Diffusion Reflection Sheet Layout for Uniform LED Luminance

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Solution Overview

Problem

Surface light emitting devices, such as those used in liquid crystal display devices and lighting, face challenges in achieving uniform luminance due to non-uniform light distribution and reflection.

Innovation Solution

A light emitting device design incorporating a diffusion reflection sheet with particles and a reflection wall that efficiently diffuses and reflects light, ensuring uniform luminance across a region, utilizing a light emitting element like LEDs without packages or lenses to reduce costs and heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional light emitting device uses LEDs with packages and lenses to achieve uniform light distribution, then luminance uniformity is improved, but device complexity and cost increase

Engineering Contradiction:
Improveluminance uniformityVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the package and lens components from the LED structure. By using a bare chip LED without these additional components, the invention simplifies the overall device structure while achieving the desired light distribution through the reflection wall and diffusion reflection sheet designs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by designing a reflection wall with specific reflective properties positioned around the LED chip, and a diffusion reflection sheet with particular optical characteristics. These localized optical structures compensate for the removal of packages and lenses, achieving uniform luminance through strategically placed components with specialized functions.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If packages and lenses are used with LEDs, then light distribution is improved, but heat generation and power consumption increase

Engineering Contradiction:
Improvelight distributionVSAvoidpower consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent removes the package and lens components that contribute to heat generation and power consumption. By using a bare chip LED directly mounted on the substrate, thermal pathways are improved and energy losses associated with additional optical components are eliminated, reducing overall power consumption while maintaining effective light distribution.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical optical system (packages and lenses) with an optical system based on reflection and diffusion principles. The reflection wall and diffusion reflection sheet create the desired light distribution through optical physics rather than mechanical optical components, reducing energy consumption and heat generation.

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

3Illumination intensity

If packages and lenses are used with LEDs, then light distribution is improved, but cost increases

Engineering Contradiction:
Improvelight distributionVSAvoidcost
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent eliminates the package and lens components from the LED assembly, directly reducing material costs and simplifying the manufacturing process. The bare chip LED approach requires fewer assembly steps and fewer components to purchase, manufacture, and quality-check, leading to lower overall production costs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses cost-effective materials for the reflection wall and diffusion reflection sheet that can be manufactured using standard fabrication processes. By optimizing the optical properties of these specific components rather than using expensive packaged LEDs with precision lenses, the invention achieves good light distribution at lower cost.

Inventive Principle:
Principle #3Local quality

4Illumination intensity

If a reflection wall and diffusion reflection sheet are used without packages, then luminance uniformity is improved, but device profile increases

Engineering Contradiction:
Improveluminance uniformityVSAvoiddevice profile
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent designs the reflection wall with a curved or angled surface that efficiently redirects light toward the diffusion reflection sheet. This curved geometry allows the reflection wall to be thin yet effective, minimizing the distance required to achieve the desired light redistribution without compromising luminance uniformity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The diffusion reflection sheet is designed as a thin film or sheet structure that provides the necessary diffusion function with minimal thickness. This thin-film approach achieves effective light diffusion and uniform luminance while adding minimal height to the overall device profile.

Inventive Principle:
Principle #30Flexible shells and thin films

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 enhances luminance uniformity and reduces power consumption while maintaining a low profile, achieving compatibility with in-plane uniformity and cost-effectiveness.

Implementation Method 1

In the diffusion reflection sheet, the entering light is efficiently diffused by and reflected from the plurality of the particles

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

Light traveling from the diffusion reflection sheet toward the reflection wall is reflected from the reflection wall and enters the diffusion reflection sheet again

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3525247B1Light emitting device
Publication Date: 2024.12.25 SONY GROUP CORP
  • EP3525247B1 patent drawingFigure 1
  • EP3525247B1 patent drawingFigure 2
  • EP3525247B1 patent drawingFigure 3~4

AI summary

A light emitting device includes: a light emitting element; a reflection wall that surrounds the light emitting element; and a diffusion reflection sheet that includes a plurality of particles and permits entrance of emitted light from the light emitting element and reflected light from the reflection wall.