OLED Multicolor Display Shared Emitter Layers
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Solution Overview
Problem
Multicolor OLED displays face challenges in power efficiency due to the need for precise patterning of OLED layers, which increases manufacturing complexity and power consumption, especially since the human eye is less sensitive to red and blue light, requiring these pixels to emit more light to achieve desired brightness.
Innovation Solution
A multicolor OLED display design featuring at least three differently colored pixels with a common light emitting layer for two pixels and a separate layer for the third, along with color filters to achieve desired spectral components, reducing the need for precise patterning and alignment, thereby simplifying manufacturing and enhancing power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate OLED electroluminescent layers are provided for each pixel with precise patterning, then color accuracy is improved, but manufacturing complexity and alignment requirements increase
Solution Approach 1:
The patent combines multiple electroluminescent layers (first light emitting layer for red and green pixels, second light emitting layer for green and blue pixels) into a shared structure that serves multiple pixels simultaneously. This merging approach reduces the number of separate patterning operations needed while maintaining the ability to produce distinct colors in different pixel regions through selective layer combinations and color filters.
Solution Approach 2:
The first and second light emitting layers are designed to serve dual purposes: the first layer contributes to both red and green pixel emission, while the second layer contributes to both green and blue pixel emission. This multi-functionality allows a single layer deposition process to create multiple color outputs, reducing manufacturing steps while maintaining color accuracy.
2Illumination intensity
If red and blue pixels emit more light to compensate for lower human eye sensitivity, then desired brightness is achieved, but power consumption increases
Solution Approach 1:
The patent introduces a yellow light emitting layer with specific spectral characteristics that emits light in the yellow region of the spectrum. By adding this layer, the display can produce yellow light directly rather than relying on high-power red and green emissions, thereby reducing overall power consumption while maintaining perceived brightness and color accuracy.
Solution Approach 2:
The patent creates composite light emission by combining multiple electroluminescent layers with different spectral outputs (red, green, blue, and yellow) and using color filters to modulate the combined light. This composite approach allows the display to achieve desired colors through efficient combination of multiple light sources rather than relying on high-power emission from less efficient red and blue pixels alone.
3Manufacturing precision
If shadow masks are used for patterning OLED layers, then selective deposition is achieved, but alignment accuracy decreases and manufacturing throughput slows
Solution Approach 1:
The patent removes the shadow mask component from the patterning process entirely. Instead of using physical masks to define pixel regions during deposition, the invention relies on direct patterning of the electroluminescent layers through alternative methods, eliminating the alignment errors and throughput limitations inherent in shadow mask approaches.
Solution Approach 2:
The patent replaces the mechanical shadow mask system with a direct patterning approach where electroluminescent layers are deposited and patterned without requiring physical masking components. This substitution eliminates the mechanical alignment steps associated with shadow masks, improving both precision and manufacturing throughput.
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 design simplifies manufacturing by reducing the number of precise alignment steps and improves power efficiency by optimizing light emission spectra, allowing for more effective color production with lower power consumption.
Implementation Method 1
an organic light emitting layer between two electrodes... capable of producing light... electroluminescent OLED layers
Implementation Method 2
a color filter layer formed by evaporating a pigment and/or an organic dye... first and second color filters in operative relationship with the first and second pixels
Data Source
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AI summary
An OLED display having at least first, second, and third differently colored pixels includes a first light emitting layer provided over a substrate for the first and second pixels and a second light emitting layer provided over the substrate for the first, second, and third pixels, wherein the first and second light emitting layers produce light having different spectra, and wherein the light produced by overlapping the first and second light emitting layers has substantial spectral components corresponding to the light output desired for the first and second pixels, and the light produced by the second light emitting layer has substantial spectral components corresponding to the light output desired for the third pixel; and first and second color filters in operative relationship with the first and second pixels.