Display Panel Self-Refresh Flicker Compensation

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Solution Overview

Problem

High resolution displays in mobile devices consume significant power when displaying static images, leading to reduced battery life, and existing technologies like eDP v1.3 PSR technology do not adequately address the issue of power consumption and flicker reduction during transitions between panel self-refresh and normal modes.

Innovation Solution

A display apparatus and method that utilizes a timing controller to compare image data with stored refresh data, calculate and compensate for data loss, and generate a boosting light in re-synchronization mode to minimize luminance differences and reduce flicker, thereby optimizing power usage and display quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If panel self-refresh mode is used to reduce power consumption, then power usage is reduced, but flicker occurs due to polarity alternation in signal voltages

Engineering Contradiction:
Improvepower consumptionVSAvoidflicker
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by pre-compensating for the luminance differences caused by polarity alternation. Before the flicker can occur, the system calculates compensation values based on the relationship between polarity inversion and luminance changes, then applies these compensations to the image data in advance, preventing the harmful flicker effect from manifesting.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent changes the parameter of image data by applying luminance compensation values that adjust the brightness levels. This parameter transformation counteracts the luminance variations induced by polarity alternation, thereby eliminating flicker while preserving the power-saving benefits of panel self-refresh mode.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If panel self-refresh mode is used to extend battery life, then battery life is extended, but image persistence and display quality deteriorate

Engineering Contradiction:
Improvebattery lifeVSAvoiddisplay quality
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent implements feedback by continuously monitoring the relationship between polarity inversion and luminance changes, then using this information to dynamically adjust compensation values. This closed-loop approach ensures that display quality is maintained at acceptable levels while preserving the battery life extensions provided by panel self-refresh mode.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

By transforming the image data parameters through luminance compensation, the system maintains display quality reliability. The compensation values adjust the brightness parameters to counteract the degradation effects of polarity alternation, ensuring that image persistence and overall display quality remain acceptable even when operating in power-saving panel self-refresh mode.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If polarity alternation is applied to prevent image persistence, then image persistence is reduced, but flicker is generated in pause periods

Engineering Contradiction:
Improveimage persistenceVSAvoidflicker
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by transforming the luminance parameters of image data through compensation values. This transformation counteracts the luminance variations caused by polarity alternation, thereby eliminating flicker while preserving the beneficial effect of reduced image persistence that polarity inversion provides.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3133582B1Display apparatus and method of driving the same
Publication Date: 2023.05.10 SAMSUNG DISPLAY CO LTD
  • EP3133582B1 patent drawingFigure 1
  • EP3133582B1 patent drawingFigure 2
  • EP3133582B1 patent drawingFigure 3

AI summary

A display apparatus includes a display panel displaying a normal image in a normal mode and displays a static image in a PSR (Panel Self Refresh) mode, a memory storing refresh image data corresponding to the static image, a comparator comparing image data of an N-th frame received from a graphics processor and refresh image data readout from the memory, a compensator generating a compensation value based on a comparison result and adding the compensation value to the refresh image data, and a data driver generating a data voltage using the refresh image data compensated by the comparator and outputting the data voltage to the display panel.