Display Panel Gamma Compensation for VRR Flicker Reduction

Solution Overview

Problem

The varying refresh rates in display panels using Variable Refresh Rate (VRR) technology cause significant brightness differences between frames, leading to screen flicker and a degraded user experience.

Innovation Solution

A method for generating target grayscale values by obtaining gamma curves for different refresh rates, determining grayscale compensation values based on brightness differences, and calculating target grayscale values to compensate for these differences, thereby stabilizing brightness across varying refresh rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If VRR technology is used to dynamically match display refresh rate with graphics card output frame rate, then power consumption is reduced and gaming performance is improved, but brightness difference between adjacent frames increases causing screen flicker

Engineering Contradiction:

Improvegaming performanceVSAvoidbrightness consistency

Core Design Contradiction:

ProductivityVSIllumination intensity

Solution Approach 1:

The patent pre-calculates and stores grayscale compensation values for different refresh rate transitions in a lookup table before actual display operation. When VRR switching occurs, the system directly retrieves the pre-computed compensation values based on the current and target refresh rates, avoiding real-time calculation delays and ensuring immediate brightness correction to prevent flicker.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent dynamically adjusts grayscale values of display pixels based on the detected refresh rate transition. By modifying the grayscale parameter in response to refresh rate changes, the system compensates for brightness variations caused by different pixel leakage characteristics at different refresh rates, thereby maintaining consistent perceived brightness during VRR operation.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If refresh rate is dynamically adjusted to match frame rate, then energy efficiency is improved, but pixel circuit leakage variation increases causing brightness inconsistency

Engineering Contradiction:

Improvepower consumptionVSAvoidbrightness stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the display system continuously monitors the actual refresh rate being used and compares it against the expected refresh rate. Based on this feedback, the system automatically selects appropriate grayscale compensation values from the lookup table and applies them to correct any brightness deviations, ensuring stable display performance under varying power consumption conditions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent pre-calculates and stores grayscale compensation values for different refresh rate transitions in a lookup table before actual display operation. When VRR switching occurs, the system directly retrieves the pre-computed compensation values based on the current and target refresh rates, avoiding real-time calculation delays and ensuring immediate brightness correction to prevent flicker.

Inventive Principle:

Principle #10Preliminary action

3Stability of the object's composition

If VBlank interval is extended to allow frame transfer, then display synchronization is improved, but brightness difference between frames increases due to varying pixel leakage

Engineering Contradiction:

Improvedisplay synchronizationVSAvoidframe brightness consistency

Core Design Contradiction:

Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The patent dynamically adjusts grayscale values of display pixels based on the detected refresh rate transition. By modifying the grayscale parameter in response to refresh rate changes, the system compensates for brightness variations caused by different pixel leakage characteristics at different refresh rates, thereby maintaining consistent perceived brightness during VRR operation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent pre-calculates and stores grayscale compensation values for different refresh rate transitions in a lookup table before actual display operation. When VRR switching occurs, the system directly retrieves the pre-computed compensation values based on the current and target refresh rates, avoiding real-time calculation delays and ensuring immediate brightness correction to prevent flicker.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12469422B2Method for generating target grayscale values and display panel

Publication Date: 2025.11.11 SHENZHEN CHINA STAR OPTOELECTRONICS SEMICON DISPLAY TECH CO LTD

AI summary

A method for generating target grayscale values, and a display panel are provided. The method for generating target grayscale values includes: obtaining multiple gamma curves corresponding to multiple refresh rates, each gamma curve defining a correlation between brightness values and grayscale values; determining a grayscale compensation value corresponding to each grayscale value at each refresh rate difference according to different brightness values corresponding to each grayscale value at different refresh rates, the refresh rate difference being a difference between two different refresh rates; and determining multiple target grayscale values according to grayscale values and corresponding grayscale compensation values, thereby improving a flickering caused by varying refresh rate.