OLED Display Cholesteric Liquid Crystal Layer External Light Reflection
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Solution Overview
Problem
OLED displays face issues with external light reflection, which deteriorates black color expression and contrast, and existing solutions to suppress reflection result in significant light loss from the organic emission layer.
Innovation Solution
The use of a polarizing plate, retardation plate, cholesteric liquid crystal layer, translucent metal layer, and polarizing plate configuration to selectively transmit and reflect circularly polarized light, minimizing external light reflection while maximizing light emission from the organic layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a polarizing plate and retardation plate are disposed to suppress reflection of external light, then external light reflection is reduced, but a large amount of light generated from the organic emission layer is also lost
Solution Approach 1:
The patent changes the optical parameters of the display structure by introducing a cholesteric liquid crystal layer with specific helical structure and pitch, which selectively reflects circularly polarized light of one handedness while transmitting the other, thereby differentiating between external light suppression and internal light emission
Solution Approach 2:
The patent employs a composite structure combining multiple functional layers including polarizing plate, retardation plate, cholesteric liquid crystal layer, and translucent metal layer, where each layer contributes specific optical properties that collectively achieve both external light reflection suppression and internal light emission preservation
2Manufacturing precision
If a polarizing plate and retardation plate are disposed to suppress reflection of external light, then black color expression and contrast are improved, but light loss from the organic emission layer increases
Solution Approach 1:
The patent modifies the optical parameters by using a cholesteric liquid crystal layer with controlled helical pitch and chirality, enabling selective reflection of circularly polarized light to enhance black color expression and contrast while preserving light emission through the opposite circular polarization state
Solution Approach 2:
The patent creates a composite optical system integrating polarizing plate, retardation plate, cholesteric liquid crystal layer, and translucent metal layer, where the synergistic interaction of these materials achieves superior black color expression and contrast without significant light loss
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 configuration effectively suppresses external light reflection, improves black color expression and contrast, reduces light loss, and enhances overall display characteristics while maintaining low power consumption and extending the lifespan of the OLED display.
Implementation Method 1
a cholesteric liquid crystal layer, a translucent metal layer, and a polarizing plate which are substantially disposed on the organic light emitting element
Implementation Method 2
selectively transmit and reflect circularly polarized light
Implementation Method 3
a polarizing plate which are substantially disposed on the organic light emitting element
Implementation Method 4
a translucent metal layer, and a polarizing plate which are substantially disposed on the organic light emitting element
Data Source
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AI summary
An organic light emitting diode (OLED) display device is disclosed. In one embodiment, the OLED device includes 1) an organic light emitting element configured to emit light, 2) a cholesteric liquid crystal (CLC) layer (584) formed over the organic light emitting element and configured to selectively transmit or reflect circularly polarized light and 3) a translucent metal layer (583) formed on the CLC layer and configured to partially transmit and partially reflect incoming light. According to at least one embodiment, the OLED can suppress reflection of external light while minimizing loss of light generated from the organic emission layer.