OLED Display Microlens Array for Thin Organic Layer Light Extraction
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Solution Overview
Problem
The manufacturing cost of organic light emitting diode (OLED) displays is increased due to the need for thick organic layers to achieve the microcavity effect, which enhances luminance efficiency but requires more organic materials.
Innovation Solution
The OLED display is designed with a reduced thickness of the organic layer, optimizing the distance between electrodes to achieve resonance and enhance light extraction efficiency while minimizing the use of organic materials, thereby reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the organic layer is thickly formed to achieve the microcavity effect, then luminance efficiency is improved, but manufacturing cost increases due to higher organic material consumption
Solution Approach 1:
The patent changes the optical parameters of the system by introducing a microlens array with specific focal lengths and aperture ratios. The microlenses concentrate light at optimized positions within the organic layer, achieving high luminance efficiency without requiring a thick organic layer. This parameter optimization allows thin organic layers (e.g., 50-200 nm) to achieve the same light extraction efficiency as much thicker layers would provide through microcavity effects alone.
2Quantity of substance
If the organic layer thickness is reduced to lower manufacturing cost, then organic material consumption decreases, but light extraction efficiency may be compromised
Solution Approach 1:
The patent introduces microlenses as intermediary optical elements that mediate between the light source (organic layer) and the external environment. These microlenses act as light concentrators that focus photons from the thin organic layer into specific directions, enhancing light extraction efficiency. The microlens array serves as an intermediary structure that compensates for the reduced light output from thinner organic layers, maintaining overall luminance efficiency while using less organic material.
3Use of energy by moving object
If a microlens array is introduced to enhance light extraction in thin organic layers, then luminance efficiency is maintained or improved, but device complexity increases
Solution Approach 1:
The patent merges the microlens array functionality with existing OLED structural elements. The microlenses are integrated into the encapsulation layers or buffer layers that already exist in the OLED structure, combining multiple functions (encapsulation/protection and light extraction enhancement) into a single integrated component. This merging approach avoids adding separate complex subsystems and reduces overall device complexity while maintaining luminance efficiency benefits.
4Use of energy by moving object
If the microlens focal length and aperture ratio are optimized, then light extraction efficiency is maximized, but manufacturing precision requirements increase
Solution Approach 1:
The patent identifies and optimizes key parameters (focal length f, aperture ratio AR) to achieve optimal light extraction efficiency. By establishing specific parameter ranges (e.g., focal length 50-500 μm, aperture ratio 0.3-0.8), the patent balances performance optimization with manufacturing feasibility. These parameter specifications provide clear design guidelines that facilitate manufacturing while maintaining high light extraction efficiency, avoiding overly stringent precision requirements.
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 maintains high luminance efficiency while decreasing the amount of organic materials needed, thus lowering the manufacturing cost of OLED displays without compromising performance.
Implementation Method 1
A microlens may be disposed on the anode electrode or on the cathode electrode. The microlens concentrates light at a position corresponding to a focal point of the microlens
Implementation Method 2
when light is repeatedly reflected off a reflective layer (e.g., an anode electrode) and a transflective layer (e.g., a cathode electrode) that are a predetermined distance (i.e., an optical path length) apart from each other, a strong interference effect occurs between the reflected light so that light of a predetermined wavelength is amplified
Implementation Method 3
a strong interference effect occurs between the reflected light so that light of a predetermined wavelength is amplified and light of other wavelengths is cancelled out
Implementation Method 4
Holes and electrons are respectively supplied from the anode and the cathode into an organic light emitting layer, and then combined with each other therein to form excitons. The OLED emits light by energy generated when the excitons fall from an excited state to a ground state
Data Source
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AI summary
An organic light emitting diode display includes: a substrate; and a plurality of red organic light emitting diodes, green organic light emitting diodes, and blue organic light emitting diodes on the substrate, each of the plurality of red organic light emitting diodes, green organic light emitting diodes, and blue organic light emitting diodes including: a first electrode on the substrate; an organic layer on the first electrode; and a second electrode on the organic layer, and the organic layer includes a light emission auxiliary layer on the first electrode and an organic light emitting layer on the light emission auxiliary layer, and the organic layer of each of the red organic light emitting diodes has a thickness of about 90 to 110nm.