Backlight Unit Optical Diffusion Member Light Leakage

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Solution Overview

Problem

Backlight units for display devices, such as LCDs, suffer from light leakage between light guide plates, which degrades the display quality by reducing the amount of light directed to the panel.

Innovation Solution

Incorporating an optical diffusion member with a diffusing part and supporting parts between light guide plates to diffuse and redirect leaked light, combined with a light source configuration that emits light in opposite directions and a reflective sheet to enhance light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple light guide plates are used to guide light to the display panel, then light distribution is improved, but light leaks through the space between the light guide plates degrading display quality

Engineering Contradiction:

Improvelight distribution to display panelVSAvoidlight leakage between light guide plates

Core Design Contradiction:

Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

An optical diffusion member is introduced as an intermediary component between the light guide plates and the display panel. This member includes a diffusing part that intercepts light leaking from between the light guide plates and redistributes it toward the display panel, converting the harmful leakage into useful illumination.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful light leakage between light guide plates into a beneficial effect by using the optical diffusion member to redirect this leaked light toward the display panel. The diffusing part captures the otherwise wasted light and redistributes it to improve overall illumination efficiency.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Use of energy by moving object

If light sources are disposed between light guide plates to emit light in opposite directions, then light utilization efficiency is improved, but light leakage through the space between light guide plates increases

Engineering Contradiction:

Improvelight utilization efficiencyVSAvoidlight leakage

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The optical diffusion member acts as a mediator that captures light leaking from the space between light guide plates and redistributes it. This allows the dual-directional light source configuration to maintain its high energy utilization while preventing the harmful leakage effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The leaked light from the dual-directional light sources, which would normally be harmful, is converted into a beneficial resource by the optical diffusion member that redirects it toward the display panel, improving overall light utilization.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If light guide plates are spaced apart to accommodate light sources, then light source installation is facilitated, but light leakage through the space between light guide plates occurs

Engineering Contradiction:

Improvelight source installationVSAvoidlight leakage

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The optical diffusion member is positioned to fill and utilize the space between the light guide plates that is necessary for light source installation. It serves as a mediator that converts the structural requirement (spaced-apart plates) from a source of leakage into an opportunity for light redistribution.

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 effectively reduces light leakage, improving the display quality by ensuring more light is directed to the display panel, thereby enhancing the overall performance of the backlight unit and display device.

Implementation Method 1

an optical diffusion member for diffusing light emitted from the light sources and leaking between the light guide plates

Methodology Applied

Scientific EffectLight diffusion: Scattering

Implementation Method 2

the diffusing part may include a reflective film attached thereto on a surface facing the optical member

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS8974070B2Backlight units and display devices including the same

Publication Date: 2015.03.10 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a display panel which displays an image, a backlight unit which supplies the display panel with light, an upper cover, and a lower cover. The upper and lower covers accommodate the display panel and the backlight unit. The backlight unit includes light guide plates spaced apart from each other, a light source part, an optical member and an optical diffusion member overlapping a space between the light guide plates. The optical diffusion member includes a diffusing part and a supporting part. The diffusing part faces the optical member, overlaps the space between the light guide plates, and diffuses light emitted from the light source part toward the optical member through the space between the light guide plates. The supporting part protrudes from a surface of the diffusing part which is opposite to the optical member, and is in a space between the light sources.