Gate Signal Line Driving Circuit for LCD Noise Suppression
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Solution Overview
Problem
Existing gate signal line driving circuits in liquid crystal display devices suffer from noise interference due to inner capacitance in transistors, causing data signals to be applied to gate signal lines as noise, which is not effectively suppressed, leading to chain-like noise generation across basic circuits.
Innovation Solution
A gate signal line driving circuit with a specific configuration that includes a first and second basic circuit, each with LOW and HIGH voltage switching elements, and a LOW voltage OFF control element, where the LOW voltage OFF control element of the first basic circuit is turned on by the switch of the HIGH voltage applying switching element of the second basic circuit, ensuring proper voltage states are maintained despite noise signals, and additional parallel switching elements are used to stabilize voltage outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a shift register circuit is formed on the same substrate as TFTs in pixel regions, then the gate signal line driving circuit can be integrated with the display panel, but noise signals are generated due to inner capacitance of transistors causing data signals to be applied to gate signal lines
Solution Approach 1:
A noise signal suppressing circuit is introduced as an intermediary component between the pixel circuit and the gate signal line. This circuit includes a noise signal suppressing transistor that is turned on during the signal LOW period to provide a low-impedance path to ground, thereby suppressing noise signals that couple onto the gate signal line through parasitic capacitance. The intermediary circuit effectively isolates the noise source from the gate signal line without affecting the overall integration architecture.
2Stability of the object's composition
If the LOW voltage applying switching element is turned on during signal LOW period to output stable LOW voltage, then stable voltage state is achieved, but the switching element is susceptible to noise signals that can partially turn it on and lower the voltage
Solution Approach 1:
The noise signal suppressing transistor is activated in advance during the signal LOW period before the main switching element operates. By pre-establishing a low-impedance path to ground through the noise signal suppressing transistor, the circuit creates a stable reference potential that prevents noise signals from coupling onto the gate signal line and affecting the main switching element's operation. This preliminary action ensures that even if noise signals are present, they cannot significantly alter the voltage state.
3Object-affected harmful factors
If noise signals are suppressed by adding control elements and switching circuits, then noise in gate signals is reduced, but the circuit complexity increases
Solution Approach 1:
The noise signal suppressing transistor is merged with the existing pixel circuit structure, sharing the same substrate and voltage supply lines. The control terminal of the noise signal suppressing transistor is connected to the gate signal line, and its source terminal is connected to the data signal line, which is already present in the pixel circuit. This merging approach allows noise suppression functionality to be added without requiring completely separate circuit structures, thereby limiting the increase in overall device complexity.
Data Source
AI summary
A gate signal line driving circuit which suppresses noises in a gate signal and a display device which uses the gate signal line driving circuit are provided. A first basic circuit provided to a gate signal line driving circuit includes a HIGH voltage applying switching element which applies a HIGH voltage to gate signal lines in response to a signal HIGH period, and a LOW voltage applying switching circuit which applies a LOW voltage to the gate signal lines in response to a signal LOW period. In response to a signal HIGH period, a switch of the LOW voltage applying switching circuit of the first basic circuit is turned off based on a signal applied to a switch of the HIGH voltage applying switching element of a second basic circuit which assumes a signal HIGH period earlier than the first basic circuit.