LCD Driving Method Trapping Impurities to Reduce Image Sticking
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Solution Overview
Problem
Conventional liquid crystal display (LCD) technologies suffer from image sticking due to the accumulation of impurities, which create a net DC voltage and inner electric field, causing liquid crystal molecules to fail to rotate correctly and resulting in distorted images.
Innovation Solution
The method involves applying high voltages on data lines during the blanking time to trap impurities, using different data-to-voltage relations, and connecting pixel areas to distinct common voltages to create voltage differences that restrict impurity movement and accumulation, thereby reducing image sticking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional LCD driving method is used with sequential scan lines, then image can be displayed continuously, but impurities accumulate and cause image sticking
Solution Approach 1:
The patent applies a preliminary action by introducing a specific voltage pattern during the blanking time period before the next frame is displayed. This preliminary voltage application prevents impurity accumulation before it can cause image sticking, thereby maintaining image quality while preserving continuous display capability.
Solution Approach 2:
The patent implements periodic action by applying a corrective voltage pattern repeatedly during each blanking time period between frames. This periodic intervention continuously prevents impurity accumulation, ensuring long-term reliability without affecting the continuous productivity of the display.
2Productivity
If data voltages are applied continuously on data lines, then image can be updated, but net DC voltage forms causing impurity accumulation
Solution Approach 1:
The patent converts the harmful net DC voltage effect into a beneficial cleaning mechanism. By intentionally applying a voltage pattern during blanking time that creates a controlled electric field, the system uses the same mechanism that causes impurity accumulation to instead create a field that repels and redistributes impurities, preventing image sticking.
Solution Approach 2:
The patent applies preliminary anti-action by introducing a counter-voltage pattern during the blanking period that opposes and neutralizes the net DC voltage effect. This preliminary counter-action prevents the formation of harmful electric fields that would otherwise cause impurity accumulation and image sticking.
3Loss of time
If scan lines turn off between frames, then blanking time is created, but impurities have time to accumulate
Solution Approach 1:
The patent maintains continuity of useful action by ensuring that even during the blanking time when scan lines are off, a beneficial voltage pattern continues to be applied to the data lines. This continuous action prevents impurity accumulation during the idle period, transforming what would be harmful downtime into a protective interval that maintains image quality.
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 traps impurities, reducing their accumulation and minimizing the image sticking effect, thereby enhancing display quality by ensuring accurate liquid crystal molecule rotation and preventing line-shape image distortions.
Implementation Method 1
applying high voltages on data lines during the blanking time to trap impurities
Implementation Method 2
The impurities P, as shown in FIG. 1, can be ions with positive or negative charges... applying high voltages on data lines during the blanking time to trap impurities
Data Source
AI summary
A driving method with reducing image sticking effect is disclosed. The driving method includes applying a voltage on the data lines for trapping impurities crossing the data lines and lowering the degree of the image sticking effect, and applying different asymmetric waveforms to different data lines for trapping impurities crossing the data lines and lowering the degree of the image sticking effect.