Bootstrap Gate Circuit for High-Speed Low-Power Displays
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Solution Overview
Problem
Existing display devices using amorphous silicon transistors face challenges in high-speed operation due to the floating state of the bootstrap transistor gate electrode, threshold voltage shifts, and an insufficient reduction in the number of connection points between the display panel and driver IC, leading to increased power consumption and limited display size and definition.
Innovation Solution
A switch controlled by a start signal is used to supply potential to the gate electrode of the bootstrap transistor, preventing charge leakage and enabling high-speed operation, while various transistor types and configurations are employed to minimize threshold voltage variations and reduce connection points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a bootstrap transistor gate electrode is left in a floating state, then the transistor can be kept on, but charge leaks from the gate electrode over time preventing high-speed operation
Solution Approach 1:
The patent applies preliminary action by proactively supplying potential to the bootstrap transistor gate electrode before charge leakage can occur. A switch controlled by a start signal periodically replenishes the potential at the gate electrode, preventing charge loss in advance and maintaining the transistor in the on-state without degradation over time.
2Reliability
If multiple connection points are used between display panel and driver IC, then signal transmission is ensured, but power consumption increases and display size/definition is limited
Solution Approach 1:
The patent merges multiple connection points into fewer connection points by integrating the shift register circuit directly into the display panel substrate. This consolidation reduces the number of external connections needed between the display panel and driver IC, thereby reducing power consumption while maintaining signal transmission reliability through the embedded circuit architecture.
3Use of energy by stationary object
If amorphous silicon transistors are used, then power consumption is reduced and cost is lowered, but threshold voltage shifts occur limiting high-speed operation
Solution Approach 1:
The patent applies preliminary action by periodically replenishing the potential at the bootstrap transistor gate electrode before threshold voltage shifts can degrade performance. This proactive potential supply compensates for the inherent threshold voltage instability of amorphous silicon transistors, enabling high-speed operation while maintaining the low power consumption and cost advantages of using amorphous silicon material.
Data Source
AI summary
An object of the invention is to provide a circuit technique which enables reduction in power consumption and high definition of a display device. A switch controlled by a start signal is provided to a gate electrode of a transistor, which is connected to a gate electrode of a bootstrap transistor. When the start signal is input, a potential is supplied to the gate electrode of the transistor through the switch, and the transistor is turned off. The transistor is turned off, so that leakage of a charge from the gate electrode of the bootstrap transistor can be prevented. Accordingly, time for storing a charge in the gate electrode of the bootstrap transistor can be shortened, and high-speed operation can be performed.