OLED Micro-Cavity Anti-Peeping via PDLC Scattering
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Solution Overview
Problem
Top emission OLED display devices face issues with view angle dependency and privacy due to micro-cavity effects caused by thin metal layers, leading to reduced visibility and potential damage to the organic layer during manufacturing.
Innovation Solution
An OLED display device structure comprising a substrate, opaque first electrode, organic functional layer, semi-transparent second electrode, and polymer dispersed liquid crystal (PDLC) layer, with a micro-cavity structure formed by the first and second electrodes, allowing for controlled voltage differences to manage the PDLC's scattering mode and ensure privacy while maintaining visibility across various angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thin metal layer (10-15 nm) is used as the upper electrode to maintain conductivity, then the electrode conductivity is improved, but the micro-cavity effect causes view angle dependency and privacy issues
Solution Approach 1:
The patent introduces a PDLC layer that can dynamically change its optical state between transparent and scattering modes by applying voltage. When voltage is applied, the PDLC layer becomes transparent allowing wide view angles; when voltage is removed, it enters scattering mode to provide privacy. This dynamic switching resolves the contradiction between maintaining electrode conductivity through thin metal layers and achieving adaptability for different viewing conditions.
2Illumination intensity
If a transparent electrode (conductive metal oxide) is used in the high energy manufacture process, then the electrode transparency is improved, but the organic layer is damaged and device functionality is compromised
Solution Approach 1:
The patent replaces the conventional transparent electrode (conductive metal oxide) with a semi-transparent metal layer combined with a PDLC layer. The metal layer provides conductivity without requiring high energy manufacturing processes that damage the organic layer, while the PDLC layer provides the necessary optical transparency when voltage is applied. This intermediary solution avoids direct contact between high energy processes and the sensitive organic functional layer.
3Illumination intensity
If the micro-cavity structure is used to improve aperture ratio, then the display brightness is improved, but the display contents cannot be clearly seen in arbitrary angles
Solution Approach 1:
The patent combines the micro-cavity structure for improved aperture ratio and brightness with a dynamically controllable PDLC layer. The micro-cavity maintains high brightness through its optical resonance properties, while the PDLC layer dynamically adjusts the viewing angle characteristics. When voltage is applied, the PDLC layer becomes transparent allowing the micro-cavity's bright display to be viewed from arbitrary angles; when voltage is removed, it scatters light to provide privacy while maintaining the micro-cavity's aperture ratio benefits.
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
The solution prevents damage to the organic layer during manufacturing, ensures privacy through controlled light scattering, and allows clear viewing of display contents from arbitrary angles, implementing anti-peeping functionality without compromising display effectiveness.
Implementation Method 1
the PDLC layer and the upper electrode are disposed on the second electrode... the PDLC layer may be transparent by controlling the voltage difference between the second electrode and the upper electrode... The emitted light with certain angle of the OLED display device is scattered into scattered status while passing through the PDLC layer
Data Source
AI summary
The disclosure provides an OLED display device and a process for manufacturing the same, wherein the OLED display device includes a substrate, a first electrode, an organic functional layer, a second electrode, a polymer dispersed liquid crystal (PDLC) layer, and an upper electrode stacked in sequence, wherein the first electrode is an opaque electrode, and the second electrode is a semi-transparent electrode, and a micro-cavity structure consists of the first electrode, the organic functional layer, and the second electrode. The disclosure implements anti-peeping function and ensures the privacy of the display contents of the OLED display device while doing no harm to the organic functional layer. The disclosure also ensures that the display contents of the OLED display device can be dearly seen in a variety of angle.