Light-Emitting Device Sub-Pixel Arrangement and Absorption Layer
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Solution Overview
Problem
Existing light-emitting devices with small pixel sizes face challenges in achieving high color gamut due to increased crosstalk and unwanted transmission of primary radiation, which reduces color-purity and gamut coverage, especially when using thin conversion elements to minimize crosstalk.
Innovation Solution
The use of quantum dots as phosphors in combination with thin conversion elements and an absorption layer to reduce crosstalk and unwanted transmission, along with a specific arrangement of sub-pixels in a two-dimensional ordered pattern to enhance color-purity and gamut coverage, allows for efficient wavelength conversion and minimal absorption of primary radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If thin conversion elements are used to minimize crosstalk, then crosstalk between sub-pixels is reduced, but unwanted transmission of primary radiation increases
Solution Approach 1:
The patent introduces an absorption layer as an intermediary component between the conversion element and the external environment. This absorption layer specifically targets and absorbs the unwanted transmitted primary radiation (blue light) while allowing the converted radiation (green and red light) to pass through, thereby resolving the contradiction between reducing crosstalk and preventing unwanted transmission
Solution Approach 2:
The patent extracts and removes the harmful unwanted transmission of primary radiation from the system by using the absorption layer to selectively eliminate blue light that passes through the thin conversion element, while preserving the desired converted radiation
2Volume of moving object
If sub-pixel size is reduced to achieve small pixel sizes, then device integration is improved, but color-purity decreases due to increased crosstalk
Solution Approach 1:
The absorption layer serves as a mediator that compensates for the increased crosstalk inherent in small pixel designs by selectively absorbing stray blue radiation that would otherwise contaminate adjacent sub-pixels, thereby maintaining color-purity despite reduced pixel dimensions
Solution Approach 2:
The patent changes the optical parameters of the system by introducing selective absorption at specific wavelengths through the absorption layer, which modifies the radiation distribution and maintains color-purity in miniaturized pixel structures
3Adaptability or versatility
If conversion element thickness is reduced to reduce crosstalk, then gamut coverage is improved, but color-purity is compromised due to increased unwanted transmission
Solution Approach 1:
The absorption layer acts as a mediator that allows thin conversion elements to achieve wide gamut coverage by enabling more complete wavelength conversion, while simultaneously compensating for the increased unwanted transmission by selectively absorbing transmitted blue radiation, thus preserving color-purity
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 significantly increases the color gamut coverage of the light-emitting device, achieving high color rendering and minimizing crosstalk between adjacent sub-pixels, thereby improving the device's ability to accurately represent a wide range of colors.
Implementation Method 1
Each of the first and second conversion elements has a thickness of at most 5 μm, in particular of at most 2 μm. The sub-pixels each have an edge length of at most 100 μm, in particular of at most 10 μm and preferably of at most 5 μm
Implementation Method 2
The light-emitting device comprises an absorption layer arranged on the first and/or second conversion element, wherein the absorption layer is configured or designed to absorb blue radiation
Data Source
AI summary
A light emitting device is disclosed. In an embodiment a light-emitting device includes a pixel comprising at least three sub-pixels, wherein the at least three sub-pixel include a first sub-pixel including a first conversion element, wherein the first conversion element includes a green phosphor, a second sub-pixel including a second conversion element, wherein the second conversion element includes a red phosphor and a third sub-pixel free of a conversion element, wherein the third sub-pixel is configured to emit blue primary radiation, wherein each sub-pixels has an edge length of at most 100 μm, and wherein the pixel is a linear chain of sub-pixels and a plurality of pixels is arranged in a two dimensional ordered pattern so that a first sub-pixel is never adjacent to a third sub-pixel in a vertical direction and in a horizontal direction of the ordered pattern.