LCD Source Driver Adaptive Column Inversion Power Management

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Solution Overview

Problem

Current liquid crystal display (LCD) technologies face challenges in balancing display quality and power consumption, with existing inversion schemes either resulting in high power consumption or issues like crosstalks and flickers, and there is a need for a method that improves imaging properties while reducing power usage.

Innovation Solution

A source driver for LCDs that employs adaptive column inversion, using a data processing unit to determine grey levels and select between frame and pixel polarity control signals to dynamically adjust the inversion method for each pixel, allowing for efficient power management and improved display quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If dot inversion or 2-line inversion is used, then display quality is improved, but power consumption increases

Engineering Contradiction:
Improvedisplay qualityVSAvoidpower consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies different inversion schemes to different regions of the display panel based on local image characteristics. By analyzing the image data and identifying regions with specific features (such as regions with similar adjacent pixel values), the system dynamically selects appropriate inversion methods for each region, optimizing the balance between display quality and power consumption locally rather than using a uniform inversion scheme across the entire panel.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If column inversion is used, then power consumption is reduced, but crosstalks and vertical flickers occur

Engineering Contradiction:
Improvepower consumptionVSAvoiddisplay quality
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent implements a dynamic inversion scheme that adapts to changing image content. The system continuously analyzes incoming image data and dynamically adjusts the inversion method based on current image characteristics. This dynamic adaptation allows the display to switch between different inversion schemes (such as column inversion, dot inversion, or 2-line inversion) depending on the specific image being displayed, thereby avoiding the artifacts associated with static inversion methods while optimizing power consumption.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If zig-zag arrangement is used, then display quality is improved, but crosstalks and horizontal bright and dark lines occur

Engineering Contradiction:
Improvedisplay qualityVSAvoidcrosstalks and horizontal bright and dark lines
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the traditional zig-zag inversion scheme by introducing conditional logic that changes the inversion parameters based on image content. Specifically, the system analyzes adjacent pixel values and determines whether to apply zig-zag inversion or alternative schemes in different regions. This parameter adaptation eliminates the harmful artifacts (crosstalks and horizontal lines) that occur in conventional zig-zag inversion while preserving the display quality improvements in regions where zig-zag is appropriate.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2317501B1Method and device for driving a liquid crystal display
Publication Date: 2016.09.07 AU OPTRONICS CORP
  • EP2317501B1 patent drawingFigure 1
  • EP2317501B1 patent drawingFigure 2(a)~2(c)
  • EP2317501B1 patent drawingFigure 3(a)~3(b)

AI summary

The Liquid Crystal Display (LCD) includes a source driver for driving a display panel to display an image data in an adaptive column inversion. In one embodiment, the source driver includes a data processing unit having a logic circuit adapted for determining N most-significant bits (MSBs) of image data signals of two neighboring data lines, such that when all of the N MSBs are equal to 1 or 0, the output of the logic circuit is 1, otherwise, the output of the logic circuit is 0, and a MUX coupled to the data processing unit and adapted for receiving a frame polarity control signal, FramePOL, and a pixel polarity control signal, XPOL, and selectively outputting the frame polarity control signal FramePOL when the output of the logic circuit is 1, or the pixel polarity control signal POL when the output of the logic circuit is 0, as a polarity control signal, POL.