OLED Pixel Transistor Shielding for Light-Induced Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current OLED display devices face challenges in efficiently initializing and maintaining the voltage of transistors, leading to potential display failures such as luminance changes and color coordinate shifts due to external light interference and leakage currents.
Innovation Solution
The proposed display device incorporates a shielding part that overlaps specific boundaries between transistor regions to block external light, and a capacitor structure that includes an initialization voltage line to stabilize transistor voltages, ensuring proper initialization and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding part is added to block external light, then light interference is reduced, but device complexity increases
Solution Approach 1:
The shielding part is segmented into multiple regions with different transparency characteristics. The first shielding part covers the boundary between source and channel regions, while the second shielding part covers the boundary between drain and channel regions. This segmentation allows selective light blocking where most needed while maintaining transistor functionality.
Solution Approach 2:
Different regions of the shielding part have different optical properties. The shielding part is configured to be transparent to external light in certain areas while blocking light in other areas. Specifically, the shielding part blocks light at critical transistor boundaries where leakage currents are most problematic, while allowing light transmission in regions where it does not interfere with transistor operation.
2Reliability
If transistor regions are covered to prevent leakage currents, then display reliability improves, but manufacturing precision requirements increase
Solution Approach 1:
The shielding part is merged with existing transistor structures, specifically positioned to cover boundaries between functional regions (source-channel and drain-channel interfaces). This integration allows the shielding function to be achieved using the same fabrication processes as the transistor itself, reducing additional precision requirements.
Solution Approach 2:
The shielding part is formed as part of the transistor fabrication sequence, with its position predetermined by the transistor layout. By establishing the shielding part's position during the transistor formation process rather than as a separate step, the positioning precision requirement is reduced to matching the existing transistor feature dimensions.
3Object-generated harmful factors
If shielding parts are positioned to block light at transistor boundaries, then leakage currents are reduced, but device complexity increases
Solution Approach 1:
The shielding function is extracted as a separate, dedicated component rather than being integrated into the transistor electrodes or channels. This allows the shielding part to be optimized specifically for light blocking without compromising transistor performance, while its simple geometric form (covering only critical boundaries) keeps the overall structure relatively simple.
Data Source
AI summary
A display device includes signal lines and pixels connected thereto. A first pixel includes a first transistor including a first gate electrode, a first channel region overlapping the first gate electrode, a first source region, and a second drain region facing the first source region, with the first channel region interposed between the first source region and the second drain region. A third transistor includes a third gate electrode, a third channel region overlapping the third gate electrode, a third drain region connected to the first gate electrode, and a third source region facing the third drain region with the third channel region interposed between the third source region and the third drain region. A shielding part overlaps a boundary between the third source region and the third channel region and does not overlap a boundary between the third drain region and the third channel region.