LCD Driving Method Inverting Reference Voltage Polarity
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Solution Overview
Problem
Image sticking in liquid crystal displays (LCDs) occurs due to ion accumulation on electric plates, causing imbalances in electric fields and random appearance of image sticking issues across the screen, which existing methods like polarity inversion fail to fully address.
Innovation Solution
A driving method and system for LCDs that uses inverse voltage polarities for both data and reference voltage signals to uniformly distribute ions within liquid crystal capacitors, preventing image sticking by driving data lines with a first voltage signal and reference voltage lines with a second signal of inverse polarity, utilizing a source driver and reference voltage driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polarity inversion methods (dot inversion, line inversion, frame inversion) are used to distribute liquid crystal ions uniformly, then image sticking is reduced, but liquid crystal ions still accumulate on electric plates after long-time operation causing image sticking to reappear
Solution Approach 1:
The patent applies voltage inversion not only to data signals but also to reference voltage signals. By inverting the reference voltage polarity along with the data signal polarity, the electric field distribution is fundamentally changed, preventing ion accumulation on specific electrodes and eliminating image sticking even after long-time operation.
Solution Approach 2:
The patent changes the voltage parameters by applying different voltage levels to reference voltage lines based on the polarity of data signals. When data signal polarity is positive, reference voltage is set to a higher level; when negative, reference voltage is set to a lower level. This dynamic parameter adjustment ensures uniform ion distribution and prevents image sticking.
2Reliability
If reference voltage level is adjusted to address image sticking, then some improvement is achieved, but image sticking cannot be fully solved because different locations on the screen have different electric field distributions
Solution Approach 1:
The patent applies different reference voltage levels to different reference voltage lines based on their specific locations and the polarity of corresponding data signals. This localized voltage adjustment creates appropriate electric field distributions at each location, effectively addressing image sticking across the entire screen regardless of position-specific variations.
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
Effectively prevents or mitigates image sticking by ensuring uniform ion distribution across liquid crystal capacitors, maintaining image quality by applying the method during power-on or power-off periods without affecting displayed content.
Implementation Method 1
allowing the liquid crystal ions to be uniformly distributed across the electric fields of the liquid crystal capacitors
Data Source
AI summary
A driving method used in a liquid crystal display (LCD) is used for preventing or mitigating an image sticking occurring on a screen of the LCD. The driving method includes driving a data line outputted to a liquid crystal capacitor on the screen with a first voltage signal; and driving a reference voltage line outputted to the liquid crystal capacitor with a second voltage signal; wherein the second voltage signal and the first voltage signal have inverse voltage polarities.