Display Panel Gate Driving to Suppress TFT Threshold Voltage Shift
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Solution Overview
Problem
Conventional display devices using amorphous silicon transistors face issues with threshold voltage shifts, leading to malfunction and increased power consumption, and require further reduction in driver IC connections and display panel size while maintaining high definition.
Innovation Solution
Alternating the application of positive and negative power sources to the gate electrode of transistors using switching transistors, with a clock signal input to one switching transistor and an inverted clock signal to another, to suppress threshold voltage shifts and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If amorphous silicon transistors are used in display devices, then manufacturing cost is reduced and ease of manufacture is improved, but threshold voltage shifts occur leading to malfunction and increased power consumption
Solution Approach 1:
The patent applies parameter changes by alternating the power supply voltage polarity (positive and negative) to the transistor gate electrode over time. This periodic parameter change prevents threshold voltage shifts in amorphous silicon transistors, maintaining reliability while preserving the ease of manufacture advantage.
Solution Approach 2:
The patent implements periodic action through alternating clock signals that switch the power supply polarity to the transistor gate. This periodic switching prevents cumulative threshold voltage shifts, ensuring stable transistor operation over time while using amorphous silicon materials.
2Ease of manufacture
If amorphous silicon transistors are used in display devices, then manufacturing cost is reduced, but power consumption increases due to threshold voltage shifts
Solution Approach 1:
By periodically changing the power supply voltage polarity applied to the transistor gate, the patent prevents threshold voltage drift that would otherwise cause increased power consumption. This maintains low power operation while preserving the cost advantages of amorphous silicon manufacturing.
Solution Approach 2:
The alternating clock signal creates periodic action that refreshes the transistor threshold voltage characteristics, preventing the accumulation of threshold shifts that would increase power consumption over time.
3Device complexity
If driver IC connections are reduced, then device complexity is reduced, but achieving high definition becomes more difficult
Solution Approach 1:
The patent makes the transistor circuit multi-functional by enabling it to perform both signal driving and self-correction of threshold voltage through the alternating power supply method. This allows reduced driver IC connections while maintaining high definition performance through the universal transistor operation.
4Area of stationary object
If display panel size is reduced, then device compactness is improved, but achieving high definition becomes more difficult
Solution Approach 1:
By implementing parameter changes in the power supply voltage, the patent enables stable transistor operation in compact display panels. This allows high definition to be achieved in smaller panels through improved transistor reliability rather than increased complexity.
Data Source
AI summary
To suppress fluctuation in the threshold voltage of a transistor, to reduce the number of connections of a display panel and a driver IC, to achieve reduction in power consumption of a display device, and to achieve increase in size and high definition of the display device. A gate electrode of a transistor which easily deteriorates is connected to a wiring to which a high potential is supplied through a first switching transistor and a wiring to which a low potential is supplied through a second switching transistor; a clock signal is input to a gate electrode of the first switching transistor; and an inverted clock signal is input to a gate electrode of the second switching transistor. Thus, the high potential and the low potential are alternately applied to the gate electrode of the transistor which easily deteriorates.