Micro-LED Display Optical Cover Window for Luminance Uniformity
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Solution Overview
Problem
Micro-LED display devices face challenges with central luminance decrease and viewing angle asymmetry due to transfer arrangement errors of ultra-small LEDs, leading to sharp luminance decreases at specific angles.
Innovation Solution
Incorporating an optical cover window with pyramid patterns that include inner bevel surfaces corresponding to the arrangement errors of LEDs, positioned to compensate for positioning inaccuracies during the transfer process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If micro-LEDs are transferred to precise positions, then luminance uniformity is improved, but manufacturing complexity increases due to the difficulty of precise positioning of ultra-small LEDs
Solution Approach 1:
The patent introduces a transfer substrate as an intermediary component that temporarily holds multiple micro-LEDs in an array configuration. This transfer substrate acts as a mediator between the micro-LED fabrication process and the final display substrate, enabling precise positioning through a two-stage transfer process that reduces the complexity of direct micro-LED placement
Solution Approach 2:
The patent divides the micro-LED array into smaller groups or rows that are transferred sequentially from the transfer substrate to the display substrate. This segmentation approach simplifies the transfer process by handling smaller batches of micro-LEDs at a time, improving positioning precision while managing manufacturing complexity
2Measurement precision
If micro-LED size is reduced for high resolution, then display resolution is improved, but positioning difficulty increases leading to arrangement errors
Solution Approach 1:
The patent performs preliminary positioning of micro-LEDs on the transfer substrate before final transfer to the display substrate. This preliminary arrangement allows for verification and correction of positions, ensuring high positioning accuracy even for ultra-small micro-LEDs required for high resolution displays
Solution Approach 2:
The patent employs alignment marks and optical detection systems to replace manual or purely mechanical positioning methods. This substitution enables precise positioning of ultra-small micro-LEDs through optical detection and automated adjustment, achieving the required positioning accuracy for high resolution displays
3Ease of manufacture
If transfer process is simplified, then manufacturing ease is improved, but arrangement errors increase causing luminance non-uniformity
Solution Approach 1:
The transfer substrate serves as a mediator that simplifies the overall manufacturing process while maintaining precision. It allows micro-LEDs to be arranged and verified before final transfer, separating the complexity of precise positioning from the final assembly process and thereby simplifying manufacturing without sacrificing accuracy
Solution Approach 2:
The patent incorporates alignment marks and detection mechanisms that provide feedback during the transfer process. This feedback system monitors the position of micro-LEDs on the transfer substrate and enables corrective adjustments, ensuring arrangement accuracy while maintaining process simplicity through automated control
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
Prevents central luminance decrease and viewing angle asymmetry, maintaining uniform luminance and preventing sharp luminance drops across various viewing angles.
Implementation Method 1
an optical cover window positioned to correspond to a transmission direction of a light emitted from the display panel and including a plurality of pyramid patterns; wherein the plurality of pyramid patterns each include an inner bevel surface corresponding to an arrangement error of the light emitting diodes
Data Source
AI summary
A light emitting diode display device includes a display panel including a light emitting diode for each sub-pixel defined on a substrate, and an optical cover window positioned to correspond to a transmission direction of a light emitted from the display panel and including a plurality of pyramid patterns, wherein the plurality of pyramid patterns each include an inner bevel surface corresponding to an arrangement error of the light emitting diodes.