Optical Member with Dye Layer for Display Black Visibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical display devices employing blue light sources and quantum dot particles face challenges in maintaining contrast ratio and black visibility due to external light interference, leading to variations in reflectivity and transmittance, which affect visual sensitivity and screen quality.
Innovation Solution
An optical member comprising a base film with a light transmission control layer containing specific dyes and a resin with a hydroxyl value of 5 mgKOH/g or less, which reduces reflectivity and transmittance variations, improving black visibility and light resistance reliability when stacked with light scattering particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If light scattering particles (TiO2) are used to scatter blue light and improve luminous efficacy, then luminous efficacy is improved, but black visibility deteriorates due to external light scattering and reflection
Solution Approach 1:
A light transmission control layer containing specific dyes is introduced as an intermediary between the light scattering particle layer and the external environment. This layer selectively absorbs external blue light (380-470 nm) while allowing internally generated red and green light to pass through, thereby resolving the contradiction between maintaining black visibility and preserving luminous efficacy
Solution Approach 2:
The patent applies different optical properties to different regions: the light scattering particles (TiO2) are positioned to scatter blue light for improved luminous efficacy in the emission region, while the light transmission control layer with specific dyes is positioned to selectively absorb external blue light in the viewing region, achieving local optimization of both luminous efficacy and black visibility
2Reliability
If carbon black is used to improve reflectivity by shielding light in the overall visible spectrum, then reflectivity is improved, but overall transmittance deteriorates
Solution Approach 1:
Instead of using carbon black that uniformly blocks all wavelengths, the patent employs dyes with specific absorption characteristics that selectively target only the blue light region (380-470 nm) where external light interference occurs, while maintaining high transmittance in the red and green wavelength regions where display light is emitted
Solution Approach 2:
The patent utilizes dyes with specific maximum absorption wavelengths (first dye: 540-630 nm, second dye: 390-470 nm, third dye: 480-530 nm, fourth dye: 640-760 nm) to selectively absorb external blue light while allowing the display's red and green light to pass through, achieving wavelength-selective optical control
3Object-affected harmful factors
If dyes are used to reduce reflectivity and improve black visibility, then black visibility is improved, but variation in reflectivity and transmittance increases after light resistance evaluation
Solution Approach 1:
The patent creates a composite light transmission control layer combining multiple dyes (first, second, third, and/or fourth dyes) with specific absorption characteristics, where each dye targets different wavelength regions. This composite approach ensures comprehensive external light blocking while maintaining stable optical properties through synergistic interactions between the dyes
Solution Approach 2:
The patent optimizes specific parameters of the dyes including maximum absorption wavelengths (first dye: 540-630 nm, second dye: 390-470 nm, third dye: 480-530 nm, fourth dye: 640-760 nm) and their concentrations to achieve stable light transmission control. The resin hydroxyl value is controlled at 5 mgKOH/g or less to prevent degradation and maintain compositional stability
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 optical member significantly reduces reflectivity and transmittance variations, enhancing visual sensitivity and screen quality by effectively absorbing external light, thereby improving the overall performance of optical display devices in bright environments.
Implementation Method 1
the light transmission control layer contains dyes or a dye mixture including at least one selected from among a first dye having a maximum absorption wavelength of about 540 nm to about 630 nm, a second dye having a maximum absorption wavelength of about 390 nm to about 470 nm, a third dye having a maximum absorption wavelength of about 480 nm to about 530 nm, and a fourth dye having a maximum absorption wavelength of about 640 nm to about 760 nm
Implementation Method 2
a resin having a hydroxyl value (OH value) of 5 mgKOH/g or less
Implementation Method 3
a layer containing the quantum dot particles may also be provided with light scattering particles, such as TiO2 and the like, which scatter blue light emitted from the backlight unit
Data Source
AI summary
Provided are an optical member and an optical display device including same, the optical member comprising: a base film; and a light transmission control layer stacked on the lower surface of the base film, wherein the light transmission control layer comprises: a dye or dye mixture including at least one of a first dye having a maximum absorption wavelength of about 540 nm to about 630 nm, a second dye having a maximum absorption wavelength of about 390 nm to about 470 nm, a third dye having a maximum absorption wavelength of about 480 nm to about 530 nm, and a fourth dye having a maximum absorption wavelength of about 640 nm to about 760 nm; and a resin having a hydroxyl value of 5 mgKOH/g or less.