OLED Display Pixel Lifetime Extension via Local Saturation Reduction

Solution Overview

Problem

Organic light emitting diode (OLED) display devices experience afterimages due to uneven pixel lifetimes, particularly with red, green, and blue pixels having shorter lifetimes than white pixels, leading to rapid luminance reduction and ineffective solutions for minimizing afterimages.

Innovation Solution

An OLED display device senses fixed regions in video content, calculates saturation information, and adjusts saturation and luminance correction rates to reduce pixel degradation, using a lookup table to determine correction rates based on saturation values, thereby minimizing afterimage occurrence and extending pixel lifetime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If luminance is reduced to decrease pixel degradation speed, then pixel lifetime is extended, but the effect of solving afterimage problem is slight because RGB pixel lifetimes remain shorter than white pixel lifetime

Engineering Contradiction:

Improvepixel lifetimeVSAvoidafterimage problem solution effectiveness

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent applies local quality by differentiating treatment between fixed regions and non-fixed regions. In fixed regions where afterimage occurs, saturation is reduced to extend pixel lifetime, while in non-fixed regions, original luminance and saturation are maintained. This localized approach allows selective pixel protection without compromising overall image quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes color parameters (saturation and luminance) dynamically based on region type and pixel lifetime status. By adjusting saturation and luminance values for pixels in fixed regions, the patent extends their operational lifetime while maintaining acceptable visual quality. The controller modifies these parameters in real-time based on detected afterimage conditions.

Inventive Principle:

Principle #35Parameter changes

2Duration of action of stationary object

If saturation is reduced in fixed regions, then pixel lifetime reduction is minimized, but image quality may deteriorate

Engineering Contradiction:

Improvepixel lifetimeVSAvoidimage quality

Core Design Contradiction:

Duration of action of stationary objectVSIllumination intensity

Solution Approach 1:

The patent applies local quality by differentiating treatment between fixed regions and non-fixed regions. In fixed regions where afterimage occurs, saturation is reduced to extend pixel lifetime, while in non-fixed regions, original luminance and saturation are maintained. This localized approach allows selective pixel protection without compromising overall image quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial action by reducing saturation only in fixed regions where afterimage is detected, rather than reducing it across the entire display. This partial application of saturation reduction minimizes the impact on overall image quality while still providing protection to vulnerable pixels in static areas.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If luminance is decreased in fixed regions, then afterimage occurrence is reduced, but overall display brightness is compromised

Engineering Contradiction:

Improveafterimage preventionVSAvoiddisplay brightness

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies local quality by differentiating treatment between fixed regions and non-fixed regions. In fixed regions where afterimage occurs, saturation is reduced to extend pixel lifetime, while in non-fixed regions, original luminance and saturation are maintained. This localized approach allows selective pixel protection without compromising overall image quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial action by reducing saturation only in fixed regions where afterimage is detected, rather than reducing it across the entire display. This partial application of saturation reduction minimizes the impact on overall image quality while still providing protection to vulnerable pixels in static areas.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS10854136B2Organic light emitting diode display device

Publication Date: 2020.12.01 LG ELECTRONICS INC

AI summary

An organic light emitting diode (OLED) display device is provided. The OLED display device includes a display configured to display a video and a controller configured to control the display, wherein the controller senses a fixed region in the video, obtains RGB data of the sensed fixed region, and reduces a saturation of the fixed region, based on the RGB data.