OELD Driving Method for RC Delay and Image Distortion

Solution Overview

Problem

Large-sized organic electroluminescent display (OELD) devices experience image distortion due to increased resistance-capacitance (RC) delay in signal lines, leading to unnatural movement of images across subdivided display areas, particularly at boundary portions between upper and lower sub-areas, caused by their fast response time.

Innovation Solution

A method of driving the display device where the upper data signal array of the (n+1)th frame is outputted to the upper display area during a first frame period, and the lower data signal array of the nth frame is outputted to the lower display area during the same frame period, ensuring simultaneous and continuous writing of data signals from top to bottom in both sub-areas to maintain natural image movement across boundaries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the display area is subdivided into multiple sub-areas and operated by separate driving circuits, then the RC delay in signal lines is reduced, but image distortion occurs at boundary portions between sub-areas due to unnatural image movement

Engineering Contradiction:

Improvedisplay image qualityVSAvoiddriving circuit configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The display area is divided into multiple sub-areas (first sub-area and second sub-area) that can be operated independently by separate driving circuits. This segmentation reduces the RC delay in signal lines by shortening the signal transmission paths within each sub-area, thereby improving display image quality while maintaining manageable device complexity through modular operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by writing data signals for the next frame to the sub-areas in advance during the current frame period. Specifically, data signals for the first sub-area of the next frame are written before the current frame completes, ensuring continuous and natural image movement across frame boundaries without distortion or interruption.

Inventive Principle:

Principle #10Preliminary action

2Speed

If data signals are written to sub-areas simultaneously during the same frame period, then image movement appears natural and continuous, but the upper sub-area displays the next frame while the lower sub-area displays the current frame causing boundary distortion

Engineering Contradiction:

Improveresponse timeVSAvoiddisplay image continuity

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent applies preliminary action by writing data signals for the next frame to the sub-areas in advance during the current frame period. Specifically, data signals for the first sub-area of the next frame are written before the current frame completes, ensuring continuous and natural image movement across frame boundaries without distortion or interruption.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic control where the timing of data signal writing varies by sub-area. The first sub-area receives data signals for the next frame at a different time than the second sub-area, which receives current frame data signals. This dynamic timing adjustment ensures that image movement appears natural and continuous across the entire display while preventing boundary distortion.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If the display area is not subdivided, then the device structure is simple, but RC delay in long signal lines causes image distortion in large-sized displays

Engineering Contradiction:

Improvedisplay structureVSAvoiddisplay image quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The display area is divided into multiple sub-areas (first sub-area and second sub-area) that can be operated independently by separate driving circuits. This segmentation reduces the RC delay in signal lines by shortening the signal transmission paths within each sub-area, thereby improving display image quality while maintaining manageable device complexity through modular operation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8049687B2Organic electroluminescent display device including upper and lower display areas and driving method thereof

Publication Date: 2011.11.01 LG DISPLAY CO LTD

AI summary

A method of driving a display device includes outputting an upper data signal array of a (n+1)th frame to an upper display area of a display panel during a first frame period; and, outputting a lower data signal array of a nth frame to a lower display area of the display panel during the first frame period is provided. The display panel has at least an upper display area and a lower display area which may be independently operable, the display areas communicating with a memory device storing and outputting a signal data array of a (n+1)th frame to an upper display area of a display panel during a first frame period; and, outputting a lower data signal array of a nth frame to a lower display area of the display panel during the first frame period.