OLED Display Microcavity and Lambertian Sub-pixel Architecture
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Solution Overview
Problem
Conventional OLED displays face challenges in achieving high color gamut and efficient light emission while maintaining low reflectivity and color stability across different viewing angles, particularly due to the limitations of cavity structures and polarizers in bright ambient conditions.
Innovation Solution
The implementation of an OLED display architecture that incorporates both Lambertian emission and microcavity sub-pixels, with a controller to dynamically adjust the emission mode based on image content and viewing conditions, utilizing plasmonic PHOLEDs and scattering outcoupling schemes to enhance efficiency and color fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If cavity structures and polarizers are used to achieve high color gamut and efficient light emission, then color saturation and emission efficiency are improved, but reflectivity increases and color stability across viewing angles deteriorates
Solution Approach 1:
The display is divided into multiple sub-pixels within each pixel, where each sub-pixel contains a specific combination of red, green, and blue emitting diodes. This segmentation allows independent control and optimization of each sub-pixel's emission characteristics, enabling high color gamut without requiring traditional cavity structures and polarizers that cause high reflectivity
Solution Approach 2:
Each sub-pixel is designed with specific local quality characteristics by selecting particular combinations of red, green, and blue LEDs with different luminances and chromaticities. This local optimization allows each sub-pixel to contribute differently to the overall color gamut while maintaining low reflectivity and consistent color stability across viewing angles
2Use of energy by moving object
If cavity structures are used to enhance light emission efficiency, then emission efficiency is improved, but viewing angle performance and color stability deteriorate
Solution Approach 1:
The system dynamically adjusts the emission characteristics by independently controlling the luminance of individual red, green, and blue LEDs within each sub-pixel. This dynamic control allows the display to maintain optimal color stability and emission efficiency across different viewing angles without relying on fixed cavity structures
Solution Approach 2:
The multi-LED sub-pixel structure serves multiple functions simultaneously: it achieves high emission efficiency through direct LED emission, maintains color stability across viewing angles through proper geometric arrangement, and enables high color gamut through selective LED combinations. This universal design replaces the need for separate cavity structures and polarizers
3Object-affected harmful factors
If circular polarizers are used to reduce reflectivity in bright environments, then reflectivity is reduced, but device complexity and light loss increase
Solution Approach 1:
The invention extracts and removes the circular polarizer component from the display structure entirely. Instead of using polarizers to manage reflectivity, the design relies on the inherent emission characteristics of the LED sub-pixels and their geometric arrangement to achieve low reflectivity and high visibility in bright environments
Solution Approach 2:
The design converts the potential harm of ambient light reflection into a benefit by using the directional emission properties of the LED sub-pixels. The specific arrangement and emission angles of the red, green, and blue LEDs are optimized to minimize reflected light while maximizing forward emission, turning the challenge of bright environment visibility into an advantage
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 enables high color gamut, low reflectivity, and efficient light emission with reduced luminance and color shifts at various viewing angles, allowing for the removal of circular polarizers and improved display performance in bright environments.
Implementation Method 1
OLEDs make use of thin organic films that emit light when voltage is applied across the device
Implementation Method 2
One application for phosphorescent emissive molecules is a full color display
Data Source
AI summary
Embodiments of the disclosed subject matter provide a device including an organic light emitting device (OLED) display having at least one pixel having a plurality of sub-pixels, where at least one color sub-pixel of the plurality of sub-pixels may be configured to output red light, green light, and/or blue light. The device may include at least one sub-pixel that is configured to have a Lambertian emission, and at least one sub-pixel having a microcavity configured for direct emission such that a first ratio of light from the direct emission sub-pixel in a cone having an angle of 0-20° in a normal direction relative to an overall light emission from the direct emission sub-pixel having at least 10%, at least 20%, and/or at least 30% higher than a second ratio of light from the Lambertian emission sub-pixel.