AMOLED Scan Driver Bidirectional Scanning Circuit
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Solution Overview
Problem
Current AMOLED screens are limited to single-direction scanning, whereas LCDs can perform bidirectional scanning, necessitating the development of a bidirectional scanning structure for AMOLED screens to enhance their competitiveness.
Innovation Solution
A scan driver with a first and second driving area, each comprising a series of driving units connected through transistors, allowing for sequential and reversible scanning by controlling the enable signals and clock signals to enable forward and reverse scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-direction scanning structure is used in AMOLED screens, then the device complexity is reduced, but the adaptability is limited compared to bidirectional scanning LCDs
Solution Approach 1:
The scan driver is divided into multiple driving units (first driving unit, second driving unit, third driving unit, fourth driving unit) that can operate independently in different scanning directions. Each driving unit contains specific transistors and nodes that can be selectively activated to achieve forward or reverse scanning, allowing the system to adapt to different scanning requirements without requiring a completely different structure.
Solution Approach 2:
The scan driver employs dynamic control through enable signals (first enable signal, second enable signal) and clock signals that can be adjusted to switch between forward and reverse scanning modes. The connection relationships between nodes (first node, second node, third node, fourth node) and transistors are dynamically controlled to change the scanning direction adaptably.
2Adaptability or versatility
If bidirectional scanning is implemented in AMOLED screens, then the adaptability and competitiveness are improved, but the device complexity increases
Solution Approach 1:
The scan driver is designed with multi-functionality to perform both forward scanning and reverse scanning using a single integrated structure. The first and second driving units can operate in forward scanning mode, while the third and fourth driving units enable reverse scanning mode. This universal design allows the same scan driver to adapt to different scanning requirements without needing separate circuits for each direction.
Solution Approach 2:
The patent combines multiple driving functions into a single scan driver structure by merging the forward scanning capability (first and second driving units) and reverse scanning capability (third and fourth driving units) into one integrated circuit. This merging approach achieves bidirectional scanning without requiring completely separate forward and reverse scan drivers, thereby controlling the increase in complexity.
Data Source
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AI summary
The present application provides scan drivers, driving methods thereof and organic light emitting displays. The scan drivers include a first driving area and a second driving area. The first driving area includes a number of first driving units, and the number of the first driving units sequentially sends a first driving signal and a third driving signal to a scan line. Input ends of the plurality of the first driving units are connected with output ends of the first driving units of a next row through a plurality of first transistors; output ends of the plurality of the first driving units are connected with input ends of the first driving units of the next row through a plurality of second transistors. The second driving area includes a number of second driving units, and the number of the second driving units sequentially sends a second driving signal to the scan line. input ends of the plurality of the second driving units are connected with output ends of the second driving units of a next row through a plurality of third transistors; and output ends of the plurality of the second driving units are connected with input ends of the second driving units of the next row through a plurality of fourth transistors.