Color Converter Layer Stack for Blue Light Reflection in Displays
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Solution Overview
Problem
Display devices with color converting layers face inefficiencies in converting blue light due to insufficient reflection and transmission of unconverted blue light, leading to reduced light output efficiency.
Innovation Solution
A display device structure incorporating a color converter with a first layer having a refractive index of 1.4 to 1.8 and a second layer with a refractive index of 1.8 to 2.0, alternately stacked to reflect unconverted blue light back to the color converting layer, increasing the amount of blue light provided and enhancing light conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a color converting layer is used to convert blue light, then color display capability is improved, but light output efficiency deteriorates due to insufficient reflection and transmission of unconverted blue light
Solution Approach 1:
The patent implements a feedback mechanism by placing a reflection layer beneath the color converting layer that reflects unconverted blue light back into the color converting layer, allowing multiple conversion opportunities and reducing energy loss from unconverted light
Solution Approach 2:
The patent introduces additional layers (first layer with refractive index 1.4-1.8, second layer with refractive index 1.8-2.0, and reflection layer) above and below the color converting layer to manipulate light paths in the vertical dimension, enhancing both transmission of converted light and reflection of unconverted light
2Productivity
If the refractive index of the first layer is set to 1.4-1.8 and the second layer to 1.8-2.0, then blue light reflection is improved, but device complexity increases due to multiple layered structures
Solution Approach 1:
The patent optimizes light conversion efficiency by precisely controlling the refractive index parameters of different layers: the first layer is set to 1.4-1.8, the second layer to 1.8-2.0, and the reflection layer to 1.8-2.2, creating optimal conditions for blue light reflection while maintaining manageable structural complexity
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 effectively increases the reflection of blue light and subsequent conversion efficiency, enhancing the overall light output of the display device by providing more blue light to the color converting layers.
Implementation Method 1
a first layer disposed on the color converting layer, the transmission layer, and the bank, a second layer disposed on the first layer, a third layer disposed on the second layer, and a color filter disposed on the third layer, the first layer includes a first sub-layer with a first refractive index, and a second sub-layer with a second refractive index, the first refractive index is equal to or greater than about 1.4 and less than about 1.8, and the second refractive index is equal to or greater than about 1.8 and equal to or less than about 2.0
Implementation Method 2
The second layer has a refractive index smaller than the first refractive index of the first layer. The third layer has a refractive index greater than the refractive index of the second layer
Data Source
AI summary
A display device includes: a display unit; and a color converter on the display unit and including a color converting layer and a transmission layer, a bank between the color converting layer and the transmission layer, a first layer on the color converting layer, the transmission layer, and the bank, a second layer on the first layer, a third layer on the second layer, and a color filter on the third layer. The first layer includes a first sub-layer with a first refractive index equal to or greater than about 1.4 and less than about 1.8, and a second sub-layer with a second refractive index equal to or greater than about 1.8 and equal to or less than about 2.0. The second layer has a refractive index smaller than those of the first layer. The third layer has a refractive index greater than that of the second layer.