Segmented Common Electrodes for LCD Feed-Through Voltage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid crystal displays driven by the line inversion method, the increased amplitude of the scanning pulse leads to a higher feed-through voltage, causing flicker and residual images, which deteriorate the display quality due to the need for additional storage lines and the electrical connection of storage lines, resulting in increased pixel electrode potential changes during non-scanning intervals.
Innovation Solution
A liquid crystal display with multiple common electrodes to which a common voltage is independently applied, divided into units, and a method that inverts the data voltage polarity in units of n/k lines, reducing the amplitude of the scanning pulse by maintaining voltage levels across divided common electrode units, thereby reducing the feed-through voltage and improving display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the line inversion method is used to drive the liquid crystal display, then power consumption is reduced, but the amplitude of the scanning pulse increases leading to higher feed-through voltage and deteriorated display quality
Solution Approach 1:
The common electrode is divided into multiple independent common electrode lines (first, second, third, and fourth common electrode lines), each capable of independently controlling the common voltage potential. This segmentation allows different portions of the display to have different common voltage levels, enabling reduced scanning pulse amplitude in certain regions while maintaining proper liquid crystal cell operation.
2Stability of the object's composition
If additional storage lines are added and storage lines are electrically connected to maintain voltage during non-scanning intervals, then liquid crystal cell voltage is maintained, but pixel electrode potential changes increase causing flicker and residual images
Solution Approach 1:
The common electrode is segmented into multiple independent lines that can be controlled separately. This allows the common voltage to be maintained at appropriate levels without requiring additional storage lines, thereby preventing excessive pixel electrode potential changes during non-scanning intervals.
Solution Approach 2:
The divided common electrode lines serve multiple functions: they maintain the common voltage potential during non-scanning intervals, control the liquid crystal cell operation, and prevent excessive pixel electrode potential changes. This eliminates the need for separate storage lines while achieving voltage stability.
3Object-affected harmful factors
If the common electrode is divided into multiple units with independently applied common voltages, then scanning pulse amplitude is reduced and feed-through voltage is minimized, but device complexity increases
Solution Approach 1:
The common electrode is divided into four independent common electrode lines, each controlled by a separate voltage signal. This segmentation enables reduced scanning pulse amplitude and minimized feed-through voltage while maintaining manageable complexity through systematic voltage control.
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 amplitude of the scanning pulse, minimizing feed-through voltage and preventing flicker and residual images, thus enhancing the display quality by independently controlling common electrode potentials and eliminating the need for additional storage lines.
Implementation Method 1
controls light transmittance of a liquid crystal using an electric field
Implementation Method 2
liquid crystal cells arranged in a matrix type... liquid crystal molecules driven by a potential difference
Implementation Method 3
A storage capacitor (hereinafter, referred to as 'Cst') is formed between a storage line supplied with the common voltage Vcom and the pixel electrode Ep of the liquid crystal cell Clc
Data Source
AI summary
A liquid crystal display and a driving method thereof having a plurality of common electrodes to which a common voltage is independently applied, and divided into more than two portions to change a potential of a common voltage into divided common electrode units, and reducing amplitude of a scanning pulse to prevent a deterioration of a display quality by a feed through voltage.