Reflective Sheet Segmentation for Display Light Leakage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light-emitting devices for display and lighting applications face challenges in achieving uniform luminance and contrast ratios, particularly when some light sources are turned off, as light leakage occurs from the on regions to the off regions, affecting the overall emission performance and picture expression.

Innovation Solution

A light-emitting device comprising a substrate with light sources, a reflective lens, a reflective sheet with inclined surfaces, and a light diffusion member, which reflects light and diffuses it to prevent leakage, ensuring uniform illumination and improved contrast ratios even in thin configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light sources are arranged with lenses to spread light over a wide range, then luminance uniformity is improved, but contrast ratio deteriorates due to light leakage from on regions to off regions

Engineering Contradiction:
Improveluminance uniformityVSAvoidlight leakage
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The reflective sheet is divided into multiple regions (first reflective region, second reflective region, third reflective region) with different reflective properties. Each region segments the light reflection function to achieve both wide-angle diffusion and directional control, preventing light leakage while maintaining luminance uniformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the reflective sheet have different local optical properties: the first reflective region has high reflectivity for on-region light, the second reflective region controls light at specific angles, and the third reflective region provides wide-angle diffusion. This local differentiation resolves the contradiction between uniformity and contrast.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If the device is thinned to reduce size, then compactness is improved, but light emission performance deteriorates

Engineering Contradiction:
Improvedevice thicknessVSAvoidlight emission performance
Core Design Contradiction:
Length of moving objectVSIllumination intensity

Solution Approach 1:

The reflective sheet extends in the lateral direction (parallel to the light source) rather than requiring increased thickness. By utilizing the lateral dimension for light control functions, the device achieves thin profile while maintaining effective light emission performance through extended reflective surfaces.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The reflective sheet acts as an intermediary element between the light source and the final emission. It mediates light distribution by reflecting and diffusing light in controlled patterns, enabling thin device design without sacrificing light emission performance.

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 achieves enhanced light emission performance by relaxing luminance distribution and improving contrast ratios, leading to better picture expression in display devices and more uniform illumination in lighting applications.

Implementation Method 1

a reflective lens provided to interpose the light source between the reflective lens and the substrate

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

light from the reflective lens is reflected by the reflective sheet

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

light from the light source is widely diffused by the reflective lens

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3761109B1Display apparatus
Publication Date: 2024.05.15 SONY GROUP CORP
  • EP3761109B1 patent drawingFigure 1A
  • EP3761109B1 patent drawingFigure 1B
  • EP3761109B1 patent drawingFigure 2

AI summary

Provided is a light-emitting device having an excellent light emission performance irrespective of its small thickness. The light-emitting device includes a base having a surface; one or more light sources that are provided on the surface of the base, and each have an optical axis; a reflective lens provided to interpose the light source between the reflective lens and the base; a reflective sheet that is provided to surround the light source along the surface of the base, and includes a first surface that makes a first angle relative to a plane that is substantially orthogonal to the optical axis to allow the first surface to be away also from the base as the first surface is away from the light source; and a light diffusion member provided to interpose the light source, the reflective lens, and the reflective sheet, between the light diffusion member and the base.