Display Device Emission Layer Thickness Uniformity via Pixel Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The emission layer in display devices does not have a substantially uniform thickness due to the 'step' formed by overlapping wirings, leading to deteriorated color characteristics and display quality.
Innovation Solution
Incorporating a pixel defining layer with specific openings for each emission layer, ensuring the emission layers do not overlap the overlap area where the wiring patterns intersect, allowing for a relatively uniform thickness and improved color characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wirings are sequentially disposed and partially overlap to form circuits, then circuit functionality is achieved, but steps are formed on the wiring layer causing non-uniform emission layer thickness
Solution Approach 1:
The pixel area is segmented into a first area for emission layers and a second area for wiring patterns. The pixel defining layer divides these areas, allowing emission layers to be disposed only in the first area where they can maintain uniform thickness, while the second area accommodates the wiring patterns that would otherwise create steps and thickness variations.
Solution Approach 2:
Different regions of the pixel are assigned different functions: the first area is optimized for light emission with uniform thickness emission layers, while the second area is dedicated to wiring patterns. This local differentiation allows each region to perform its function optimally without compromising the other.
2Device complexity
If emission layer thickness is non-uniform due to wiring steps, then device structure is simplified, but color characteristics of emitted light deteriorate
Solution Approach 1:
By segmenting the pixel into distinct first and second areas separated by the pixel defining layer, the emission layers are confined to regions free from wiring-induced steps. This ensures uniform thickness and consistent color characteristics while maintaining the necessary wiring structure for device functionality.
Solution Approach 2:
The pixel defining layer acts as an intermediary structure that physically separates the emission layer region from the wiring pattern region. This mediator prevents the wiring steps from affecting the emission layer thickness, thereby preserving color characteristics while allowing the wiring layer to maintain its functional structure.
3Area of stationary object
If emission layers are disposed over wiring patterns, then aperture ratio is increased, but emission layer thickness becomes non-uniform
Solution Approach 1:
The pixel defining layer segments the pixel area into a first area for emission layers and a second area for wiring patterns. This segmentation allows the emission layers to achieve maximum uniform thickness in the first area while the wiring patterns are confined to the second area, effectively resolving the conflict between aperture ratio and thickness uniformity.
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 enhances the color characteristics and display quality by maintaining a uniform thickness of the emission layers, thereby improving the luminance and color coordinates of the displayed light.
Implementation Method 1
a first emission layer to emit light having a blue color, the first emission layer disposed in the first opening
Data Source
AI summary
A display device including a pixel includes: a substrate; a first pattern disposed on the substrate; a conductive, second pattern disposed on the first pattern and partially overlapping the first pattern; a conductive, third pattern disposed on the second pattern and partially overlapping the second pattern; a conductive, fourth pattern disposed on the third pattern and partially overlapping the third pattern, wherein the first pattern, the second pattern, the third pattern, and the fourth pattern overlap each other in a first area of the pixel; a pixel defining layer disposed on the fourth pattern and including a first opening overlapping a second area of the pixel without overlapping the first area; and a first emission layer to emit light having a blue color, the first emission layer disposed in the first opening.