OLED Display Through-Hole Interconnects for Luminance Uniformity
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Solution Overview
Problem
Conventional organic light emitting diode (OLED) displays face challenges with high surface resistance of transparent cathode electrodes, leading to uneven voltage distribution and luminance issues, particularly as display size increases, which affects video quality and aperture ratio.
Innovation Solution
The solution involves a flat panel display design where an organic light emitting diode is placed on the front surface and a driving element on the rear surface, connected via through-holes and electrodes that overlap with a bank, allowing for a high aperture ratio and improved video quality by maximizing the display area and minimizing manufacturing process interference between elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If transparent cathode electrodes are used in OLED displays, then visibility and design flexibility are improved, but surface resistance increases causing uneven voltage distribution and luminance issues
Solution Approach 1:
The cathode electrode is divided into multiple segments: a transparent cathode electrode and additional auxiliary cathode electrodes positioned at specific locations. This segmentation allows the main transparent cathode to maintain visibility while auxiliary electrodes provide localized electrical support to ensure uniform voltage distribution and luminance across the display.
Solution Approach 2:
Auxiliary cathode electrodes act as intermediaries between the power supply and the transparent cathode electrode. These auxiliary electrodes are positioned strategically to mediate voltage distribution, ensuring uniform electrical potential across the OLED structure without compromising the transparency and visual quality of the main cathode electrode.
2Area of stationary object
If all display elements are formed on one surface of the substrate, then manufacturing process is simplified, but display area is reduced due to overlapping of driving elements and light emitting elements
Solution Approach 1:
The display structure transitions from a two-dimensional layout where all elements are on one surface to a three-dimensional configuration with elements distributed across front and rear surfaces of the substrate. The light emitting elements (OLEDs) are positioned on the front surface while driving elements (thin film transistors) are positioned on the rear surface, connected through conductive structures, thereby maximizing the front surface display area while maintaining functional connectivity.
3Area of stationary object
If display size is increased to improve viewing experience, then resolution and visual quality may be improved, but surface resistance effects become more pronounced causing uneven voltage distribution
Solution Approach 1:
For larger display sizes, the cathode electrode structure is segmented into a transparent main cathode electrode and multiple auxiliary cathode electrodes distributed across the display area. This segmentation ensures that even as display size increases, the auxiliary electrodes are positioned to maintain uniform voltage distribution across the entire surface, preventing luminance non-uniformity that would otherwise worsen with increased display area.
Solution Approach 2:
Auxiliary cathode electrodes are strategically positioned at specific locations within the display structure, particularly targeting areas where voltage distribution issues are most pronounced in larger displays. This local quality approach ensures that electrical support is provided precisely where needed, maintaining luminance uniformity across the entire large display area.
Data Source
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AI summary
The present disclosure relates to a display device including a light emitting element display. The present disclosure suggests a flat panel display comprising: a substrate (SUB); a driving element disposed on a first surface of the substrate (SUB); an organic light emitting diode (OLE) disposed on a second surface of the substrate (SUB); a through-hole (VH) penetrating the substrate (SUB) from the first surface to the second surface; and a connecting electrode (CN) filling the through-hole (VH) for linking the driving element to the organic light emitting diode (OLE).