LCD Image Sticking Removal via Polarity Pattern Inversion

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Solution Overview

Problem

LCD devices using both interlaced mode and FRC mode experience image sticking due to polarity bias, which existing methods fail to address effectively when applied simultaneously.

Innovation Solution

An LCD device and driving method that generate and invert FRC and polarity patterns at predetermined intervals, forming multiple groups parallel to gate lines to prevent polarity bias, using an image-sticking removal apparatus to convert input video and output polarity-inverted data voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If interlaced mode and FRC mode are used simultaneously, then data transfer efficiency is improved and image quality is maintained, but polarity bias accumulates causing image sticking

Engineering Contradiction:

Improvedata transfer efficiencyVSAvoidimage sticking

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies polarity inversion to the data voltages output by the data driver. The polarity pattern generator generates inversion signals that flip the polarity of data voltages at predetermined intervals, effectively counteracting the accumulated polarity bias that causes image sticking while maintaining the benefits of interlaced mode and FRC mode operation

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements periodic polarity inversion at predetermined time intervals. The polarity pattern generator creates inversion signals that are applied periodically to reverse the polarity of data voltages, which prevents continuous polarity bias accumulation and eliminates image sticking artifacts

Inventive Principle:

Principle #19Periodic action

2Object-affected harmful factors

If polarity inversion is applied to remove image sticking, then image sticking is removed, but display quality may be affected due to flicker effects

Engineering Contradiction:

Improveimage stickingVSAvoiddisplay quality

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent divides the display panel into multiple regions corresponding to different gate lines and segments the polarity inversion process into multiple patterns. The polarity pattern generator creates different polarity inversion patterns for different regions, allowing selective inversion that reduces flicker effects while maintaining image sticking removal effectiveness

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the polarity inversion parameters by changing the inversion timing and pattern based on the operational mode. The system adapts the polarity inversion strategy between interlaced and progressive modes, optimizing the balance between image sticking removal and display quality maintenance

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9165515B2Liquid crystal display device and driving method thereof

Publication Date: 2015.10.20 LG DISPLAY CO LTD

AI summary

A liquid crystal display (LCD) device and method of driving an LCD device are provided. The LCD device includes: a panel, including: a plurality of gate lines, and a plurality of data lines, an image-sticking removal apparatus configured to, when an interlaced input video is received from an external system: generate an FRC pattern to be added into the input video and a polarity pattern used to output the input video to form one group, and generate at least two or more the groups formed in parallel to the gate lines during one frame, and a data driver configured to: convert image data inputted from the image-sticking removal apparatus into data voltages, invert a polarity of each of the data voltages on the basis of the polarity pattern, and output the polarity-inverted data voltages to the respective data lines.