External Light-Absorbing Layer for OLED Moire Reduction
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Solution Overview
Problem
Display devices, particularly OLEDs, face issues with external light reflection causing a moire phenomenon that obstructs the user's view and degrades image quality due to light being reflected from the opposite electrode and wiring lines around the transmission area.
Innovation Solution
An external light-absorbing layer is strategically placed on the thin film encapsulation layer to overlap the inclined portions of the pixel-defining layer and wiring lines, blocking reflected light and preventing the moire phenomenon, while a polarizing plate and light control films are used to further enhance image quality by controlling light emission directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an OLED display device is used to achieve wide viewing angle and excellent contrast, then image quality is improved, but external light reflection causes moire phenomenon that degrades image quality
Solution Approach 1:
An external light absorbing layer is introduced as an intermediary component between the OLED display structure and the external environment. This layer specifically absorbs reflected light from the opposite electrode and wiring lines, preventing the moire phenomenon while maintaining the OLED's inherent wide viewing angle and contrast advantages
Solution Approach 2:
The external light absorbing layer is strategically positioned only in specific regions where reflection problems occur (around the transmission area and opposite electrode), rather than covering the entire display. This localized approach eliminates harmful reflections without compromising the overall image quality and viewing characteristics of the OLED display
2Illumination intensity
If a light-absorbing layer is added to block external light reflection, then image quality is improved, but device structure becomes more complex
Solution Approach 1:
The external light absorbing layer is applied only in specific regions where reflection problems occur (around the transmission area and opposite electrode), rather than covering the entire display. This localized approach eliminates harmful reflections without unnecessarily increasing overall device complexity
Solution Approach 2:
The external light absorbing layer is integrated with the existing OLED encapsulation structure, forming a composite multi-layer system. This combines the protective encapsulation function with the light-absorbing function in a unified structure, avoiding the need for separate independent components
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 effectively reduces external light reflection, preventing the moire phenomenon and improving image quality by ensuring that light is not emitted in distracting directions, thus enhancing the display's overall performance.
Implementation Method 1
an external light-absorbing layer at least partially overlapping the emission area and arranged on the thin film encapsulation layer
Data Source
AI summary
A display device having improved image quality characteristics including a substrate including a transmission area and an emission area defined by a pixel-defining layer; a display element including a pixel electrode at least partially exposed by the pixel-defining layer, an intermediate layer arranged on the pixel electrode, and an opposite electrode arranged on the intermediate layer; a thin film encapsulation layer arranged on the display element, the thin film encapsulation layer including at least one inorganic encapsulation layer and at least one organic encapsulation layer; and an external light-absorbing layer at least partially overlapping the emission area and arranged on the thin film encapsulation layer.