Liquid Crystal Display Flicker Reduction via Dot Inversion

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Solution Overview

Problem

Conventional liquid crystal displays experience flicker at low frequencies, particularly in line inversion drive methods, which affects luminance and power consumption, while dot inversion drive methods require higher voltages to reduce flicker but limit power savings.

Innovation Solution

A display design incorporating intersecting drain and gate lines with first and second pixel portions, each with subsidiary capacitances and signal providing circuits that manage voltage supply sources to reduce voltage requirements and facilitate dot or block inversion drives, thereby minimizing flicker and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If line inversion drive method is used to reduce power consumption, then power consumption is reduced, but flicker becomes observable

Engineering Contradiction:

Improvepower consumptionVSAvoidflicker

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional line inversion drive method by implementing dot inversion drive method, where voltage polarity is inverted at the pixel level rather than at the line level. This inversion approach redistributes the voltage stress across multiple pixels, preventing the accumulation of image persistence effects that cause flicker in line inversion methods while maintaining reduced power consumption.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the display into individual pixel units for voltage inversion control, rather than treating entire scan lines as units. By controlling voltage polarity at the pixel level through separate pixel electrodes and common electrodes, the system achieves more fine-grained control that prevents flicker while maintaining energy efficiency.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If dot inversion drive method is used to reduce flicker, then flicker is reduced, but voltage requirement increases

Engineering Contradiction:

ImproveflickerVSAvoidvoltage

Core Design Contradiction:

Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The patent introduces intermediary voltage supply structures including separate pixel electrodes and common electrodes for each pixel, along with subsidiary capacitances that act as voltage buffers. These intermediary elements enable the dot inversion drive method to operate at lower voltage by distributing and buffering the voltage stress across multiple components rather than requiring high voltage swings.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the voltage supply parameters by introducing multiple voltage supply sources (first and second voltage supply sources) that can independently control the voltage at pixel electrodes and common electrodes. This parameter control enables the system to achieve dot inversion drive with reduced voltage requirements through coordinated voltage management.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If conventional line inversion drive method is used, then image persistence is controlled, but flicker appears in line shape

Engineering Contradiction:

Improveimage persistenceVSAvoidflicker pattern

Core Design Contradiction:

Stability of the object's compositionVSShape

Solution Approach 1:

The patent inverts the conventional approach by switching from line inversion to dot inversion drive method. This inversion changes the spatial pattern of voltage application from line-based to pixel-based, which transforms the flicker pattern from line-shaped to scattered, making it less observable while maintaining image persistence control.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies different voltage control characteristics to different pixels through local electrode structures. Each pixel has its own pixel electrode and common electrode configuration that allows independent voltage control, enabling localized optimization of image persistence while distributing flicker effects across the entire display rather than concentrating them in line patterns.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7532189B2Liquid crystal display capable of making flicker difficult to be observed and reducing power consumption

Publication Date: 2009.05.12 SANYO ELECTRIC CO LTD

AI summary

The present invention provides a display capable of making flicker difficult to be observed and of reducing power consumption. The display comprises first and second pixel portions including subsidiary capacitances having a first electrode which is connected to a pixel electrode and a second electrode; first and second subsidiary capacitance lines which are connected to the second electrodes of the subsidiary capacitances of the first and second pixel portions, respectively; and a signal providing circuit including a plurality of signal providing circuit portions which provide first and second signals to the first and second subsidiary capacitance lines, respectively.