OLED Color Filter Cavity Structure for Light Mixing Suppression
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Solution Overview
Problem
Existing display devices with organic layers and color filters suffer from light mixing and color mixing due to inefficient light extraction, as light from one pixel can travel into adjacent color filters, leading to reduced luminance and color purity.
Innovation Solution
A display device design featuring a protective layer with cavity portions between adjacent color filters, which suppresses light leakage into adjacent sub-pixels and enhances light extraction efficiency by reflecting light back into the intended pixel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a black matrix is disposed between adjacent color filters to suppress light mixing, then light and color mixing is reduced, but light extraction efficiency deteriorates due to light absorption
Solution Approach 1:
A reflective layer is introduced as an intermediary component between adjacent color filters. This reflective layer serves as a mediator that redirects stray light back toward the intended pixel while allowing the color filters to maintain their light-absorbing function for color purification. The reflective layer does not directly absorb light like the black matrix but instead reflects it, thereby reducing light mixing without sacrificing light extraction efficiency.
Solution Approach 2:
The optical properties of the interface region are changed by introducing a reflective layer with high reflectivity. This parameter change transforms the interface from a light-absorbing region (as in the black matrix approach) to a light-redirecting region, thereby improving light extraction efficiency while maintaining the light mixing suppression function.
2Object-affected harmful factors
If the sides of adjacent color filters are aligned to suppress light mixing, then light and color mixing is reduced, but light extraction efficiency deteriorates due to light absorption at the interface
Solution Approach 1:
The reflective layer acts as an intermediary that addresses the light absorption problem at the aligned interface. By placing this reflective layer at the interface between adjacent color filters, stray light that would otherwise be absorbed is instead reflected back into the intended pixel, maintaining both the light mixing suppression benefit of alignment and the light extraction efficiency.
3Loss of energy
If light is allowed to travel freely to improve light extraction efficiency, then light extraction efficiency improves, but light and color mixing increases between adjacent pixels
Solution Approach 1:
The reflective layer is selectively positioned at the interface regions between adjacent color filters, creating local optical control. In these specific local regions, the reflective layer redirects stray light to prevent color mixing. In other regions (above the color filters), light can travel freely to maintain high light extraction efficiency. This local application of the reflective function resolves the contradiction between free light travel and color mixing prevention.
Solution Approach 2:
The reflective layer serves as a localized intermediary that intervenes only where needed (at the interfaces between adjacent pixels) to prevent color mixing, while allowing light to travel freely in other regions, thereby maintaining overall light extraction efficiency.
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 design effectively reduces light and color mixing, improving luminance and color purity by reflecting light back into the intended pixel, while also protecting the color filters and light-emitting elements from external factors.
Implementation Method 1
enhances light extraction efficiency by reflecting light back into the intended pixel
Data Source
AI summary
Provided is a display device and an electronic device that can suppress mixing of light and mixing of colors with efficient light extraction. The display device includes a plurality of light-emitting elements having an organic layer, a plurality of color filters disposed at positions corresponding to the respective light-emitting elements, and a protective layer covering the side portions of the plurality of color filters. At a position between the adjacent color filters, a cavity portion is formed in the protective layer.