Diffusion Reflection Sheets for LCD Brightness Uniformity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional liquid crystal display (LCD) devices suffer from non-uniform brightness due to light leakage and reflection issues, resulting in bright lines and points, which are not effectively addressed by existing optical sheet configurations and light shielding units.

Innovation Solution

The implementation of first and second diffusion reflection sheets with air distributed randomly on the inner surfaces of the lamp housing and light guide plate, respectively, to diffuse and reflect light uniformly, eliminating the need for a light shielding unit and minimizing the number of optical sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional optical sheets and light shielding units are used to address brightness uniformity, then some light uniformity is achieved, but the device complexity increases and light loss occurs

Engineering Contradiction:

Improvebrightness uniformityVSAvoidnumber of optical sheets and light shielding units

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the light shielding unit from the optical path by redistributing light uniformly at the source through diffusion reflection sheets. This removes the need for additional light shielding components that complicate the device structure while maintaining brightness uniformity.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The diffusion reflection sheet is designed to perform multiple functions simultaneously: it diffuses light, reflects light uniformly, and eliminates the need for separate light shielding units. This multi-functional component reduces overall device complexity while achieving the desired optical uniformity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Illumination intensity

If multiple optical sheets are provided to achieve uniform brightness, then optical uniformity is improved, but light loss increases and device complexity increases

Engineering Contradiction:

Improveoptical uniformityVSAvoidlight loss

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The diffusion reflection sheet performs preliminary light diffusion and uniform distribution at the light source stage, before light enters the optical path. This preliminary action ensures uniform brightness without requiring multiple subsequent optical sheets, thereby reducing light loss through fewer optical interfaces.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the potentially harmful effect of light reflection and leakage into a beneficial uniform light distribution by using diffusion reflection sheets that intentionally diffuse and reflect light uniformly at the source, transforming what would be wasted light into useful uniform illumination.

Inventive Principle:

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

3Illumination intensity

If light shielding unit is added to prevent non-uniform brightness, then brightness uniformity is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvebrightness uniformityVSAvoidmanufacturing difficulty

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent removes the light shielding unit from the design by achieving uniform brightness through diffusion reflection at the source. This extraction eliminates the manufacturing steps and assembly requirements associated with light shielding units, simplifying production.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the optical parameters at the light source by introducing diffusion reflection sheets that modify light distribution characteristics. This parameter change at the source eliminates the need for light shielding units, thereby simplifying manufacturing processes and reducing assembly complexity.

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 provides a planar optical source with enhanced optical uniformity, improving display quality and reducing light loss, thereby eliminating bright lines and points, and minimizing the number of optical sheets required for uniform brightness.

Implementation Method 1

first and second diffusion reflection sheets with air distributed randomly on the inner surfaces of the lamp housing and light guide plate, respectively, to diffuse and reflect light uniformly

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

first and second diffusion reflection sheets with air distributed randomly on the inner surfaces of the lamp housing and light guide plate, respectively, to diffuse and reflect light uniformly

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS9063267B2Liquid crystal display device

Publication Date: 2015.06.23 LG DISPLAY CO LTD

AI summary

A liquid crystal display (LCD) device includes: an LC panel; a lamp disposed below the LC panel, for supplying light to the LC panel; a lamp housing having an opening, for encompassing and protecting the lamp; first and second diffusion reflection sheets disposed on end portions of inner lower and upper surfaces of the lamp housing, respectively; and a light guide plate disposed to be adjacent to the opening of the lamp housing, for guiding light emitted from the lamp to the LC panel.