Shift Register Unit With Replacement Circuit For Level Conversion
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Solution Overview
Problem
The existing shift register units face issues with slow level conversion speed due to the influence of pull-down nodes, leading to abnormal outputs and potential display failures, particularly exacerbated by process defects and device performance degradation.
Innovation Solution
The proposed shift register unit includes an input circuit, a replacement circuit, an output circuit, and a pull-down circuit, where the replacement circuit sets the second node to an inactive level when the input terminal is active, and the output circuit sets the output terminal to an active level using a clock signal when the first node is active, thereby reducing obstacles from the pull-down circuit and speeding up level conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pull-down circuit is used to control the output terminal, then the output can be reset to inactive level, but the level conversion speed becomes slow due to pull-down node influence
Solution Approach 1:
The patent extracts the problematic pull-down node (second node) from the signal path by introducing a replacement circuit. The replacement circuit directly controls the pull-down transistor gate, isolating the first node from the slow pull-down node influence while maintaining the ability to reset the output terminal to inactive level through the pull-down circuit.
Solution Approach 2:
The patent introduces a replacement circuit as an intermediary between the input terminal and the pull-down circuit. This intermediary (replacement circuit with second node) acts as a mediator that can quickly set the pull-down transistor gate state without being influenced by the slow pull-down node, thereby accelerating the level conversion speed while maintaining output stability.
2Device complexity
If the first node is directly controlled by the input circuit, then the level conversion can be simple, but the pull-down node causes abnormal outputs and display failures
Solution Approach 1:
The patent segments the control path by introducing a separate replacement circuit (second node) that specifically manages the pull-down transistor gate control. This segmentation isolates the first node from the problematic pull-down node influence, preventing abnormal outputs and display failures while keeping the overall circuit structure relatively simple.
Solution Approach 2:
The patent extracts the problematic pull-down node influence from the first node by introducing a dedicated replacement circuit. The replacement circuit takes out the gate control function from the first node's direct control, preventing the pull-down node from causing abnormal outputs while maintaining a relatively simple circuit structure.
3Speed
If the replacement circuit sets the second node to inactive level when input is active, then level conversion speed increases, but the circuit configuration becomes more complex
Solution Approach 1:
The patent merges the replacement circuit with the existing pull-down circuit structure, where the second node directly controls the pull-down transistor gate. This merging approach accelerates level conversion speed by eliminating the slow pull-down node influence while adding minimal circuit configuration complexity, as the replacement circuit integrates seamlessly with the existing pull-down mechanism.
Data Source
AI summary
A shift register unit, a scan driving circuit, an array substrate, a display device, and a driving method are provided. The shift register unit includes an input circuit, a replacement circuit, an output circuit, and a pull-down circuit; the input circuit is respectively connected to the input terminal and the first node, and is configured to set the first node to an active level when the input terminal (IN) is at an active level; the replacement circuit is respectively connected to the input terminal and the second node, and is configured to set the second node to an inactive level when the input terminal is at an active level.