Common Electrode Drive Circuit for LCD Flickering Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LCDs suffer from flickering images due to voltage jumps caused by parasitic capacitors, which affect the consistency of grey levels and overall display quality, as existing solutions like the Multi-Level Gate method do not adequately address the varying voltage jumps across different pixels.
Innovation Solution
A common electrode drive circuit that applies different common voltages to various positions on the liquid crystal panel based on the specific voltage jumps at each pixel, ensuring the differences in common voltages are consistent with the voltage jumps, thereby reducing the phenomenon of flickering images and improving overall display performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single common voltage is applied to the entire common electrode layer, then the circuit structure is simple, but voltage jumps occur due to parasitic capacitors causing flickering images and inconsistent grey levels
Solution Approach 1:
The common electrode layer is divided into multiple regions along the data line direction, with each region receiving a different common voltage. This segmentation allows the voltage in each region to be independently adjusted to compensate for position-dependent voltage jumps caused by parasitic capacitors, thereby eliminating flickering images and ensuring consistent grey levels across the display.
Solution Approach 2:
Different common voltages are applied to different positions of the common electrode layer based on the local voltage jump characteristics at each pixel position. This local quality adjustment ensures that each region's common voltage is optimized for its specific location, compensating for the varying influence of parasitic capacitors across the display area.
2Reliability
If different common voltages are applied to different positions of the common electrode layer, then flickering images are reduced and grey level consistency is improved, but the device complexity increases
Solution Approach 1:
The common electrode layer is divided into multiple regions along the data line direction, with each region receiving a different common voltage. This segmentation allows the voltage in each region to be independently adjusted to compensate for position-dependent voltage jumps caused by parasitic capacitors, thereby eliminating flickering images and ensuring consistent grey levels across the display.
Solution Approach 2:
The common voltage parameter is varied across different positions of the common electrode layer to match the spatial distribution of voltage jumps. By changing the voltage parameter locally rather than uniformly, the system compensates for parasitic capacitor effects without requiring complex additional circuitry beyond multiple voltage output terminals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the occurrence of flickering images by making the variation in common voltages consistent with the voltage jumps across the panel, leading to improved display performance and consistency in grey levels across the entire image.
Implementation Method 1
As a parasitic capacitor Cgd is generated between the gate electrode g and the drain electrode d, obvious fluctuation of voltage generated when the gate line Gn is switched on and off will be applied to the pixel electrode p through the parasitic capacitor Cgd, causing a voltage jump ΔV in the pixel electrode voltage
Implementation Method 2
The liquid crystal capacitor Clc exerts an electrical field on liquid crystal molecules to orientate the liquid crystal molecules
Implementation Method 3
a liquid crystal capacitor Clc is created between the pixel electrode p and the common electrode layer on which a common voltage Vcom is applied. The liquid crystal capacitor Clc exerts an electrical field on liquid crystal molecules to orientate the liquid crystal molecules
Data Source
AI summary
A common electrode drive circuit for a liquid crystal display, comprising a plurality of output terminals connected to a plurality of common voltage input terminals of a common electrode layer of the liquid crystal display and adapted for inputting common voltages into the plurality of common voltage input terminals, the common electrode layer driving liquid crystal together with pixel electrodes of the liquid crystal display. The common voltages input by the plurality of output terminals decrease gradually from a data-line beginning end for data signal input to a data-line tail end for data signal input of the liquid crystal display.