OLED Display Substrate Shielding Layout for First-Column Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED display devices face issues with non-uniform brightness due to asymmetry in the 7T1C pixel circuit design, particularly affecting the first column of pixel driving units, leading to darker pixels and reduced display quality.
Innovation Solution
A 'small pepper' design is implemented in the first column of pixel driving units, where light shielding patterns overlap with the threshold compensation transistor to shield the channel, reducing leakage and ensuring uniform brightness across the display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional 7T1C pixel circuit design is used, then the display device achieves basic functionality with standard circuit configuration, but brightness uniformity deteriorates due to asymmetry affecting the first column of pixel driving units
Solution Approach 1:
The patent applies local quality by introducing a specialized light shielding pattern (referred to as 'small pepper' design) specifically for the first column of pixel driving units, while other columns use conventional designs. This localized modification addresses the asymmetry-induced brightness non-uniformity in the first column without altering the overall circuit architecture, thereby improving brightness uniformity while minimizing added complexity.
2Ease of manufacture
If the first column of pixel driving units is left without special treatment, then the device structure remains simple and symmetric, but display quality deteriorates due to dark lines appearing on the screen border
Solution Approach 1:
The patent introduces a local modification in the form of a light shielding pattern specifically for the first column of pixel driving units. This 'small pepper' design creates a localized asymmetric structure that compensates for the electrical asymmetry in the first column, preventing dark lines on the screen border while maintaining structural simplicity in all other columns.
3Manufacturing precision
If light shielding patterns are added to the first column pixel driving units, then brightness uniformity improves by shielding the channel and reducing leakage, but device complexity increases due to additional patterns
Solution Approach 1:
The patent implements a localized light shielding pattern ("small pepper" design) exclusively in the first column of pixel driving units where asymmetry causes brightness non-uniformity. This targeted approach shields the channel to reduce leakage current and improve brightness uniformity, while avoiding unnecessary complexity in other columns that already function correctly.
Solution Approach 2:
The patent applies light shielding patterns selectively only to the first column of pixel driving units rather than uniformly across all columns. This partial action approach addresses the specific problem area (first column asymmetry) without adding excessive complexity to the entire display device, implementing just enough shielding where needed to prevent dark lines and ensure uniformity.
Data Source
AI summary
A display substrate and a display device are provided. The display substrate includes a base substrate; a display region, on the base substrate and including a plurality of pixel driving units, each of the plurality of pixel driving units includes a threshold compensation transistor, a first light-emitting control transistor, an active layer of the threshold compensation transistor includes a first channel region corresponding to the first gate electrode, a second channel region corresponding to the second gate electrode, and an intermediate region between the first channel region and the second channel region; and a plurality of light shielding patterns.