Light Guide Plate Diffusion Materials for LCD Color Mixing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional LCD devices using LEDs for backlighting suffer from color un-uniformity due to the directional characteristics of point light sources, leading to enlarged device size and weight, as elongated light guide plates are required for effective color mixing.

Innovation Solution

Incorporating diffusion materials with optical characteristics different from the base material in the light guide plate, dispersed uniformly or non-uniformly, to diffuse and mix light from LED sources, reducing the distance needed for color mixing and minimizing color irregularity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the dimension of the light guide plate is elongated to reduce color un-uniformity, then color uniformity is improved, but the size and weight of the LCD device are increased

Engineering Contradiction:

Improvecolor uniformityVSAvoidweight of LCD device

Core Design Contradiction:

Manufacturing precisionVSWeight of stationary object

Solution Approach 1:

The patent changes the optical parameters of the light guide plate by incorporating diffusion materials with different refractive indices. This allows the light guide plate to achieve effective color mixing over a shorter distance, thereby reducing the required plate length and the overall device weight while maintaining color uniformity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining the base light guide plate material with diffusion materials having different optical characteristics. This composite structure enables enhanced light scattering and color mixing efficiency, allowing for a more compact device design that reduces weight without sacrificing color uniformity.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If the dimension of the light guide plate is elongated to reduce color un-uniformity, then color uniformity is improved, but the size of the LCD device is enlarged

Engineering Contradiction:

Improvecolor uniformityVSAvoidsize of LCD device

Core Design Contradiction:

Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The patent modifies the optical parameters of the light guide plate by introducing diffusion materials with specific refractive indices. This parameter change enables effective color mixing within a shorter distance, thereby reducing the required light guide plate length and the overall device size while maintaining color uniformity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by integrating diffusion materials with different optical properties into the light guide plate. This composite structure enhances light scattering and color mixing efficiency, allowing for a more compact device design that reduces size without compromising color uniformity.

Inventive Principle:

Principle #40Composite materials

3Length of stationary object

If diffusion materials are dispersed in the light guide plate, then color mixing is improved over shorter distance, but the complexity of the light guide plate structure is increased

Engineering Contradiction:

Improvelength of light guide plateVSAvoidcomplexity of light guide plate structure

Core Design Contradiction:

Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent changes the material parameters of the light guide plate by incorporating diffusion materials with different refractive indices. This parameter modification enables effective color mixing over a shorter distance, reducing the light guide plate length while the manufacturing process remains relatively simple through direct material composition.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining the base light guide plate material with diffusion materials having different optical characteristics. This composite structure, while slightly more complex in material composition, simplifies the overall device structure by eliminating the need for elongated plate designs and reduces the number of separate components required.

Inventive Principle:

Principle #40Composite materials

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 approach allows for a reduction in the size and weight of LCD devices while maintaining color uniformity, as the diffusion materials effectively mix colors closer to the LED sources, reducing the length of the light guide plate and minimizing color irregularity.

Implementation Method 1

diffusion materials have an optical characteristic different from that of a base material of the light guiding plate

Methodology Applied

Scientific EffectLight scattering: Scattering

Implementation Method 2

diffusion materials are dispersed in the light guide plate, and wherein the diffusion materials have an optical characteristic different from that of a base material of the light guiding plate

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS7597467B2Lighting unit and liquid crystal display device using the lighting unit

Publication Date: 2009.10.06 HANNSTAR DISPLAY CORP

AI summary

In a liquid crystal display device using LEDs emitting a plurality of colors as the light sources, diffusion materials are dispersed in a light guide plate. The light guide plate is used to guide and mix the plurality of colors with one another. The diffusion materials are made of a material having optical characteristics, such as a refractive index, different from those of a base material of the light guide plate.