current display apparatuses face challenges in reducing bezel width, improving productivity, achieving a slim size, securing rigidity, enhancing contrast ratio, and increasing light recycling efficiency.

Innovation Solution

The display apparatus incorporates a deformation preventing layer with a lower coefficient of thermal expansion, a quantum dot sheet with an air layer, and a Dual Brightness Enhancement Film (DBEF) with a condensing prism pattern, along with a prism sheet and diffuser sheet, to minimize thermal deformation and optimize light recycling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the bezel width is reduced to achieve a slim display apparatus, then the aesthetic appearance and screen-to-body ratio are improved, but the structural rigidity and stability of the display apparatus deteriorate

Engineering Contradiction:
Improvebezel widthVSAvoidstructural rigidity
Core Design Contradiction:
Length of stationary objectVSStrength

Solution Approach 1:

The patent employs a composite optical stack comprising multiple functional layers including a quantum dot sheet, a deformation preventing layer, a diffuser sheet, and a prism sheet. This composite structure provides both optical functionality and mechanical support, enabling reduced bezel width while maintaining structural rigidity through the combined properties of different materials.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The deformation preventing layer is strategically positioned between the quantum dot sheet and diffuser sheet to provide localized mechanical support and thermal stability. This layer has different material properties (lower coefficient of thermal expansion) compared to adjacent layers, creating local quality enhancement that prevents deformation in critical areas without requiring overall increase in bezel width.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If multiple optical layers are added to improve light recycling efficiency and contrast ratio, then the optical performance is enhanced, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvelight recycling efficiencyVSAvoidoptical structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

Each optical layer in the stack serves multiple functions: the quantum dot sheet converts wavelengths and enhances color gamut while also acting as a structural element; the deformation preventing layer provides both thermal stability and mechanical support; the diffuser sheet distributes light uniformly and maintains optical coupling. This multi-functionality reduces the need for additional separate components, managing complexity while improving light recycling efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines multiple optical functions into an integrated optical stack where layers are optically coupled together. The quantum dot sheet, deformation preventing layer, diffuser sheet, and prism sheet work as a unified system to recycle light, enhance contrast ratio, and maintain structural integrity, rather than treating them as separate independent components.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If the quantum dot sheet is placed close to the light source to improve light recycling, then the energy efficiency increases, but thermal deformation of the optical layers worsens

Engineering Contradiction:
Improvelight recycling efficiencyVSAvoidthermal deformation
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The deformation preventing layer acts as an intermediary between the quantum dot sheet and the diffuser sheet. This layer has a lower coefficient of thermal expansion than the adjacent polymer-based optical layers, serving as a thermal buffer that prevents heat-induced deformation from propagating through the optical stack while allowing the quantum dot sheet to remain close to the light source for efficient light recycling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the material parameter (coefficient of thermal expansion) of the deformation preventing layer to be lower than adjacent layers. This parameter change enables the layer to resist thermal deformation under elevated temperatures near the light source, allowing the quantum dot sheet to operate at optimal positions for light recycling without suffering from thermal deformation issues.

Inventive Principle:
Principle #35Parameter changes

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 configuration reduces bezel width, enhances productivity and rigidity, improves contrast ratio, and increases light recycling efficiency, resulting in a more efficient and effective display apparatus.

Implementation Method 1

a deformation preventing layer disposed between the diffuser sheet and the quantum dot sheet and including a first material having a lower coefficient of thermal expansion than the diffuser sheet or the quantum dot sheet

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a prism sheet disposed on a first side of the quantum dot sheet that is opposite to a second side of the quantum dot sheet on which the deformation preventing layer is disposed

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

the quantum dot sheet includes a quantum dot layer and an air layer, the air layer formed on a side of the quantum dot layer that faces the prism sheet

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 4

a Dual Brightness Enhancement Film (DBEF) disposed in front of the deformation preventing layer and provided to transmit a portion of the light passing therethrough and to reflect another portion of the light passing therethrough

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4010761B1Display apparatus
Publication Date: 2024.08.21 SAMSUNG ELECTRONICS CO LTD
  • EP4010761B1 patent drawingFigure 1
  • EP4010761B1 patent drawingFigure 2
  • EP4010761B1 patent drawingFigure 3~5

AI summary

A display apparatus includes a liquid crystal panel, a light source configured to provide light to the liquid crystal panel, and an optical member disposed between the liquid crystal panel and the light source. The optical member includes a diffuser sheet that is configured to diffuse the light from the light source, and a deformation preventing layer including a first material having a lower expansion or contraction rate than the diffuser sheet.