Liquid Crystal Display Scanning Signal Line Ripple Reduction
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Solution Overview
Problem
In liquid crystal display apparatuses using long-term reversal driving, a ripple in the electric potential of data signal lines occurs due to parasitic capacitors, leading to decreased display quality, especially in large panels where the ripple size increases with distance from the signal source.
Innovation Solution
The display apparatus alternates the activation of scanning signal lines in sets, canceling out the potential effects of deactivation and activation, thereby reducing the ripple in the data signal lines by ensuring that the fall of potential is offset by the rise of potential, improving display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If long-term reversal driving is used to reduce data signal rounding, then pixel charging rate improves and electricity consumption decreases, but ripple generates in data signal lines causing display quality deterioration
Solution Approach 1:
The patent applies preliminary anti-action by introducing gate pulses with opposite polarity changes at specific timings to counteract the ripple effects. When one scanning signal line experiences a potential rise or fall causing ripple, another scanning signal line simultaneously experiences an opposite change that cancels out the ripple, thereby preventing display quality deterioration while maintaining long-term reversal driving benefits
2Object-affected harmful factors
If scanning signal lines are activated sequentially to reduce ripple, then display quality improves, but device complexity increases
Solution Approach 1:
The patent segments the scanning signal lines into multiple groups that can be independently controlled. By dividing the panel's scanning lines into several sets and activating them in an alternating sequence, the system reduces ripple effects without requiring complete redesign of the driving circuitry, thus managing complexity through modular control
3Manufacturing precision
If set interval is provided between temporally adjacent gate pulses, then rounded part of source signal is prevented from being written, but ripple increases in size with distance from supply source
Solution Approach 1:
The patent uses counterweight by introducing opposite polarity gate pulses that act as compensating forces. When a gate pulse causes potential rise or fall leading to ripple, another gate pulse with opposite polarity change acts as a counterweight to balance the potential and reduce ripple size, especially effective for distant data signal lines where ripple accumulation is more significant
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
This approach effectively reduces the ripple in the electric potential of data signal lines, preventing its increase with distance from the signal source, thereby enhancing display quality and suitability for high-speed and large-sized liquid crystal displays.
Implementation Method 1
a ripple (wavelike variation) generates in an electric potential of the data signal line at a time of rise (at a start of a scanning period) and fall (at a termination of the scanning period) of the gate pulse, caused by the parasitic capacitor generated at an intersection of the data signal line and the scanning signal line
Data Source
AI summary
In at least one embodiment a ripple, generated in an electric potential of data signal lines even in long-term reversal driving, is reduced and display quality is improved. In at least one example embodiment, the liquid crystal display apparatus of the present invention includes scanning signal lines and data signal lines, in which one scanning pulse is outputted to select one scanning signal line, each of the data signal lines receives data signals whose polarities are reversed per one vertical scanning period while in one horizontal scanning period, one of two data signal lines receives a data signal having a polarity and the other of the two data signal lines receives another data signal having another polarity, the two data signal lines being arranged adjacent to each other, scanning pulses are successively outputted in sets of two, and at a timing in which two scanning pulses fall, two scanning pulses rise.