Integrated Optical Structure to Prevent Backlight Warping and Scratches

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Solution Overview

Problem

Traditional backlight modules experience warping, deformation, and delamination due to differing thermal expansion coefficients of materials used in the diaphragm and diffuser, leading to scratches on the polarizer under the liquid crystal panel.

Innovation Solution

Integrally injection-mold the substrate, brightness enhancement, and diffuser layers using the same basic material, such as polystyrene, polycarbonate, or polymethyl methacrylate, with air gaps and protruding portions for adherence, eliminating the need for optical adhesive and reducing movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If optical adhesive is used to bond the diaphragm and diffuser together, then the scratch problem is improved, but warping, deformation and delamination occur in high temperature or extremely cold environments

Engineering Contradiction:
Improvescratch protectionVSAvoidstructural stability in extreme temperatures
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent merges the diaphragm and diffuser into a single integrated optical sheet formed by injection molding. This eliminates the need for optical adhesive bonding between separate components, thereby avoiding the delamination and warping issues that occur when different materials with different thermal expansion coefficients are bonded together in extreme temperature environments.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses composite material structure where the optical sheet integrates multiple functional layers (diaphragm layer and diffuser layer) made from the same basic material (transparent polymer). This ensures uniform thermal expansion characteristics throughout the structure, preventing warping and deformation in high temperature or extremely cold environments while maintaining scratch protection.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the diaphragm and diffuser are stacked together in a separate stacking manner, then the manufacturing process is simplified, but the movable space between layers causes scratches on the polarizer

Engineering Contradiction:
Improvestacking processVSAvoidpolarizer scratches
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent combines the diaphragm and diffuser into a single integrated optical sheet with no gaps between layers. This eliminates the movable space that causes scratching while maintaining manufacturing simplicity through injection molding, which can produce complex multi-layer structures in one step.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the mechanical stacking and adhesive bonding system with an injection molding process that directly forms the integrated optical sheet. This substitution eliminates the need for separate assembly steps and adhesive materials, reducing both manufacturing complexity and the risk of layer movement that causes scratches.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Prevents warping, deformation, and delamination in extreme temperatures, reduces light energy loss, and minimizes scratches on the polarizer, enhancing the backlight module's luminous efficiency and structural integrity.

Implementation Method 1

a light exit surface of the brightness enhancement layer is set to a triangular prism structure

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a light exit surface of the brightness enhancement layer is set to a triangular prism structure

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

the basic material of the diffuser layer is doped with a light diffusing agent

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 4

the thermal expansion coefficients of the two differ by several times

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 5

the brightness enhancement layer after the triangular prism structure being transferred is cooled

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4715459A1Optical structure, backlight module, display apparatus, and preparation method for optical structure
Publication Date: 2026.03.25 SHENZHEN SKYWORTH DISPLAY TECH CO LTD
  • EP4715459A1 patent drawingFigure 1~2
  • EP4715459A1 patent drawingFigure 3~4
  • EP4715459A1 patent drawingFigure 5

AI summary

The present application provides an optical structure, a backlight module, a display device, and a method for preparing the optical structure. The optical structure includes a substrate layer, a brightness enhancement layer, and a diffuser layer. the substrate layer, the brightness enhancement layer, and the diffuser layer are of the same basic material and are integrally injection-molded.