OLED Driving Method for Odd-Even Scan Line Segmentation

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Solution Overview

Problem

Organic light emitting displays face non-uniformity in image display due to variations in the threshold voltage of driving transistors, which is not adequately addressed by current manufacturing processes, leading to insufficient data writing and threshold voltage compensating periods, especially at high driving frequencies like 120 Hz.

Innovation Solution

The implementation of a concurrent driving method where odd and even scan lines are alternately driven in each frame, with a data arranging unit generating and supplying second data frames by averaging or selecting from contiguous frames, ensuring sufficient line time for charge storage in pixel capacitors, thereby extending the data writing and threshold voltage compensating periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If high driving frequency (120 Hz) is used to improve response speed and reduce flicker, then the display refresh rate increases, but the data writing period and threshold voltage compensating period become insufficient

Engineering Contradiction:

Improveresponse speedVSAvoiddata writing period

Core Design Contradiction:

SpeedVSDuration of action of moving object

Solution Approach 1:

The patent segments the scan lines into odd and even groups, driving them in alternating frames. This segmentation allows each scan line group to receive dedicated scanning time in its respective frame, effectively doubling the available writing time for each group without increasing the overall frame rate. The odd scan lines are driven in odd frames while even scan lines are driven in even frames, creating sufficient data writing and compensation periods at high refresh rates.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If conventional scanning method drives all scan lines in each frame, then the scanning process is simple, but the line time for charge storage becomes insufficient

Engineering Contradiction:

Improvescanning method complexityVSAvoidline time

Core Design Contradiction:

Device complexityVSDuration of action of stationary object

Solution Approach 1:

The patent divides scan lines into odd and even segments, driving them in alternating frames. This segmentation strategy assigns specific time slots to each segment, ensuring that odd scan lines receive full scanning attention in odd frames and even scan lines do the same in even frames. Consequently, each segment obtains sufficient line time for charge storage and threshold voltage compensation without complicating the overall scanning architecture.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If threshold voltage compensation is performed adequately, then image non-uniformity is reduced, but the data writing period must be extended

Engineering Contradiction:

Improvetransistor characteristic uniformityVSAvoiddata writing period

Core Design Contradiction:

Manufacturing precisionVSDuration of action of moving object

Solution Approach 1:

By segmenting scan lines into odd and even groups with alternating frame driving, the patent creates dedicated time windows for threshold voltage compensation within each frame. This segmentation allows sufficient compensation time for each segment without requiring extension of the overall data writing period, as each segment receives adequate attention in its designated frames.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs threshold voltage compensation during the data writing period by utilizing the alternating frame structure. The compensation action is preliminarily integrated into the writing process itself, allowing threshold voltage adjustment to occur concurrently with data writing for odd and even scan lines in their respective frames, thereby eliminating the need for separate extended compensation time.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for a sufficiently long data writing and threshold voltage compensating period, ensuring stable image emission and reducing flicker, even at high driving frequencies, by optimizing the line time for each scan line.

Implementation Method 1

the organic light emitting display display images using organic light emitting diodes (OLEDs) that generate light by re-combination of electrons and holes

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS9047820B2Organic light emitting display and method of driving the same

Publication Date: 2015.06.02 SAMSUNG DISPLAY CO LTD

AI summary

A method of driving an organic light emitting display capable of providing a sufficient (e.g., a sufficiently long) data writing period and/or threshold voltage compensating period is provided. The method includes supplying scan signals to odd scan lines in a writing period of an odd frame set to be in a non-emission state, and supplying scan signals to even scan lines in a writing period of an even frame set to be in the non-emission state.