Chamfered Wave Generating Circuit for TFT-LCD Gate Drive Feed-Through Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The display quality of TFT-LCD display apparatuses is poor due to parasitic capacitance between the gate and source of Thin Film Transistors (TFTs), leading to significant potential drops and feed-through issues that result in darkened pictures.
Innovation Solution
A driving circuit with a chamfered wave generating circuit that discharges the power supply voltage under a timing control signal to generate a target chamfered wave signal, which is then output to the gate driving module, reducing potential drops and feed-through by creating a periodical chamfered wave signal with a big sawtooth depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional scanning pulse signal is applied to the gate of TFT, then the gate driving module can provide scanning signals, but the parasitic capacitance causes significant potential drops and feed-through leading to poor display quality
Solution Approach 1:
The chamfered wave generating circuit performs preliminary action by pre-charging and pre-discharging the gate line before the actual scanning pulse is applied. This preliminary charging/discharging action prepares the gate line to handle the scanning signal while minimizing the impact of parasitic capacitance, thereby reducing feed-through effects and improving display quality
Solution Approach 2:
The invention applies preliminary anti-action by introducing opposite polarity charges through the chamfered wave generating circuit before the harmful feed-through effect occurs. The circuit generates compensating charges that counteract the potential drops caused by parasitic capacitance, preventing the darkening effect before it happens
2Speed
If the gate potential changes level rapidly, then the scanning speed is improved, but the parasitic capacitance causes significant potential drops leading to feed-through
Solution Approach 1:
The chamfered wave generating circuit performs preliminary charging and discharging actions at controlled rates before the main scanning transition. This preliminary action allows the gate line to be prepared for rapid changes while minimizing the impact of parasitic capacitance, enabling fast scanning without significant potential drops
Solution Approach 2:
The invention applies dynamics by making the charging and discharging rates adjustable and adaptive. The chamfered wave generating circuit can dynamically control the rate of voltage change to optimize between scanning speed and potential stability, allowing rapid scanning when needed while maintaining potential stability through controlled charge/discharge cycles
Data Source
AI summary
A driving circuit, a driving method and a display apparatus are provided. The driving circuit comprises: a gate driving module; a timing control module; and a chamfered wave generating circuit, an input terminal thereof being connected with the timing control module, an output terminal thereof being connected with an input terminal of the gate driving module, and being configured to discharge a power supply voltage provided by a power supply of the display apparatus under an effect of a timing control signal output by the gate driving module, so that the gate driving module outputs a chamfered wave scanning signal. The display quality of the display apparatus can be improved.