Display Device Insulating Layer EL Alignment
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Solution Overview
Problem
Current display technologies face challenges in achieving high resolution, high display quality, and high contrast while maintaining a reliable manufacturing process, particularly in forming light-emitting elements with precise alignment and minimal non-light-emitting areas between pixels.
Innovation Solution
The implementation of a display device structure featuring two light-emitting elements with EL layers and a common electrode, where an insulating layer with an inorganic material is used to separate and position the EL layers closely, allowing for precise alignment and increased aperture ratio, and a method of forming EL layers without a shadow mask to reduce deviations and enhance resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a shadow mask is used to form EL layers, then the alignment between pixel electrodes and EL layers can be achieved, but deviations occur that reduce manufacturing precision
Solution Approach 1:
The patent removes the shadow mask from the manufacturing process entirely. EL layers are formed by sequentially depositing organic compounds directly onto pixel electrodes without requiring a shadow mask, thereby eliminating alignment deviations caused by mask positioning and achieving both high precision and reliability
Solution Approach 2:
The mechanical shadow mask alignment system is replaced with a sequential deposition process controlled by substrate movement. The substrate is precisely positioned and moved during deposition to form EL layers directly over pixel electrodes, substituting mechanical mask alignment with controlled substrate positioning
2Manufacturing precision
If the distance between pixel electrodes is reduced to increase resolution, then higher resolution is achieved, but the complexity of forming precise EL layers increases
Solution Approach 1:
The patent divides the EL layer formation into sequential steps for different organic compounds (hole-transporting, light-emitting, electron-transporting compounds). Each compound is deposited in a separate step with precise substrate positioning, allowing complex multi-layer EL structures to be formed with high precision at reduced pixel spacing
Solution Approach 2:
The patent adds the time dimension to the formation process by using sequential deposition with substrate movement. Instead of forming all EL layers simultaneously with a shadow mask, the substrate is moved to different positions during deposition, creating precise spatial patterns through temporal sequencing of deposition steps
3Illumination intensity
If non-light-emitting areas between pixels are minimized to increase aperture ratio, then display quality improves, but contrast ratio deteriorates
Solution Approach 1:
The patent applies different organic compounds with specific functions to different regions of the EL layer. Hole-transporting compounds are deposited in regions adjacent to pixel electrodes, light-emitting compounds in central regions, and electron-transporting compounds in other areas. This local functional differentiation allows precise control of light emission zones, maximizing aperture ratio while maintaining contrast through controlled light emission only in intended regions
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 enables the creation of high-resolution displays with improved contrast and display quality by minimizing non-light-emitting areas and increasing the effective light-emitting area ratio, while also simplifying the manufacturing process to achieve high yield and reliability.
Implementation Method 1
An insulating layer is provided between the first pixel electrode and the second pixel electrode. The insulating layer includes a first region overlapping with the first EL layer, a second region overlapping with the second EL layer, and a third region positioned between the first region and the second region and overlapping with neither the first EL layer nor the second EL layer.
Implementation Method 2
By applying voltage to this element, light emission can be obtained from the light-emitting organic compound.
Data Source
AI summary
A high-resolution display device is provided. A display device having both high display quality and high resolution is provided. The display device includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first pixel electrode, a first EL layer, and a common electrode. The second light-emitting element includes a second pixel electrode, a second EL layer, and the common electrode. An insulating layer containing an inorganic insulating material is provided between the first pixel electrode and the second pixel electrode. The insulating layer includes a first region overlapping with the first EL layer, a second region overlapping with the second EL layer, and a third region positioned between the first region and the second region. A side surface of the first EL layer and a side surface of the second EL layer are positioned over the insulating layer to face each other. The common electrode is provided along the side surface of the first EL layer, the side surface of the second EL layer, and a top surface of the insulating layer. A width of the insulating layer is larger than or equal to 2 times and smaller than or equal to 4 times a distance between the first pixel electrode and the second pixel electrode.