Fluorescent Backlight Polarization for LCD Brightness

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Liquid crystal displays (LCDs) face challenges in achieving bright images with excellent visibility under bright ambient light conditions while maintaining low power consumption and long-term reliability, as existing solutions either fail to improve brightness or compromise on color range and material stability.

Innovation Solution

The implementation of an electro-optical switching element that utilizes light conversion means to convert non-polarized light into linearly polarized light, shifts wavelengths to longer values, and uses a backlight system emitting light with wavelengths of 385 nm or more, thereby enhancing light efficiency and reducing exposure to damaging UV radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If LEDs are used as backlight to expand color range, then color expression is improved, but brightness is not improved

Engineering Contradiction:

Improvecolor rangeVSAvoidbrightness

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent combines LED backlight with fluorescent conversion layer to achieve both wide color range and high brightness. The fluorescent layer converts LED light to match the color filter spectrum, simultaneously expanding color expression and maintaining brightness levels.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the spectral parameters of the backlight by introducing fluorescent materials that convert LED wavelengths to match the color filter transmission spectrum, achieving optimal color expression while maintaining brightness.

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If UV radiation is used for backlight to improve brightness, then brightness is improved, but long term reliability deteriorates

Engineering Contradiction:

ImprovebrightnessVSAvoidmaterial stability

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent introduces fluorescent conversion layers as intermediaries that convert UV radiation to visible light. This mediator approach allows the system to benefit from UV-induced brightness while protecting the liquid crystal materials from direct UV exposure, thereby maintaining long-term reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts harmful UV radiation into beneficial visible light through fluorescent materials. The UV light that would otherwise damage the liquid crystal is transformed into useful visible light for illumination and display, simultaneously improving brightness and protecting materials.

Inventive Principle:

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

3Adaptability or versatility

If colour filters are used to achieve proper color, then color accuracy is improved, but light absorption increases

Engineering Contradiction:

Improvecolor accuracyVSAvoidlight absorption

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent changes the spectral parameters of the backlight to match the color filter transmission characteristics. By adjusting the fluorescent conversion layer to emit light that aligns with the color filter spectrum, the system minimizes light absorption while maintaining color accuracy.

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 approach results in bright images with clear visibility under bright ambient light conditions, low power consumption, and improved long-term reliability by efficiently utilizing both backlight and ambient light, while minimizing damage to liquid crystal materials.

Implementation Method 1

light conversion means capable to convert the state of polarization of the light from non-polarized light either to linear polarized light or to circular polarized light

Methodology Applied

Scientific EffectPolarization conversion: Polarisation

Implementation Method 2

a fluorescent backlight emitting polarised light

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS8879024B2Liquid crystal display with a fluorescent backlight emitting polarised light

Publication Date: 2014.11.04 MERCK PATENT GMBH

AI summary

The instant invention relates to electro-optical switching elements and displays comprising them. In particular, it relates to electro-optical switching elements comprising one or more light conversion means capable to convert light (e.g. ambient light and/or light from a backlight system), wherein each of said light conversion means o is capable to convert the state of polarization of the light from non-polarized light either to linear polarized light or to circular polarized light and, at the same time, o optionally is capable to shift the wavelength of the light to longer values and—at least one of said conversion means o is capable to shift the wavelength of the light to longer values and—a liquid crystal material, which is capable of switching,—one or more means to polarize light, and—optionally a means for illumination such as e.g. a backlight.