Scan Line Pull-Down Circuit for RC-Loaded Display Panels
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Solution Overview
Problem
The increasing resistance capacitance loading (RC Loading) in large display panels leads to deteriorated scan signal falling edges, reduced pixel charging time, and increased pixel mischarging risk due to transmission losses.
Innovation Solution
Incorporation of pull-down circuits with forward and reverse scan pull-down units connected to scan lines, which receive specific scan signals and control signals to uniformly pull down the potential of scan lines, enhancing falling edge uniformity and charging time while preventing mischarging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the display panel size is increased and resolution is improved, then the display quality is improved, but the RC loading of scan lines increases causing transmission loss
Solution Approach 1:
A pull-down circuit is introduced as an intermediary component between the scan line and the pixel circuit. This pull-down circuit actively pulls down the scan line potential to compensate for the voltage drop caused by RC loading, thereby maintaining signal transmission quality without reducing display resolution or size.
2Area of stationary object
If the scan line resistance capacitance loading is increased, then the display panel can support larger size and higher resolution, but the falling edge of scan signals is deteriorated
Solution Approach 1:
The pull-down circuit provides a feedback mechanism that detects the voltage level of the scan line and actively pulls it down to the reference low level. This feedback action compensates for the voltage drop along the scan line due to RC loading, ensuring uniform falling edges across the entire display panel regardless of its size.
3Length of stationary object
If the scan signal transmission loss is increased, then the display panel can be designed with narrower frames, but the pixel charging time is reduced
Solution Approach 1:
The pull-down circuit performs a preliminary action by actively pulling down the scan line potential before the pixel charging process begins. This preliminary pull-down action ensures that the scan line is at the correct reference level, which then allows for proper pixel charging without requiring extended frame widths to compensate for signal degradation.
4Length of stationary object
If the scan signal falling edge is deteriorated, then the display panel can achieve narrow frame design, but the pixel mischarging risk is increased
Solution Approach 1:
The pull-down circuit serves as a protective intermediary between the scan line and the pixel circuit. It ensures that even when RC loading causes voltage drops, the pixel circuit receives a properly leveled scan signal, thereby preventing mischarging while enabling narrow frame design.
Data Source
AI summary
The present disclosure provides a display panel and a display device. The display panel includes a plurality of scan lines and at least one pull-down circuit unit. The pull-down circuit includes a forward scan pull-down unit and/or a reverse scan pull-down unit. The forward scan pull-down unit receives a (n+m)th scan signal, a first control signal, and a reference low level signal, and is connected to the nth scan line. The reverse scan pull-down unit receives a (n−m)th scan signal, a second control signal, and the reference low level signal, and is connected to the nth scan line.