Thin Film Transistor LCD Driving Method for Flicker and Power Reduction

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Solution Overview

Problem

Liquid crystal display (LCD) technologies face flicker issues and increased power consumption due to the row inversion and dot inversion driving methods, respectively, which affect the longevity of liquid crystal molecules and drive system costs.

Innovation Solution

A method that rearranges video data output from dot-inversion or row-inversion drivers to apply alternating up-down thin film transistor configurations, allowing for the display results of either method without the need for specific drivers, thereby avoiding flicker and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If row inversion driving method is used, then liquid crystal molecule life is extended, but flicker problem occurs

Engineering Contradiction:

Improveliquid crystal molecule lifeVSAvoidflicker

Core Design Contradiction:

Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies dot inversion instead of row inversion to reverse the polarity assignment at the pixel level rather than the row level. This inversion approach maintains opposite polarity driving benefits while eliminating the flicker caused by row-level voltage changes, as the flicker is associated with the coupling capacitor discharge effect that occurs during row inversion transitions.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements alternating up-down thin film transistor configurations within each pixel region, creating local structural variations that enable precise control of voltage application. This local differentiation allows the system to achieve dot inversion driving where adjacent pixels have different polarity assignments, thereby extending liquid crystal molecule life while avoiding the flicker problem through localized polarity management.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If dot inversion driving method is used, then flicker problem is reduced, but power consumption increases

Engineering Contradiction:

ImproveflickerVSAvoidpower consumption

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent uses row inversion driving method instead of dot inversion, thereby obtaining the display results of dot inversion (opposite polarity driving) while avoiding the high power consumption associated with dot inversion. The row inversion approach maintains the benefits of polarity reversal for liquid crystal molecule protection while reducing power consumption by limiting voltage transitions to row-level rather than pixel-level operations.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the display into rows and applies inversion at the row level rather than at the pixel level. This segmentation approach reduces the total number of voltage transitions required, as entire rows are inverted together rather than individual pixels, thereby reducing power consumption while still achieving the opposite polarity driving effect needed to prevent liquid crystal degradation.

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If dot inversion driving method is used, then flicker problem is reduced, but driver area increases

Engineering Contradiction:

ImproveflickerVSAvoiddriver area

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent applies row inversion instead of dot inversion to achieve opposite polarity driving with reduced driver complexity. The row inversion approach requires simpler driver circuitry compared to dot inversion, as it needs to control polarity at the row level rather than at each individual pixel, thereby reducing the required driver area while still eliminating the flicker problem through proper polarity management.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent designs the thin film transistor structure with alternating up-down configurations that can accommodate both row inversion and dot inversion driving methods through software control alone. This universal structure allows the same hardware to achieve multiple driving modes, eliminating the need for specialized dot-inversion driver circuits and reducing overall driver area while maintaining the ability to reduce flicker.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS7463232B2Thin film transistor LCD structure and driving method thereof

Publication Date: 2008.12.09 HANNSTAR DISPLAY CORP

AI summary

The video data output from the dot-inversion driver is re-arranged in the present invention. According this re-arranged method, the video data output from the even data lines or odd data lines is delayed for one scan line scan time. Then, the re-arranged video data are applied to the liquid crystal display structure whose thin film transistors connected with the same scan line are arranged in alternatingly up-down form to store row-inversion driving data in the pixel region.