LED Optical Grating Electrode Polarization

Solution Overview

Problem

Conventional LEDs require polarization converters in LCD systems, leading to increased manufacturing costs and reduced light utilization due to the absorption of light with perpendicular polarization directions by polarizers, resulting in low light utilization rates.

Innovation Solution

The LED design incorporates a second electrode configured as an optical grating that allows light with a specific polarization direction to pass through while reflecting and re-emitting light with a perpendicular polarization direction, enhancing light utilization efficiency by using a metal electrode with lower resistance and improved luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If polarizers are added to convert LED light to polarized light for LCD systems, then the light polarization requirement is met, but the light utilization rate decreases due to absorption of perpendicular polarized light

Engineering Contradiction:

Improvelight polarization capabilityVSAvoidlight utilization rate

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent extracts the polarization function from separate polarizer components and integrates it directly into the LED electrode structure. The second electrode is designed as an optical grating that inherently polarizes light during emission, eliminating the need for external polarizers and avoiding their light absorption losses.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the electrical conduction function and the optical polarization function into a single electrode structure. The second electrode simultaneously serves as both the electrical contact for the LED and the polarization converter, combining multiple functions into one component to improve overall system efficiency.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If polarizers are used to achieve polarized light output, then the LCD system compatibility is improved, but the manufacturing cost increases

Engineering Contradiction:

ImproveLCD system compatibilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the electrical conduction function and the optical polarization function into a single electrode structure. The second electrode simultaneously serves as both the electrical contact for the LED and the polarization converter, combining multiple functions into one component to improve overall system efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the polarization function from separate polarizer components and integrates it directly into the LED electrode structure. The second electrode is designed as an optical grating that inherently polarizes light during emission, eliminating the need for external polarizers and avoiding their light absorption losses.

Inventive Principle:

Principle #2Taking out (Extraction)

3Power

If conventional LED electrodes are used, then the electrical conduction is achieved, but the light emission efficiency is reduced due to higher resistance and lower luminance

Engineering Contradiction:

Improveelectrical conductionVSAvoidluminance

Core Design Contradiction:

PowerVSIllumination intensity

Solution Approach 1:

The patent employs a composite electrode structure combining metal materials with optimized geometric patterns (optical grating). This composite design achieves both low electrical resistance for efficient current conduction and specific optical properties for enhanced light emission and polarization, resolving the contradiction between electrical performance and optical performance.

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 configuration improves light emission efficiency by allowing polarized light to be effectively utilized, reducing the need for multiple polarizers and increasing the overall light utilization rate in LCD systems, thereby enhancing display quality.

Implementation Method 1

The second electrode is an optical grating which allows light with a first polarization direction to pass through and is capable of reflecting light with a second polarization direction perpendicular to the first polarization direction

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 2

The light emitting principle is to convert electric energy into light. In other words, by applying a current to the compound semiconductor, redundant energy is released in a form of light through the combination of electrons and electron holes

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS8434886B2Light emitting diode, backlight module and liquid crystal display apparatus

Publication Date: 2013.05.07 INNOLUX CORP

AI summary

A light emitting diode for a backlight module and/or a liquid crystal display apparatus includes a semiconductor structure, a first electrode and a second electrode. The semiconductor structure includes a first type doped semiconductor layer, a light emitting layer, and a second type doped semiconductor layer. The light emitting layer is disposed between the first type doped semiconductor layer and the second type doped semiconductor layer. The first electrode is electrically connected to the first type doped semiconductor layer. The second electrode is electrically connected to the second type doped semiconductor layer. The second electrode is an optical grating which allows light with a first polarization direction to pass through and is capable of reflecting light with a second polarization direction perpendicular to the first polarization direction.