Color Conversion Sheet Using Organic Light-Emitting Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color conversion methods using organic light-emitting materials in displays and lighting apparatuses are insufficient in achieving high color purity and wide color gamut, which limits their ability to improve color reproducibility.
Innovation Solution
A color conversion sheet is developed with two distinct layers, each containing specific organic light-emitting materials and binder resins, where the organic light-emitting materials exhibit peak wavelengths in different ranges, and the solubility parameters of the binder resins are carefully selected to optimize light emission and reduce inter-material interaction, allowing for independent emission of green and red light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If quantum dots are used as color conversion material, then color purity is improved, but durability deteriorates due to vulnerability to heat and water/oxygen
Solution Approach 1:
The patent replaces quantum dots with organic light-emitting materials that have shorter operational lifetimes but can be easily replaced and are less vulnerable to environmental degradation. The organic materials are encapsulated in protective resin layers to extend their service life while maintaining ease of replacement.
Solution Approach 2:
The patent creates a composite structure combining organic light-emitting materials with protective resin matrices and encapsulation layers. This composite approach provides both the desired color emission properties and protection against heat and moisture, resolving the durability issue while maintaining color purity.
2Measurement precision
If cadmium-containing quantum dots are used, then color purity is improved, but environmental harm increases
Solution Approach 1:
The patent adopts cadmium-free organic light-emitting materials that can be synthesized without toxic heavy metals. These materials achieve comparable color purity through molecular design and are environmentally benign, eliminating cadmium contamination risks while maintaining performance.
Solution Approach 2:
The patent changes the fundamental material parameters from inorganic quantum dot composition to organic molecular structures. By adjusting molecular configurations and chemical compositions of organic dyes or luminescent compounds, the patent achieves narrow emission spectra (high color purity) without relying on cadmium-containing materials.
3Reliability
If organic light-emitting materials are used instead of quantum dots, then durability is improved, but color purity deteriorates
Solution Approach 1:
The patent optimizes parameters of organic light-emitting materials including molecular structure design, substitution patterns, and chemical composition to narrow emission bandwidths. By carefully selecting organic compounds with specific HOMO-LUMO energy gaps and restricted vibrational modes, the patent achieves both high durability and improved color purity simultaneously.
Solution Approach 2:
The patent uses composite formulations combining multiple organic light-emitting materials with complementary emission characteristics. This allows achieving narrow overall emission spectra through spectral combining while maintaining the durability advantages of organic materials resistant to environmental degradation.
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 solution achieves high color purity and a wide color gamut, enabling improved color reproducibility by optimizing the emission peak wavelengths and intensities of blue, green, and red colors, resulting in a more vivid and large color gamut.
Implementation Method 1
Color conversion means converting light emission from a light-emitting body into light with a longer wavelength and means converting blue light emission into green or red light emission
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A color conversion sheet according to a mode of the present invention is a color conversion sheet that converts incident light into light with a wavelength longer than that of the incident light and includes the following layer (A) and layer (B). This color conversion sheet is used for a light source unit, a display, and a lighting apparatus. The layer (A): a layer containing an organic light-emitting material (a) that exhibits light emission with a peak wavelength observed in a region of 500 nm or more and 580 nm or less by using excitation light in a wavelength range of 400 nm or more and 500 nm or less and a binder resin; and the layer (B): a layer containing an organic light-emitting material (b) that exhibits light emission with a peak wavelength observed in a region of 580 nm or more and 750 nm or less by being excited by either or both of excitation light in a wavelength range of 400 nm or more and 500 nm or less and light emission from the organic light-emitting material (a) and a binder resin.