White OLED Color Conversion Film for Cyan and Yellow-Orange Light
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Solution Overview
Problem
White OLED display devices currently generate white light with low color purity and low backlight conversion rate due to the method of exciting yellow fluorescence with blue light and mixing it with blue light.
Innovation Solution
A method of manufacturing a white OLED display device involving a color filter layer with an organic fluorescent color conversion film formed by cross-linking reactions between rhodamine derivatives and acrylic resin in a silicone resin, converting cyan light into green and yellow-orange light into red, thereby improving color gamut and conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If white light is generated by exciting yellow fluorescence with blue light and mixing it with blue light, then the white OLED can be manufactured with a simple structure, but the color purity and backlight conversion rate are low
Solution Approach 1:
The patent divides the color conversion function into separate modules: a yellow fluorescent material layer for converting blue light to yellow, and distinct red and green fluorescent material layers for converting cyan light to red and green respectively. This segmentation allows each layer to be optimized for its specific wavelength conversion, improving color purity while maintaining the overall simplicity of the white OLED structure.
Solution Approach 2:
The patent applies local quality by using different fluorescent materials with specific emission characteristics in different regions of the display. The yellow fluorescent material is positioned to convert blue light, while red and green fluorescent materials are positioned to convert cyan light, creating localized color conversion zones that collectively produce high-purity white light with enhanced color gamut.
2Ease of manufacture
If white light is generated by exciting yellow fluorescence with blue light and mixing it with blue light, then the manufacturing process remains simple, but the backlight conversion rate is low
Solution Approach 1:
The patent optimizes the emission wavelengths and quantum efficiencies of the fluorescent materials used. By selecting materials with peak emission wavelengths that closely match the required red, green, and blue wavelengths, and by optimizing their thickness and composition, the patent achieves high backlight conversion rates. The yellow fluorescent material converts blue light efficiently, while the red and green fluorescent materials convert cyan light with high quantum efficiency, minimizing energy loss.
3Productivity
If conventional white OLED structure is used, then the device can be manufactured with current technology, but color reproduction and device stability are insufficient
Solution Approach 1:
The patent introduces an intermediary encapsulation layer between the fluorescent material layers and the external environment. This encapsulation layer acts as a barrier against moisture and oxygen, preventing degradation of the organic fluorescent materials. The layer allows the device to maintain its manufacturing simplicity while significantly improving long-term stability and reliability by protecting the sensitive organic compounds from environmental damage.
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 enhances color reproduction and light conversion efficiency, preventing ion penetration and improving device stability by blocking water and oxygen, thus addressing the limitations of existing white OLED technology.
Implementation Method 1
the first conversion film converts cyan light emitted by the white OLED light source into green light
Implementation Method 2
the second conversion film converts yellow-orange light emitted by the white OLED light source into red light
Implementation Method 3
the first conversion film is formed by a cross-linking reaction between a rhodamine 6G derivative and an acrylic resin in a silicone resin, and the second conversion film is formed by a cross-linking reaction between a rhodamine 101 derivative and an acrylic resin in a silicone resin
Data Source
AI summary
A white organic light emitting diode (OLED) display device and a method of manufacturing the same are provided. By making an organic fluorescent color conversion film including a first conversion film and a second conversion film respectively disposed on a green color resist and a red color resist, the first conversion film converts cyan light into green light, and the second conversion film converts yellow orange light into red light. This can improve color gamut and color conversion rate of the white OLED display device and improve density of the organic color conversion film and stability of a device.