Organic Light-Emitting Display Diffraction Layer for Screen Door Reduction
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Solution Overview
Problem
Existing display devices, particularly organic light emitting displays and head-mounted displays, face challenges in maximizing the effective emission area ratio and minimizing blurring and screen door effect (SDE).
Innovation Solution
Incorporating a diffraction pattern layer with specific periodicity and dimensions on the display device, which diffracts light to increase the effective emission area ratio and reduce blurring by controlling the diffraction angles and distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional display structure is used, then the device complexity is low, but the effective emission area ratio is insufficient
Solution Approach 1:
The display device is segmented into multiple functional layers including a substrate, display element, encapsulation layer, and diffraction pattern layer. This segmentation allows each layer to perform its specific function optimally, contributing to increased effective emission area ratio while maintaining manageable device complexity through modular design
Solution Approach 2:
The patent introduces a diffraction pattern layer that manipulates light in the optical dimension rather than simply increasing physical display area. By creating multiple virtual images through diffraction at different angles, the effective emission area is expanded without proportionally increasing the physical device footprint
2Measurement precision
If the diffraction distance is increased to reduce blurring, then the blurring degree is minimized, but the device complexity increases
Solution Approach 1:
The patent optimizes the diffraction distance parameter within a specific range (0.05 to 0.2 times the pixel pitch) to minimize blurring. By carefully selecting and adjusting this parameter, the system achieves reduced blurring while avoiding the need for complex additional components that would increase device complexity
3Productivity
If the diffraction pattern layer is added to increase effective emission area, then the effective emission area ratio is increased, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies particular parameter ranges for the diffraction pattern layer including period (0.5 to 2.0 times the pixel pitch), thickness (50 to 200 nm), and diffraction distance (0.05 to 0.2 times pixel pitch). These standardized parameter specifications simplify manufacturing by providing clear design guidelines while achieving the goal of increased effective emission area ratio
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
Enhances the effective emission area ratio and minimizes blurring, improving the overall display quality and luminous efficiency of the organic light emitting displays.
Implementation Method 1
a plurality of diffraction patterns which are disposed on a path of light emitted from the first display element and generate a reference emission pattern and a first duplicate emission pattern by diffracting light emitted from the first display element
Data Source
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AI summary
A display device includes a substrate (110), a first display element (PX1) which is disposed on the substrate and emits light into a emitter cone, a distnace and encapsulation layer (160) and a diffractive structure on the emcapsultaion layer comprising a plurality of binray diffractive patterns (170) arranged at a first period in a first direction. The duty cycle of the diffractive grating is chosen between 0,4 and 1. The grating reduces the screen door effect or pattern noise effect experienced in a head-up display.